Comparison of the Gonial Angle in Panoramic and Lateral Cephalometric Radiographs in Different Skeletal Patterns

Superimposition of left and right structures is an issue in lateral cephalometric radiographs in dentistry, making it challenging to measure structures, including the gonial angle. Panoramic radiography contains fewer superimposing structures; therefore, it could measure the gonial angle. This study aimed to compare the gonial angle in panoramic and lateral cephalometric radiographs in different skeletal patterns.

In this cross-sectional study, 240 panoramic and lateral cephalometric radiographs were collected from the archives of Sari Dental School. The gonial angle of each radiograph was traced and measured with a conveyor. Data analysis was performed using ANOVA and paired t-test, and P-value <0.05 were considered significant.

The paired t-test of the gonial angle did not show a statistically significant difference between different skeletal groups when measured using panoramic and lateral cephalometric radiographs. According to the results, the p-value of the difference between the right and left gonial angles in skeletal class III patients (p=0.019) was obtained larger than the test level (p=0.05).  Therefore, it can be concluded that there is a statistically significant difference between the size of the left and right gonial angles in panoramic radiographs of skeletal class III patients. 

Panoramic radiography can be an accurate alternative to lateral cephalometric radiographs for measuring the gonial angle in different skeletal patterns due to the lower radiation it exposes to the patient.