Objective: This study aimed to confirm the usefulness of cephalometric prediction (CP) in the diagnostic and treatment planning stages of surgical-orthodontic treatment. Few reports have been published on the prediction accuracy of manual CP and it has not been sufficiently investigated. Therefore, this study compared treatment predictions based on manual CP and treatment outcomes in cases of skeletal maxillary protrusion.
Methods: The subjects were 28 patients with skeletal maxillary protrusions who underwent orthodontic treatment at Tokyo Dental College Chiba Hospital. Subjects were divided into the following two groups: patients treated surgically with sagittal split ramus osteotomy (SSRO) only (1-jaw group; n = 13), and patients who underwent both SSRO and Le Fort I osteotomy (2-jaw group; n = 15). Distances and angles were measured and compared between manual CP prepared from lateral cephalograms taken at the initial examination and lateral cephalograms at the completion of treatment.
Results: Tests of the difference in the predicted amount of movement and the actual movement revealed no significant differences in the 1-jaw group, and no significant differences except for Gonion in the 2-jaw group. The predicted positioning and actual positioning resulting from treatment were also compared. In the maxilla, no significant differences were seen between the treatment predictions and surgical results in the 2-jaw group. In the mandible, there were no significant differences in both the 1-jaw and 2-jaw groups.
Conclusion: Manual CP accurately predicted the positioning of the maxillary and mandibular bones in surgical-orthodontic treatment for skeletal maxillary protrusion, and is useful both at diagnosis and when establishing a treatment plan.
