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3D-Geomorphometrics tooth shape analysis in hypodontia

Lookup NU author(s): Dr Wendy Dirks, Dr Nick Jepson, Dr Khaled Khalaf



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Assessment of tooth morphology is an important part of the diagnosis and management of hypodontia patients. Several techniques have been used to analyze tooth form in hypodontia patients and these have shown smaller tooth dimensions and anomalous tooth shapes in patients with hypodontia when compared with controls. However, previous studies have mainly used 2D images and provided limited information. In the present study, 3D surface-imaging and statistical shape analysis were used to evaluate tooth form differences between hypodontia and control patients. Eighteen anatomical landmarks were recorded on the clinical crown of the lower left first permanent molar of 3D scanned study models of hypodontia and control subjects. The study sample group comprised of 120 hypodontia patients (40 mild, 40 moderate and 40 severe hypodontia patients) and 40 age- and sex-matched controls. Procrustes coordinates were utilized to scale and superimpose the landmark coordinate data and then were subjected to principal component analysis (PCA). Subsequently, differences in shape as well as size were tested statistically using allometric analysis and MANOVA. Significant interaction was found between the two factor variables “group” and “sex” (p< 0.002). Overall expected accuracies were 66% and 56% for females and males respectively in the cross-validated discriminant-analysis using the first 20 PCs. Hypodontia groups showed significant shape differences compared with the control subjects (p< 0.0001). Significant differences in tooth crown shape were also found between sexes (p< 0.0001) within groups. Furthermore, the degree of variation in tooth form was proportional to the degree of the severity of the hypodontia. Thus quantitative measurement of tooth shape in hypodontia patients may enhance the multidisciplinary management of those patients. - See more at:

Publication metadata

Author(s): Al-Shahrani I, Dirks W, Jepson N, Khalaf K

Publication type: Article

Publication status: Published

Journal: Frontiers in Physiology: Craniofacial Biology

Year: 2014

Volume: 5

Online publication date: 23/04/2014

Acceptance date: 31/03/2014

Date deposited: 08/09/2015

ISSN (electronic): 1664-042X

Publisher: Frontiers Research Foundation


DOI: 10.3389/fphys.2014.00154

PubMed id: 24795649

Notes: Article 154 is 12 pp.


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