A one-arm surgical trial of obstructive sleep apnea (OSA) patients before and 12 months after Bilateral Internal Ramus Distraction of the mandible (BIRD).

BACKGROUND: An innovative approach for the primary and definitive treatment of obstructive sleep apnea (OSA) in adult patients is presented: Bilateral Internal Ramus Distraction of the mandible (BIRD), which is a slow, progressive and more stable procedure to advance the mandibular bone. This study investigated whether this surgical approach is useful to cure OSA. METHODS: Study design was of an interventional (surgical) one-arm trial of OSA patients assessed before and 12 months after BIRD. All patients were evaluated by pre- and post-operative polysomnography and three-dimensional scans. The amount of skeletal advancement, percentage of upper airway volume increase and postoperative value of mandibular occlusal plane were the predictor variables. Changes in the apnoea-hypopnoea index (AHI), oxygen desaturation index (ODI), and percentage of time with saturation under 90% (TC90) were the main outcome variables. FINDINGS: Thirty-two subjects with a mean ± SD age of 41.9 ± 13.3 years and 87.5% male were included, and they were followed-up 32 ± 14.2 months. AHI was 47.9 ± 23.1 per hour before surgery and the Epworth Sleepiness Scale (ESS) was 13.4 ± 4.4. Postoperative AHI was 4.8 ± 5.6 per hour 12 months after surgery (P < 0.001), with 81.2% of the patients considered cured (AHI<5) and 18.8% suffering from a mild-to-moderate residual OSA. ESS decreased to 1.9 ± 1.8 at the end of the surgical treatment (P < 0.001). 3D changes revealed an upper airway volume increase of 188.4% ± 73.5% (P < 0.001). INTERPRETATION: Lengthening the mandibular ramus by distraction osteogenesis to cure OSA appears to be more effective and safer when compared to other surgical protocols, especially in very severe cases with initial AHI>50/h. Titration of the mandibular advancement weekly using respiratory polygraphy allows better healing control and customization of the skeletal advancement, enhancing the aesthetic result.

Maxillomandibular advancement as the initial treatment of obstructive sleep apnoea: Is the mandibular occlusal plane the key?

Maxillomandibular advancement (MMA) can be effective for managing obstructive sleep apnoea (OSA); however, limited information is available on the predictor surgical variables. This study investigated whether normalization of the mandibular occlusal plane (MOP) was a determinant factor in curing OSA. Patients with moderate or severe OSA who underwent MMA were evaluated by preoperative and postoperative three-dimensional (3D) scans and polysomnograms. The postoperative value of MOP and the magnitude of skeletal advancement were the predictor variables; change in the apnoea-hypopnoea index (AHI) was the main outcome variable. Thirty-four subjects with a mean age of 41±14years and 58,8% female were analysed. The Epworth Sleepiness Scale (ESS) was 17.4±5.4 and AHI was 38.3±10.7 per hour before surgery. Postoperative AHI was 6.5±4.3 per hour (P<0.001) with 52.94% of the patients considered as cured, and 47.06% suffering from a mild residual OSA with ESS 0.8±1.4 (P<0.001). 3D changes revealed a volume increase of 106.3±38.8%. The mandible was advanced 10.4±3.9mm and maxilla 4.9±3.2mm. MOP postoperative value was concluded to be the best predictor variable. Treatment planning should include MOP normalization and a mandibular advancement between 6 and 10mm. The maxillary advancement would depend on the desired aesthetic changes and final occlusion.

Intraoral mandibular distraction osteogenesis: special attention to treatment planning.

PURPOSE: To demonstrate our experience using internal devices for unidirectional distraction osteogenesis in treating different mandibular hypoplasias (with or without maxillary deformities). An algorithmic table for diagnosis, and treatment planning is presented. PATIENTS AND METHODS: Twenty internal distraction devices were used in 16 patients with mandibular hypoplasia. Deficiency in length of the mandible was calculated on three-dimensional computed tomography scans. The device was activated by a transcutaneous pin on the fifth postoperative day. Distraction was achieved at rates of 0.5 mm/12 h. After a variable period of consolidation the devices were removed. Mean follow-up was 18 months. RESULTS: Successful distraction osteogenesis was achieved in all patients. No premature consolidation or pseudoarthrosis was observed. Improvement of facial aesthetics was produced in all cases. Final occlusion was excellent in those cases where no simultaneous maxillary deformity was present. Orthodontic treatment was applied in all cases. Results remained stable one year postoperatively. CONCLUSIONS: The occlusal results obtained in this series show that we can plan distraction as a definitive treatment in cases with isolated mandibular hypoplasia. When an additional maxillary deformity is present, mandibular distraction must be performed first if indicated, but a maxillary procedure will be necessary later.

Distraction osteogenesis of the ascending ramus for mandibular hypoplasia using extraoral or intraoral devices: a report of 8 cases.

PURPOSE: This report presents the results of distraction osteogenesis using unidirectional extraoral and intraoral devices in 8 patients with different grades of vertical mandibular ramus hypoplasia. PATIENTS AND METHODS: Eight patients with hypoplastic mandibles underwent unilateral lengthening of the ascending ramus using unidirectional extraoral or intraoral devices. Intraoral mandibular distraction was performed on 5 patients with deficiencies of the vertical ramus up to 24 mm. External devices were used in 3 patients with more severe hypoplasias. An intraoral osteotomy was performed, and progressive distraction at rates of 0.5 mm/12 hours was initiated after 5 days. Once the desired length was reached, the device was maintained in place for 8 to 12 weeks. Three-dimensional computed tomography scans were taken in all the patients to plan the procedure and to compare the changes postoperatively. RESULTS: Successful distraction osteogenesis was achieved in all patients. The amount of mandibular lengthening ranged from 17 to 32 mm. Complications with the external devices such as rotation of the proximal bony fragment (2 cases) and loosening of the external screws at the end of the consolidation period (1 case) were observed. CONCLUSIONS: The results suggest that the intraoral device can be used as the method of choice for distraction osteogenesis of the ascending ramus of the mandible in patients with large deficiencies. Preoperative and postoperative 3-dimensional computed tomographic scans are essential in treatment planning.

Tumor DNA content as a prognostic indicator in squamous cell carcinoma of the oral cavity and tongue base.

BACKGROUND: Nuclear deoxyribonucleic acid (DNA) content is a prognostic factor in several tumors, and decisions regarding treatment have been made using this parameter. Nevertheless, there is no agreement in head and neck cancer. The purpose of the present study was to ascertain whether tumor DNA content correlated with prognosis in cases of primary squamous cell carcinoma (SCC) of the oral cavity and tongue base. METHODS: A retrospective study of formalin-fixed, paraffin-embedded tissue from patients with histologically confirmed SCC of the oral cavity and tongue base was performed using flow cytometry. Tumor DNA content was studied in 109 sets of specimens from previously untreated patients. All of them underwent surgical resection at the University "Hospital de La Princesa" between 1982 and 1992. Clinical parameters (age, sex, site of primary tumor, clinical stage, adjuvant therapy received, and disease-free and overall survival) and histologic parameters (histopathologic stage, tumor differentiation, type of inflammatory infiltration, presence of perineural invasion) were recorded in all cases. An exhaustive statistical analysis was applied. RESULTS: Only the histograms of 93 patients were adequate for consideration. In flow cytometric analysis, DNA aneuploidy was observed in 51 tumors (55%). The proportion of aneuploid tumors was significantly higher in advanced-stage carcinomas (p < .05), tumors with perineural invasion (p < .05) and in men (p < .05). In the 24 patients with lymph node metastasis, the incidence of aneuploidy was 82% (19 of 24) (p < .05). The rate of metastasis and aneuploidy increased as the degree of differentiation decreased (p < .05 for both). Patients with aneuploid carcinomas in both early and advanced stages had shorter relapse-free and overall survival periods than did the patients with diploid tumors (p < .001 for both). A Cox regression analysis demonstrated that ploidy was the single most important prognostic factor in determining relapse and death (p < .001 for both). CONCLUSIONS: The results indicate that tumor DNA analysis by flow cytometry appears to be useful as a supplement to clinical and histologic evaluation in predicting the tendency of SCC of the oral cavity and tongue base to metastasize to regional lymph nodes and to predict the outcome of the disease.

Primary mandibular reconstruction with bridging plates.

25 cases in which the mandible was resected and reconstructed using a reconstruction plate (AO titanium reconstruction system and Leibinger titanium reconstruction system) are presented. 16 patients suffered from oral carcinoma, 7 presented with odontogenic tumours and 2 had chronic osteomyelitis of the mandible. The mean age was 54.2 years, the male to female ratio was 2.6:1. 3 patients had a reconstruction plate for mandibular resection without continuity defect (marginal resection), in all the other patients the reconstruction plate bridged a mandibular resection with a continuity defect: 13 were located in the body, body-angle or ascending ramus with preservation of the mandibular condyle; 4 hemimandibulectomies with disarticulation of the TMJ; and 5 involved the anterior arch, crossing the midline. 12 patients received radiotherapy (3 pre-operatively). Only 3 patients with significant local side effects needed the treatment to be stopped for a period of time. There was no perioperative mortality. Only one plate was removed. Although minor complications were noted in 11 patients, the general improvement in the functional and cosmetic balance of the patients when compared with patients in whom no plate was used, justifies the use of this reconstruction system, in our opinion.