Orthodontics
Foroozan Farahbod; Sepideh Dadgar; Farhad Sobouti; Ali Malekzadeh Shafaroudi; Sajad Yousefi; Ali Nowruzy
Abstract
Background: 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. ...
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Background: 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.Methods: 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.Results: 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. Conclusion: 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.
Azita Tehranchi; Nazila Ameli; E. Hasanrezaee
Abstract
Background and aim: The objective of this study was to investigate the relationship between the gonial angle changes and occlusal plan steepness in patients underwent Bilateral Sagittal Split Osteotomy (BSSO) surgery.Materials and method: In this analytical retrospective clinical trial, 18 males and ...
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Background and aim: The objective of this study was to investigate the relationship between the gonial angle changes and occlusal plan steepness in patients underwent Bilateral Sagittal Split Osteotomy (BSSO) surgery.Materials and method: In this analytical retrospective clinical trial, 18 males and 12 females were studied who had been underwent BSSO surgery for mandibular advancement in. Cephalometric landmarks were calculated on the patients' lateral radiographs taken before and 1-6 months postsurgery using Dolphin software. The patients assigned into 3 groups according to different occlusal plan steepness. Landmarks' changes before and after surgery were analyzed by Paired t-test. The changes occurred regarding the normal and flat facial types assessed by Student t-test while the relationship between the presurgical occlusal plan and the landmark changes was evaluated using the Pearson Coefficient.Results: After BSSO, the gonial angle had increased in all patients with the mean value of 6.83ᴼ (P˂0.0001) but occlusal plan steepness increased to an insignificant value (mean 2.82ᴼ). Increased values of the gonial angle were similarly reported in the patients with normal occlusal plan steepness and flat occlusal plan while no significant relationship was found between occlusal plan steepness before the surgery and the gonial angle changes after surgery. However, fair more increase occurred in patients with normal steepness than lower ones. Conclusions: The results showed that there is no significant relationship between the gonial angle changes after surgery and the occlusal plan steepness prior the surgery of BSSO for mandibular advancement.
