This study evaluated the efficacy of poly(lactic-co-glycolic acid) (PLGA) mesh sheets for alveolar bone reconstruction in the anterior maxilla with significant bone defects. This prospective case series included 4 male patients (mean age, 34.5 years; range, 20-49 years) with anterior maxillary bone defects. Bone augmentation was performed using a staged guided bone regeneration technique with PLGA mesh sheets as barrier membranes and a 1:1 mixture of autogenous and xenogeneic bone as grafting material. The effectiveness of bone augmentation was evaluated using preoperative and postoperative computerized tomography data at 1 and 6 months. Secondary outcomes included complications such as wound infection and dehiscence. The treatment of the 4 patients required 7 PLGA mesh sheets and particulate bone, followed by 9 implant placements. Wound healing was uneventful except for 1, wherein wound dehiscence and graft loss were observed. One patient had an exposed PLGA mesh sheet during healing, necessitating its removal. The mean vertical bone gain was 2.3 ± 0.5 mm, and the mean horizontal gain was 3.7 ± 1.3 mm at 1 month postoperatively. Sites without wound dehiscence exhibited a bone decrease rate of 6.5%-21.1%, whereas successful bone height and width increases were observed across treated sites. Bone augmentation using PLGA mesh sheets proved effective in reconstructing horizontal and vertical alveolar bone dimensions. This technique provides adequate support for implant placement, demonstrating its potential utility in cases of substantial alveolar bone deficiency.

This study aimed to measure the association between condylar morphology and a measure of the maxillary centroid following bimaxillary surgery using mandibular-dependent splints. The study included skeletal Class III and Class II malocclusion patients, excluding those with facial asymmetry. Based on computed tomography imaging patients were characterized into normal or abnormal temporomandibular joint (TMJ) groups. A computer-aided design/computer-aided manufacturing splints were fabricated to reposition the maxilla in Le Fort I osteotomy. The primary outcome measure was the absolute differences between the maxillary centroid’s the planned and actual postoperative positions calculated by superimposing computed tomography scans. The secondary outcome was the measure of other variations in linear and angular maxilla discrepancies. The demographic covariates included the age and sex of the patients. The operative covariates consisted of the dentofacial deformity and the planned movement of the maxilla. Seventy patients with skeletal maxillofacial deformities were included for analysis: 44 patients in the normal and 26 in the abnormal TMJ group. The average maxillary misalignment was 1.04±0.48 mm in the normal and 1.53±0.63 mm in the abnormal TMJ group (P<0.001). A statistically significant relationship existed between the discrepancies of the maxillary centroid and dentofacial deformity (η=0.656, P<0.001). These findings suggest an increased propensity for maxillary malposition in skeletal Class II patients. Furthermore, condylar morphology is a significant prognostic factor influencing maxillary repositioning errors in bimaxillary surgery with mandibular-dependent splints.

The clinical differences between odontogenic myxoma (OM) and odontogenic myxofibroma (OMF), and the clinical significance of their classifications, remain unclear. This study reviewed the clinicopathological characteristics of patients with OM or OMF and evaluated the fibrous component of the specimens. Medical records of 21 patients with OM or OMF who underwent tumour resection were reviewed. The percentage of fibrous tissue on the representative sections was evaluated using haematoxylin and eosin- and Masson's trichrome-stained specimens. Histopathological diagnoses included 11 OMs and 10 OMFs with no tumour recurrence except for two cases in which the dredging method was applied. More cortical bone perforation was observed in OM than in OMF cases, without significant differences. Location-locularity and apparent diffusion coefficient value (ADC)-cortical bone perforation were significantly correlated in all OM and OMF cases. The percentage of fibrous tissue in specimens showed bimodal distribution bordered by 45%. There was a significant association between diagnosis based on 45% fibrous tissue criterion and the final pathological diagnosis. Our study showed a tendency for cortical bone perforation in OM compared to OMF and correlation between ADC and cortical bone perforation. According to the histopathological analyses, the fibrous component of each case was bimodal with 45%, which may be a criterion to distinguish between OM and OMF. Accumulating knowledge, such as significant differences in prognosis, may allow for minimal surgical treatment options based on the diagnosis according to this novel histopathological criterion.

Reconstruction using a vascularized bone composite flap is currently the standard treatment after resection of the mandible and various types of plates are used. In our department, we mainly perform reconstruction using the scapula and have used three types of plates: mini plates, reconstruction plates, and custom-made plates that have recently been covered by insurance in Japan. In this paper, we compared the miniplate and the reconstruction plate and found that the ischemic time in the cases of the reconstruction plate was shorter than that of the miniplate. In addition, we show an overview of a vascularized scapular flap reconstruction case using a custom-made plate after hemimandibulectomy.

OBJECTIVE:There are cases in which patients complain of nasal obstruction after Le Fort I osteotomy, but the relationship with postoperative morphological changes in the nasal cavity, including the septum and inferior turbinate, is not clear.STUDY DESIGN:The authors evaluated the three-dimensional relationship of the morphological changes in the inferior turbinate before and after surgery in 84 patients who underwent Le Fort I osteotomy. Three classifications were made according to superior amount of maxillary movement at the base of nasal cavity.RESULTS:The high elevation group (4.0 mm or more) had 31 sides, the moderate elevation group had 93 sides, and the low elevation group (less than 2.0 mm) had 44 sides. The volume of inferior turbinate was 76.9 ± 12.8% of that before surgery in the high elevation group. The high- and moderate-elevation groups had significantly higher changes than the low elevation group, and the rate of contact between inferior turbinate and nasal cavity floor was 67.7%.CONCLUSIONS:After Le Fort I osteotomy, the volume of inferior turbinate tissue decreased in proportion to the amount of elevation of the maxilla. Although the soft tissue volume may be reduced due to adaptation of respiratory function, the inferior nasal passage was not completely ventilated in the high elevation group. If the elevation exceeds 4.0 mm counterclockwise with maxillary movement, it is necessary to consider the concomitant inferior turbinate resection because it may lead to nasal obstruction.

Objectives: Cysts of the mandible are common and are often found clinically in oral surgery. Marsupialization for relatively large cystic lesions may be performed to reduce the size of the lesion and to obtain a histopathological diagnosis. For cystic lesions of the mandible, the effect of marsupialization has many advantages, such as a reduction in lesion size, the avoidance of mental nerve palsy, and preservation of the teeth. It is still unclear whether there is a difference in the reduction rate based on patient age and pathology (dentigerous cyst, odontogenic keratocyst, radicular cyst, ameloblastoma (unicystic type)) and initial size of the lesion. Methods: The subjects included 55 patients with cystic lesions with a major axis of 3 cm or greater (16 dentigerous cysts, 20 odontogenic keratocysts, 7 radicular cysts, and 12 ameloblastoma) who underwent treatment at our department. Using simulation software (ProPlanCMF (R)), the volume of the lesion was extracted from the CT data before and after the marsupialization, and the three-dimensional reduction rate before and after marsupialization was calculated. Results: No significant difference was observed between the subgroups in terms of histopathological diagnosis, patient age or size of lesion. Although the effect of marsupialization on cystic lesions with a major axis of 3 cm or more showed a significant difference between 3.0 months and 4.5 months, the difference was not significant between 4.5 months and 6.0 months. Conclusions: An indication for the enucleation timing after marsupialization is 4.5 months when the rate of decrease after fenestration slows down. (C) 2021 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.

Owing to a high recurrence rate, radical jaw resection is regarded as the first choice of treatment for odontogenic myxoma. However, there have been several reports on the effectiveness of conservative surgical treatment preserving inferior alveolar nerve for odontogenic myxoma of the mandible. A 37-year-old woman presented with a complaint of pain around her mandibular left third molar. Odontogenic myxoma was diagnosed by using biopsy. The tumor occupied a part of the cortical bone and contained the inferior alveolar nerve. We performed enucleation and curettage, which preserved the inferior alveolar nerve. Ten years after the treatment, there were no symptoms of recurrence or nerve paralysis. Here, we discuss the conservative treatment of odontogenic myxoma, focusing on inferior alveolar nerve preservation.