Positional changes of temporomandibular joint disk and condyle with insertion of anterior repositioning splint / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To measure the positional changes of temporomandibular joint (TMJ) disk and condyle with insertion of anterior repositioning splint (ARS) using magnetic resonance imaging (MRI) for further understanding of the splint therapy mechanisms.</p><p><b>METHODS</b>Twenty-two patients with temporomandibular joint clicks were included. 31 TMJs were diagnosed as anterior disk displacement with reduction (disk-displaced group), and the other 13 TMJs were normal (normal group). All joints were scanned oblique-sagittally by MRI before splint treatment in three positions including closed-mouth position of centric occlusion (the position before insertion of ARS), incisors' edge to edge position, and mandibular least forward protrusion position (the position after insertion of ARS).</p><p><b>RESULTS</b>1) Disk-condyle angle: In closed-mouth position, the average angle was 54.23 degrees in the disk-displaced group, while it was 9.80 degrees in the normal group; in incisors' edge to edge position and mandibular least forward protrusion position, the angle was reduced to normal in most of the disk-displaced cases. 2) Disk position: From closed-mouth position to incisors' edge to edge position or mandibular least forward protrusion position, the forward displaced disk moved backward significantly, while the disk with normal position did not change significantly in the three positions. 3) Condyle position: From closed-mouth position to incisors' edge to edge position or mandibular least forward protrusion position, the condyle moved forward and downward significantly both in the disk-displaced group and in the normal group.</p><p><b>CONCLUSION</b>With insertion of the splint, the condyle moved anteriorly and inferiorly and the disk moved posteriorly, most of the anterior displaced disks could be reduced to normal positions in the joint fossa. The result indicated that the splint protruded condyle forward and prevented the backward reduced disk from displacing forward again during mouth closing.</p>

Gene mutation and expression of SH-3BP-2 in cherubism / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To detect the mutation and expression of SH-3BP-2 in Chinese patients of cherubism and to investigate the possible relationship of gene mutation and multinucleated giant cells in lesions.</p><p><b>METHODS</b>Genomic DNA was extracted from paraffin-imbedded tissues and peripheral blood samples of 10 cases of cherubism (6 familial cherubism and 4 sporadic cherubism). SH-3BP-2 mutations were detected by PCR-direct sequencing. The nature of multinucleated giant cells in lesions was detected by enzyme histochemical staining and immunohistochemical staining using paraffin-imbedded tissues sections. The SH-3BP-2 protein was detected by immunohistochemical staining.</p><p><b>RESULTS</b>Three missense mutations (G1520A, G1505A, G1505C) in exon 9 of SH-3BP-2 were identified which led to 3 transitions (Gly420Glu, Arg415Gln, Arg415Pro). There were no abnormalities in exon 3 of SH-3BP-2 except 1 case which had not PCR products. The protein SH-3BP-2, the calcitonin receptor and the tartrate-resistant acid phosphatase were detected in the cytoplasm of all multinucleated giant cells and parts of monokaryon matrix cells in 8 paraffin-imbedded samples.</p><p><b>CONCLUSIONS</b>The SH-3BP-2 mutation may participate in the differentiation and maturation of osteoclast-like cells in the lesion of cherubism.</p>