How does bone thickness affect the split pattern of sagittal ramus osteotomy?

This study examined the influence of bone thickness on the split pattern of sagittal ramus osteotomy at 62 sites using Dolphin 3D software. Four measurements of thickness were obtained from the preoperative computed tomography scans: measurement A was made 1.5mm above the lingula, using the coronal and sagittal planes; measurement B was made at the same height as measurement A and 1mm from the anterior border of the ramus; measurement C was obtained 5mm distal to the last molar and 5mm below the upper border of the mandible; measurement D was made in the area between the first and second molars, 6mm above the mandibular border. Three-dimensional postoperative images were used to classify the split pattern into types, based on the classification of Plooij et al. The data were analyzed using the Kruskal-Wallis test, followed by Dunn post-hoc test. Thirty-five sagittal splits were type I, one was type II, 19 were type III, and seven were type IV. Type I presented the greatest thickness, whereas type IV presented the lowest. There was a statistically significant difference in thickness only for measurement A, when types I and IV were compared. The results indicate that thinner mandibular rami are more prone to bad splits.

Sequencing of bimaxillary surgery in the correction of vertical maxillary excess: retrospective study.

The aim of this study was to evaluate the precision of bimaxillary surgery performed to correct vertical maxillary excess, when the procedure is sequenced with mandibular surgery first or maxillary surgery first. Thirty-two patients, divided into two groups, were included in this retrospective study. Group 1 comprised patients who received bimaxillary surgery following the classical sequence with repositioning of the maxilla first. Patients in group 2 received bimaxillary surgery, but the mandible was operated on first. The precision of the maxillomandibular repositioning was determined by comparison of the digital prediction and postoperative tracings superimposed on the cranial base. The data were tabulated and analyzed statistically. In this sample, both surgical sequences provided adequate clinical accuracy. The classical sequence, repositioning the maxilla first, resulted in greater accuracy for A-point and the upper incisor edge vertical position. Repositioning the mandible first allowed greater precision in the vertical position of pogonion. In conclusion, although both surgical sequences may be used, repositioning the mandible first will result in greater imprecision in relation to the predictive tracing than repositioning the maxilla first. The classical sequence resulted in greater accuracy in the vertical position of the maxilla, which is key for aesthetics.

Extranodal follicular dendritic cell sarcoma of the palate.

Follicular dendritic cell tumors are uncommon and usually occur in lymph nodes. We report the case of a follicular dendritic cell tumor that occurred in the palate of a 14-year-old boy and manifested itself as a nodular mass. Histologically, the neoplasm consisted of spindle-shaped or oval-shaped cells with eosinophilic cytoplasms and nuclei with delicate, dispersed chromatin. The lesional cells were principally arranged in diffuse, fascicular patterns with vaguely whorled or storiform areas. Focal multinucleate tumor giant cells and lymphocytes were observed throughout the neoplasm. Immunohistochemically, tumor cells were positive for the follicular dendritic cell markers CD21, CD35, and CD23 and for S-100 protein, CD68, and muscle-specific actin. Tumor cells were negative for LCA, CD20, EMA, CK (AE1/AE3), HMB45, and CD34. Lymphocytes were positive for LCA and CD45RO. Although follicular dendritic cell sarcoma is a very uncommon tumor, it should be included in the differential diagnosis of tumors in this location.