Suggestion of a new standard in measuring the mandible via MRI and an overview of reference values in young women

PURPOSE

Adult idiopathic condylar resorption (AICR) mainly affects young women, but generally accepted diagnostic standards are lacking. Patients often need temporomandibular joint (TMJ) surgery, and often jaw anatomy is assessed by CT as well as MRI to observe both bone and soft tissue. This study aims to establish reference values for mandible dimensions in women from MRI only and correlate them to, e.g., laboratory parameters and lifestyle, to explore new putative parameters relevant in AICR. MRI-derived reference values could reduce preoperative effort by allowing physicians to rely on only the MRI without additional CT scan.

METHODS

We analyzed MRI data from a previous study (LIFE-Adult-Study, Leipzig, Germany) of 158 female participants aged 15-40 years (as AICR typically affects young women). The MR images were segmented, and standardized measuring of the mandibles was established. We correlated morphological features of the mandible with a large variety of other parameters documented in the LIFE-Adult study.

RESULTS

We established new reference values for mandible morphology in MRI, which are consistent with previous CT-based studies. Our results allow assessment of both mandible and soft tissue without radiation exposure. Correlations with BMI, lifestyle, or laboratory parameters could not be observed. Of note, correlation between SNB angle, a parameter often used for AICR assessment, and condylar volume, was also not observed, opening up the question if these parameters behave differently in AICR patients.

CONCLUSION

These efforts constitute a first step towards establishing MRI as a viable method for condylar resorption assessment.

Adolescent internal condylar resorption (AICR) of the temporomandibular joint can be successfully treated by disc repositioning and orthognathic surgery, part 2: Treatment outcomes

OBJECTIVE

To evaluate treatment outcomes for patients with TMJ adolescent internal condylar resorption (AICR) treated by a specific surgical protocol, including: (1) Removal of bilaminar tissue surrounding the condyle, (2) Articular disc repositioning with Mitek anchor technique, and (3) Concomitant orthognathic surgery.

METHODS

This study evaluated 24 AICR patients treated by the specific surgical protocol with clinical subjective and objective examinations and lateral cephalogram assessments for surgical changes and long-term outcomes.

RESULTS

Mean age at diagnosis was 16.5 years, and mean follow-up was 30.3 months. All 24 patients had significant reduction in TMJ pain, facial pain, and headaches, with improvement in jaw function, diet, and disability. Cephalometric analysis showed significant surgical changes but good long-term occlusal and skeletal stability.

CONCLUSION

Patients with AICR treated with the specific surgical protocol demonstrated good skeletal and occlusal stability as well as improvement in TMJ pain, headaches, jaw function, diet, and disability.