Prevalence of impacted third molars among orthodontic patients in different malocclusions

The aim of this retrospective study was to investigate the prevalence and pattern of third molar impaction and missing third molars in patients over 18 years in different anteroposterior skeletal patterns among central Indian populations.

The study reviewed 357 orthopantomograms of patients attending the Government College of Dentistry, Indore, Madhya Pradesh. Patients were evaluated to determine the prevalence of third molar impaction, angulation, and level of eruption in Class I, Class II, and Class III patients using Winter's classification to determine angulation of third molars and Pell and Gregory classification for level of impaction.

Out of 357 patients, 187 (52.3%) were present with at least one impacted teeth. The third molar impaction was most commonly present in Class II malocclusion (60.65%). Overall, the most common angulation of impaction in both genders was the mesioangular (39%), and the most common level of impaction in both arches was Level B. In Class I, Class II and Class III malocclusion vertical angulation was the most common finding in the maxillary arch and mesioangular angulation in the mandibular arch. No significant association was observed between different types of malocclusion and third molar impaction (P > 0.4648).

This study found that almost half of the adult patients above 18 years had at least one impacted third molar. The anteroposterior relationship does not have any significant role for the third molar impaction.