Assessing age-related change in Japanese mental foramen opening direction using multidetector computed tomography

Area of Science:

• Anatomy
• Forensic Anthropology
• Radiology

Background:

• The mental foramen (MF) is a key anatomical landmark in the mandible.
• Understanding age-related changes in MF morphology is crucial for forensic identification and anthropological studies.
• Previous research has not conclusively established age-related directional changes in the mental foramen opening.

Purpose of the Study:

• To investigate age-related changes in the opening direction of the mental foramen (MF) in a Japanese population.
• To analyze directional shifts in the superior-inferior and anterior-posterior planes of the MF opening.
• To assess potential sex differences in these age-related morphological changes.

Main Methods:

• Utilized post-mortem multi-detector computed tomography (MDCT) scans of 121 Japanese subjects (66 males, 55 females) with at least 20 teeth.
• Measured the superior-inferior angle (coronal plane) and anterior-posterior angle (transverse plane) of the MF opening on CT reconstructed images.
• Employed multiple regression analysis to evaluate associations between age and the measured angles, stratified by sex.

Main Results:

• In males, the superior-inferior angle showed a quadratic relationship with age, increasing until the early 50s and then decreasing.
• A linear decrease with age was observed for the anterior-posterior angle in males.
• No significant age-related associations were found for either angle in female subjects, indicating sex-specific changes.

Conclusions:

• The study demonstrates age-related directional changes in the mental foramen opening specifically in Japanese males.
• These findings contrast with previous studies and highlight a superior to inferior shift until the early 50s, followed by an inferior shift, and an anterior shift with age in males.
• The observed changes in male Japanese subjects could be valuable for forensic science applications, particularly in age estimation and identification.