Panoramic radiographs for investigating skeletal patternsA comparative study

Introduction: The most commonly used diagnostic aids in orthodontics are lateral cephalograms and panoramic radiographs (OPG). The OPG forms an indispensible orthodontic screening tool in providing information about the teeth, their root length, axial inclinations, morphology and structure, eruption sequence and spatial relationships [1] which is mostly qualitative in nature. The purpose of this study was to evaluate whether the use of OPG could be extended for evaluating skeletal patterns and dentofacial characteristics which are routinely measured on lateral cephalograms. Materials and Methods: A total of 80 subjects were chosen, they were divided into two groups: Group A and Group B. Group A included 40 skeletal Class I, dental Class I adults with age range of 18-27 years. Group B included 40 skeletal ClassII, dental Class II Div 1 children with age range of 10 -15 years. The lateral cephalogram and OPG were taken under standard conditions using skeletal cephalostat and various parameters were measured and compared. Results and Conclusion: From this study it was concluded that angular measurements on OPG can be used to predict the corresponding angular measurements from the lateral cephalograms, both for the dental and skeletal parameters but the vertical linear measurements cannot be predicted accurately from OPG. The regression equations obtained from this study showed that the Go-Gn/S-N, ANS-PNS/Go-Me (palatal plane/mandibular plane), and Co-Go/Go-Me parameters could be predicted from OPG within statistically significant levels, and their predictability levels were 20.47%, 31.7%, and 10.88%, respectively for group A and 32.0%.22.08% and 52.36% respectively for group B.