Third-molar mineralization as a function of available retromolar space

Area of Science:

• Dentistry
• Oral and Maxillofacial Surgery
• Radiology

Background:

• Third molars (M3s) often experience impaction, leading to potential complications.
• Predicting M3 impaction is crucial for timely and effective treatment planning.

Purpose of the Study:

• To investigate the association between the stage of third molar (M3) mineralization and the available jaw space for eruption.
• To determine if M3 mineralization is delayed in cases of impaction or limited eruption space.

Main Methods:

• Retrospective analysis of cone beam computed tomography (CBCT) scans from 69 individuals (17-24 years old).
• Assessment of 197 upper and lower M3s, measuring crown diameter (CD) and retromolar space (RS).
• Comparison of M3 mineralization stages between impacted and erupting teeth, and by relative eruption space (RS/CD ratio).

Main Results:

• Significantly delayed M3 mineralization was observed in impacted teeth compared to erupting ones.
• Mineralization was also delayed in M3s with eruption space less than their mesiodistal crown diameter (RS/CD < 1).
• A moderate positive correlation between M3 mineralization stage and jaw space was found, stronger in the mandible.

Conclusions:

• M3 mineralization stage is associated with both impaction and the amount of retromolar space.
• These associations are consistent across both the maxilla and mandible.
• M3 mineralization stage may serve as a clinically valuable predictor for M3 impaction, warranting further research.