EFFECT OF MANDIBULAR THIRD MOLARS ON INCISAL MANDIBULAR CROWDING IN PATIENTS WITHOUT PREVIOUS ORTHODONTIC TREATMENT

Third molars are characterized by variability in the presence or absence in the oral cavity, time of their formation and calcification. Mandibular incisal crowding is described as the discrepancy between the mesiodistal widths of the four permanent incisors and the available space in the alveolar process. The aim of this research is to assess the potential influence of mandibular third molars on the development of lower incisor crowding through determination of retromolar eruption space and eruption level of third molars. Examinations are performed on mandibular study plaster orthodontic models and orthopantomographic images of patients, aged between 12 and 22 years. Based on the Little’s index of irregularity: the sample is divided in two groups. Retromolar eruption space was determined by: determination of the Ganss Ratio. Evaluation of the eruption level of the mandibular third molars is determined according to Pell and Gregory. There was no significant difference between patients from the study and control groups in terms of Ganss ratio value(t-test (11)=-0.261 p=0.7989). A significant difference was determined between patients from the study and control groups in terms of dental crowding (t-test (11)=-4.679 p=0.0007). In patients with the index of irregularity > 3mm Level B eruption of mandibular third molars was present with higher frequency (75%) in the examination group and (40%) in the control group. There is no great correlation between the retromolar eruption space for the third molars, the level of eruption and the mandibular incisal crowding.