Comparison of magnetic resonance imaging findings in patients with intermittent closed lock and acute closed lock of the temporomandibular joint: a cross-sectional retrospective study.

OBJECTIVE: This study aimed to estimate the disc status in intermittent closed lock (ICL) and permanent closed lock (CL) temporomandibular disorders (TMDs) to test the hypothesis that the disc morphology and degree of anterior disc displacement affect the outcomes of these disorders. MATERIALS AND METHODS: All patients were clinically examined according to the Diagnostic Criteria for Temporomandibular Disorders Axis I protocol, and magnetic resonance imaging (MRI) confirmed ICL and CL. Fifty-six joints of 56 patients with ICL and 110 joints of 110 patients with acute CL with a locking period of less than 3 months were included. Patients with acute CL were further classified into two groups: those with CL that could be successfully manipulated (CLs group) and those with acute CL without the possibility of unlocking (CLu group). MRI was used to assess the degree of anterior displacement, lateral displacement of the disc, disc deformity, and joint effusion. MRI findings were compared among the joints in the ICL, CLs, and CLu groups. RESULTS: The degree of anterior displacement and disc deformity prevalence significantly differed among the ICL, CLs, and CLu groups. No significant intergroup differences were observed in terms of lateral displacement or joint effusion. CONCLUSIONS: These results suggest that anteriorly displaced discs and deformation of discs associated with TMD progression affect disc reducibility.

Diagnosis and treatment of oral focal mucinosis: a case series.

BACKGROUND: Oral focal mucinosis, the oral counterpart of cutaneous focal mucinosis, is a rare disease. As it has no characteristic clinical or radiological features, diagnosis is established by histopathological and immunohistological examination. We present three cases of oral focal mucinosis occurring in the retromolar (which is extremely rare) and gingival regions. CASE PRESENTATION: Case 1 involved a 26-year-old Japanese man with radiolucency in the right retromolar region on panoramic radiograph and computed tomography; no obvious protrusion was observed in the region. This finding was clinically diagnosed as a tumor of the retromolar region. Case 2 involved a 60-year-old Japanese woman. A tumor-like mass of tissue was identified on the buccal gingiva at the maxillary right canine and first premolar region. The lesion measured 7 × 6 mm and exhibited elastic hardness and healthy-colored mucosa. The lesion was diagnosed as an epulis. Case 3 involved a 47-year-old Japanese woman. A tumor-like mass of tissue was identified on the buccal gingiva at the maxillary right canine and first premolar region. The lesion measured 10 × 10 mm and exhibited elastic hardness and redness of the surface mucosa. This lesion was also diagnosed as an epulis. Resection was performed in all three cases, and the lesions were histopathologically diagnosed as oral focal mucinosis. Postoperative courses were uneventful and, thus far, there have been no recurrences. CONCLUSIONS: Although it is difficult to diagnose oral focal mucinosis based on clinical symptoms and imaging findings, the disease should be considered a possibility when diagnosing benign oral tumors. We believe that an emphasis on histopathologic study is essential to confirm the clinical suspicion.

A lesion categorized between ghost cell odontogenic carcinoma and dentinogenic ghost cell tumor with CTNNB1 mutation.

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant neoplasm characterized by the presence of ghost cells. It is considered to arise either de novo or from a preexisting benign precursor, calcifying odontogenic cyst (COC), or dentinogenic ghost cell tumor (DGCT). We report a case of a 44-year-old Japanese male with a left maxillary tumor. The patient received treatment to resect the left maxillary cyst 25 years prior; however, the details were uncertain. The tumor was resected with clear margins. Taken together with the results of histological and immunohistochemical examinations, the tumor was categorized between GCOC and DGCT, and we diagnosed the tumor as GCOC suggesting similarity to DGCT. Further, we focused on CTNNB1, which encodes ß-catenin and is frequently mutated in COCs. In this tumor, we identified CTNNB1 Ser33Cys, one of the mutations typically found in COCs. This finding suggests that CTNNB1 is a common target for the pathogenesis of tumors accompanied by ghost cells.

Association of Temporomandibular Joint Pain According to Magnetic Resonance Imaging Findings in Temporomandibular Disorder Patients.

PURPOSE: This study investigated the associations between magnetic resonance imaging (MRI) findings and pain in the temporomandibular joint (TMJ). MATERIALS AND METHODS: The study included 646 TMJs of 323 consecutive patients with temporomandibular disorders; of these, 222 (34.4%) had TMJ pain whereas 424 (65.6%) had no TMJ pain. MRIs were used to evaluate disc position, osteoarthritis, joint fluid, and bone marrow edema. Internal derangement was classified as normal, anterior disc displacement with reduction, and anterior disc displacement without reduction (ADDWOR); condylar morphology was classified as normal, moderate bony change, and severe bony change. The odds ratio (OR) for each MRI variable for nonpainful versus painful TMJs was computed using logistic regression analysis. RESULTS: Compared with joints with normal disc position, the OR of those with ADDWOR was 2.74 (P < .001) for TMJ pain. Similarly, compared with joints with normal condylar morphology, the OR of those with severe bony change was 4.62 (P = .02) for TMJ pain. In addition, the risk of TMJ pain increased by 2.37 in joints with joint fluid (P < .001) and by 2.34 in joints with bone marrow edema (P = .006). The risk of TMJ pain increased significantly with ADDWOR in combination with severe bony change, joint fluid, and bone marrow edema. CONCLUSIONS: These results suggest an association between TMJ pain and ADDWOR, severe bony change, joint fluid, and bone marrow edema. Thus, combining various MRI variables may improve the diagnostic accuracy of TMJ pain.

Temporomandibular joint intermittent closed lock: clinic and magnetic resonance imaging findings.

OBJECTIVE: This study was carried out to describe the clinical and magnetic resonance imaging (MRI) findings of patients with intermittent closed lock (ICL) of the temporomandibular joint (TMJ). STUDY DESIGN: This retrospective study included 58 joints with ICL and 526 joints without ICL as controls. We compared the MRI findings between the patients with and without ICL and investigated clinical and MRI finding of ICL patients. We divided ICL patients into 2 groups based on the treatment efficacy: effective and ineffective. RESULTS: There were significant differences in the prevalence of disk deformity between the joints with and without ICL. Masticatory muscle pain was observed in 41.7% of the effective group and in 80% of the ineffective group, respectively. CONCLUSIONS: These results suggest that there is a relationship among the onset of ICL and disk deformation. Masticatory musclepain was significantly observed in the ineffective group.