Elisa Tervahauta1, Jonna Nokela2, Ville Vuollo1, Pertti Pirttiniemi1, Anna-Sofia Silvola1. 1. Research Unit of Oral Health Sciences, Faculty of Medicine, Medical Research Center, Oulu University Hospital and University of Oulu, University of Oulu, Oulu, Finland. 2. Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, Oulu, Finland.
Abstract
OBJECTIVE: To analyse the associations between the widths and forms of dental arches, malocclusions and crowding in middle-aged adult population. MATERIALS AND METHODS: The study material is part of the Northern Finland Birth Cohort 1966 (NFBC1966); the subjects were examined at the age of 46 years. A total of 781 adults with full dentition and no orthodontic treatment history were included. Overjet, overbite, cross-bite and scissor bite were examined during clinical examination. The widths and forms of dental arches, molar relationships and crowding were measured using three-dimensional (3D) dental models. RESULTS: Dental arches were significantly larger in males than in females. Class II (CII) occlusion and increased overjet (≥6 mm) were associated with narrow maxilla (P < .001, P < .05 respectively). Subjects with lateral cross-bite had significantly narrower maxilla and wider mandible (P < .05) than subjects with normal lateral occlusion. In subjects with CII occlusion, square or tapered maxilla and tapered or ovoid mandible were significantly more frequent compared to subjects with Class I (CI) occlusion (P < .05). CII occlusion was significantly associated with crowding in the maxilla (P < .01). CONCLUSION: Narrow and tapered-shaped maxilla was related to CII occlusion, which was associated with dental crowding in the maxilla. Malocclusions were more likely to be found together with other malocclusions than alone.
OBJECTIVE: To analyse the associations between the widths and forms of dental arches, malocclusions and crowding in middle-aged adult population. MATERIALS AND METHODS: The study material is part of the Northern Finland Birth Cohort 1966 (NFBC1966); the subjects were examined at the age of 46 years. A total of 781 adults with full dentition and no orthodontic treatment history were included. Overjet, overbite, cross-bite and scissor bite were examined during clinical examination. The widths and forms of dental arches, molar relationships and crowding were measured using three-dimensional (3D) dental models. RESULTS: Dental arches were significantly larger in males than in females. Class II (CII) occlusion and increased overjet (≥6 mm) were associated with narrow maxilla (P < .001, P < .05 respectively). Subjects with lateral cross-bite had significantly narrower maxilla and wider mandible (P < .05) than subjects with normal lateral occlusion. In subjects with CII occlusion, square or tapered maxilla and tapered or ovoid mandible were significantly more frequent compared to subjects with Class I (CI) occlusion (P < .05). CII occlusion was significantly associated with crowding in the maxilla (P < .01). CONCLUSION: Narrow and tapered-shaped maxilla was related to CII occlusion, which was associated with dental crowding in the maxilla. Malocclusions were more likely to be found together with other malocclusions than alone.