Recommendations for standard criteria for the positional and morphological evaluation of temporomandibular joint (TMJ) osseous structures: a systematic review

Objective

This systematic review aimed to appraise the reliability and comprehensiveness of imaging methods in articles that used three-dimensional assessment of the temporomandibular joint (TMJ), which used either computed tomography (CT) or cone beam computed tomography (CBCT), in order to propose a standardized imaging method.

Study Design

Six databases/search engines were searched up until September 2022. The outcomes of interest included measurements of the mandibular condyle, glenoid fossa, joint spaces, or the entire TMJ. Two checklists were used: one to assess the risk of bias, with a maximum score of 37, and the other, a predesigned checklist consisting of 22 items to evaluate the comprehensiveness of the methods used, with a maximum score of 33.

Results

Of the 2567 articles retrieved, only 14 studies (which used CBCT) were deemed eligible and thus included in the qualitative analysis. Three studies were deemed of low risk of bias (with scores of 29/37 in two studies and 28/37 in one study), while the remaining studies were rated as high to moderate quality, primarily due to improper reporting of inter-observer agreement, varying reliability values, and a limited number of cases included in the reliability analysis. Regarding the comprehensiveness of the methods used, only 4 studies achieved relatively high scores (26/33 in three studies and 24/33 in one study). The deficiencies observed were related to the reporting of variables such as slice thickness and voxel size, absence of or improper reporting of intra- and inter-examiner reliability analyses, and failure to assess all osseous components of the TMJ.

Conclusion

CBCT-based methods used to assess the positions and morphology of TMJ bony structures appear to be imperfect and lacking in comprehensiveness. Hence, criteria for a standardized assessment method of these TMJ structures are proposed.