Contralateral mandibular outer cortex "sandwich" bone grafting for correcting lower facial asymmetry with normal occlusal relationship
10.3760/cma.j.cn114453-20240215-00046
- VernacularTitle:对侧下颌骨外板夹心植骨矫正咬合关系正常的面下部不对称
- Author:
Guoping WU
1
;
Tong LU
;
Yuming QU
;
Sheng GAO
;
Zhiyang XIE
;
Kaili YAN
;
Chongxu QIAO
;
Shunchao YAN
;
Shu WANG
;
Wensong SHANGGUAN
Author Information
1. 南京医科大学友谊整形外科医院整形外科，南京 210029
- Keywords:
Facial asymmetry;
Mandible;
Outer cortex;
Osteotomy;
Sandwich bone graft
- From:
Chinese Journal of Plastic Surgery
2024;40(10):1049-1058
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the clinical outcomes of using autologous mandibular outer cortex "sandwich" grafting to augment mandible for correcting lower facial asymmetry with normal occlusal relationships.Methods:A retrospective analysis was conducted on the clinical data of patients with lower facial asymmetry treated at the Department of Plastic Surgery, the Affiliated Friendship Plastic Surgery Hospital of Nanjing Medical University, from January 2016 to December 2019. Preoperative cone-beam CT (CBCT) scans of the maxillofacial region were obtained to acquire three-dimensional data of the maxillofacial skeleton. Computer-aided design was used to determine the osteotomy range of the mandibular outer cortex and design osteotomy guide template. The outer cortex of the larger mandibular side (donor site) was harvested according to the osteotomy guide template and sectioned. The segmented mandibular outer cortex was then contoured to match the arc of the recipient side’s mandibular outer cortex and fixed to the inner side of the recipient mandibular outer cortex, thus increasing the width and thickness of the expanded mandible. Follow-up was conducted at 7th day and 6 months postoperatively, CBCT scan was performed to measure the changes in ramus height (Co-Go), mandibular body length (Go-Me), and mandibular outer cortex thickness, and volume, and the patient satisfaction with facial appearance (1 to 5 points, with higher scores indicating higher satisfaction), were assessed to evaluate surgical outcomes. Statistical analysis was performed using SPSS 12.0 software. Paired t-tests were used to compare patient satisfaction scores preoperatively and six months postoperatively. Repeated measurement ANOVA was used to compare Co-Go and Go-Me measurements preoperatively, 7th day, and 6 months postoperatively. If a statistically significant difference is found, further analysis using post-hoc testing(Tukey’s HSD test) will be conducted to examine the data. Results:Sixteen patients with lower facial asymmetry were included, comprising of 5 males and 11 females, aged 18 to 40 years, with an average age of 25.2 years. Surgical method included contralateral mandibular outer cortex "sandwich" grafting to the expanded mandible in 9 cases and simultaneous genioplasty in 7 cases. Follow-up ranged from 6 months to 5 years, with an average follow-up of 18.6 months. All patients experienced numbness of the lower lip postoperatively, which resolved within six months, and no severe complications occurred. The symmetry of lower facial contour improved significantly and remained stable. Patient satisfaction score for facial appearance increased from (1.63±0.62) points preoperatively to (4.19±0.75) points six months postoperatively( P<0.01). The differences in Co-Go on the donor side and Go-Me on the recipient side across the three time points(preoperatively, 7th day and 6 months postoperatively) were not statistically significant(all P>0.05). However, the differences in Go-Me on the donor side and Co-Go on the recipient side across the three time points were statistically significant(all P<0.05). On the donor side, the mandibular outer cortex thickness decreased by a maximum of 6 mm on 7th day postoperatively and increased by a maximum of 2 mm at 6 months postoperatively compared to 7th day. On the recipient side, mandibular outer cortex thickness increased by a maximum of 6 mm on 7th day postoperatively and decreased by a maximum of 2 mm at six months postoperatively compared to 7th day. The volume of the mandibular outer cortex on the recipient side increased by (4 415.94±1 017.21)mm 3 at 7th day postoperatively compared to preoperatively, and decreased by (202.63±300.85)mm 3 at 6 months postoperatively. Conclusion:For lower facial asymmetrical with normal occlusal relationships and no occlusal plane deviation, contralateral mandibular outer cortex "sandwich" bone grafting can effectively increase the width and volume of the mandible on the grafted side, achieving favorable clinical outcomes.
