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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
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ABSTRACT: To identify abnormalities in airway size and shape that correlate with the presence and severity of obstructive sleep apnea (OSA).
This was a retrospective case series of patients undergoing treatment of OSA who had preoperative computed tomographic (CT) scans of the upper airway available. Patients who had undergone CT scanning for nonairway pathologic features during the same period served as the controls. Digital 3D-CT reconstructions were made and 12 parameters of airway size and 4 of shape were analyzed. The posterior airway space, middle airway space, and hyoid to mandibular plane distance were measured on the lateral cephalograms of the patients with OSA. Bivariate analysis was used to identify the factors associated with the presence and severity of OSA as measured by the respiratory disturbance index (RDI). Multiple regression analysis identified the factors that correlated with the RDI.
Of the 44 patients with OSA, 15 (10 men and 5 women) had pre- and postoperative CT scans available. In addition, 17 patients (11 men and 6 women) were used as controls. The airway length was significantly increased in the patients with OSA (P < .01). On bivariate analysis, the length, lateral/retroglossal anteroposterior dimension ratio and genial tubercle to hyoid bone distance were associated with the RDI (P < .03). On multiple regression analysis, length (P < .01) had a positive correlation and the lateral/retroglossal anteroposterior dimension ratio (P = .04) an inverse correlation with the RDI.
The results of this study indicate that the presence of OSA is associated with an increase in airway length. Airways that were more elliptical in shape and mediolaterally oriented (greater lateral/retroglossal anteroposterior dimension ratio) had a decreased tendency toward obstruction.
Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 02/2010; 68(2):354-62. · 1.58 Impact Factor
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ABSTRACT: The purposes of this study were to establish normative data for airway size and shape and to evaluate differences associated with age and sex using 3-dimensional (3-D) imaging. Patients being evaluated by computed tomography (CT) for pathologic conditions not related to the airway were included. Using 3-D Slicer (Harvard Surgical Planning Laboratory, Brigham and Women's Hospital, Boston, MA), a software program, digital 3-D CT reconstructions were made and parameters of airway size analyzed: volume (VOL), surface area (SA), length (L), mean cross-sectional area (mean CSA), minimum retropalatal (RP), minimum retroglossal (RG), minimum cross-sectional area (min CSA), and lateral (LAT) and anteroposterior (AP) retroglossal airway dimensions. Evaluation of airway shape included LAT/AP and RP/RG ratios, uniformity (U), and sphericity, a measure of compactness (Psi). Children were stratified by stage of dentition: primary, 0 to 5 years; mixed, 6 to 11 years; permanent, 12 to 16 years; and adults, older than 16 years. Differences in airway parameters by age and sex were analyzed. Forty-six CT scans (31 males) were evaluated. Adults had larger (VOL, SA, L, mean CSA, and LAT), more elliptical (increased LAT/AP, P = 0.01), less uniform (U, P = 0.02), and less compact (decreased Psi, P = 0.001) airways than children. Among children, those in the permanent dentition demonstrated greater VOL (P < 0.01), SA (P < 0.01), L (P < 0.01), and mean CSA (P < 0.01) than those in the primary dentition. There were no gender differences in airway parameters. Understanding differences in 3-D airway size and morphology by age may serve as a basis for evaluation of patients with obstructive sleep apnea and may help to predict and to evaluate outcomes of treatment.
The Journal of craniofacial surgery 01/2009; 20 Suppl 1:657-63. · 0.81 Impact Factor
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ABSTRACT: The purpose of this study was to assess the effectiveness of ultrasonography in visualizing the lingual nerve, calculating its distance from the lingual cortex at the area of the third molar, and in detecting injuries.
Using a standardized protocol, lingual nerve dissections were performed in Yorkshire pig cadaver heads. After nerve isolation was confirmed, the nerve was left intact, fully transected, or partially transected. The dissection flap was repositioned and the pig heads were given to 3 blinded evaluators. Using a handheld ultrasound device, the evaluators were asked to determine the status of the nerve and categorize their finding as intact, fully transected, or partially transected. The recorded ultrasound images from the 9 study specimens were then analyzed and the distances of the lingual nerves from the alveolus were measured.
After becoming familiar with the ultrasonographic appearance of the lingual nerve, all of the evaluators were able to visualize and identify the nerve using the ultrasound machine. Lingual nerve injuries were accurately categorized in 17 out of the 27 total attempts (success rate, 63%). The average distance of the nerve from the alveolar cortex was measured to be an average distance of 1 mm.
The results of this study indicate that ultrasonography can be effectively used to visualize the lingual nerve.
Journal of Oral and Maxillofacial Surgery 12/2007; 65(11):2295-300. · 1.64 Impact Factor
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Journal of Oral and Maxillofacial Surgery 10/2007; 65(9):1865-8. · 1.64 Impact Factor
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ABSTRACT: Distraction osteogenesis is a technique for skeletal lengthening that exploits the body's innate capacity for bone formation in response to tension forces on the repair callus. The authors developed a distraction osteogenesis model with a semiburied device in the Yucatan minipig mandible because of similarities between human and porcine mandibular anatomy, temporomandibular function, chewing patterns, and bone turnover rates. The purpose of this study was to measure histomorphometric bone fill after different latency periods, rates of distraction, and duration of neutral fixation in the minipig mandible. In addition, the relationship between histomorphometric bone fill and clinical stability was investigated. Mandibular osteotomies in 20 female Yucatan minipigs weighing 25 to 30 kg were distracted with modified semiburied distraction devices. Variables included 0-day or 4-day latency; 1-mm, 2-mm, or 4-mm daily distraction rates; gap size of 7 or 12 mm; and evaluation after neutral fixation for various lengths of time. Specimens were fixed in 2% paraformaldehyde, pH 7.4, before being embedded in methylmethacrylate. Sections were prepared from the region just below the inferior alveolar canal. The area of new bone formation within the gap was measured and expressed as a percentage of the total area of the distraction gap. Bone fill ranged from 0 to 100 percent. A pilot study with 7-mm advancements showed similar bone fill with 0-day or 4-day latency, but with poor reproducibility. Mandibles that were distracted to 12 mm at 1 mm per day exhibited nearly complete bone fill, either with 0-day latency (average, 93 percent) or 4-day latency (average, 100 percent). Mandibles that had been distracted for 3 days at 4 mm per day showed moderate osteogenesis and clinical stability with increasing time of neutral fixation. Bone fill was significantly correlated with clinical stability (Spearman r = 0.801, p = 0.001). Histological examination showed exuberant periosteal osteogenesis in distracted mandibles, even in those that showed poor bone fill and clinical stability. Thus, the periosteum appears to be a major source of new bone formation. These results show that osteogenesis was nearly complete with 1 mm per day and 0-day or 4-day latency. These results are consistent with the authors' previously reported clinical and radiographic observations that a latency period is not necessary for successful healing of the mandibular distraction osteogenesis wound.
Plastic & Reconstructive Surgery 03/2004; 113(2):566-73. · 3.38 Impact Factor
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ABSTRACT: We present the cases of 4 patients with clear cell odontogenic carcinoma and a contrasting case of a patient with a calcifying epithelial odontogenic tumor from Massachusetts General Hospital. Differential diagnosis, distinguishing characteristics, and data from 32 cases in the literature are also reported. Because this rare tumor behaves aggressively with both regional and distant spread, a better understanding of its biologic behavior is imperative.
The 4 patients with clear cell odontogenic carcinoma were women and had an average age of 65 years (range, 40 to 77 years). Three tumors were in the posterior mandible and 1 was in the maxilla. Three patients complained of pain; bony expansion and tooth mobility were noted in isolated cases. A comparison is made with other reported cases, and factors associated with recurrence and survival are presented.
All patients were treated with resection, and 1 patient received postoperative radiotherapy. Two patients with positive surgical margins underwent further resection. All patients have been followed an average of 2 years (range, 0.5 to 4 years) and presently have no evident disease.
Recognition of this unusual tumor and differentiating it from other clear cell neoplasms is critical in developing an appropriate treatment plan. Management should include wide en bloc resection and long-term follow-up.
Journal of Oral and Maxillofacial Surgery 06/2003; 61(5):580-6. · 1.64 Impact Factor
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ABSTRACT: A standardized, noninvasive technique to assess healing of the mandibular distraction wound is not available. Current methods include clinical examination, plain radiography, and computed tomography. These imaging techniques are expensive and obligate the patient to serial radiation exposure. In addition, anatomic overlap and metal artifacts may obscure the distraction gap. In contrast, ultrasound has been shown to be a noninvasive, efficient, and inexpensive way to evaluate bone healing. The purpose of this study was to test the feasibility of ultrasound to evaluate an experimental mandibular distraction osteogenesis wound.
Distraction devices were placed via a submandibular incision into 24 minipigs. The protocol consisted of 0-day latency and distraction rates of 1, 2, or 4 mm/d for a 12-mm gap. The wounds were assessed in vivo after 0, 8, 16, and 24 days of neutral fixation. Ex vivo radiographs were used to estimate bone fill using a semiquantitative score. A semiquantitative ultrasound score was assigned, and the beam penetration depth was measured in millimeters.
In all groups, clinical stability of the distraction wound increased with the duration of fixation. Plain radiographs, taken during neutral fixation, showed that the desired distraction gap was achieved and maintained. The ultrasound score increased with fixation time, whereas beam penetration depth decreased as expected. Ex vivo radiographs showed increasing bone fill score with time and paralleled the ultrasound score.
The results of this feasibility study indicate that ultrasound is potentially useful for the assessment of bone formation in distraction osteogenesis wounds.
Journal of Oral and Maxillofacial Surgery 10/2002; 60(9):1038-44. · 1.64 Impact Factor
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ABSTRACT: . Three-dimensional planning tools will enable the use of minimally-invasive distraction osteogenesis for the correction of craniomaxillofacial deformities by simulating treatment, precisely quantifying movement vectors, and aiding pre and post-treatment evaluation. Current techniques extrapolate 3D surgical movements and outcomes based on standard 2D radiographs. Surgical planning and outcome evaluation would be greatly improved by an accurate, reproducible and reliable 3D treatment planning system. Building upon a software foundation that includes the 3D Slicer of the Brigham & Women's Hospital, and the Visualization Toolkit (VTK) of Schroeder, Martin & Lorensen, we add algorithms that support interactive cutting of large triangulated surface models, collision detection, landmark-based registration, and cephalometric analysis. The oriented bounding-box tree (OBB tree) structure is used throughout to enhance the interactivity of selection, collision detection, and cuttin...
11/2000;
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Medical Image Computing and Computer-Assisted Intervention - MICCAI 2000, Third International Conference, Pittsburgh, Pennsylvania, USA, October 11-14, 2000, Proceedings; 01/2000
