# Determination of normal post-mortem computed tomography (PMCT) parameters for the temporomandibular joint

## TL;DR

This study defines normal post-mortem TMJ configurations using a new measurement tool to improve forensic diagnosis accuracy.

## Contribution

The study introduces the TMJ PAT method to assess TMJ anatomy in post-mortem CT scans, aiding forensic investigations.

## Key findings

- 99% of cases showed the condyle positioned at or posterior to the articular eminence.
- A positive TMJ PAT measurement indicates an anteriorly displaced condyle, suggesting potential pathology.
- The TMJ PAT method demonstrated strong interrater reliability and can be used by those with limited expertise.

## Abstract

Post-mortem radiology, particularly post-mortem computed tomography (PMCT), has become an important tool in forensic death investigation, offering valuable insights into the cause and manner of death. However, the interpretation of post-mortem findings requires understanding the normal anatomical changes that occur after death, as artifacts can mimic pathology, complicating diagnosis. The objective of this study was to define the normal configuration of the temporomandibular joint (TMJ) in the post-mortem setting, using a newly developed measurement method, the TMJ PAT (perpendicular assessment tool), to assess the relationship between the mandibular condyle and the articular eminence on PMCT scans. A retrospective analysis was conducted on 100 non-decomposed, non-traumatic adult deaths. The TMJ configuration was assessed bilaterally using PMCT scans, and the condylar position was measured in relation to the articular eminence. Results indicated that in 99% of cases the apex of the condyle was positioned at or posterior to the eminence. The study established that a positive TMJ PAT measurement, indicating an anteriorly displaced condyle, is abnormal and suggests a potential pathology, such as temporomandibular joint dislocation (TMJD). Interrater reliability of the method was strong, demonstrating its potential utility in forensic pathology practice. This method can be applied by those with limited expertise in forensic radiology, making it valuable for use in diverse settings, including resource-poor environments. The study’s findings enhance the understanding of post-mortem TMJ anatomy and provide a reliable tool for distinguishing normal from abnormal TMJ configurations, crucial for accurate analysis in the death investigation setting. Future research should explore the application of this method in cases involving trauma and hanging, to further investigate phenomena such as Suspension-Associated Dislocation of the TMJ (SAD TMJ).