Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Nov 23;23(1):915.
doi: 10.1186/s12903-023-03653-0.

Tomographic analysis of relationship of mandibular morphology and third molars eruption

Jéssica de Fátima Segantin  1 , Gabriela Barbosa Bisson  2 , Letícia Liana Chihara  1 , Osny Ferreira Júnior  1
Affiliations

Tomographic analysis of relationship of mandibular morphology and third molars eruption

Jéssica de Fátima Segantin et al. BMC Oral Health. .

Abstract

Background: Lower third molars (L3M) are the last teeth to erupt in the oral cavity. Uneruption of these teeth still raises questions about its causes, in the literature (1) genetic factors, (2) dental lamina activity and, mainly, (3) insufficient growth and development of the bone bases are included. While the lack of space theory influenced by mandibular morphology and size of L3M was argued to be the main reason for L3M impaction, there is a limitation in the literature in examining such association using more accurate tomographic analysis obtained from CBCT. This work aimed to evaluate the relationship between mandibular morphology and the eruption of L3M.

Methods: In this regard, 85 Cone Beam Computed Tomographies (CBCT), with 147 L3M, were selected from the archives of the Department of Surgery, Stomatology, Pathology and Radiology, Bauru School of Dentistry, obtained using an Accuitomo® Morita device and using the Dolphin Imaging 11.9 software. L3M eruption was related to linear measurements of jaw length (Co-Gn), retromolar space dimension (D2R), mesiodistal width of the L3M crowns, mandibular first molars (L1M) and mandibular canines (LC) and the angle mandibular (Ar-Go-Me). Independent samples t-test, chi-square tests and logistic regression were performed adopting a significance level of 5%.

Results: The average mandible length of 116.446 mm + 6.415 mm, retromolar space of 11.634 mm + 2.385 mm, mesiodistal size of the L3M of 10.054 mm + 0.941 mm, sum of the mesiodistal widths of the L1M and LC of 15.564 mm + 1.218 mm and mandibular angle of 127.23° + 6.109. There was no statistically significant association between these factors and the eruption.

Conclusion: With the results obtained in this study, we conclude that the length and angle of the mandible, teeth size and dimension of the retromolar space are not associated with the L3M eruption.

Keywords: Mandible; Third molar; Tomography; Tooth eruption.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Effective mandible length with Co-Gn points
Fig. 2
Fig. 2
Size of teeth A) Measurement of lower first molars (L1M) and canines (LC), B) Measurement of lower third molars (L3M)
Fig. 3
Fig. 3
Measurement of retromolar space (D2-R)
Fig. 4
Fig. 4
Marking the points of interest in sagittal reformatting: Ar-Go-Me and the gonial angle measurement provided by the software
Fig. 5
Fig. 5
CBCT selection flowchart
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Muhsin H, Brizuela M. StatPearls. Treasure Island (FL): StatPearls Publishing; 2023. Oral surgery, extraction of mandibular third molars. - PubMed
    1. Barone S, Antonelli A, Averta F, et al. Does Mandibular Gonial Angle Influence the Eruption Pattern of the Lower Third Molar? A Three-Dimensional Study. J Clin Med. 2021;10(18):4057. doi: 10.3390/jcm10184057. - DOI - PMC - PubMed
    1. Demirel O, Akbulut A. Evaluation of the relationship between gonial angle and impacted mandibular third molar teeth. Anat Sci Int. 2020;95(1):134–142. doi: 10.1007/s12565-019-00507-0. - DOI - PubMed
    1. KalaiSelvan S, Ganesh SKN, Natesh P, Moorthy MS, Niazi TM, Babu SS. Prevalence and pattern of impacted mandibular third molar: an institution-based retrospective study. J Pharm Bioallied Sci. 2020;12(Suppl 1):S462–S467. doi: 10.4103/jpbs.JPBS_140_20. - DOI - PMC - PubMed
    1. Adeyemo WL, James O, Oladega AA, et al. Correlation between height and impacted third molars and genetics role in third molar impaction. J Maxillofac Oral Surg. 2021;20(1):149–153. doi: 10.1007/s12663-020-01336-9. - DOI - PMC - PubMed

MeSH terms