The association of third molars with mandibular incisor crowding in a group of the Yemeni population in Sana'a city: cone-beam computed tomography.

Background: Multiple factors contribute to mandibular incisor crowding. However, the role of wisdom teeth in these irregularities remains a controversial issue among clinicians. Therefore, this study aimed to determine the potential association between mandibular incisor crowding and the presence or absence of lower wisdom teeth using CBCT image analysis.

Materials and methods: A total of 64 CBCT images of adult patients were recruited. These CBCT images were classified into two groups according to the presence or absence of the lower wisdom teeth on the panoramic view. After the classification, the severity of crowding was calculated by utilizing Little's irregularity index. Points such as A point, Nasion, and B point (Supramentale) were identified on the software program. The significance level was set at P < 0.05.

Results: There was no statistically significant correlation (P = 0.780) in the crowding of the mandibular incisor among the groups with the presence or absence of the lower wisdom teeth. Group 1 (with wisdom teeth) was 5.85 ± 4.05 mm, classified as a moderate irregularity; similarly, group 2 (without wisdom teeth) showed moderate irregularity with a mean value of 5.32 ± 3.12 mm. There was an incisor crowding with a severe irregularity in 18 patients (28.1%), a minimal irregularity in 15 patients (23.4%), a moderate irregularity in 14 patients (21.9%), a very severe irregularity in 10 patients (15.6%), and a perfect alignment in 7 patients (10.9%).

Conclusions: The presence and absence of lower wisdom teeth do not influence the mandibular incisor crowding.