Evaluation of Different Fixation Methods Combinations After L-Shaped Osteotomy Reduction Malarplasty: An In Vitro Biomechanical Study

Mohammed Qasem Al-Watary; Jiansuo Hao; Yingyou He; Libin Song; Heyou Gao; Khaled Alkebsi; Saddam Ahmed Elayah; Bin Ye; Jihua Li

doi:10.1007/s00266-024-03960-z

Evaluation of Different Fixation Methods Combinations After L-Shaped Osteotomy Reduction Malarplasty: An In Vitro Biomechanical Study

Aesthetic Plast Surg. 2024 Mar 22. doi: 10.1007/s00266-024-03960-z. Online ahead of print.

Authors

Mohammed Qasem Al-Watary¹, Jiansuo Hao², Yingyou He¹, Libin Song³, Heyou Gao¹, Khaled Alkebsi⁴, Saddam Ahmed Elayah⁴, Bin Ye¹, Jihua Li⁵

Affiliations

¹ State Key Laboratory of Oral Diseases and National Center for Stomatology and National Clinical Research Center for Oral Diseases, Orthognathic and TMJ Surgery Department, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
² Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Department of Temporomandibular Joint, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, China.
³ Department of Stomatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, 200000, China.
⁴ State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Cleft Lip and Palate Center, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
⁵ State Key Laboratory of Oral Diseases and National Center for Stomatology and National Clinical Research Center for Oral Diseases, Orthognathic and TMJ Surgery Department, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China. leejimwa6698@sohu.com.

PMID: 38519573
DOI: 10.1007/s00266-024-03960-z

Abstract

Background: This in vitro study compared the stability of different fixation method combinations for the zygomatic complex after simulated L-shaped osteotomy reduction malarplasty, a common facial contouring surgery in East Asia with high postoperative complications due to poor fixation methods.

Materials and methods: The study used 108 zygoma replicas with various fixation methods combinations in the zygomatic body (L-shaped plate with short wing on zygoma and on the maxilla, two bicortical screws, one bicortical screw with L-shaped plate, square plate, and rectangular plate) and zygomatic arch (Mortise-Tenon structure, 3-hole plate, and Mortise-Tenon structure plus short screw). The failure force under incremental load was applied through the Instron tensile machine to a well-stabilized model using a rubber band simulating the masseter muscle and recorded the increasing force digitally. ANOVA test was used for comparison between recorded values (P < 0.05).

Results: The results showed that the most stable combination was a six-hole rectangular plate and a Mortise-Tenon structure plus one short screw (358.55 ± 51.64 N/mm2). The results also indicated that the placement vector of the fixation methods around the L-shaped osteotomy and the use of the two-bridge fixation method were important factors in enhancing the stability of the zygomatic complex.

Conclusion: The study suggested that surgeons should choose appropriate fixation methods based on these factors to reduce postoperative complications and improve surgical outcomes.

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Keywords: 3D zygoma replica; Dual approach reduction malarplasty; Instron tensile machine; Masseter muscle; Mortise–Tenon structure; Prominent zygoma.