[Show abstract][Hide abstract] ABSTRACT: The purpose of this project was to test a surgical navigation tool designed to help execute a surgical treatment plan. It consists of an electromagnetically tracked pencil that is used to mark bone intraoperatively. The device was tested on a precision block, an ex vivo pig mandible and during performance of six endoscopic vertical ramus osteotomies on pig cadavers. The difference between actual pencil position and that displayed by the computer was measured three times each at ten 2mm holes on the block (n=30 observations) and on the ex vivo mandible (n=11 measurements). Errors between planned and actual osteotomy locations for the cadaver procedures were measured. The mean distance between known and displayed locations was 1.55 ± 0.72 mm on the precision block and 2.10 ± 0.88 mm on the pig mandible. The error measured marking the same point on the block multiple (n=5) times was 0.58 ± 0.37 mm. The mean error on the simulated osteotomies was 2.35 ± 1.35 mm. Osteomark was simple to use and permitted localisation of holes and osteotomies with acceptable accuracy. In the future, the device and algorithms will be revised to further decrease error and the system will be tested on live animals.
International Journal of Oral and Maxillofacial Surgery 11/2011; 41(2):265-70. · 1.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate changes in airway size and shape in patients with obstructive sleep apnea (OSA) after maxillomandibular advancement (MMA) and genial tubercle advancement (GTA).
This was a retrospective cohort study, enrolling a sample of adults with polysomnography-confirmed OSA who underwent MMA + GTA. All subjects who had preoperative and postoperative 3-dimensional computed tomography (CT) scans to evaluate changes in airway size and shape after MMA + GTA were included. Preoperative and postoperative sleep- and breathing-related symptoms were recorded. Descriptive and bivariate statistics were computed. For all analyses, P < .05 was considered statistically significant.
During the study period, 13 patients underwent MMA + GTA, of whom 11 (84.6%) met the inclusion criteria. There were 9 men and 2 women with a mean age of 39 years. The mean body mass index was 26.3; mean respiratory disturbance index (RDI), 48.8; and mean lowest oxygen saturation, 80.5%. After MMA + GTA, there were significant increases in lateral and anteroposterior airway diameters (P < .01), volume (P = .02), surface area (P < .01), and cross-sectional areas at multiple sites (P < .04). Airway length decreased (P < .01) and airway shape (P = .04) became more uniform. The mean change in RDI was -60%.
Results of this preliminary study indicate that MMA + GTA appears to produce significant changes in airway size and shape that correlate with a decrease in RDI.
Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 03/2011; 69(3):677-86. · 1.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Distraction osteogenesis to expand the facial skeleton is an alternative to standard orthognathic surgery for selected patients with obstructive sleep apnea. For children with congenital micrognathia or midface hypoplasia, distraction osteogenesis allows large advancements without the need for bone grafting and with less risk of relapse. For later-onset obstructive sleep apnea, distraction osteogenesis may represent an alternative when acute bone movement is expected to be difficult (scarring from previous surgery or radiation therapy) or when the risk for inferior alveolar nerve damage is unacceptable (patients older than 40 years).
Oral and maxillofacial surgery clinics of North America 11/2009; 21(4):459-75.
[Show abstract][Hide abstract] ABSTRACT: Temporomandibular joint (TMJ) ankylosis in children is a challenging problem. Surgical correction is technically difficult and the incidence of recurrence after treatment is high. The purpose of the present report is to describe the protocol currently used at the Massachusetts General Hospital for the management of TMJ ankylosis in children. It has been our observation that the most common cause of treatment failure is inadequate resection of the ankylotic mass and failure to achieve adequate passive maximal opening in the operating room. The 7-step protocol consists of 1) aggressive excision of the fibrous and/or bony ankylotic mass, 2) coronoidectomy on the affected side, 3) coronoidectomy on the contralateral side, if steps 1 and 2 do not result in a maximal incisal opening greater than 35 mm or to the point of dislocation of the unaffected TMJ, 4) lining of the TMJ with a temporalis myofascial flap or the native disc, if it can be salvaged, 5) reconstruction of the ramus condyle unit with either distraction osteogenesis or costochondral graft and rigid fixation, and 6) early mobilization of the jaw. If distraction osteogenesis is used to reconstruct the ramus condyle unit, mobilization begins the day of the operation. In patients who undergo costochondral graft reconstruction, mobilization begins after 10 days of maxillomandibular fixation. Finally (step 7), all patients receive aggressive physiotherapy. A case series of children with ankylosis treated using this protocol is presented.
Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 10/2009; 67(9):1966-78. · 1.58 Impact Factor