Patient-specific Computer modified titanium plate in Unilateral angle fractures

Purpose: Various treatment modalities have been stated to avoid faulty healing of the mandibular angle fracture and the subsequent functional and esthetic disasters. In this study, we aimed to design a new patient-specific titanium plate to overcome Champy’s acknowledged drawbacks and avoid splaying of the inferior border of the mandible.
Patients and methods: This study included eight patients suffering from a displaced unilateral mandibular angle fracture with a mean age of 37 years. They all needed open reduction and internal fixation. Preoperative evaluation included the clinical examination through inspection of malocclusion and measurement of maximum inter-incisal mouth opening, along with the radiographic assessment through the screening panoramic view and the 3-D CT examination to determine the amount of displacement between the fractured segments. Computer mirroring of the intact side was done to virtually reduce the fractured side to design a patient-specific plate. This plate aimed to fit on the superior ventral surface of the external oblique ridge, namely; Champ’s osteosynthesis line. Downward extended lingual shelf and two buccal arms were added in the plate, to only immobilize the mandible lingually along with fixing both fractured segments buccaly with screws, while fixing the segments superiorly at Champy’s line with the standard plate shaft. The titanium PS-plate was processed and fixed in place using 2.0 screws through the standard intra-oral approach after Maxillo-mandibular fixation using ivy-loops. Immediate postoperative mandibular function was allowed. Postoperative clinical assessment of the occlusion and the Maximum inter-incisal opening (MIO) was performed at one week, 1 month and 3 months. Postoperative radiographic CT assessment was performed through measuring the linear inter-fragmentary gap between the fractured segments at the inferior mandibular border.
Results: The surgeries in all cases were uneventful. Surgical site was normal with no signs of infection or dehiscence except in only one case, which showed primary intra-oral plate exposure. The preoperative parasthesia recorded in three patients was improved postoperatively, however without its complete disappearance. MIO was significantly improved over the follow-up period to reach a mean of 40.3 mm after 3 months. Radiographic examination, over the follow-up period, revealed the exact alignment of the fractured segments in normal position throughout the whole thickness of the mandible at the fracture line with no inferior border distraction.
Conclusion: This study provided a newly designed plate capable of eliminating the splaying of the inferior border of the mandible in other literature-documented intra-oral plating techniques, which was also profitable in sparing the disadvantages of extra-oral approaches.