Is Incisor Location Similar for Study Models and Cephalogram ? ? - a Comparative Study

BACKGROUND: Variations were observed when the same parameter was analyzed in different types of orthodontic diagnostic records affecting our diagnosis and treatment planning. We appraised the linear distance from most prominent point of upper and lower incisors to AB plane from standardized photograph of study models and compare with lateral cephalogram. MATERIALS AND METHODS: A total of 30 standardized photographs of study models and lateral cephalogram were obtained from patients who had full complement of teeth till permanent second molar's and incisors fully erupted. Patients with age group of 15 to 25 years and normal overjet and overbite of 2-4 mm were included. All the standardized photographs were loaded on a computer with Adobe photoshop and dolphin imaging solution 11.5. Incisor positions of upper and lower teeth were analyzed in relation to A-B Plane after calibrating the images. OBSERVATIONS: A mean value of 9.40 ± 2.48mm for position of upper central incisors and 2.48±1.75mm for position of lower incisor in relation to AB plane was observed. Statistical analysis revealed significant difference in positioning of upper and lower incisors in relation to AB plane. CONCLUSION: The perpendicular linear distance from most prominent point of upper and lower incisor were not the same and it was less on standardized photographs of the study models when compared with cephalograms. The difference between the standardised photographic study models and lateral cephalogram on incisor location has to be considered during orthodontic treatment planning.