Predictors of Third Molar Impaction: A Systematic Review and Meta-analysis.

Area of Science:

• Dentistry
• Oral Surgery
• Public Health

Background:

• Third molar (M3) impaction is a common dental issue.
• Understanding its global prevalence is crucial for public health planning and resource allocation.
• Previous estimates vary, necessitating a comprehensive meta-analysis.

Purpose of the Study:

• To conduct a meta-analysis evaluating the global prevalence of third molar (M3) impaction.
• To analyze impaction prevalence based on location (mandible vs. maxilla), sex, impaction angle, and number of impacted M3s.
• To identify potential biases and limitations in existing M3 impaction research.

Main Methods:

• A systematic literature search was performed across PubMed, ISI Web of Science, and Google Scholar.
• Included studies reported M3 impaction prevalence from radiographic examinations in individuals aged 17 years and older.
• Risk of bias was assessed, and data from 49 studies involving 83,484 individuals were analyzed.

Main Results:

• The overall worldwide prevalence of M3 impaction was 24.40%.
• Mandibular M3 impaction was significantly more common than maxillary impaction (odds ratio > 1).
• Mesioangular impaction was the most frequent type, and impaction of one or two M3s was more common than three or four.

Conclusions:

• The global prevalence of third molar impaction is 24.40%, which is lower than some previous estimates.
• While mandibular impactions are more prevalent, there is no significant difference in impaction rates between sexes.
• The findings highlight the need for careful consideration of M3 impaction prevalence in clinical practice and public health strategies.