Influence and Impact of Mandibular Ramal Dimensions on the Incidence of Lower Third Molar Impaction

Abstract

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.

Proposal and Validation of a New Index to Assess the Difficulty of Lower Third Molar Extraction

“…A reduced gonial angle value was significantly associated with a deeply affected molar in the ramus, and at the same time, a progressive decrease in the gonial angle meant a more horizontal position of the molar closer to the mandibular canal (p < 0.05), and finally, a lower gonial angle showed a reduced retromolar space with a more complex impacted third molar (p < 0.05), so there is a correlation. In contrast, an article published by Jeevitha et al [25] finds no existing correlation between both aspects, although it is relevant to highlight it used 2D radiographs. Multiple recent studies compared other aspects of craniofacial morphology, concluding in a similar way: facial types influence the kind of impaction, for example, the growth potential of the mandible in brachyfacial types may provide sufficient space for third molar eruption, which is a more common impaction of the molars in dolichocephalic [26], and individuals with increased maximal cranial width and decreased anterior facial height have a higher risk of impaction of third molars in the mandible [27].…”

Impacted Mandibular Third Molars Associated Pathologies

“…It was the goal of this research to look at panoramic radiographs of Jordanians with impacted mandibular third teeth to see how often certain pathologic abnormalities were present. Caries in the partially erupted impacted mandibular third molar, as well as caries in the neighbouring mandibular second molar, are present, as are odontomes and external root resorption [8].…”