Heesoo Oh1, Ryan Knigge2,3, Anna Hardin2, Richard Sherwood2,3, Dana Duren2,3, Manish Valiathan4, Emily Leary3, Kieran McNulty5. 1. Craniofacial Research Instrumentation Lab, Department of Orthodontics, University of Pacific Arthur A. Dugoni School of Dentistry, San Francisco, California. 2. Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri. 3. Department of Orthopaedic Surgery, Missouri Orthopaedic Institute, University of Missouri, Columbia, Missouri. 4. Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, Ohio. 5. Evolutionary Anthropology Lab, Department of Anthropology, University of Minnesota, Minneapolis, Minnesota.
Abstract
OBJECTIVES: To assess the potential of predicting adult facial types at different stages of mandibular development. SETTING AND SAMPLE POPULATION: A total of 941 participants from the Bolton-Brush, Denver, Fels, Iowa, Michigan and Oregon growth studies with longitudinal lateral cephalograms (total of 7166) between ages 6-21 years. MATERIAL AND METHODS: Each participant was placed into one of three facial types based on mandibular plane angle (MPA) from cephalograms taken closest to 18 years of age (range of 15-21 years): hypo-divergent (MPA < 28°), normo-divergent (28°≤ MPA ≤ 39°) and hyper-divergent (MPA > 39°). Cephalograms were categorized into 13 age groups 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 and 18-21. Twenty-three two-dimensional anatomical landmarks were digitized on the mandible and superimposed using generalized Procrustes analysis, which projects landmarks into a common shape space. Data were analysed within age categories using stepwise discriminant analysis to identify landmarks that distinguish adult facial types and by jackknife cross-validation to test how well young individuals can be reclassified into their adult facial types. RESULTS: Although each category has multiple best discriminating landmarks among adult types, three landmarks were common across nearly all age categories: menton, gonion and articulare. Individuals were correctly classified better than chance, even among the youngest age category. Cross-validation rates improved with age, and hyper- and hypo-divergent groups have better reclassification rates than the normo-divergent group. CONCLUSIONS: The discovery of important indicators of adult facial type in the developing mandible helps improve our capacity to predict adult facial types at a younger age.
OBJECTIVES: To assess the potential of predicting adult facial types at different stages of mandibular development. SETTING AND SAMPLE POPULATION: A total of 941 participants from the Bolton-Brush, Denver, Fels, Iowa, Michigan and Oregon growth studies with longitudinal lateral cephalograms (total of 7166) between ages 6-21 years. MATERIAL AND METHODS: Each participant was placed into one of three facial types based on mandibular plane angle (MPA) from cephalograms taken closest to 18 years of age (range of 15-21 years): hypo-divergent (MPA < 28°), normo-divergent (28°≤ MPA ≤ 39°) and hyper-divergent (MPA > 39°). Cephalograms were categorized into 13 age groups 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 and 18-21. Twenty-three two-dimensional anatomical landmarks were digitized on the mandible and superimposed using generalized Procrustes analysis, which projects landmarks into a common shape space. Data were analysed within age categories using stepwise discriminant analysis to identify landmarks that distinguish adult facial types and by jackknife cross-validation to test how well young individuals can be reclassified into their adult facial types. RESULTS: Although each category has multiple best discriminating landmarks among adult types, three landmarks were common across nearly all age categories: menton, gonion and articulare. Individuals were correctly classified better than chance, even among the youngest age category. Cross-validation rates improved with age, and hyper- and hypo-divergent groups have better reclassification rates than the normo-divergent group. CONCLUSIONS: The discovery of important indicators of adult facial type in the developing mandible helps improve our capacity to predict adult facial types at a younger age.
Authors: Anna M Hardin; Manish Valiathan; Heesoo Oh; Ryan P Knigge; Kieran P McNulty; Emily V Leary; Dana L Duren; Richard J Sherwood Journal: Orthod Craniofac Res Date: 2019-10-01 Impact factor: 1.826
Authors: Ryan P Knigge; Anna M Hardin; Kevin M Middleton; Kieran P McNulty; Hee Soo Oh; Manish Valiathan; Dana L Duren; Richard J Sherwood Journal: Anat Rec (Hoboken) Date: 2022-02-11 Impact factor: 2.227
Authors: Richard J Sherwood; Hee Soo Oh; Manish Valiathan; Kieran P McNulty; Dana L Duren; Ryan P Knigge; Anna M Hardin; Christina L Holzhauser; Kevin M Middleton Journal: Anat Rec (Hoboken) Date: 2020-10-12 Impact factor: 2.227