Mandible-First Sequencing Increase Surgical Accuracy for Patients With Skeletal Class II Malocclusion Concomitant With Unstable Condyle-Fossa Relation

Shoupeng Wang; Weiwen Ge; Lei Qi; Ningning Cao; Jian Meng; Lei Zhang

doi:10.1097/SCS.0000000000009890

Mandible-First Sequencing Increase Surgical Accuracy for Patients With Skeletal Class II Malocclusion Concomitant With Unstable Condyle-Fossa Relation

J Craniofac Surg. 2023 Dec 6. doi: 10.1097/SCS.0000000000009890. Online ahead of print.

Authors

Shoupeng Wang^{1

2

3

4

5}, Weiwen Ge^{1

2

3

4}, Lei Qi^{1

2

3

4}, Ningning Cao^{1

2

3

4}, Jian Meng⁵, Lei Zhang^{1

2

3

4}

Affiliations

¹ Department of Oral and Cranio-Maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine.
² College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology.
³ National Clinical Research Center for Oral Diseases.
⁴ Shanghai Key Laboratory of Stomatology, Shanghai.
⁵ Department of Stomatology, Central Hospital of Xuzhou City, Xuzhou, Jiangsu Province, China.

PMID: 38055333
DOI: 10.1097/SCS.0000000000009890

Abstract

The aim of this study was to explore whether mandible-first sequencing increases the surgical accuracy in bimaxillary orthognathic surgery for patients with skeletal class II malocclusion concomitant with the unstable condyle-fossa relation. A retrospective evaluation of 19 patients who had undergone virtually planned double-splint orthognathic surgery with different operation sequences was performed: maxilla-first (n=9) or mandible-first (n=10) surgery. The centroid position, translational, and rotational differences in the maxilla were evaluated by comparing the virtual plans with actual results. The stability was assessed by comparing the actual results with the follow-up outcomes 6 months postoperatively. The accuracy of the maxilla centroid position was improved in mandible-first sequencing surgery: mandible-first 1.87±0.94 mm versus maxilla-first 2.70±0.75 mm (P<0.05). Moreover, no significant difference was detected in the translational and orientational discrepancies between the 2 groups. Neither sequencing procedure differed in the overall stability: maxilla-first (1.48±1.13 mm) versus mandible-first (1.57±0.90 mm). This study indicated that the mandible-first surgery leads to a more accurate maxilla position than the maxilla-first surgery for patients with skeletal class II malocclusion concomitant with the unstable condyle-fossa relation.