Allison P Gremba1, Seth M Weinberg2, J Douglas Swarts3, Margaretha L Casselbrant3. 1. Department of Anthropology, University of Pittsburgh Dietrich School of Arts and Sciences, United States. Electronic address: apc22@pitt.edu. 2. Center for Craniofacial and Dental Genetics, Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, United States. 3. Department of Otolaryngology, University of Pittsburgh School of Medicine, United States.
Abstract
OBJECTIVES: Past studies using traditional morphometric approaches have reported a handful of differences in craniofacial dimensions between individuals with and without otitis media (OM). In this study, a geometric morphometry (GM) approach was used to determine if craniofacial shape is different among children with no history of OM and a history of recurrent acute OM (RAOM) at two different ages. METHODS: Nineteen standard landmarks were identified on lateral cephalometric radiographs from 79 children (41 Control, 38 RAOM) at 4 years and 52 children (27 Control, 25 RAOM) at 6 years of age. Following Procrustes superimposition of the landmark coordinate data, comparisons of group differences in overall size and shape were performed. Discriminant function analysis and principal component analysis were used to determine which, if any, aspects of shape variation distinguished RAOM from Control groups. RESULTS: At 4 years of age, craniofacial size and shape were significantly different between RAOM and Control groups (p<0.05). Shape differences were evident in the relative positions of the mandible, cranial base, external acoustic meatus, sphenoid and palate. Those shape differences were not found in the 6-year old group. CONCLUSIONS: At 4 years of age, the RAOM and Control groups have distinct craniofacial morphologies, but by 6 years of age these differences have largely disappeared. This is consistent with the clinical observation that excess RAOM risk resolves around 6 years of age and the hypothesis that this resolution is partially a result of age-related craniofacial changes.
OBJECTIVES: Past studies using traditional morphometric approaches have reported a handful of differences in craniofacial dimensions between individuals with and without otitis media (OM). In this study, a geometric morphometry (GM) approach was used to determine if craniofacial shape is different among children with no history of OM and a history of recurrent acute OM (RAOM) at two different ages. METHODS: Nineteen standard landmarks were identified on lateral cephalometric radiographs from 79 children (41 Control, 38 RAOM) at 4 years and 52 children (27 Control, 25 RAOM) at 6 years of age. Following Procrustes superimposition of the landmark coordinate data, comparisons of group differences in overall size and shape were performed. Discriminant function analysis and principal component analysis were used to determine which, if any, aspects of shape variation distinguished RAOM from Control groups. RESULTS: At 4 years of age, craniofacial size and shape were significantly different between RAOM and Control groups (p<0.05). Shape differences were evident in the relative positions of the mandible, cranial base, external acoustic meatus, sphenoid and palate. Those shape differences were not found in the 6-year old group. CONCLUSIONS: At 4 years of age, the RAOM and Control groups have distinct craniofacial morphologies, but by 6 years of age these differences have largely disappeared. This is consistent with the clinical observation that excess RAOM risk resolves around 6 years of age and the hypothesis that this resolution is partially a result of age-related craniofacial changes.