|3D-Geomorphometrics tooth shape analysis in hypodontia
Al-Shahrani, I [ 1 ]; Dirks, W [ 2 ]; Jepson, N [ 2 ]; Khalaf, K [ 3 ]
FRONTIERS IN PHYSIOLOGY
Volume: 5, Article Number: 154, DOI: 10.3389/fphys.2014.00154, Published: APR 23 2014
Publisher FRONTIERS RESEARCH FOUNDATION, PO BOX 110, LAUSANNE, 1015, SWITZERLAND
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.
Author Keywords:hypodontia; Procrustes analysis; shape analysis; teeth
KeyWords Plus:GEOMETRIC MORPHOMETRIC-ANALYSIS; MAXILLARY LATERAL INCISORS; PLANAR PROCRUSTES ANALYSIS; CLINICAL-FEATURES; SIZE; ANOMALIES; TEETH; INDIVIDUALS; MANAGEMENT; REVOLUTION
Reprint Address: Al-Shahrani, I E-mail Addresses:firstname.lastname@example.org
King Khalid Univ, Coll Dent, Dept Prevent Dent Sci, Div Orthodont, POB 3263, Abha 61471, Saudi Arabia.
[ 1 ] King Khalid Univ, Coll Dent, Dept Prevent Dent Sci, Div Orthodont, Abha 61471, Saudi Arabia
[ 2 ] Univ Newcastle, Sch Dent Sci, Dept Orthodont, Ctr Oral Hlth Res, Newcastle Upon Tyne, Tyne & Wear, England
Newcastle University - UK
[ 3 ] Univ Aberdeen, Dent Sch & Hosp, Aberdeen, Scotland
University of Aberdeen