Comparison of gonial angle determination from cephalograms and orthopantomogram.

INTRODUCTION

Gonial angle is an important parameter of the craniofacial complex giving an indication about the vertical parameters and symmetry of the facial skeleton. Both orthopantomogram (OPG) and lateral cephalograms can be used for the measurement of gonial angle. Because of the superimpositions seen on lateral cephalograms, reliable measurement of the gonial angle becomes difficult. The aim of the present study is to check the possible application and reliability of OPG for gonial angle determination by clarifying whether there is any significant difference between the determination of gonial angle from OPG and cephalogram.

MATERIALS AND METHODS

Gonial angle measurements were made on lateral cephalograms and orthopantomograms of 98 patients - 44 males (mean age 25.9 years) and 54 females (mean age 21.3 years), and compared using Statistical Package for Social Sciences.

RESULTS

One-way analysis of variance demonstrated no significant differences between the values of gonial angles determined by lateral cephalogram and panoramic radiography. Pearson correlation showed a high correlation between cephalometric and OPG gonial angle value.

CONCLUSION

Panoramic radiography can be used to determine the gonial angle as accurately as a lateral cephalogram. For determination of the gonial angle, an OPG may be a better choice than a lateral cephalogram as there are no interferences due to superimposed images of anatomical structures as in a lateral cephalogram. Thus, the present study substantiates the possibility of enhancing the clinical versatility of the panoramic radiograph, which is an indispensable tool for dental diagnosis.