Angular and linear mandibular measurements: Comparison between 2D and 3D using digital software

Aim is to compare the external gonial angle, ramus length, body length and total length in two dimension from lateral cephalogram and three dimensional model from CBCT using digital software. Materials - A total of 30 samples were selected between the age group of 18 to 30 years who fit into the inclusion criteria, their three dimensional model was constructed using CBCT slices in nemoceph and two dimension image was standardized with three dimensional model by selecting two fixed points on scale. Linear and angular measurements were performed on right and left side of three dimensional model and a mean value is obtained which will be compared with two dimension and arrive at results from statistical analysis. Results showed significant difference in the mean values of mandibular body length and total length in two dimension and three dimension. Showed no significant difference in the mean values of gonial angle and ramal length in two dimension and three dimension. Conclusion - the three dimensional model provided a more realistic image to determine the linear and angular measurements. The mandibular body length and total length showed significant difference due to more accurate and reliable marking of menton in three dimension. The symphyseal shadow was selected as menton in two dimension while in three dimension inferior most point in midline was selected.