DOI: 10.1097/scs.0000000000009584 ISSN:

Comparison of Posttreatment Stability Between Mandibular Setback Surgery-Early and Conventional Surgery in Class III Patients: A 4.6-Year Follow-Up

Yonsoo Shin, Tae-Hyun Choi, Ji-Young Yoon, Young-Kyun Kim, Pil-Young Yun, Nam-Ki Lee
  • General Medicine
  • Otorhinolaryngology
  • Surgery

Objectives:

This retrospective study aims to compare long-term stability between the mandibular setback surgery-early (MSE) approach, involving minimal orthodontics, and the mandibular setback conventional surgery (MCS) approach, involving sufficient orthodontics, in Class III patients with mandibular prognathism.

Methods:

Among 210 patients who underwent orthognathic surgery, a total of 40 subjects were enrolled based on standardized inclusion criteria: only mandibular surgery, <5 mm setback difference between right and left of the mandible, orthodontics with fixed appliances, and more than 2 years of follow-up after treatment. These patients were allocated to the MSE (n = 20) and MCS groups (n = 20) according to the duration of presurgical orthodontics. Changes in cephalometric measurements were compared between the MSE and MCS groups before surgery (T0), 1 month after surgery (T1), at the end of treatment (T2), and posttreatment retention (T3).

Results:

The MSE and MCS groups had a mean presurgical orthodontic duration of 2 and 9.5 months, respectively. From T1 to T2, the MSE group showed a significantly larger forward movement of the mandible than the MCS group (2.1 versus 0.7 mm; P < 0.001). In addition, from T2 to T3 (average 4.6 years), the MSE group presented anterior relapse of 0.6 mm in the mandible, but there were no statistically significant intergroup differences.

Conclusion:

Although the MSE group showed greater postsurgical forward mandibular relapse than the MCS group, the two groups exhibited similar skeletal and dental stability during the posttreatment retention.

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