A Comparative Evaluation of Keyhole Plate and Conventional 4-Hole Miniplate in the Management of Fractures of Angle of Mandible

Abstract

Introduction:  Mandibular angle fractures are common and challenging to treat due to limited surgical access and difficulty in plate adaptation. Conventional 4-hole miniplates, though widely used, often require increased instrumentation and time. The keyhole plate, with a pear-shaped hole design, was introduced to simplify placement and improve surgical convenience. This study aimed to compare the clinical and radiological outcomes of keyhole plate versus conventional 4-hole miniplate in mandibular angle fractures.
Objectives:The objectives of the study are to compare efficiency of keyhole plate and conventional miniplates by assessing certain parameters like 1) Time taken for placement of keyhole plate and conventional miniplate in the fracture site during fixation of fracture 2) Postoperative occlusion 3) Mouth-opening of the patient. 4) Bite force 5) Postoperative complications such as pain, wound healing, mal-union and non union. 
Methods: A prospective comparative study was conducted on 30 patients with mandibular angle fractures at Government Dental College and Hospital, Vijayawada. Patients were randomized into two groups: Group A (15 patients) treated with keyhole plate and Group B (15 patients) with conventional miniplates. Clinical parameters evaluated were intraoperative time for plate application, postoperative occlusion and mouth opening, bite force recovery, complications such as pain, wound healing, malunion, and non-union during a 6-month follow-up.
Results: The mean application time was significantly shorter for keyhole plates (18.4 min) compared to conventional plates (24.3 min; p = 0.00016). Both groups showed significant improvements in occlusion, mouth opening, and bite force, with no statistically significant intergroup differences. Pain decreased significantly postoperatively in both groups. All patients achieved satisfactory wound healing; 4 patients developed transient paresthesia (1 in Group A, 3 in Group B). No cases of malunion or non-union were observed.  
Conclusions:  Keyhole plates significantly reduce operative time and improve surgical convenience compared to conventional miniplates, while providing comparable clinical and radiological outcomes. Larger studies with extended follow-up are warranted to validate these findings