Original article
Progressive changes in patients with skeletal Class III malocclusion treated by 2-jaw surgery with minimal and conventional presurgical orthodontics: A comparative study

https://doi.org/10.1016/j.ajodo.2015.09.018Get rights and content

Highlights

  • Minimal and conventional presurgical orthodontics for skeletal Class III patients were compared.

  • Treatment outcomes were assessed after a year.

  • Skeletal changes were similar in the groups.

  • Counterclockwise rotation of the mandible should be considered for minimal presurgical orthodontics patients.

Introduction

In this study, we aimed to compare treatment efficacy and postsurgical stability between minimal presurgical orthodontics and conventional presurgical orthodontics for patients with skeletal Class III malocclusion.

Methods

Forty patients received minimal presurgical orthodontics (n = 20) or conventional presurgical orthodontics (n = 20). Lateral cephalograms were obtained before treatment, before orthognathic surgery, and at 1 week, 3 months, 6 months, and 12 months after surgery.

Results

Changes of overjet and mandibular incisal angle before surgery were greater in the conventional presurgical orthodontics group than in the minimal presurgical orthodontics group. Postsurgical horizontal changes in Points A and B, overjet, and mandibular incisal angle showed significant differences among the time points. Most of the horizontal and vertical relapses in the maxilla and the mandible occurred within the first 6 months in both groups.

Conclusions

Minimal presurgical orthodontics and conventional presurgical orthodontics showed similar extents and directions of skeletal changes in patients with Class III malocclusion. However, orthodontists and surgeons should preoperatively consider the postsurgical counterclockwise rotation of the mandible when using minimal presurgical orthodontics. Close and frequent observations are recommended in the early postsurgical stages.

Section snippets

Material and methods

This retrospective cohort study included consecutive patients who underwent orthognathic and orthodontic treatment at Peking University School and Hospital of Stomatology in Beijing, China, from 2010 to 2014. The inclusion criteria were as follows: skeletal Class III malocclusion (ANB, ≤0°, with or without facial asymmetry); no extractions, except for the third molars; history of bimaxillary surgery (1-piece LeFort I osteotomy, bilateral sagittal split ramus osteotomy, and genioplasty, if

Results

There were no significant differences in the initial skeletal and dental measurements between the MPO and CPO groups (Table II).

As shown in Table III, the presurgical and total durations in the MPO group were significantly shorter than those in the CPO group (P <0.001). A comparison of the mean changes in the cephalometric parameters from initial treatment to orthognathic surgery (T0-T1) between the MPO and CPO groups is given in Table IV. The changes in IMPA (MPO, 0.41°; CPO, 7.72°; P <0.01)

Discussion

In this study, we evaluated progressive skeletal and dental changes and postsurgical stability based on cephalometric investigations at various intervals in patients with skeletal Class III malocclusion treated with different presurgical treatment protocols (MPO or CPO). The comparisons included serial skeletal and dental changes and postsurgical stability between the groups. We also assessed the progressive tendency of changes in the horizontal and vertical dimensions.

Recently, Lee et al22

Conclusions

In this study, patients with skeletal Class III malocclusions were treated with MPO or CPO followed by bimaxillary surgery and observed for 12 months. The following conclusions were drawn.

  • 1.

    There were no significant differences in skeletal changes and treatment efficacy after surgery in the MPO and CPO groups, but the patients in the MPO group had much shorter presurgical durations and greater improvements of their facial esthetics at an early stage of treatment.

  • 2.

    During the postsurgical phase, the

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All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest, and none were reported.

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