Objective: To calculate the major constriction area of the oropharynx, using 3-dimensional images derived from cone beam computed tomography (CBCT), in order to: 1. Obtain normal level indexes according to the age group 2. Correlate the major constriction area of the oropharynx with its sagittal depth and its total volume. Methods: Forty-one scans from the 3D-i-CAT computerized tomograph were evaluated by the software InVivoDental 5.0. Results: The values of the major constriction areas of the oropharynx were obtained, related to the age. There was a positive strong correlation only for the oropharynx major constriction area and its total volume. The correlation between the oropharynx sagittal depth and its major constriction area was positive and moderate. In relation to its sagittal depth and its total volume, the correlation was positive and weak. Conclusions: 1. To the age group 6-12 years, the values ranged from 52.03 to 194.37 mm²; to 13-18 years, ranged from 134.82 to 264.18mm², and to the age group >19 years, from 95.87 to 229.73 mm²; 2. The linear measurement of the sagittal depth of the oropharynx, as performed over lateral cephalometric radiographs, is not much reliable when compared to those achieved from tomographic images.