Resident Hospital Goyang, Kyonggi-do, Republic of Korea
Disclosure(s):
Junghoon Kim, PhD: No financial relationships to disclose
Abstract:
Objectives: This study aimed to evaluate the alveolar bone change of maxillary and mandibular anterior teeth in skeletal Class III patients who had orthognathic surgery. Materials and
Methods: 14 skeletal Class III patients who had orthognathic surgery and orthodontic treatment were included in this study. The cephalometric images and CT images at T0(initial), T1(before surgery), and T2(at least 1 year after surgery) were used for measurements. The inclination of maxillary and mandibular anterior teeth were measured on the cephalometric image, and alveolar bone heights and widths of buccal and palatal(lingual) sides were measured in CT images. Alveolar bone heights were defined as the distance from the CEJ to the alveolar crest of the most coronal part of the labial and palatal(lingual) surface, and alveolar bone widths were estimated at 3, 6, and 9mm levels from CEJ(cementoenamel junction) for each tooth.
Results: All incisors except for labial side of maxillary lateral incisors showed reduced labial and palatal(lingual) alveolar bone heights at T1 and T2. For alveolar bone width of maxillary incisors, only palatal bone width decreased and there was no change on labial bone width. In mandibular incisors, alveolar bone width showed a different pattern according to the time and the site. Lingual bone width decreased during orthodontic decompensation(T0-T1) and labial bone width decreased after surgery(T1-T2).
Conclusion: In skeletal Class III patients who have pre-surgical orthodontic treatment, alveolar bone height and width of anterior teeth decrease due to the decompensation of anterior teeth. Such alveolar bone change cannot be recovered more than a year after orthognathic surgery. In conclusion, correction of compensated anterior teeth in skeletal Class III patients should be conducted with caution. If excessive anterior teeth movement is expected, alternative treatment plans such as premolar extraction, rapid palatal expansion, and anterior segmental osteotomy should be considered.
