The association between the zygomatic change and bone setback or resection in L-shaped reduction malarplasty
10.3760/cma.j.cn114453-20240509-00122
- VernacularTitle:L形颧骨颧弓缩窄术内推和去骨量与颧骨外形高点变化的对应关系
- Author:
Qing ZHAO
1
;
Yumo WANG
;
Yiyuan WEI
;
Xiaoshuang SUN
;
Yifan WU
;
Zihang ZHOU
;
Jihua LI
Author Information
1. 口腔疾病研究国家重点实验室 国家口腔疾病临床医学研究中心 四川大学华西口腔医院正颌及关节外科，成都 610041
- Keywords:
Zygoma;
Reduction malarplasty;
Zygomatic morphology;
Osteotomy;
Bone resection;
Bone setback;
Linear relation
- From:
Chinese Journal of Plastic Surgery
2024;40(10):1041-1048
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the association between zygomatic change and bone setback or resection and propose a quantitative guidance for L-shaped reduction malarplasty by linear regression analysis based on computed tomographic (CT) scan images.Methods:A retrospective observational study was conducted on patients who underwent L-shaped reduction malarplasty with mortice and tenon joint at the zygomatic arch in Department of Orthognathic and Temporomandibular Joint Surgery, West China Hospital of Stomatology, Sichuan University from January 2017 to September 2022. Bone setback and resection were performed in cases required a classical L-shaped osteoectomy with oblique bone resection (Group Ⅰ). Bone setback was performed in cases required a modified L-shaped osteotomy without bone resection (Group Ⅱ). Wound healing and the occurrence of complications were followed up after operation. The amount of bone setback and resection were calculated by using preoperative and postoperative CT scan images. The unilateral width changes of the anterior, middle, and posterior zygomatic regions(ΔZBP-MFP, ΔZMP-MFP, ΔZAP-MFP, respectively) as well as zygomatic protrusion change(Δzygomatic protrusion) were also evaluated. SPSS 20.0 software was used for statistical analysis. The measurement data was expressed as Mean±SD. Zygomatic width and protrusion change of the two groups was compared by independent t-test. Comparison of complication rates between the two groups was performed using the χ2 test. Correlation analysis using Pearson correlation coefficients was performed between bone resection or setback and zygomatic width or protrusion change. Linear regression analysis was also performed. Results:A total of 80 patients were enrolled. Group Ⅰ consisted of 40 patients [6 males and 34 females; aged (25.2±3.8) years, ranging from 19 to 33 years] who underwent a classical L-shaped osteotomy with both bone setback and resection, while Group Ⅱ consisted of 40 patients [10 males and 30 females; aged (26.0±3.0) years, ranging from 20 to 35 years] who underwent a modified L-shaped osteotomy with bone setback but without bone resection. All patients healed uneventfully during the follow-up period[(12.5±3.3) months, ranging from 5 to 20 months]. There was no significant difference in the incidence of complications such as infection, transient paresthesia, severe swelling and hematoma between the two groups ( P>0.05). No severe complications, such as facial asymmetry, sagging cheek, bone nonunion, were observed. All patients significantly improved facial contours. There was a statistically significant difference (all P<0.01) in ΔZBP-MFP [ (2.52±0.76) mm vs. (1.85±0.40) mm], ΔZMP-MFP [ (3.30±0.54) mm vs. (2.94±0.51) mm] and Δzygomatic protrusion [ (4.42±1.20) mm vs. (3.59±0.84) mm] between Group Ⅰ and Group Ⅱ. No statistical difference was found in ΔZAP-MFP ( P>0.05). Significant correlation was observed between the bone setback or resection and the changes of anterior, middle zygomatic width as well as protrusion in both the two groups ( r=0.60-0.92, all P<0.01), and the linear regression equation was established. The correlation between bone setback or resection and the posterior zygomatic width change was not significant ( P>0.05). Conclusion:There are linear correlations between the unilateral anterior, middle zygomatic width change, zygomatic protrusion change and the unilateral bone setback or resection. The linear regression equations can be used as a quantitative guidance for preoperative surgical planning.
