Can Orthopantomogram be utilized in Dentoskeletal Measurements as Compared to Lateral Cephalograms?

Objective: To enhance the orthopantomogram’s (OPG) clinical application by establishing its capability in investigating some dentoskeletal specifications compared to lateral cephalograms (LCRs) in light of the importance of reducing routine patient’s exposure to radiation.
Methods: Pretreatment OPGs and LCRs of 120 patients (ranging in age from 10-15 years) with dental and skeletal class I, II and III relationships (40 patients/group) respectively, were collected randomly from the Orthodontic Department, Faculty of Dentistry, Mansoura University. The selected OPGs and LCRs had to be taken in the same day by the same apparatus and in ideal position according to the manufacturer’s instructions. Two-way ANOVA was used to detect possible differences between classes and types of radiographs followed by multiple comparisons (post hoc test) between each 2 groups using the Bonferroni correction if significant differences were noted.
Results: There was a statistically significant difference in the assessed parameters using OPGs between groups for the anterior mandibular height (AHMn), the distance from the incisal edge of the most extruded lower central incisor to the anterior mandibular line (ii-Mla) and the distance from the mesial cusp tip of the mandibular permanent first molar to the mandibular line (mi-ML) only. In LCRs, there was a significant difference between classes for AHMn and mi-ML only.
A significant difference was detected between OPGs and LCRs for AHMn and mi-ML only (p<.05). However, no difference was found in the other parameters between the two types of radiographs for all classes. Measurements of panoramic radiographs were significantly higher than cephalometric radiographs for AHMn and mi-ML.
Conclusion: OPG could be considered a reliable alternative for LCR for assessment of many angular and linear dentoskeletal characteristics in different classes to reduce the radiation dose involved in routine diagnostic purposes, so that the use of LCRs could be restricted to certain indications.