Bio

Academic Appointments


Administrative Appointments


  • Co-Director, Stanford-NASA National Biocomputation Center, Stanford University (1997 - 2007)
  • Director Craniofacail Anomalies Center, LPCH (1992 - 2007)
  • Chief Pediatric Surgery, LPCH (1997 - 2005)
  • Chairman, Department of Functional Restoration, Stanford University Medical School (1994 - 2001)
  • Head Division of Plastic Surgery, Stanford university medical School (1992 - 2002)

Honors & Awards


  • Chauteaubriand Fellowship, French Government (1987)
  • Distinguished Alumnus, St Olaf College (1992)
  • Fulbright Fellow, France, Fulbright Foundation (1980)

Research & Scholarship

Current Research and Scholarly Interests


Surgical correction and the study of growth and development of craniomaxillofacial anomalies and deformities.

1. Histochemical Analysis of Facial Muscles.
2. Cranial Sutural Manipulation.
3. Stability of Mandibular and Maxillary Surgery
4. Growth Factors in Infant Cranial Sutures.
5. Virtual Surgery
6. 3-D Biocomputation 4. Osteodistraction

Teaching

2014-15 Courses


Publications

All Publications


  • Authors' response. American journal of orthodontics and dentofacial orthopedics Schendel, S. A., Jacobson, R. L. 2015; 147 (2): 159-160

    View details for DOI 10.1016/j.ajodo.2014.11.009

    View details for PubMedID 25636543

  • Three-dimensional upper-airway changes with maxillomandibular advancement for obstructive sleep apnea treatment AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS Schendel, S. A., Broujerdi, J. A., Jacobson, R. L. 2014; 146 (3): 385-393

    Abstract

    Airway size increases are associated with maxillomandibular advancement (MMA) surgery and improvement or elimination of obstructive sleep apnea (OSA). The 3-dimensional morphologic, volumetric, height, cross-sectional surface area, and diameter changes of the upper airway in patients with OSA after MMA, however, are not well understood.Patients with moderate or severe OSA who underwent MMA surgery were evaluated by preoperative and postoperative cone-beam computed tomography scans and polysomnograms. The upper airway space was also divided into retropalatal and retroglossal spaces and was analyzed for volumetric, height, cross-sectional surface area, transverse, and anteroposterior diameter changes.Ten consecutive OSA patients with an average preoperative apnea/hypopnea index of 46 and treated with MMA surgery were included in this study. There were 8 men and 2 women, with an average age of 46 years and an average body mass index of 28. There was an average of a 2.5-fold increase in the total volume of the upper airway space. The retropalatal space increased by 3.5-fold. The retroglossal space increased by 1.5-fold. The greatest change in a cross-sectional area occurred in the transverse axis in both the retroglossal and retropalatal spaces. The average apnea/hypopnea index was 4 postoperatively.MMA surgery results in a significant increase in the volume and a morphologic airway change from a round to an elliptical f shape in the upper airway space in patients with OSA. The combination of these actions reduces the collapsibility of the upper airway space, hence improving or resolving the OSA.

    View details for DOI 10.1016/j.ajodo.2014.01.026

    View details for Web of Science ID 000341305800017

    View details for PubMedID 25172261

  • Combined Orthognathic Distraction Procedure: Le Fort I Maxillary Osteotomy and Mandibular Curvilinear Distraction Osteogenesis. A New Technique for Craniofacial Management PLASTIC AND RECONSTRUCTIVE SURGERY Schendel, S. A., Hazan-Molina, H., Aizenbud, D. 2014; 133 (4): 874-877

    Abstract

    Dentofacial deformities are traditionally treated by maxillary and mandibular osteotomies conducted separately or simultaneously. Recently, distraction osteogenesis has become an irreplaceable part of the surgical armamentarium, for its ability to induce new bone formation between the surfaces of bone segments that are gradually separated by incremental traction, along with a simultaneous expansion of the surrounding soft-tissue envelope. The aim of this article is to describe a combined surgical technique consisting of simultaneous maxillary Le Fort I advancement and mandibular surgical repositioning by means of bilateral sagittal split osteotomy with a curvilinear distractor based on a preliminary computerized presurgical prediction.

    View details for DOI 10.1097/PRS.0000000000000055

    View details for Web of Science ID 000335988600038

    View details for PubMedID 24675190

  • 3-Dimensional Facial Simulation in Orthognathic Surgery: Is It Accurate? JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Schendel, S. A., Jacobson, R., Khalessi, S. 2013; 71 (8): 1406-1414

    Abstract

    PURPOSE: The purpose of this study was to measure the accuracy of 3D computer simulation of soft tissue changes after orthognathic surgery. MATERIALS AND METHODS: Consecutive patients who underwent orthognathic surgery were studied by photogrammetric facial scanning and cone-beam computed tomography before and after surgery. The photogrammetric scan was then fused to the cone-beam computed tomogram, creating a patient-specific image. The surgery was simulated in 3D form and the simulated soft tissue face was compared with the actual facial scan obtained 6 months postoperatively. Absolute millimeter differences between the simulated and actual postoperative changes in selected cephalometric skin markings were computed. RESULTS: The study was composed of 23 subjects (mean age, 31 yr; 13 women and 10 men). Eighteen different cephalometric landmarks were measured (total, 28). For 15 landmarks, the difference between actual and simulated measurements was smaller than 0.5 mm. Only 3 landmarks had a difference of 0.5 mm, and these were in the region of the labial landmarks. CONCLUSION: Based on the present study, 3-dimensional computer surgical simulation of the soft tissue of the face for routine orthognathic surgery is accurate enough for routine clinical use.

    View details for DOI 10.1016/j.joms.2013.02.010

    View details for Web of Science ID 000321735300021

    View details for PubMedID 23642546

  • Using bioabsorbable fixation systems in the treatment of pediatric skull deformities leads to good outcomes and low morbidity CHILDS NERVOUS SYSTEM Gephart, M. G., Woodard, J. I., Arrigo, R. T., Lorenz, H. P., Schendel, S. A., Edwards, M. S., Guzman, R. 2013; 29 (2): 297-301

    Abstract

    Bioabsorbable fixation systems have been widely employed in pediatric patients for cranial reconstruction, obviating the complications of hardware migration and imaging artifact occurring with metallic implants. Recent concern over complications unique to bioabsorbable materials, such as inflammatory reaction and incomplete resorption, necessitates additional conclusive studies to further validate their use in pediatric neurosurgery and craniofacial surgery. Likewise, long-term follow-up in this clinical cohort has not previously been described.We included consecutive pediatric patients under the age of 2, from Lucile Packard Children's Hospital, who underwent cranial vault reconstruction with the use of a bioabsorbable fixation system between 2003 and 2010. Hospital records were queried for patient characteristics, intraoperative data, and postoperative complications.Ninety-five patients with the following preoperative pathologies were analyzed: craniosynostosis (87), cloverleaf skull (5), frontonasal dysplasia (1), and frontonasal encephalocele (2). Median age was 6 months (range 1-24 months). Average case duration was 204 minutes (range 40-392 min), with median of 154 mL blood loss (range 30-500 mL). Ninety-three percent of patients had 1-4 plates implanted with 48% receiving three plates. The median number of screws used was 59 (range 0-130). The median length of hospital stay was 4 days (range 2-127 days) with an average follow-up of 22 months (five postoperative visits). The complications related to hardware implantation included swelling (1%) and broken hardware (1%), the latter of which required reoperation.The bioabsorbable fixation systems for cranial vault reconstruction in children less than 2 years of age is safe with tolerable morbidity rates.

    View details for DOI 10.1007/s00381-012-1938-y

    View details for Web of Science ID 000314028100019

    View details for PubMedID 23099613

  • Preface. Oral and maxillofacial surgery clinics of North America Schendel, S. A. 2012; 24 (4): ix-?

    View details for DOI 10.1016/j.coms.2012.09.001

    View details for PubMedID 22981079

  • Airway Growth and Development: A Computerized 3-Dimensional Analysis JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Schendel, S. A., Jacobson, R., Khalessi, S. 2012; 70 (9): 2174-2183

    Abstract

    The present study was undertaken to investigate the changes in the normal upper airway during growth and development using 3-dimensional computer analysis from cone-beam computed tomography (CBCT) data to provide a normative reference.The airway size and respiratory mode are known to have a relationship to facial morphology and the development of a malocclusion. The use of CBCT, 3-dimensional imaging, and automated computer analysis in treatment planning allows the upper airway to be precisely evaluated. In the present study, we evaluated the growth of the airway using 3-dimensional analysis and CBCT data from age 6 through old age, in 1300 normal individuals.The airway size and length increase until age 20 at which time a variable period of stability occurs. Next, the airway at first decreases slowly in size and then, after age 40, more rapidly. Normative data are provided in the present study for age groups from 6 to 60 years in relation to the airway total volume, smallest cross-sectional area and vertical length of the airway.This 3-dimensional data of the upper airway will provide a normative reference as an aid in the early understanding of respiration and dentofacial anatomy, which will help in early treatment planning.

    View details for DOI 10.1016/j.joms.2011.10.013

    View details for Web of Science ID 000308319900030

    View details for PubMedID 22326177

  • The future in craniofacial surgery: computer-assisted planning. Rambam Maimonides medical journal Schendel, S. A., Hazan-Molina, H., Rachmiel, A., Aizenbud, D. 2012; 3 (2)

    Abstract

    Advancements in computers, prototyping, and imaging, especially over the last 10 years, have permitted the adoption of three-dimensional imaging protocols in the health care field. In this article, the authors present an integrated simulation system for craniofacial surgical planning and treatment. Image fusion technology, which involves combining different imaging modalities, was utilized to create a realistic prototype and virtual image that can be manipulated in real time. The resultant data can then be shared over the Internet with distantly located practitioners.

    View details for DOI 10.5041/RMMJ.10079

    View details for PubMedID 23908836

  • Treatment of Maxillomandibular Deformities With Internal Curvilinear Distraction ANNALS OF PLASTIC SURGERY Schendel, S. A. 2011; 67 (6): S1-S9

    Abstract

    Internal curvilinear distraction is successful in achieving clinically significant distraction with stable occlusion in our patient population of infants, adolescents, and adults. When distracting the mandible, the curve of the distractor, the position of the distractor, and the osteotomy site are accountable for the final result. The curved distractor can mimic part of the natural logarithmic growth of the maxillomandibular complex. In addition, the result is predictable based on this design and the internal nature of the distractor, which can be left in place longer than other distractor types. Distraction can be combined with orthognathic surgery in certain cases resulting in increased benefit. This new procedure is called distraction orthognathics.

    View details for DOI 10.1097/SAP.0b013e3182183599

    View details for Web of Science ID 000298085900001

    View details for PubMedID 22123543

  • Image Fusion in Preoperative Planning FACIAL PLASTIC SURGERY CLINICS OF NORTH AMERICA Schendel, S. A., Duncan, K. S., Lane, C. 2011; 19 (4): 577-?

    Abstract

    This article presents a comprehensive overview of generating a digital Patient-Specific Anatomic Reconstruction (PSAR) model of the craniofacial complex as the foundation for a more objective surgical planning platform. The technique explores fusing the patient's 3D radiograph with the corresponding high-precision 3D surface image within a biomechanical context. As taking 3D radiographs has been common practice for many years, this article describes various approaches to 3D surface imaging and the importance of achieving high-precision anatomical results to simulate surgical outcomes that can be measured and quantified. With the PSAR model readily available for facial assessment and virtual surgery, the advantages of this surgical planning technique are discussed.

    View details for DOI 10.1016/j.fsc.2011.07.002

    View details for Web of Science ID 000311862900003

  • Maxillary, Mandibular, and Chin Advancement: Treatment Planning Based on, Airway Anatomy in Obstructive Sheep Apnea JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Schendel, S., Powell, N., Jacobson, R. 2011; 69 (3): 663-676

    Abstract

    Surgical correction of obstructive sleep apnea (OSA) syndrome involves understanding a number of parameters, of which the 3-dimensional airway anatomy is important. Visualization of the upper airway based on cone beam computed tomography scans and automated computer analysis is an aid in understanding normal and abnormal airway conditions and their response to surgery. The goal of surgical treatment of OSA syndrome is to enlarge the velo-oropharyngeal airway by anterior/lateral displacement of the soft tissues and musculature by maxillary, mandibular, and possibly, genioglossus advancement. Knowledge of the specific airway obstruction and characteristics based on 3-dimensional studies permits a directed surgical treatment plan that can successfully address the area or areas of airway obstruction. The end occlusal result can be improved when orthodontic treatment is combined with the surgical plan. The individual with OSA, though, is more complicated than the usual orthognathic patient, and both the medical condition and treatment length need to be judiciously managed when OSA and associated conditions are present. The perioperative management of the patient with OSA is more complex and the margin for error is reduced, and this needs to be taken into consideration and the care altered as indicated.

    View details for DOI 10.1016/j.joms.2010.11.010

    View details for Web of Science ID 000288109400010

    View details for PubMedID 21353928

  • Fronto-orbital Advancement Using an En Bloc Frontal Bone Craniectomy NEUROSURGERY Guzman, R., Looby, J. F., Schendel, S. A., Edwards, M. S. 2011; 68 (3): 68-74

    Abstract

    Fronto-orbital advancement is a procedure commonly performed in craniofacial centers for coronal and metopic suture synostosis. Several variations of the technique have been reported.To describe our modifications to the anterior cranioplasty procedure and the results of our surgical series.Using our craniofacial database, we retrospectively analyzed the records of all patients undergoing fronto-orbital advancement for craniosynostosis. The same team of neurosurgeons and plastic surgeons performed all procedures. Demographic data, operative time, blood loss, length of stay, and clinical outcome were analyzed.Of 248 patients treated for craniosynostosis, a total of 70 patients underwent fronto-orbital advancement. Nineteen presented with metopic, 26 with unilateral coronal, 17 with bilateral coronal, and 8 with multiple synostosis. Median age at surgery was 6.5 months. Mean operative time was 210 minutes; mean blood loss was 167 mL; and length of stay was 4.5 days. A positive correlation was found between operative time and blood loss (r = 0.1, P < .01) and age at surgery and blood loss (r = 0.3, P < .0001). There was a minor morbidity rate of 2.9%. A good reconstruction was obtained in all patients using our en bloc fronto-orbital advancement without any midline osteotomies at a mean follow-up of 15 months.A team approach and the application of a standardized surgical technique should make it safer to operate in young children, shorten the surgical time, and lead to a reduction in blood loss. Reconstructing the frontal bone as an entire unit yielded excellent correction for coronal and metopic synostosis.

    View details for DOI 10.1227/NEU.0b013e31820780cd

    View details for Web of Science ID 000287734500011

  • Fronto-orbital Advancement Using an En Bloc Frontal Bone Craniectomy NEUROSURGERY Guzman, R., Looby, J. F., Schendel, S. A., Edwards, M. S. 2011; 68
  • Reliability of panoramic radiographs for the assessment of mandibular elongation after distraction osteogenesis procedures ORTHODONTICS & CRANIOFACIAL RESEARCH Hazan-Molina, H., Molina-Hazan, V., Schendel, S. A., Aizenbud, D. 2011; 14 (1): 25-32

    Abstract

    To determine whether panoramic radiographs could be used for evaluation of changes in the vertical and horizontal dimensions following internal curvilinear mandibular distraction osteogenesis.A retrospective cohort study included 25 patients who underwent bilateral mandibular distraction surgery. Three panoramic radiographs and lateral cephalograms from each patient were available: before distraction, immediately upon termination of the distraction process, and at the end of the follow-up period. The radiographs were traced by plotting Condylion, Gonion, and Menton. The linear distances between Condylion and Gonion and between Gonion and Menton were measured on each side, and the correlation was calculated.No significant differences were found between the values of the linear measurements determined by lateral cephalograms and panoramic radiographs (p ? 0.079), excluding one measurement. The correlation test for these radiographs showed very high, positive and statistically significant correlations, for both sides of the internal mandibular distraction (r > 0.77, p ? 0.0001), apart from three measurements.Panoramic radiographs, with mandibular length (Co-Go and Go-Me) measurements, can be used as an alternative to lateral cephalograms, i.e. as a reliable tool for assessing vertical and horizontal dimensional changes resulting from internal mandibular distraction achieved by a curvilinear distractor.

    View details for DOI 10.1111/j.1601-6343.2010.01504.x

    View details for Web of Science ID 000286169200003

    View details for PubMedID 21205166

  • Midfacial trauma and facial growth: A longitudinal case study of monozygotic twins AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS Aizenbud, D., Morrill, L. R., Schendel, S. A. 2010; 138 (5): 641-648

    Abstract

    The purpose of this article is to present a long-term follow-up of the growth of the face and the nasomaxillary complex in a pair of identical twins, one of whom had suffered severe midfacial trauma at age 2 years. Growth of the face and the nasomaxillary complex was longitudinally assessed and compared by means of facial photographs and cephalometric x-rays. Twin A suffered Le Fort II and III fractures with an associated frontal bone injury in early childhood and subsequently developed significant midface hypoplasia; twin B had no trauma and normal facial growth and development. Facial profile difference between the twins gradually became more pronounced until age 19. Twin A had obvious retrusion of the midfacial region, including the nasal bones on visual examination and radiographic study. At age 20, she underwent orthognathic surgical correction of the traumatic deformity. Her unaffected sibling, twin B, provided the genetic facial phenotype for the surgical orthognathic reconstruction.

    View details for DOI 10.1016/j.ajodo.2008.10.026

    View details for Web of Science ID 000283801700033

    View details for PubMedID 21055606

  • Curvilinear Mandibular Distraction Results and Long-Term Stability Effects in a Group of 40 Patients PLASTIC AND RECONSTRUCTIVE SURGERY Aizenbud, D., Hazan-Molina, H., Thimmappa, B., Hopkins, E. M., Schendel, S. A. 2010; 125 (6): 1771-1780

    Abstract

    The mandibular internal curvilinear distractor design produces a curvilinear vector to provide ideal three-dimensional curvilinear movements compared with the limited straight unidirectional predecessor devices. In this manner, it corrects craniofacial deformities as anatomically as possible, allowing simultaneous bidirectional (rotational and translational) mandibular movement and multidirectional distraction. The aim of this study was to quantify the sagittal and vertical mandibular changes achieved through curvilinear distraction and to assess the long-term effect of this generated bone.Forty patients (20 male and 20 female), with ages ranging from 5 to 55 years, who underwent mandibular distraction from December of 1999 to August of 2007 at Lucile Packard Children's Hospital in Stanford, California, were included. Preoperatively, postoperatively, and at follow-up (at least 2 years following distraction), panoramic and lateral cephalometric radiographs were traced by plotting different skeletal landmark points and were then analyzed.All patients tolerated the curvilinear distraction process well through completion. The average of the mandibular body elongation recorded was 8 to 9 mm and 6 to 8 mm in the panoramic and cephalometric radiographs, respectively; whereas the vertical change of the mandibular ramus achieved was 10 to 12 mm and 10 to 11 mm, respectively. The curvilinear distraction effect on the mandible was found to be significantly stable when the long-term follow-up measurements were compared with the postoperative data revealed in the panoramic and lateral cephalometric radiographs for the two dimensions.The internal curvilinear device is an effective tool that achieves a stable mandibular distraction, resulting in the correction of craniofacial deformities.

    View details for DOI 10.1097/PRS.0b013e3181d9937b

    View details for Web of Science ID 000278380700026

    View details for PubMedID 20517103

  • Sagittal Split Genioplasty: A New Technique JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Schendel, S. A. 2010; 68 (4): 931-934

    View details for DOI 10.1016/j.joms.2009.09.082

    View details for Web of Science ID 000276579200038

    View details for PubMedID 20307778

  • Automated 3-Dimensional Airway Analysis From Cone-Beam Computed Tomography Data JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Schendel, S. A., Hatcher, D. 2010; 68 (3): 696-701

    View details for DOI 10.1016/j.joms.2009.07.040

    View details for Web of Science ID 000279280800037

    View details for PubMedID 20171491

  • Mandibular Internal Curvilinear Distraction - Long Term Follow-Up XX CONGRESS OF THE EUROPEAN ASSOCIATION OF CRANIO-MAXILLO-FACIAL-SURGERY Aizenbud, D., Hazan-Molina, H., Thimmappa, B., HOPKINS, E. M., Molina-Hazan, V., Schendel, S. A. 2010: 87-94
  • CURVILINEAR DISTRACTION JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Schendel, S. A. 2009; 67 (12): 2696-2697

    View details for DOI 10.1016/j.joms.2009.06.026

    View details for Web of Science ID 000272497800026

    View details for PubMedID 19925996

  • Monozygotic Twin Sister as a Template for Facial Trauma Reconstruction PLASTIC AND RECONSTRUCTIVE SURGERY Aizenbud, D., Morrill, L. R., Schendel, S. A. 2009; 124 (6): 443E-445E

    View details for DOI 10.1097/PRS.0b013e3181bcf535

    View details for Web of Science ID 000272615600076

    View details for PubMedID 19952610

  • Three-Dimensional Imaging and Computer Simulation For Office-Based Surgery JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Schendel, S. A., Jacobson, R. 2009; 67 (10): 2107-2114

    Abstract

    Advancements in computers and imaging, especially over the last 10 years, have permitted the adoption of 3-dimensional imaging protocols in the health care field. In addition, the affordability and ease of use of these modalities allow their widespread adoption and use in diagnosis and treatment planning. This is particularly important when the deformities are complex involving both function and esthetics, such as those in the dentofacial area and with orthognathic surgery.Image fusion involves combining images from different imaging modalities to create a virtual record of an individual called a patient-specific anatomic reconstruction (PSAR). We describe the system and show its use in 1 case.Image fusion and, more specifically, PSAR permit a more accurate analysis of deformity as an aid to diagnosis and treatment planning.Three-dimensional imaging and computer simulation can be effectively used for planning office-based procedures. The PSAR can be used to perform virtual surgery and establish a definitive and objective treatment plan for correction of a facial deformity. The end result is improved patient care and decreased expense.

    View details for DOI 10.1016/j.joms.2009.04.111

    View details for Web of Science ID 000270520900009

    View details for PubMedID 19761904

  • Airway Analysis: With Bilateral Distraction of the Infant Mandible JOURNAL OF CRANIOFACIAL SURGERY Looby, J. F., Schendel, S. A., Lorenz, H. P., Hopkins, E. M., Aizenbud, D. 2009; 20 (5): 1341-1346

    Abstract

    Mandibular distraction was proven to be a valuable tool for lengthening the hypoplastic mandible and relieving airway obstruction in infants. However, analysis of presurgical and postsurgical three-dimensional computed tomography and polysomnogram studies is lacking. The aim of this study was to describe the effect of distraction on the airway by evaluating the clinical, three-dimensional radiographic and polysomnogram studies before and after distraction.Seventeen infants with micrognathia who underwent internal curvilinear mandibular distraction from April 2005 through April 2008 at Lucile Packard Children's Hospital were included. Preoperative and postoperative computed tomography, polysomnograms, and feeding evaluations were obtained and compared after distraction.The mean patient age before surgery was 105 days. All patients tolerated the distraction process with a mean mandibular advancement of 18.1 mm. One patient experienced a temporary marginal mandibular nerve palsy that resolved, and 1 postoperative wound infection was encountered. Preoperatively, the mean retroglossal oropharyngeal cross-sectional area was 41.53 mm. This was associated with a mean preoperative apnea-hypopnea index (AHI) of 10.57 and a minimum oxygen desaturation of 83%. After distraction, the mean airway increased to 127.77 mm. All patients had clinical improvement of their respiratory status; the mean postoperative AHI was 2.21, and the minimum oxygen desaturation was 90%. The result was a 209% cross-sectional airway increase. All patients progressed to oral feeds by 3.5 months postoperatively.Mandibular distraction is effective at relieving anatomic airway obstruction in infants with micrognathia and obstructive sleep apnea while avoiding some previously reported associated complications.

    View details for DOI 10.1097/SCS.0b013e3181ae4139

    View details for Web of Science ID 000270369000008

    View details for PubMedID 19816252

  • Magnesium-Based Bone Cement and Bone Void Filler: Preliminary Experimental Studies JOURNAL OF CRANIOFACIAL SURGERY Schendel, S. A., Peauroi, J. 2009; 20 (2): 461-464

    Abstract

    Bone cement has great potential in craniofacial surgery in the repair of osseous defects secondary to surgery or trauma. This includes the use of bone cement as a bone void filler for full-thickness cranial defects and as augmentation of deficient bones. Ideally, this material should be easily available, biocompatible, resorbable, bone inductive, and have adhesive qualities to bone. Calcium-based bone cements have some of these qualities but have a higher than desirable failure rate. OsteoCrete, a new magnesium-based bone cement and bone void filler, was compared to Norian in critical-sized skull defects and cementing bone flaps in rabbits. Both materials were successful; however, OsteoCrete had a faster resorption and replacement by bone rate than Norian. Bone flap position and apparent stability were also superior with OsteoCrete. There were no adverse reactions to either cement. A magnesium-based bone cement presents with advantages when compared with a comparator calcium-based cement in craniofacial surgery.

    View details for DOI 10.1097/SCS.0b013e31819b9819

    View details for Web of Science ID 000264570300042

    View details for PubMedID 19305245

  • A Web-Based, Integrated Simulation System for Craniofacial Surgical Planning PLASTIC AND RECONSTRUCTIVE SURGERY Schendel, S. A., Montgomery, K. 2009; 123 (3): 1099-1106

    Abstract

    Advances in computing over the last 10 years have rapidly improved imaging and simulation in health care. Implementation of three-dimensional protocols and image fusion techniques are moving diagnosis, treatment planning, and teaching to a next-generation paradigm. In addition, decreasing cost and increasing availability make generalized use of these techniques possible.In this article, the authors present a Web-based, integrated simulation system for craniofacial surgical planning and treatment. Image fusion technology was utilized to create a realistic virtual image that can be manipulated in real time. The resultant data can then be shared over the Internet by distantly located practitioners.Initial use of this system proved to be beneficial from a planning standpoint and to be accurate as to the reliability of landmark identification. Additional case studies are needed to further document the results of actual surgical simulation.This technology presents significant advantages in surgical planning and education, both of which can improve patient safety and outcomes.

    View details for DOI 10.1097/PRS.0b013e318199f653

    View details for Web of Science ID 000264017900042

    View details for PubMedID 19319079

  • Quantification appraisal of mandibular internal curvilinear distraction CRANIOFACIAL SURGERY 13: PROCEEDINGS OF THE THIRTEEN CONGRESS OF THE INTERNATIONAL SOCIETY OF CRANIOFACIAL SURGERY AND PARIS DISTRACTION SYMPOSIUM Aizenbud, D., Hazan-Molina, H., Thimmappa, B., HOPKINS, E. M., Molina-Hazan, V., Schendel, S. A. 2009: 21-28
  • Internal maxillary distraction with a new bimalar device JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Kahn, D. M., Broujerdi, J., Schendel, S. A. 2008; 66 (4): 675-683

    Abstract

    Distraction osteogenesis of the Le Fort I segment is advocated for patients who require significant advancement of the maxilla or who have a soft tissue envelope compromised by scar tissue. We present a technique for maxillary distraction using an interconnecting intraoral device anchored to the malar prominences above the osteotomy and either the maxilla and/or the dentition below the level of the osteotomy.Ten patients with nonsyndromic cleft lip and palate, mean age of 18, underwent Le Fort I maxillary distraction osteogenesis for management of maxillary hypoplasia. A Le Fort I osteotomy is performed and a Spectrum Intraoral Midface Multi-Vector Distractor (OsteoMed, Addison, TX) is placed leaving a 1 mm to 2 mm distraction gap. After a 2 to 4 day latency period, distraction begins at a rate of 1 mm a day. Once the desired occlusion is achieved the device is left in place for a minimum of 2 months for consolidation.Preoperative Sella-Nasion-A point measurements from lateral cephalograms averaged 74 degrees (range, 70-76 degrees). Postoperative Sella-Nasion-A point averaged 81 degrees (range, 75-89 degrees). Preoperative overjet averaged -7.4 mm (range, -3 to -13 mm). Postoperative overjet averaged 2.6 mm (range, 1-3 mm). Average distraction was 9 mm (range, 6-16 mm). The average vertical movement was 7.2 mm in an inferior direction (range, 0-15 mm). The results remained stable at a follow-up of 30 months.We report on distraction of the Le Fort I segment using an internal device. The device design allows the forces of distraction to be shared across a larger surface area delivering a uniform and reliable vector of distraction with increased stability.

    View details for DOI 10.1016/j.joms.2007.09.006

    View details for Web of Science ID 000254589200009

    View details for PubMedID 18355590

  • Computer simulation of curvilinear mandibular distraction: Accuracy and predictability PLASTIC AND RECONSTRUCTIVE SURGERY Scolozzi, P., Link, D. W., Schendel, S. A. 2007; 120 (7): 1975-1980

    Abstract

    The purpose of this study was to retrospectively evaluate the accuracy and reliability of a computer simulation system that predicts the results of an internal curvilinear mandibular distractor in the treatment of hemifacial microsomia and severe mandibular retrognathia.A two-dimensional computer analysis and simulation system was developed based on cephalometric radiographs and patient photographs. The software was used to generate and superimpose digital templates, corresponding to the actual distractor and logarithmic spiral, onto the lateral cephalometric tracings. The digital distractor's template was then adjusted to fit the radiographic projection of the actual distractor on the 1-week postoperative lateral cephalograph as precisely as possible. It was then activated along the spiral growth curve template until the ideal position of the mandible was reached. This computational surgical simulation tracing was then superimposed onto the actual postdistraction lateral cephalometric radiograph and tracing. Thus, the predicted and actual mandibular distraction movements were compared.In all of the cases, the computational distraction (skeletal and soft tissues) tracing fit the actual postdistraction tracing with an accuracy to within 1 mm.The current study demonstrated that a specific curvilinear distraction can (1) closely reproduce the natural logarithmic spiral movement of the mandibular growth, (2) be closely approximated and thus predicted by a computer simulation system, and (3) be used for correction of mandibular deformities such as hemifacial microsomia and severe mandibular retrognathia.

    View details for DOI 10.1097/01.prs.0000287327.66824.2f

    View details for Web of Science ID 000251668400028

    View details for PubMedID 18090762

  • Infant mandibular distraction with an internal curvilinear device JOURNAL OF CRANIOFACIAL SURGERY Miller, J. J., Kahn, D., Lorenz, H. P., Schendel, S. A. 2007; 18 (6): 1403-1407

    Abstract

    Mandibular distraction has proven to be a valuable tool for lengthening the hypoplastic mandible and relieving airway obstruction in infants. Numerous devices have been developed to achieve the desired mandibular lengthening. Complications including poor vector control, need to mold regenerate, facial scarring, external pin loosening, and bulky hardware have been associated with previous devices. In an attempt to circumvent some of these problems, the senior author developed an internal curvilinear device (Osteomed Corporation, Dallas, TX), which is applicable to the infant mandible. The aim of this paper is to describe the use of this distractor as well as its indications and outcomes.Twelve micrognathic infants (ages range from 9 days to 8 months) who underwent mandibular distraction between March 2005-May 2006 at Lucile Packard Children's Hospital were included in the study. Preoperative workup included an evaluation by a multidisciplinary team including a pediatric otolaryngologist, neonatal intensivist, pediatric pulmonologist, occupational therapist, and craniofacial surgeon. Pre and postoperative maxillomandibular discrepancy, sleep study, feeding evaluation, and three-dimensional computerized tomography scans were compared. All patients tolerated the distraction process well to completion without postoperative complication, except for one patient who had temporary facial nerve weakness, which resolved in 2 months. All patients with obstructive apnea had the obstructive component improved. The last six patients had pre and postoperative polysomnograms to document the improvement. Two patients with neurologic impairment had persistent central apnea. One nonsyndromic patient with inability to feed and feeding-related airway obstruction was taking complete oral feeds 2 weeks after distraction.Mandibular distraction with an internal curvilinear device is effective at relieving airway obstruction in micrognathic infants, while avoiding some previously reported complications.

    View details for Web of Science ID 000251517500026

    View details for PubMedID 17993889

  • Idiopathic condylar resorption and micrognathia: The case for distraction osteogenesis JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Schendel, S. A., Tulasne, J., Linck, D. W. 2007; 65 (8): 1610-1616

    View details for DOI 10.1016/j.joms.2007.05.001

    View details for Web of Science ID 000248706000027

    View details for PubMedID 17656291

  • Surgical orthognathic management of sleep apnea JOURNAL OF CRANIOFACIAL SURGERY Schendel, S. A., Powell, N. B. 2007; 18 (4): 902-911

    Abstract

    Management of obstructive sleep apnea syndrome (OSAS) requires a clear understanding of both the medical and surgical components of the treatment and interpretation of the subjective and objective data such as the polysomnagram. Medical management is primarily by continuous positive airway pressure (CPAP) and is the first line of treatment. Surgical management consists of several phases based on the severity and location of the anatomical abnormalities. The last phase of surgical management consists of maxillo-mandibular advancement by a Le Fort I osteotomy and bilateral sagittal split ramus osteotomies of the mandible. The orthognathic procedure is based on the existing skeletal deformity, occlusion and severity of the OSAS. The surgical technique must also take into consideration not only the usual orthognathic principles but the added medical complexity of these patients in the immediate pre and post operative periods.

    View details for Web of Science ID 000248513100034

    View details for PubMedID 17667685

  • Flash Pulmonary Edema: An Unusual Presentation during Orthognathic Surgery PLASTIC AND RECONSTRUCTIVE SURGERY Broujerdi, J. A., Keifa, E., Nekhendzy, V., Schendel, S. A. 2007; 119 (6): 133E-137E
  • Invited discussion: Surgical treatment of Treacher Collins syndrome ANNALS OF PLASTIC SURGERY Miller, J. J., Schendel, S. A. 2006; 56 (5): 555-556
  • A surgical simulator for planning and performing repair of cleft lips JOURNAL OF CRANIO-MAXILLOFACIAL SURGERY Schendel, S., Montgomery, K., Sorokin, A., Lionetti, G. 2005; 33 (4): 223-228

    Abstract

    The objective of this project was to develop a computer-based surgical simulation system for planning and performing cleft lip repair. This system allows the user to interact with a virtual patient to perform the traditional steps of cleft-lip repair (rotation-advancement technique).The system interfaces to force-feedback (haptic) devices to track the user's motion and provide feedback during the procedure, while performing real-time soft-tissue simulation. An 11-day-old unilateral cleft lip, alveolus and palate patient was previously CT scanned for ancillary diagnostic purposes using standard imaging protocols and 1mm slices. High-resolution 3D meshes were automatically generated from this data using the ROVE software developed in-house. The resulting 3D meshes of bone and soft tissue were instilled with physical properties of soft tissues for purposes of simulation. Once these preprocessing steps were completed, the patient's bone and soft tissue data are presented on the computer screen in stereo and the user can freely view, rotate, and otherwise interact with the patient's data in real time. The user is prompted to select anatomical landmarks on the patient's data for preoperative planning purposes, then their locations are compared against that of a 'gold standard' and a score, derived from their deviation from that standard and time required, is generated. The user can then move a haptic stylus and guide the motion of the virtual cutting tool. The soft tissues can thus be incised using this virtual cutting tool, moved using virtual forceps, and fused in order to perform any of the major procedures for cleft lip repair. Real-time soft tissue deformation of the mesh realistically simulates normal tissues and haptic-rate (>1 kHz) force-feedback is provided. The surgical result of the procedure can then be immediately visualized and the entire training process can be repeated at will. A short evaluation study was also performed. Two groups (non-medical and plastic surgery residents) of six persons each performed the anatomical marking task of the simulator four times.Results showed that the plastic surgery residents scored consistently better than the persons without medical background. Every person's score increased with practice, and the length of time needed to complete the 11 markings decreased. The data was compiled and showed which specific markers consistently took users the longest to identify as well as which locations were hardest to accurately mark.These findings suggest that the simulator is a valuable training tool, giving residents a way to practice anatomical identification for cleft lip surgery without the risks associated with training on a live patient. Educators can also use the simulator to examine which markers are consistently problematic, and modify their training to address these needs.

    View details for DOI 10.1016/j.jcms.2005.05.002

    View details for Web of Science ID 000230975800001

    View details for PubMedID 15975810

  • User interface paradigms for patient-specific surgical planning: lessons learned over a decade of research COMPUTERIZED MEDICAL IMAGING AND GRAPHICS Montgomery, K., Stephanides, M., Schendel, S., Ross, M. 2005; 29 (2-3): 203-222

    Abstract

    This paper covers work in virtual reality-based, patient-specific surgical planning over the past decade. It aims to comprehensively examine the user interface paradigms and system designs during that period of time and to objectively analyze their effectiveness for the task. The goal is to provide useful feedback on these interface and implementation paradigms to aid other researchers in this field. First, specialized systems for specific clinical use were produced with a limited set of visualization tools. Later, through collaboration with NASA, an immersive virtual environment was created to produce high-fidelity images for surgical simulation, but it underestimated the importance of collaboration. The next system, a networked, distributed virtual environment, provided immersion and collaboration, but the immersive paradigm was found to be of a disadvantage and the uniqueness of the framework unwieldy. A virtual model, workbench-style display was then created using a commercial package, but limitations of each were soon apparent. Finally, a specialized display, with an integrated visualization and simulation system is described and evaluated. Lessons learned include: surgical planning is an abstract process unlike surgical simulation; collaboration is important, as is stereo visualization; and that high-resolution preoperative images from standard viewpoints are desirable, but interaction is truly the key to planning.

    View details for DOI 10.1016/j.compmedimag.2004.09.014

    View details for Web of Science ID 000227961600011

    View details for PubMedID 15755538

  • Magnetic resonance imaging and surgical repair of cleft palate in a four-week-old canine (Canis familiaris): An animal model for cleft palate repair CONTEMPORARY TOPICS IN LABORATORY ANIMAL SCIENCE Tolwani, R. J., Hagan, C. E., Runstadler, J. A., Lyons, H., Green, V. L., Bouley, D. M., Rodriguez, L. F., Schendel, S. A., Moseley, M. E., Daunt, D. A., Otto, G., CORK, L. C. 2004; 43 (6): 17-21

    Abstract

    Successful cleft palate repair (palatoplasty) was accomplished in a male canine pup from a kindred with autosomal recessive transmission for a complete cleft palate phenotype. This case represents the potential application of a new animal model for cleft palate repair. This reproducible congenital defect provides a clinically relevant model to improve research into the human anomaly, as compared with previous iatrogenic or teratogenically induced animal models. This case report presents the basis for new repair techniques and for studying the genetic basis of the cleft palate defect.

    View details for Web of Science ID 000225806200004

    View details for PubMedID 15636550

  • Mandibular distraction osteogenesis by sagittal split osteotomy and intraoral curvilinear distraction JOURNAL OF CRANIOFACIAL SURGERY Schendel, S. A., Linck, D. W. 2004; 15 (4): 631-635

    Abstract

    Mandibular distraction combining the sagittal split ramus osteotomy and an intraoral curved distractor is efficacious to lengthen the mandibular body and ramus. The sagittal split permits immediate rotation of the proximal segment and lengthening while still providing a large surface interface for regenerative bone. The buried curved distractor enables mandibular lengthening along the normal logarithmic grow spiral as shown by Moss and Rickets. In addition, it is well tolerated by the patient and can remain in place for a long duration to provide support. In summary, this combination of surgical techniques provides certain advantages for distraction of the mandible.

    View details for Web of Science ID 000222503200019

    View details for PubMedID 15213543

  • A surgical simulator for cleft lip planning and repair MEDICINE MEETS VIRTUAL REALITY 11 Montgomery, K., Sorokin, A., Lionetti, G., Schendel, S. 2003; 94: 204-209

    Abstract

    The objective of this project was to develop a computer-based surgical simulation system for cleft lip planning and repair. This system allows the user to interact with a virtual patient to perform the traditional steps of cleft-lip repair. The system interfaces to force-feedback (haptic) devices to track the user's motion and provide feedback during the procedure, while performing real-time soft-tissue simulation. An eleven-day old unilateral cleft-lip and palate patient was previously CT scanned for ancillary diagnostic purposes using standard imaging protocols and 1mm slices. High-resolution 3D meshes were automatically generated from this data using the ROVE software created in our lab. The resulting 3D meshes of bone and soft-tissue were instilled with physical properties of soft tissues for purposes of simulation. Once these preprocessing steps were completed, the patient's bone and soft-tissue data are presented on the computer screen in stereo and the user can freely view, rotate, and otherwise interact with the patient's data in real-time. The user is prompted to select anatomical landmarks on the patient data for preoperative planning purposes, then their locations are compared against that of a "gold standard" and a score, derived from their deviation from that standard and time required, is generated. The user can then move a haptic stylus and guide the motion of the virtual cutting tool. The soft tissues can thus be incised using this virtual cutting tool, moved using virtual forceps, and fused in order to perform any of the major procedures for cleft-lip repair. Real-time soft tissue deformation of the mesh realistically simulates normal tissues and haptic-rate (>1kHz) force-feedback is provided. The surgical result of the procedure can then be immediately visualized and the entire training process can be repeated at will. A short evaluation study was also performed. Two groups (nonmedical and plastic surgery residents) of six-people each performed the anatomical marking task of the simulator four times. Results showed that the plastic surgery residents scored consistently better than the people without medical background. Every person's score increased with practice, and the length of time needed to complete the eleven markings decreased. The data was compiled and showed which specific markers consistently took users the longest to identify as well as which locations were hardest to accurately mark. Our findings suggest that the simulator is a valuable training tool, giving residents a way to practice anatomical identification for cleft lip surgery without the risks associated with training on a live patient. Educators can also use the simulator to examine which markers are consistently problematic, and modify their training to address these needs.

    View details for Web of Science ID 000189484800042

    View details for PubMedID 15455894

  • Biomechanics of mandibular distraction osteogenesis 3RD INTERNATIONAL CONGRESS ON CRANIAL AND FACIAL BONE DISTRACTION PROCESSES Safa, B., Kahn, D., Lorenz, H. P., Heegaard, J. H., Kosek, J., Schendel, S. A. 2001: 27-32
  • A preliminary report on the use of semi-buried curvilinear distractor in the human mandible 3RD INTERNATIONAL CONGRESS ON CRANIAL AND FACIAL BONE DISTRACTION PROCESSES Schendel, S., Kahn, D., Linck, D., Hopkins, E. 2001: 255-258
  • A novel semi-buried curvilinear osteodistractor for the mandible 3RD INTERNATIONAL CONGRESS ON CRANIAL AND FACIAL BONE DISTRACTION PROCESSES Schendel, S. A., Safa, B., Kahn, D. 2001: 287-289
  • Virtual reality based surgical assistance and training system for long duration space missions Montgomery, K., Thonier, G., Stephanides, M., Schendel, S. I O S PRESS. 2001: 315-321

    Abstract

    Access to medical care during long duration space missions is extremely important. Numerous unanticipated medical problems will need to be addressed promptly and efficiently. Although telemedicine provides a convenient tool for remote diagnosis and treatment, it is impractical due to the long delay between data transmission and reception to Earth. While a well-trained surgeon-internist-astronaut would be an essential addition to the crew, the vast number of potential medical problems necessitate instant access to computerized, skill-enhancing and diagnostic tools. A functional prototype of a virtual reality based surgical training and assistance tool was created at our center, using low-power, small, lightweight components that would be easy to transport on a space mission. The system consists of a tracked, head-mounted display, a computer system, and a number of tracked surgical instruments. The software provides a real-time surgical simulation system with integrated monitoring and information retrieval and a voice input/output subsystem. Initial medical content for the system has been created, comprising craniofacial, hand, inner ear, and general anatomy, as well as information on a number of surgical procedures and techniques. One surgical specialty in particular, microsurgery, was provided as a full simulation due to its long training requirements, significant impact on result due to experience, and likelihood for need. However, the system is easily adapted to realistically simulate a large number of other surgical procedures. By providing a general system for surgical simulation and assistance, the astronaut-surgeon can maintain their skills, acquire new specialty skills, and use tools for computer-based surgical planning and assistance to minimize overall crew and mission risk.

    View details for Web of Science ID 000169103300061

    View details for PubMedID 11317762

  • Unilateral cleft lip repair - State of the art CLEFT PALATE-CRANIOFACIAL JOURNAL Schendel, S. A. 2000; 37 (4): 335-341

    Abstract

    A number of surgical techniques are utilized to correct the unilateral cleft lip, including variations of the rotation-advancement technique. This attests to the variability of the original deformity and the esthetic and functional results from any one technique, especially those based on traditional geometric rearrangement of the skin and associated tissues.Most recent advances in cleft lip repair have occurred in two main areas. The morphological result has been improved by functional muscular reconstruction of the lip with or without orthopedic molding. Early correction of the nasal deformity has also been readvocated based on newer principles with excellent results demonstrated.Further work continues in these areas and improved outcomes will continue to be seen along with a clearer understanding of surgical affects on growth and development.

    View details for Web of Science ID 000088074300001

    View details for PubMedID 10912710

  • Development and application of a virtual environment for reconstructive surgery. Computer aided surgery Montgomery, K., Stephanides, M., Schendel, S. 2000; 5 (2): 90-97

    Abstract

    This paper details the development and application of a Virtual Environment for Reconstructive Surgery (VERS). It addresses the technical and user-interface challenges in developing such a system, and the lessons learned during application of the system in the case of a 17-year-old boy with a severe facial defect arising from the removal of a soft-tissue sarcoma.Computed tomography (CT) scans were segmented into bone and soft-tissue classifications using traditional and novel algorithms, a surface mesh was generated, and imaging artifacts were removed, yielding a mesh suitable for visualization. This patient-specific mesh was then used in a virtual environment by the surgeons for preoperative visualization of the defect, planning of the surgery, and production of a custom surgical template to aid in repairing the defect.This system was successfully used to plan the surgery of the patient and to produce a custom, patient-specific template that was used to harvest bone from a donor site in order to reconstruct the defect.Despite technical challenges, virtual-environment surgical planning is useful as a clinical tool for preoperative visualization, cephalometric analysis, and surgical intervention. It can provide a more precise surgical result than would otherwise be realized using traditional methods.

    View details for PubMedID 10862131

  • A single surgeon's experience with the Delaire palatoplasty Schendel, S. A., Lorenz, H. P., Dagenais, D., Hopkins, E., Chang, J. LIPPINCOTT WILLIAMS & WILKINS. 1999: 1993-1997

    Abstract

    The purpose of this review was to evaluate the clinical outcomes regarding velopharyngeal insufficiency and fistulization in patients with cleft palate who underwent primary repair with the one-stage Delaire palatoplasty. All patients who had a primary Delaire-type palatoplasty performed by the senior surgeon over a 10-year period (1988 to 1998) were studied. During this period, each consecutive patient with an open palatal cleft underwent the same type of repair by the same surgeon. Speech quality and velopharyngeal competence as determined by a single speech pathologist were recorded. A total of 95 patients were included in this series. The average length of follow-up was 31 months (range, 1 to 118 months). Average age at time of surgery was 13.3 months (range, 6 to 180 months). Thirty-one patients (32.6 percent) had significant associated anomalies. The average length of hospital stay was 1.9 days (range, 1 to 8 days) with a trend in recent years toward discharge on postoperative day 1. There were no intraoperative complications, either surgical or anesthetic. Three patients (3.2 percent) developed palatal fistula; none of them required repair. Six patients (6.3 percent) had velopharyngeal incompetence. In patients with more than 1 year of follow-up, the incidence of velopharyngeal incompetence was 9.2 percent (6 of 65). The incidence of fistula after the Delaire palatoplasty was lower than usually reported. The incidence of velopharyngeal incompetence requiring pharyngoplasty was equal to or lower than that seen after other types of palatoplasty, suggesting superior soft-palate muscle function attributable to approximation of the musculus uvulae. The Delaire palatoplasty results in a functional palate with low risk for fistula formation and velopharyngeal incompetence.

    View details for Web of Science ID 000083854900009

    View details for PubMedID 11149761

  • Basic fibroblast growth factor and transforming growth factor beta-1 expression in the developing dura mater correlates with calvarial bone formation PLASTIC AND RECONSTRUCTIVE SURGERY Mehrara, B. J., Most, D., Chang, J., Bresnick, S., Turk, A., Schendel, S. A., Gittes, G. K., Longaker, M. T. 1999; 104 (2): 435-444

    Abstract

    Numerous studies have found dura mater-calvarial mesenchyme interactions during calvarial bone induction; however, the exact molecular mechanisms governing these inductive events remain unknown. Recent studies have implicated basic fibroblast growth factor (FGF-2) and transforming growth factor-beta1 (TGF-beta1) in regulating bone formation. The purpose of this study was, therefore, to investigate the expression of FGF-2 and TGF-beta1 during calvarial bone formation in rats. Eight rats were killed on embryonic days 14, 18, and 20 and neonatal day 1 (n = 32). Four animals at each time point were analyzed by in situ hybridization, and the remainder were analyzed by immunohistochemistry. The results indicated that the dura mater underlying the developing calvarial bone strongly expressed FGF-2 and TGF-beta1 mRNA at all time points examined. In contrast, minimal growth factor expression was noted in the overlying calvarial mesenchyme until embryonic day 18, but it increased significantly with increasing age. Importantly, FGF-2 and TGF-beta1 mRNA expression in the dura mater underlying the developing calvarium preceded and was significantly greater than expression in the calvarium mesenchyme (p < 0.05). Interestingly, minimal expression of FGF-2 and TGF-beta1 mRNA was noted for all time points in the dura mater underlying the posterior frontal suture and within the posterior frontal suture connective tissue (p < 0.01 when compared with the dura mater underlying the developing calvarium). Immunohistochemical findings closely paralleled mRNA expression, with intense staining for FGF-2 and TGF-beta1 in the dura mater underlying the developing calvarial mesenchyme. Increasing FGF-2 and TGF-beta1 staining was noted within calvarial osteoblasts with increasing age, particularly in cells located near the endocranial surface (i.e., in contact with the developing dura mater). These findings, together with the known biologic functions of FGF-2 and TGF-beta1, implicate these growth factors in the regulation of calvarial bone growth by the developing dura mater. The possible mechanisms of this interaction are discussed.

    View details for Web of Science ID 000081608500017

    View details for PubMedID 10654687

  • Studies in cranial suture biology: Up-regulation of transforming growth factor-beta 1 and basic fibroblast growth factor mRNA correlates with posterior frontal cranial suture fusion in the rat PLASTIC AND RECONSTRUCTIVE SURGERY Most, D., Levine, J. P., Chang, J., Sung, J., McCarthy, J. G., Schendel, S. A., Longaker, M. T. 1998; 101 (6): 1431-1440

    Abstract

    The mechanisms involved in normal cranial suture development and fusion as well as in the pathophysiology of craniosyostosis are not well understood. The purpose of this study was to investigate the expression of several cytokines--transforming growth factor-beta-1 (TGF-beta1), basic fibroblast growth factor (bFGF), and interleukin-6 (IL-6)--during cranial suture fusion. TGF-beta exists in three mammalian isoforms that are abundant in bone and stimulate calvarial bone formation when delivered locally. Other bone growth factors including basic fibroblast growth factor and the interleukins regulate bone growth and are mitogenic for bone marrow cells and osteoblasts. The involvement of growth factors in the pathophysiology of craniosynostosis is supported by recent genetics data linking fibroblast growth factor receptor mutations to syndromal craniosynostoses. In this experimental study, in situ hybridization was used to localize and quantify the gene expression of TGF-beta1, bFGF, and IL-6 during cranial suture fusion. In the Sprague-Dawley rat, the posterior frontal cranial suture normally undergoes fusion between 12 and 22 days of age, whereas all other cranial sutures remain patent. All in situ analyses of fusing posterior frontal sutures were compared with the patent, control, sagittal sutures. Posterior frontal and sagittal sutures, together with underlying dura, were harvested from rats at 8, 12, 16, and 35 days of postnatal life to analyze posterior frontal suture activity before, during, and after fusion. In situ hybridization was performed on frozen sections of these specimens using DNA probes specific for TGF-beta1, bFGF, and IL-6 mRNA. A negative control probe to IL-6 in the sense orientation was also used to validate the procedure. Cells expressing cytokine-specific mRNA were quantified (in cells positive per 10(-1) mm2) and analyzed using the unpaired Student's t test. Areas encompassing the fibrous suture and the surrounding bone plates were analyzed for cellular mRNA activity. IL-6 mRNA expression showed a minimal rise in the posterior frontal suture at days 12 and 16, with an average count of 10 and 6 cells per 10(-1) mm2, respectively. The sagittal suture remained negative for IL-6 mRNA at all time points. TGF-beta1 and bFGF analyses were most interesting, showing marked increases specifically in the posterior frontal suture during the time of active suture fusion. On postnatal day 8, a 1.5-fold increase in posterior frontal suture TGF-beta1 mRNA was found compared with sagittal sutures (p = 0.1890, unpaired Student's t test). This difference was increased 26-fold on day 12 in posterior frontal suture TGF-beta1 expression (p = 0.0005). By day 35, posterior frontal suture TGF-beta1 mRNA had nearly returned to prefusion levels, whereas TGF-beta1 mRNA levels in the sagittal suture remained low. A similar upregulation of bFGF mRNA, peaking at day 12, was observed in posterior frontal but not sagittal sutures (p = 0.0003). Furthermore, both TGF-beta1 and bFGF mRNA samples with intact dura showed an intense dural mRNA expression in the time preceding and during active posterior frontal suture fusion but not in sagittal tissues. Our data demonstrate that TGF-beta1 and bFGF mRNA are up-regulated in cranial suture fusion, possibly signaling in a paracrine fashion from dura to suture. TGF-beta1 and bFGF gene expression were dramatically increased both in and surrounding the actively fusing suture and followed the direction of fusion from endocranial to epicranial. These experimental data on bone growth factors support the recent human genetics data linking growth factor/fibroblast growth factor receptor deletions to syndromal craniosynostoses. The ultimate aim of these studies is to understand the underlying mechanisms regulating suture growth, development, and fusion so surgeons may one day manipulate the biology of premature cranial suture fusion.

    View details for Web of Science ID 000073423800001

    View details for PubMedID 9583470

  • Apert's syndrome correlates with low fibroblast growth factor receptor activity in stenosed cranial sutures JOURNAL OF CRANIOFACIAL SURGERY Bresnick, S., Schendel, S. 1998; 9 (1): 92-95

    Abstract

    Recent genetic studies have shown that Apert's syndrome results from mutations of the fibroblast growth factor (FGF) receptor 2 gene. We were interested in investigating the expression of FGF receptor 2 at the tissue level in children with Apert's syndrome. We studied FGF receptor activity in cranial sutures of children with Apert's syndrome and nonsyndromic, isolated craniosynostosis. Fourteen children between the ages of 6 months and 12 months were studied. Five of these children had Apert's syndrome with coronal suture stenosis. Nine children had an isolated, nonsyndromic coronal stenosis. Stenosed and nonstenosed cranial sutures were removed at the time of cranioplasty, fixed, decalcified, and paraffinized. Immunohistochemistry was performed with labeled, specific anti-FGR receptor 2 antibodies. We found lower levels of FGF receptor 2 staining in both stenosed and unstenosed sutures of children with Apert's syndrome compared with those from children with a nonsyndromic suture stenosis. Furthermore, fused sutures from children with Apert's syndrome demonstrated lower levels of FGF receptor 2 staining than unfused sutures from the same sample. The findings suggest that Apert's syndrome correlates with low FGF receptor 2 activity in cranial sutures. These results are consistent with and similar to our findings in Crouzon's syndrome, and support genetic studies showing localized mutational changes occurring at the FGF receptor 2 gene for both Apert's and Crouzon's syndromes. Furthermore, the findings suggest the possibility that variable expression of FGF receptor 2 occurs at the tissue level in patients with Apert's syndrome.

    View details for Web of Science ID 000071544100020

    View details for PubMedID 9558576

  • A case study using the virtual environment for reconstructive surgery VISUALIZATION '98, PROCEEDINGS Montgomery, K., Stephanides, M., Schendel, S., Ross, M. 1998: 431-?
  • Adverse outcomes in orthognathic surgery and management of residual problems CLINICS IN PLASTIC SURGERY Schendel, S. A., Mason, M. E. 1997; 24 (3): 489-?

    Abstract

    Adverse outcomes in orthognathic surgery include both functional and aesthetic components that frequently coexist. Reasons for this occurrence are multifactorial and can be classified in broad categories of diagnosis, treatment planning, technical execution, and unpreventable outcomes. Management of the residual deformities is both functional and aesthetic as based on correctly delineating the problem and its cause.

    View details for Web of Science ID A1997XL79900007

    View details for PubMedID 9246515

  • Preliminary report: A ceramic containing crosslinked collagen as a new cranial onlay and inlay material ANNALS OF PLASTIC SURGERY Schendel, S., Bresnick, S., CHOLON, A. 1997; 38 (2): 158-162

    Abstract

    Simple ceramic bone graft materials have demonstrated significant limitations for use in craniomaxillary reconstruction. We investigated a new, alloplastic composite bone grafting material containing particulate hydroxyapatite and crosslinked collagen in a time-sequence study. Five rabbits underwent surgical placement of high-loading and low-loading composite onlay and inlay grafts in the parietal region of the skull. Animals were sacrificed at either 1, 2, 4, or 6 months postoperatively. All rabbits demonstrated tissue continuity and healing of both onlay and inlay grafts to the outer table of the skull. Bony ingrowth was shown in both onlays and inlays with bone proliferation and vascularization. Bony ingrowth was seen as early as 1 month postoperatively. Inlay grafts healed flush to the outer table, while onlay grafts maintained at least 80% of graft volume at 6 months postoperatively. We conclude that a composite bone grafting material containing a ceramic and collagenous matrix may offer significant advantages to the reconstructive surgeon. The material appears to be easy to handle and carve, is biologically tolerated, and is able to maintain graft volume. Further studies of this new composite material are warranted.

    View details for Web of Science ID A1997WH42100011

    View details for PubMedID 9043585

  • The effect of bovine bone morphogenetic protein (bBMP) on the resorption of autogenous onlay bone grafts in the craniofacial skeleton CRANIOFACIAL SURGERY 7 Menard, R., Turk, A., Schendel, S. 1997: 17-18
  • A mathematical model for mandibular distraction osteogenesis JOURNAL OF CRANIOFACIAL SURGERY Schendel, S. A., Heegaard, J. H. 1996; 7 (6): 465-468

    Abstract

    In this paper, we look at the mechanobiological processes involved in mandibular distraction and, as a first approximation, propose an elastoplastic uniaxial model.

    View details for Web of Science ID A1996VU66100013

    View details for PubMedID 10332267

  • Treatment of periorbital edema with human corticotropin-releasing factor after blepharoplasty JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Schendel, S. A., Stephanides, M. 1996; 182 (3): 226-232

    Abstract

    This prospective study of 32 patients was undertaken to ev evaluate the formation of postoperative periorbital edema after administration of human corticotropin-releasing factor (hCRF). Human corticotropin-releasing factor has strong antiedematous properties as a result of direct action on blood vessels independent of endocrine function and has been shown to have a positive effect on vascular permeability in animal studies independent of corticosteroid effects.Human corticotropin-releasing factor was administered intravenously preoperatively to patients undergoing blepharoplasty in doses of 2, 4, and 8 mu g/kg body weight as a randomized, double-blind, placebo-controlled study. The periorbital edema was measured by the use of a three-dimensional laser scanner to determine facial and eyelid volume changes as specified times postoperatively.Human corticotropin-releasing factor was well tolerated when administered intravenously over a ten-minute period to healthy patients undergoing blepharoplasty. Mild transitory flushing and hypotension were the most common adverse events. Transient decreases in systolic and diastolic blood pressure and increases in heart rate occurred at hCRF doses greater than 2 mu g/kg and were most prominent at 8 mu g/kg. The 8 mu g/kg hCRF dose also showed a trend toward less postoperative edema but this was not statistically significant at the p<0.05 level.Human corticotropin-releasing factor appears to be safe for intravenous use in patients undergoing blepharoplasty; however, its efficacy in reducing postoperative edema as a single preoperative administration was not conclusively demonstrated in this study. Further research with a larger study population and other dosing regimens is indicated.

    View details for Web of Science ID A1996TY53800006

    View details for PubMedID 8603242

  • CORRECTION OF SCAPHOCEPHALY SECONDARY TO VENTRICULAR SHUNTING PROCEDURES PLASTIC AND RECONSTRUCTIVE SURGERY SHUSTER, B. A., Norbash, A. M., Schendel, S. A. 1995; 96 (5): 1012-1019

    Abstract

    Craniosynostosis following ventricular shunting procedures for hydrocephalus has become a recognized complication of shunting procedures. Secondary synostosis results from a decrease in intracranial volume leading to collapse of the cranial vault. Since this represents a distinct etiopathogenesis different from that typically involved, the surgical approach should be altered. Eight patients with secondary scaphocephaly underwent surgical reconstruction. The clinical data and radiographic studies were reviewed for these patients. The surgical approach consisted of sagittal or parasagittal strip craniectomies, lateral osteotomies with bone-flap expansion, occipital and frontal remodeling as needed, and the application of rigid fixation to maintain contour and prevent recurrent collapse of the cranial vault. Patient follow-up ranged from 3 to 37 months. Five of these patients were premature infants, an association not previously recognized in the literature. Satisfactory results were obtained in all patients. Keeping the craniectomy sites parent and achieving a more normal cranial contour through cranial remodeling have provided good results in this population.

    View details for Web of Science ID A1995RX59300002

    View details for PubMedID 7568474

  • EXPANDING CRANIAL DEFECTS FOLLOWING CRANIOFACIAL SURGERY PLASTIC AND RECONSTRUCTIVE SURGERY UMANSKY, W., Schendel, S. A. 1995; 96 (4): 969-971

    Abstract

    Growing skull fractures or posttraumatic leptomeningeal cysts are a known complication of skull fractures sustained in infancy and childhood. They usually present as progressively enlarging cranial masses at the site of the linear skull fractures. The pathogenesis is believed to require an underlying dural tear that allows herniation of the growing pulsatile brain and leads to resorption of the overlying bone. Similar enlarging cranial masses have been reported following craniofacial surgery. Our case occurred following reconstruction of a stenosed metopic suture. The treatment of this unusual complication of craniofacial surgery requires sound dural repair. An understanding of the similarity between this complication and the more common growing skull fractures of childhood is essential to a sound approach to diagnosis and treatment.

    View details for Web of Science ID A1995RT10300032

    View details for PubMedID 7652074

  • TREATMENT OF THE CRANIOFACIAL COMPLICATIONS OF BECKWITH-WIEDEMANN SYNDROME PLASTIC AND RECONSTRUCTIVE SURGERY Menard, R. M., Delaire, J., Schendel, S. A. 1995; 96 (1): 27-33

    Abstract

    Variable degrees of macroglossia have been noted in patients with Beckwith-Wiedemann syndrome. Past studies have shown that a major effect of the macroglossia is protrusion of dentoalveolar structures, resulting in an anterior open bite and a prognathic mandibular appearance secondary to an abnormally obtuse gonial angle and increased effective mandibular length. In our series of 11 Beckwith-Wiedemann syndrome patients we have observed that early correction of the macroglossia by means of partial glossectomy has resulted in decreased anterior open bite and mandibular prognathism as compared with patients managed conservatively.

    View details for Web of Science ID A1995RG78800004

    View details for PubMedID 7604127

  • CROUZONS-DISEASE CORRELATES WITH LOW FIBROBLASTIC GROWTH-FACTOR RECEPTOR ACTIVITY IN STENOSED CRANIAL SUTURES JOURNAL OF CRANIOFACIAL SURGERY Bresnick, S., Schendel, S. 1995; 6 (3): 245-248

    Abstract

    Reports have demonstrated that Crouzon's disease is associated with a gene on chromosome 10 coding for the fibroblastic growth factor (FGF) receptor 2. The purpose of this investigation was to evaluate the FGF receptor 2 levels in cranial sutures of children with Crouzon's disease and nonsyndromic, isolated craniosynostosis. Twelve children between the ages of 6 and 24 months were studied. Four patients had Crouzon's disease with coronal suture stenosis. The 8 remaining had a nonsyndromic, isolated coronal stenosis. Stenosed and adjacent nonstenosed cranial sutures were removed at cranioplasty and promptly fixed, decalcified, and embedded in paraffin. Immunohistochemical analysis of cranial sutures was performed with labeled, specific anti-FGF receptor 2 antibodies. In children with Crouzon's disease, we found significantly lower levels of FGF receptor 2 staining in stenosed sutures compared with nonstenosed sutures. In addition, sutures from children with Crouzon's disease demonstrated lower levels of FGF receptor 2 activity in both stenosed and nonstenosed sutures compared with children with a nonsyndromic, isolated coronal stenosis. However, there were no significant differences in FGF receptor 2 staining between stenosed and nonstenosed sutures in children with a nonsyndromic, isolated coronal stenosis. These findings suggest that low FGF receptor 2 activity in cranial sutures correlates with Crouzon's disease. This work supports genetic studies and yet shows that patients with Crouzon's disease have low FGF receptor 2 activity in cranial sutures. The findings also suggest that there may be etiological differences between syndrome- and nonsyndrome-associated craniosynostoses in children.

    View details for Web of Science ID A1995QY84700011

    View details for PubMedID 9020696

  • Scanning electron microscopic analysis of craniosynostotic sutures CRANIOFACIAL SURGERY 6 Menard, R. M., Schendel, S. A. 1995: 367-368
  • Low levels of fibroblastic growth factor receptor 2 activity correlates with Crouzon's disease CRANIOFACIAL SURGERY 6 Bresnick, S., Schendel, S. 1995: 343-346
  • HISTOCHEMICAL ANALYSIS OF CLEFT-PALATE MUSCLE PLASTIC AND RECONSTRUCTIVE SURGERY Schendel, S. A., CHOLON, A., Delaire, J. 1994; 94 (7): 919-923

    Abstract

    Research has clarified the abnormal insertions and orientations of the involved musculature in cleft palate. However, little is known about the physiologic aspects of these muscles, specifically from a histochemical perspective. In this study, 30 muscle specimens were removed from the palatal cleft margin in patients undergoing primary palatoplasty. Nine patients had combined cleft lip and palate deformity, and seven had an isolated cleft palate. Biopsies were taken from the area of the musculus uvulus in all specimens and examined by histochemical techniques. The percentage of type 1 and type 2 fibers was different in isolated cleft palate as compared with cleft lip and palate specimens, being, respectively, 56.7 percent type 1 and 43.3 percent type 2 and 62.0 percent type 1 and 38.0 percent type 2 fibers. This is the opposite ratio from other facial muscles but is in line with the literature regarding normal palatal muscle. Isolated cleft palate muscle fibers also were minimally decreased in diameter as compared with normal facial muscle. Fiber diameters of the combined cleft lip and palate muscles were severely decreased in size compared with those muscles found in the cleft lip. Abnormal mitochondrial accumulations also were found in cleft lip and palate muscle specimens but not in isolated cleft palate muscle specimens. We consider the decrease in muscle diameter found in isolated cleft palate to be secondary to functional atrophy, while that in the cleft lip and palate specimens is secondary to a primary hypoplasia together with a functional atrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

    View details for Web of Science ID A1994PV33900003

    View details for PubMedID 7972479

  • MULTIPLE-SUTURE SYNOSTOSIS SUBSEQUENT TO VENTRICULAR SHUNTING PLASTIC AND RECONSTRUCTIVE SURGERY Schendel, S. A., Shuer, L. M. 1994; 93 (5): 1073-1077

    View details for Web of Science ID A1994ND65800028

    View details for PubMedID 8134467

  • THE ASSOCIATION OF CLEFT-LIP AND PALATE WITH AICARDI SYNDROME PLASTIC AND RECONSTRUCTIVE SURGERY UMANSKY, W. S., Neidich, J. A., Schendel, S. A. 1994; 93 (3): 595-597

    Abstract

    In summary, Aicardi syndrome is defined by its tetrad of infantile spasms, agenesis of the corpus callosum, mental retardation, and chorioretinal lacunae. We report a case of Aicardi syndrome with associated cleft lip and palate. This is an infrequent finding that is present in approximately 3 percent of reported cases. Plastic surgeons should be aware of this association when treating patients with cleft lip and palate.

    View details for Web of Science ID A1994MZ50600026

    View details for PubMedID 8115518

  • AN ANALYSIS OF LE-FORT-I MAXILLARY ADVANCEMENT IN CLEFT-LIP AND PALATE PATIENTS PLASTIC AND RECONSTRUCTIVE SURGERY ESKENAZI, L. B., Schendel, S. A. 1992; 90 (5): 779-787

    Abstract

    We present a series of 24 consecutive cleft lip and palate patients aged 16 to 46 years (mean age 27 years) who underwent Le Fort I maxillary advancement by the senior author over the past 8 years. Two groups, one of 12 patients with wire fixation and one of 12 patients with miniplate fixation, were evaluated. Each group had 10 unilateral and 2 bilateral clefts. All patients were grafted with autogenous bone (8 cranial, 14 iliac, and 2 mandibular). Horizontal advancement was 3 mm to 2 cm (with a mean of 7.8 mm). Vertical movement ranged from a shortening of 5 mm to a lengthening of 1.3 cm (mean 2.3 mm of lengthening). The amount and timing of relapse were compared in both the horizontal and vertical dimensions. The plated group was more stable in both the horizontal and vertical dimensions (p < 0.05). No significant skeletal relapses occurred after the first year. Statistically significant dental relapse occurred only in the wired group. Three patients developed transverse collapse of the small maxillary cleft segment, and four developed incisor angulation to compensate for maxillary skeletal relapse. The presence of a pharyngeal flap at the time of advancement appeared to increase relapse in both horizontal and vertical dimensions (p < 0.03), but there were too few patients (7 of 24) with pharyngeal flaps to prove this conclusively. We also concluded that pterygomandibular grafting is not necessary to achieve excellent results using miniplate fixation; autogenous grafting of the anterior maxillary osteotomy alone provides the necessary stability.

    View details for Web of Science ID A1992JW18000007

    View details for PubMedID 1410030

  • NASAL CONSIDERATIONS IN ORTHOGNATHIC SURGERY AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS Schendel, S. A., Carlotti, A. E. 1991; 100 (3): 197-208

    Abstract

    The functional correction of dentofacial deformities by orthognathic surgery produces major changes in facial appearance. Facial esthetics must therefore be equally appreciated by the orthodontist and the maxillofacial surgeon. The orthodontist must perform a thorough esthetic facial evaluation along with his usual orthodontic evaluation. The treatment plan must then be based on the esthetic evaluation and knowledge of the facial changes caused by orthodontic treatment and skeletal jaw surgery. Central to facial form is the nose. This article will outline the proper functional and esthetic evaluation of the nose in relation to the face. Nasal and upper lip changes associated with maxillary procedures will also be covered in detail. In light of these two areas, proper treatment planning and sequencing will be discussed.

    View details for Web of Science ID A1991GE85500003

    View details for PubMedID 1877544

  • PATHOPHYSIOLOGY OF CLEFT-LIP MUSCLES FOLLOWING THE INITIAL SURGICAL REPAIR PLASTIC AND RECONSTRUCTIVE SURGERY Schendel, S. A., Pearl, R. M., DeArmond, S. J. 1991; 88 (2): 197-200

    Abstract

    Muscle biopsy specimens taken from the upper lip and perialar area during the time of secondary lip revision and studied by histochemical techniques demonstrate persistent connective-tissue and muscle abnormalities even at a distance from the cleft margins. Some of these changes are consistent with surgically induced denervation-reinnervation of muscle groups in the surgical field. Increased amounts of connective tissue also were found, most likely secondary to the original deformity and the subsequent surgical procedures. Both these changes may be important factors in subsequent abnormal growth and development of the underlying midfacial structures. This study also demonstrated the resolution of previously noted mitochondrial abnormalities found in the primary cleft lip patient.

    View details for Web of Science ID A1991FY79100003

    View details for PubMedID 1852810

  • THE ILIAC CREST CARTILAGINOUS CAP ANNALS OF PLASTIC SURGERY Schendel, S. A., Pearl, R. M. 1990; 25 (1): 29-31

    Abstract

    Bone and cartilage grafts can be procured from the ilium either separately or as composite chondroosseous grafts when sufficient cartilage is present. The thickness and anatomy of this iliac cartilaginous cap was analyzed in relationship to age in 50 individuals. Histology was that of normal hyaline cartilage. The cartilage alone was more pliable with little memory when compared with auricular or septal cartilage. The cartilage/bone junction was very strong. Cartilage thickness ran from close to 1 cm at age 5 to a diminished zero at age 25.

    View details for Web of Science ID A1990DN58200007

    View details for PubMedID 2378494

  • Sports related Nasal Injuries Sports Med Schendel, S. 1990; 18 (10): 59-74
  • TRANSORAL PLACEMENT OF RIGID FIXATION FOLLOWING SAGITTAL RAMUS SPLIT OSTEOTOMY JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Tulasne, J. F., Schendel, S. A. 1989; 47 (6): 651-652

    View details for Web of Science ID A1989U841300029

    View details for PubMedID 2723868

  • PATHO-PHYSIOLOGY OF CLEFT-LIP MUSCLE PLASTIC AND RECONSTRUCTIVE SURGERY Schendel, S. A., Pearl, R. M., DeArmond, S. J. 1989; 83 (5): 777-784

    Abstract

    Although attention has been focused for decades on the correction of cleft lip deformities, our knowledge about the etiology of such deformities has remained presumptive. Sixty-six muscle biopsy specimens from cleft lip infants were obtained at the time of primary closure. Histochemical stains, histographic analysis, and electron microscopy were performed. A nonneurogenic muscle atrophy was seen that varied in severity, with muscle fibers near the cleft being the most atrophic and disorganized. Muscle fibers stained with the modified Gomori trichrome technique also demonstrated "ragged red" fibers typical of a mitochondrial myopathy. Electron microscopy confirmed large accumulations of mitochondria distorting the fibrils. These mitochondria also were increased in size and densely packed with cristae. This study thus demonstrates that the muscles in cleft lip deformities are not normal. Instead, they reflect either myopathy in the facial mesenchymal mitochondrion or at least a delay in maturation. We hypothesize that some of the morphologic deformities associated with cleft lip may cause a failure of mesenchymal reinforcement of the facial processes at a critical time in development.

    View details for Web of Science ID A1989U402700002

    View details for PubMedID 2469093

  • VANBUCHEM DISEASE - SURGICAL-TREATMENT OF THE MANDIBLE ANNALS OF PLASTIC SURGERY Schendel, S. A. 1988; 20 (5): 462-467

    Abstract

    First described in 1955, Van Buchem disease is an infrequently occurring hereditary sclerosing bone dysplasia. It is more properly called hyperostosis corticalis generalisata. The most striking feature is an unusual enlargement of the mandible with a normal dental occlusion. Skull base, spine, and pelvic bone involvement is also seen. The defect appears to be an increase in cortical bone thickness or sclerosis. The condition first appears around puberty in the autosomal recessive type and in early childhood with the autosomal dominant type. Reported here is a family with Van Buchem disease, in which surgical recontouring of the mandible was performed for one of the members. The surgery was performed by a combined intraoral/extraoral technique with good aesthetic results and minimal morbidity. A differential diagnosis and workup is also presented.

    View details for Web of Science ID A1988N220300011

    View details for PubMedID 3377422

  • AN ANALYSIS OF FACTORS INFLUENCING STABILITY OF SURGICAL ADVANCEMENT OF THE MAXILLA BY THE LEFORT-1 OSTEOTOMY JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Carlotti, A. E., Schendel, S. A. 1987; 45 (11): 924-928

    Abstract

    Skeletal stability after maxillary surgical advancement was studied in 30 patients. Postoperative movement of all measured skeletal and dental points were on the average negligible. Equal stability was seen in maxillary advancement alone and with concomitant mandibular surgery. Eight cases examined individually showed larger than desired postoperative movements. In six of these cases the undesirable postoperative changes were secondary to undesirable preoperative orthodontic flaring of the incisors. The Begg orthodontic technique, because of its tendency to axially rotate teeth, was shown to produce more variability in tooth position than edgewise orthodontics. This study confirms that no preoperative flaring of the maxillary incisors should be attempted; instead, the teeth should be retracted and placed over basal bone with a normal axial inclination. Occlusal correction should then be accomplished by surgery. Suspension wires and bone grafting are sufficient to obtain skeletal stability in cases of maxillary advancement up to 11 mm. In cases where the surgery is more complex, rigid fixation is recommended.

    View details for Web of Science ID A1987K794100008

    View details for PubMedID 3478439

  • COMPUTED AXIAL TOMOGRAPHIC ASSESSMENT OF CRANIOORBITAL ANATOMY IN UNILATERAL CLEFTS ANNALS OF PLASTIC SURGERY Schendel, S. A., Delaire, J. 1986; 17 (2): 120-124

    Abstract

    Anatomy of the cranioorbital region in the unoperated infant with cleft lip/palate, is not well known. In this study, computed axial tomography was performed in 7 infants with unoperated unilateral cleft lip combined with cleft palate but no recognized craniofacial syndromes, and on 5 age-matched control infants. Significant differences were found between the infants with cleft lip/palate and the normal infants. There was more plagiocephaly in the cleft group, and the flattened forehead on the involved side was associated with less facial projection. The angles of the petrous portions of the temporal bones and midsagittal plane were also significantly more obtuse in the cleft group. In the normal group the lateral orbital walls and petrous portions of the temporal bones formed a large symmetrical X. This X in the cleft groups was distorted and not readily recognizable. There were also trends indicating possible differences in the orbital and ethmoid orientations in the two groups.

    View details for Web of Science ID A1986D565700006

    View details for PubMedID 3273084

  • FACIAL CHANGES ASSOCIATED WITH SURGICAL ADVANCEMENT OF THE LIP AND MAXILLA JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Carlotti, A. E., ASCHAFFENBURG, P. H., Schendel, S. A. 1986; 44 (8): 593-596

    Abstract

    A study of maxillary advancements performed with concomitant nasolabial muscle reconstruction demonstrated a predictable soft tissue/osseous ratio of 1:0.9, with the lip moving forward on the average of 90% of the dentition. Lip shortening was not found in this group of patients.

    View details for Web of Science ID A1986D511700004

    View details for PubMedID 3461138

  • VARIATIONS OF TOTAL VERTICAL MAXILLARY EXCESS JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Schendel, S. A., Carlotti, A. E. 1985; 43 (8): 590-596

    Abstract

    The long-face syndrome is a well-recognized entity, yet the pathogenesis of this malformation remains obscure and variations are generally not recognized. Fifty lateral cephalometric radiographs of patients who underwent vertical maxillary reductions were studied using the architectural and structural analysis of Delaire. Several subgroups of vertical maxillary excess that had not been recognized previously were identified. The most common dysmorphic type was the classically described long-face syndrome; the next most common consisted of patients who had short upper lips, normal maxillas, and long faces secondary to vertical chin excess. In all, six different variations of vertical maxillary excess were identified. Concomitantly, in the majority of cases there was associated vertical mandibular chin excess. It is suggested that these variations may have differing pathogeneses.

    View details for Web of Science ID A1985AND9400009

    View details for PubMedID 3859608

  • FAMILIAL OSTEODYSPLASIA HEAD & NECK SURGERY Schendel, S. A., Delaire, J. 1982; 4 (4): 335-343

    Abstract

    A family with characteristics that have striking similarities to the syndrome of familial osteodysplasia is reported. The inheritance pattern appears to be autosomal dominant. The typical facies has a lack of vertical facial development and a functional prognathism caused by overclosure of the mandible and opening of the gonial angle. Midfacial hypoplasia and a pointed chin are characteristic. Alveolar and sutural bone growth in the face is diminished and associated with partial dental agenesis. Variable cranial digital markings and possible synostosis are also seen. These typical facial changes are associated with other bony and systemic abnormalities. The long bones have a flask shape and occasionally have increased cortical thickness. The superior pubic ramus is often thin and scoliosis is common. The dermatoglyphic pattern demostrates a distal triradius and small whorl abnormalities. The most significant laboratory values are an increased erythrocyte sedimentation rate and C3 complement found on the erythrocytes. The plasma fibrinogen level was low in all family members.

    View details for Web of Science ID A1982NM98800011

    View details for PubMedID 7085324

  • AN ARCHITECTURAL AND STRUCTURAL CRANIOFACIAL ANALYSIS - A NEW LATERAL CEPHALOMETRIC ANALYSIS ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY ORAL RADIOLOGY AND ENDODONTICS Delaire, J., Schendel, S. A., Tulasne, J. F. 1981; 52 (3): 226-238

    Abstract

    The architectural and structural craniofacial analysis is based upon mutual balance of the cranial and facial bony structures. With this technique, the bases and calvaria of the cranium and then the face can be studied successively in relation to the cranium and craniospinal articulation. Statistical averages are avoided, and individual proportions influenced by the unique features of each skeleton are relied upon. The dentition is placed within the cephalic context, and therapy etiologic factors of dentofacial dysmorphoses which would not otherwise be demonstrated by conventional analysis are made obvious. This technique is particularly useful to the maxillofacial surgeon, as it clearly demonstrates all of the maxillofacial deformities and the pathologic balances that need to be corrected. In severe craniofacial malformations, it offers better possibilities than other cephalometric analysis methods of detecting the various cranial and facial anomalies which characterize these conditions.

    View details for Web of Science ID A1981MH25900001

    View details for PubMedID 6945527

  • FUNCTIONAL MUSCULOSKELETAL CORRECTION OF SECONDARY UNILATERAL CLEFT-LIP DEFORMITIES - COMBINED LIP-NOSE CORRECTION AND LE FORT I OSTEOTOMY JOURNAL OF MAXILLOFACIAL SURGERY Schendel, S. A., Delaire, J. 1981; 9 (2): 108-116

    Abstract

    Secondary cleft lip-palate deformities frequently involve a combination of skeletal, cartilagenous, dental and muscular deformities. Correction of these deformities should be based on normalization of function by restoring normal anatomy as much as possible. Functional correction of the lip musculature is best done at the same time as surgical correction of the skeletal-dental deformities. In this article, we outline a fundamental technique for secondary lip-nose correction based on muscle reorientation and a concomitant Le Fort I maxillary osteotomy.

    View details for Web of Science ID A1981LR46800008

    View details for PubMedID 6943241

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