Influence and Impact of Mandibular Ramal Dimensions on the Incidence of Lower Third Molar Impaction: A Prospective Study

CONTEXT: The incidence of third molar impaction is very frequent in the dental arch; however, the etiology remains unclear. Assessment of ramal parameters might aid in deducing the chance of the lower third molar being impacted. AIMS: To investigate the mandibular ramus features that could contribute to the etiology of mandibular third molar impaction. SETTINGS AND DESIGN: A prospective study. METHODS AND MATERIALS: In total 1,125 patients (568 males and 557 females) who satisfied the inclusion and exclusion criteria were included in the study. Six linear and four angular measurements such as ramal height, ramal width, mandibular body length, third molar width, the body of mandible width, retromolar space, angle of the impacted tooth, the angle between condyle and coronoid process, gonial angle, and inclination of the lower posterior teeth were made using digital panoramic radiographs and recorded. Also, the occurrence of impacted lower third molar was noted. STATISTICAL ANALYSIS USED: Comparisons between groups were done using Student's t-test. Pearson correlation was used to assess the degree of relationship between retromolar space and mandibular measurements. RESULTS: Control group showed significantly greater measurements in most of the variables, whereas the impacted group showed no significant difference. A significant correlation of retromolar space is found with body height, third molar width, and angle of impaction. CONCLUSIONS: The present study found that the configuration of the mandibular ramus appears to be discrete in many aspects in the erupted other than impacted lower third molars subjects, which might be a possible cause for the impaction.