Is there any difference in the development of mandibular third molars according to the type of impaction: An orthopantomographic study in south Indian children and adolescents

Development of third molars and their influence on the dental arch is a major concern in clinical dentistry especially, orthodontics and oral surgery. Lately, their position, eruption potential and development has become a subject of interest in forensic practice. The present study was aimed to determine whether if there is any difference in the development of the mandibular third molars according to the impaction type. Orthopantomographs (n = 1112) from 478 males and 634 females between 15 and 22 years old were analysed. In each radiograph, impaction status and the developmental stage of mandibular third molars were determined. Descriptive statistics were performed at developmental stages D to H. For stage G, there was a delay by 0.74 and 0.62 years for mesioangular impaction, 0.89 and 0.33 years for horizontal impaction, 1.43 and 0.9 years for distoangular impaction and 1.74 and 1.1 years for vertical impaction, in males and females. For stage H, delay by 0.17 and 0.74 years, 0.05 and 0.06 years, 0.48 and 1.48 years and 0.62 and 0.62 years, respectively for all impaction variants in both sexes. Mean chronological age of the distoangular and vertically impacted mandibular third molars were higher in certain developmental stages than mesioangular and horizontal impactions. Our findings concluded that distoangular and vertical impaction variants mineralize more slowly than mesioangular and horizontal variants, however these differences were smaller. Therefore, no distinction is required between impaction types for dental age estimation especially in the prediction of the age of majority (18 years).