Postoperative stability of bioresorbable plates made of 85:15 poly (L-lactide-co-glycolide) in Le Fort I osteotomy.

OBJECTIVE: Recently, RapidSorb plates (DePuy Synthes) made of 85.15 poly (L-lactide-co-glycolide) have been used for orthognathic surgery; however, reports regarding their effectiveness are limited. We aimed to compare the postoperative stability of RapidSorb plates, RapidSorb combined with titanium (MOJ plates), and MOJ plates in patients who underwent Le Fort I osteotomy at Tokyo Medical and Dental University Hospital. STUDY DESIGN: The use of RapidSorb in the maxilla is a load-sharing application and therefore constitutes an approved indication. Discrepancies in the maxillary positions were measured using postoperative computed tomography data at 1 week and 1 year using the centroid method 3-dimensionally. Treatment with RapidSorb alone showed a more vertical discrepancy in the maxilla treatment with MOJ and RapidSorb+MOJ. The RapidSorb4 group was subdivided into 2 groups (under and over 1.0-mm) based on the change in the maxillary centroid. RESULTS: The bone gap at the lateral border of the piriform aperture was significantly larger in the over-1.0-mm group than in the 1.0-mm group. CONCLUSIONS: The fixation of RapidSorb alone is not appropriate in load-bearing and unstable applications but is not contraindicated for load-sharing indications. Fixation with RapidSorb combined with MOJ was clinically effective, with results similar to titanium plate-only fixation regarding postoperative stability.

Retrospective analysis of schwannoma in the oral and maxillofacial region: clinicopathological characteristics and specific pathology of ancient change.

Schwannomas are benign tumours that originate from the Schwann cells of the nerve. Despite the frequency of their occurrence in the head and neck, data relating to their clinicopathological features in the region are limited. This study reviews the clinicopathological characteristics and specific pathology of ancient (degenerative) change in 40 cases in the oral and maxillofacial region. Medical records were reviewed of the 40 cases treated at Tokyo Medical and Dental University Hospital Faculty of Dentistry between 2000 and 2020. The most frequently involved site was the tongue, and the average tumour size was 13.2 mm. Degenerative changes were observed in eight cases. All tumours were completely excised through biopsy or local excision, and no recurrence was observed on clinical follow up. Statistical analyses revealed significant associations (p < 0.05) between ancient change and tumour size, and between ancient change and the apparent diffusion coefficient (ADC) value derived from diffusion-weighted magnetic resonance imaging (MRI). Analysis suggests that schwannoma progresses over a long period and subsequently undergoes secondary ancient changes. Pathological events such as cystic formation and haemorrhage that are associated with ancient changes, cause hypocellularity and lead to high ADC values. These values may indicate ancient change and should be considered when distinguishing schwannoma from other lesions.