Pattern of third molar impaction in Libyan population: A retrospective radiographic study

Objectives: The aim of the present study was to radiographically evaluate the pattern of third molar impaction in a sample of Libyan patients, in terms of age, gender, angulation of impaction, level of eruption and available retromolar space using panoramic radiographs. Furthermore, cross tabulation between patterns of impaction and gender⧹arch were evaluated for any significant difference.

Study design: This retrospective study comprised 300 orthopantomograms (OPGs) of patients attending a private dental clinic in Benghazi between 2008 and 2013. Radiographic assessment was carried out to evaluate the prevalence of impaction, angular position of impaction, level of eruption and available retromolar space. Results were analysed using Pearson’s coefficient test and Student’s t-test

Results: Among 1200 third molars reviewed, 843 (70%) were classified as impacted, of which 371 (44%) were in the maxilla and 472 (56%) were in the mandible. The most prevalent angular position was mesioangular (34.6%) followed by vertical (31.3%) and distoangular (27.7%). A significant association existed between angular position and arch (P < 0.001).

Class IIA was the most common Pell and Gregory classification (38.6%). Significant association was found between the level of eruption and arch (P < 0.001). Bilateral impaction was more common than unilateral impaction in both arches.

Conclusion: Our study highlights mesioangular impaction as the most frequently encountered angular position. The most common level of eruption was Level B; and the majority of impacted third molars (72.7%) had less than adequate space for eruption.