Computer manufactured Patient-specific Auto-reducible plate versus standard Trapezoid plate in Unilateral Subcondylar fractures

Abstract

Purpose: Subcondylar fractures account for a high incidence of mandibular fractures representing a frustrating clinical dysfunction and serious complications when maltreated. This study aimed to compare the computer designed and manufactured patient-specific auto-reducible plate to the standard trapezoid plate in attempt to reach the optimal geometrical design for subcondylar fracture plate fixation. Patients and methods:A total of sixteen patients suffering from unilateral subcondylar fracture were included in this study from the outpatient clinic of the department of oral and maxillofacial surgery, faculty of Dentistry, Cairo University. All patients were subjected to preoperative clinical evaluation and 3-D CT examination to assess the degree of fracture displacement and condylar location. The selected patients were divided into two groups, eight patients each. In group A patients, virtual fracture reduction through mirroring of the unaffected intact side was performed, which was then used as a template for designing and processing of the titanium patient-specific condylar plate via direct metal laser sintering. While in group B patients, the unilateral sub-condylar fractures were manually reduced into position and fixed in place by the standard trapezoidal mini-plate. Fixation of the plates in both groups was then performed using 2.0 mini-screws. Postoperative clinical assessment of the occlusion, Maximum inter-incisal opening (MIO) and mandibular deviation was done at one week, 1 month & 3 months. Immediate postoperative radiographic assessment was performed through the superimposition of the postoperative CT data of the fixed fracture on the preoperative virtually reduced mandibular model as a reference CT data to validate and compare the accuracy of the achieved postoperative fixation in both groups. Results:The surgeries in all cases proceeded without any complications. Surgical site examination was normal with no signs of infection. The occlusion was satisfactory at the end of the study interval despite the initial slight immediate postoperative occlusal discrepancy found in both groups. Deviation was not completely absent in both groups at the end of the follow-up period. The MIO ranged from 39-47 mm at the end of the study with no significant difference between both groups. The CT scan revealed the almost precise adaptation of both plates in place with no significant difference, however, with the advantageous fracture auto-reduction, intra-operative time saving and ease of application recorded with the use of the PS-condylar plate in group A patients. The mean operating time for reduction and fixation using the PS-condylar plate was 90 minutes compared to a mean of 88 minutes using the standard reduction and trapezoid plate fixation technique. (3268)Khaled Amr, et al.