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. 2025 Mar 20;25(1):410.
doi: 10.1186/s12903-025-05733-9.

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

Khalid Aldhorae #  1   2 , Ramy Ishaq  3 , Salah Alhaidary  2 , Ashraf Mohammed Alhumaidi  2 , Mohammed M Al Moaleem  4 , Ghamdan Al Harazi  3 , Naela Al-Mogahed  3 , Hani Homaid  1 , Sadam Ahmed Elayah  5
Affiliations

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

Khalid Aldhorae et al. BMC Oral Health. .

Abstract

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.

Keywords: CBCT; Mandibular incisor crowding; Third molars; Wisdom teeth.

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Conflict of interest statement

Declarations. Ethics approval and consent to participate: Sana’a University’s ethical committee ethically approved this study for medical research, which was conducted in accordance with the guidelines of the Declaration of Helsinki. Written informed consent was obtained from all patients in the study. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Construction of multiplanar windows of the CBCT-based length measurements, Coronal plane (a), Sagittal plane (b), Axial plane (c), and 3D plane (d)
Fig. 2
Fig. 2
Point A on the multiplanar windows, 3D plane (a), Axial plane (b), Sagittal plane (c), and Coronal plane (d)
Fig. 3
Fig. 3
Nasion on the multiplanar windows, 3D plane (a), Axial plane (b), Sagittal plane (c), and Coronal plane (d)
Fig. 4
Fig. 4
Point B on the multiplanar windows, 3D plane (a), Axial plane (b), Sagittal plane (c), and Coronal plane (d)
Fig. 5
Fig. 5
Measurement of Little’s irregularity index using CBCT axial view
See this image and copyright information in PMC

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