Scott T Frey1. 1. Department of Orthodontics, School of Dental Medicine, Colorado University, Aurora, Colo 80045, USA. stfrey@gmail.com
Abstract
OBJECTIVE: To determine whether a visual classification of anterior malar support using vector relationships is supported by cephalometric analysis. MATERIALS AND METHODS: Forty white subjects between the ages of 10 and 12 years, without craniofacial syndromes or previous orthodontic treatment, were equally divided into groups based on visual assessment of negative and positive vector relationships. Group A comprised 20 subjects (10 male, 10 female) exhibiting a positive vector relationship. Group B comprised 20 subjects (10 male, 10 female) displaying a negative vector relationship. Sella-nasion-orbitale (SNO) angulations were measured to evaluate the subjects' anteroposterior position of the malar eminence relative to the cranial base. Gender differences and significant differences in SNO measurements between groups A and B were assessed with Mann-Whitney U-tests. RESULTS: There was no statistically significant difference between genders. SNO angulations in the negative vector group were smaller than the positive vector controls by an average of 6.0 degrees, and the difference was highly significant (P < .0001). CONCLUSION: Compared with subjects exhibiting a positive vector relationship, individuals displaying a negative vector relationship had significantly reduced malar support. Anterior malar projection can be effectively classified through visual assessment of vector relationships.
OBJECTIVE: To determine whether a visual classification of anterior malar support using vector relationships is supported by cephalometric analysis. MATERIALS AND METHODS: Forty white subjects between the ages of 10 and 12 years, without craniofacial syndromes or previous orthodontic treatment, were equally divided into groups based on visual assessment of negative and positive vector relationships. Group A comprised 20 subjects (10 male, 10 female) exhibiting a positive vector relationship. Group B comprised 20 subjects (10 male, 10 female) displaying a negative vector relationship. Sella-nasion-orbitale (SNO) angulations were measured to evaluate the subjects' anteroposterior position of the malar eminence relative to the cranial base. Gender differences and significant differences in SNO measurements between groups A and B were assessed with Mann-Whitney U-tests. RESULTS: There was no statistically significant difference between genders. SNO angulations in the negative vector group were smaller than the positive vector controls by an average of 6.0 degrees, and the difference was highly significant (P < .0001). CONCLUSION: Compared with subjects exhibiting a positive vector relationship, individuals displaying a negative vector relationship had significantly reduced malar support. Anterior malar projection can be effectively classified through visual assessment of vector relationships.
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