The clinical application and biomechanical analysis of zygomatic implant supported prostheses in unilateral maxillary defect restoration
10.3760/cma.j.cn114453-20201207-00612
- VernacularTitle:颧种植体支持式赝复体修复单侧上颌骨缺损的临床应用及生物力学评价
- Author:
Zhaoqi SUN
1
;
Zhen QIAN
;
Mingyi WANG
Author Information
1. 上海交通大学医学院附属第九人民医院·口腔医学院，口腔颌面-头颈肿瘤科，国家口腔疾病临床医学研究中心，上海市口腔医学重点实验室，上海市口腔医学研究所 200011
- Keywords:
Zygoma;
Dental implant;
Biomechanics
- From:
Chinese Journal of Plastic Surgery
2021;37(5):501-507
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the clinical application and biomechanical characteristics of zygomatic implant supported prosthesis (ZIP) in restoring unilateral maxillary defect and to provide theoretical support for clinical treatment.Methods:A total of 8 patients with unilateral maxillary defect admitted to the Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine from January 2016 to June 2018 were selected. Inclusion criteria: unilateral maxillary defect, 18 to 70 years old, no systemic chronic disease, no radiotherapy history, healthy residual dentition, no moderate to severe periodontitis, no loose teeth, and no obvious malocclusion. Two zygomatic implants were implanted on the affected side, and the defects were restored with removable prostheses (RP) immediately after the operation. ZIP was manufactured and placed 6-12 months after implantation. And then, the quality of life after wearing RP and ZIP was evaluated with Dental Impact on Daily Living scale (DIDL). The subjective feelings of patients were evaluated from five aspects of appearance, pain, oral comfort, eating and chewing and general performance. The results were statistically analyzed by independent sample t test. A three dimension model of skull was established with the CT data of a 25-year-old healthy male and the models of zygomatic implants and prosthesis were constructed at the same time. In this composite model, a 150 N vertical force was loaded on the occlusal surface of the prosthetic prosthesis to simulate the bite force, and the stress distribution and concentration points of the zygomatic implant, prosthetic clasps, palatal plate, abutment and other parts were analyzed. The differences between RP and ZIP restoration were compared. Results:A total of 8 patients with unilateral maxillary defect were selected, including 5 males and 3 females, aged from 18 to 63 years, with an average of 48.9 years. A total of 16 zygomatic implants were implanted in 8 patients, and ZIP repair was completed 9-10 months after operation. The result of DIDL scale showed that, in terms of appearance, oral comfort, eating and chewing, general performance, the score of ZIP group was 0.79±0.15, 0.70±0.15, 0.63±0.24, 0.73±0.13 respectively, all of which were significantly higher than those of RP group -0.41±0.22, 0.35±0.22, -0.09±0.34, 0.30±0.19 respectively. Nevertheless, the score of ZIP group in terms of pain was 0.29±0.15, which was lower than that of RP group (0.48±0.23). Except for pain, the other differences were statistically significant ( P<0.05). The biomechanical analysis showed that, compared with RP group, the stress of ZIP was distributed mainly in the zygomatic implants. And the stress of palatal plates, clasps and abutments was reduced significantly and distributed evenly, with no obviously stress concentration point. Conclusions:ZIP can improve appearance, reduce discomfort and increase mastication efficiency. It is a better choice for unilateral maxillary defect restoration.
