Evaluation of the lateral pterygoid muscle area, attachment type, signal intensity and presence of arthrosis, effusion in the TMJ according to the position of the articular disc.

PURPOSE: The aim of this study was to evaluate the lateral pterygoid muscle (LPM) area, attachment type, signal intensity and presence of arthrosis, effusion in the temporomandibular joint (TMJ) by magnetic resonance imaging (MRI) according to the position of the articular disc. METHODS: The study included a total of 126 TMJs belonging to 69 patients over the age of 18 years who had MRI due to TMJ complaints. The position of the articular disc, the area, attachment type, and signal intensity of the LPM, the presence of arthrosis on the condyle surface, and the presence of effusion in the joint space were evaluated. RESULTS: The attachment type of the LPM did not show a statistically significant difference according to the position of the articular disc. The groups were not statistically different in terms of LPM intensity. Although the distribution of the LPM area was found to be low in the anterior disc displacement with reduction (R+DD) group and high in the anterior disc displacement without reduction (R-DD) group. It was determined that the rate of arthrosis at the condyle head was significantly higher in the R-DD group compared to the normal disc position group. The incidence of effusion was found significantly higher in the R-DD and R+DD groups than joints with normal disc position. CONCLUSIONS: Pathological changes in LPM and TMJ can be detected by MRI. In the group with R-DD, the rate of arthrosis at the condyle head, effusion, LPM area, and intensity of the Sup. LPM were higher.

Evaluation the relationship between the position and impaction level of the impacted maxillary third molar teeth and marginal bone loss, caries and resorption findings of the second molar teeth with CBCT scans.

OBJECTIVE: To evaluate the relationship between the position and impaction level of the impacted maxillary third molar teeth and marginal bone loss, caries and resorption findings on the distal surface of the second molar teeth with cone beam computerized tomography (CBCT) scans. METHODS: All CBCT images of 189 impacted maxillary teeth belonging to 121 patients were examined by an observer. After determining the position and impaction level of the impacted maxillary third molar teeth, presence of caries, resorption and marginal bone loss in the distal of the second molar tooth were evaluated. IBM SPSS Statistics 22.0 (IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp.) was used for statistical analyses and calculations. Data were analysed using the Chi-square test and Fisher's exact test. RESULTS: A statistically significant difference was found in terms of the impaction level of the impacted maxillary third molar tooth and the presence of caries in the distal surface of the second molar tooth, in terms of the impaction level of the impacted third molar tooth and the presence of marginal bone loss in the distal surface of the second molar tooth. A similar difference was found in terms of the impaction level of the impacted third molar tooth and the presence of root resorption in the distal surface of the second molar tooth. CONCLUSION: These data on the natural history of impacted maxillary third molars may contribute to both more accurate estimates of the risk of complications associated with these teeth and determination of the prophylactic approach to asymptomatic impacted third molars.