title: Diagnostic index of 3D osteoarthritic changes in TMJ condylar morphology.
abstract: The aim of this study was to investigate imaging statistical approaches for classifying 3D osteoarthritic morphological variations among 169 Temporomandibular Joint (TMJ) condyles. Cone beam Computed Tomography (CBCT) scans were acquired from 69 patients with long-term TMJ Osteoarthritis (OA) (39.1 ± 15.7 years), 15 patients at initial diagnosis of OA (44.9 ± 14.8 years) and 7 healthy controls (43 ± 12.4 years). 3D surface models of the condyles were constructed and Shape Correspondence was used to establish correspondent points on each model. The statistical framework included a multivariate analysis of covariance (MANCOVA) and Direction-Projection- Permutation (DiProPerm) for testing statistical significance of the differences between healthy control and the OA group determined by clinical and radiographic diagnoses. Unsupervised classification using hierarchical agglomerative clustering (HAC) was then conducted. Condylar morphology in OA and healthy subjects varied widely. Compared with healthy controls, OA average condyle was statistically significantly smaller in all dimensions except its anterior surface. Significant flattening of the lateral pole was noticed at initial diagnosis (p < 0.05). It was observed areas of 3.88 mm bone resorption at the superior surface and 3.10 mm bone apposition at the anterior aspect of the long-term OA average model. 1000 permutation statistics of DiProPerm supported a significant difference between the healthy control group and OA group (t = 6.7, empirical p-value = 0.001). Clinically meaningful unsupervised classification of TMJ condylar morphology determined a preliminary diagnostic index of 3D osteoarthritic changes, which may be the first step towards a more targeted diagnosis of this condition.
authors.affiliation: University of Michigan, 1011 North University Avenue, Ann Arbor, MI, USA 48109 ; UNESP Univ Estadual Paulista, 1680 Humaita Street, Centro, Araraquara, SP, BR, 14801-903.
authors.forename: Liliane R
authors.initials: LR
authors.lastname: Gomes
authors.affiliation: Private practice, Salvador, BA, BR, 41940-455.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gomes
authors.affiliation: University of North Carolina, 101 Manning Drive, Chapel Hill, NC, USA, 27599.
authors.forename: Bryan
authors.initials: B
authors.lastname: Jung
authors.affiliation: University of North Carolina, 101 Manning Drive, Chapel Hill, NC, USA, 27599.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Paniagua
authors.affiliation: University of Michigan, 1011 North University Avenue, Ann Arbor, MI, USA 48109.
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Ruellas
authors.affiliation: UNESP Univ Estadual Paulista, 1680 Humaita Street, Centro, Araraquara, SP, BR, 14801-903.
authors.forename: João Roberto
authors.initials: JR
authors.lastname: Gonçalves
authors.affiliation: University of North Carolina, 101 Manning Drive, Chapel Hill, NC, USA, 27599.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Styner
authors.affiliation: Baylor University Medical Center, 3501 Junius Street, Dallas, TX, USA, 75246.
authors.forename: Larry
authors.initials: L
authors.lastname: Wolford
authors.affiliation: University of Michigan, 1011 North University Avenue, Ann Arbor, MI, USA 48109.
authors.forename: Lucia
authors.initials: L
authors.lastname: Cevidanes
keywords: 3D imaging; Bone Overgrowth; Bone Resorption; Osteoarthritis; Temporomandibular Joint Disorders