Despite many advances in internal fixation, angle fractures remain among the most difficult and unpredictable fractures to treat compared with those of other areas of mandible. The large number of studies on mandibular angle fracture treatment attests to the fact that no single approach has been shown to be ideal, and that treatment of mandibular angle fractures remains conceptually controversial, with a bothersome complication rate. During the last decade significant attention has been placed on fixation of angle fractures using a variety and combination of transorally placed small plates secured with monocortical screws.1,2 Fixation using such plates has been shown to simplify surgery and reduce surgical morbidity but failed to surpass the predictability of rigid fixation with 2.4mm and reconstruction plates.3 Although there have been a number of studies on linear and curvilinear plates for mandibular fracture fixation, there have been only a few reports on the use of low profile 3-dimensional strut or mesh plates.1,4 In fact, the majority of studies on strut plates were in vitro biomechanical studies.3,5 The geometry of 3D strut plates conceptually allows for an increased number of screws, stability in 3 dimensions, and resistance against torque forces while maintaining low profile and malleability.5 Since less literature is available on use of curved 3-dimensional strut plates which is specifically designed for mandibular angle, studies are to be made.
Decisions regarding treatments approaches for open reduction of mandible angle fracture often relate to surgeons experience and training, modified by the factors that can affect uncomplicated healing such as fracture displacement, comminution of the fracture, infection, dentition and atrophic changes of the mandible.6
Intraoral approach performed through an mucosal incision, results in no external scarring or injury to marginal mandibular nerve and allows direct visualization and confirmation of desired occlusion during placement of hardware.
Transoral open reduction was used to treat mandibular fractures in the pre-antibiotic era by Kazanjain in 1933. He concluded that this approach resulted in less inflammatory reaction than extraoral exposure “due to the fact that the parts are not traumatized so much as if we had operated externally”. The principle disadvantages of open reduction like increased operating time, scarring, nerve damage encouraged surgeons to develop transoral techniques for mandibular fracture repair.7
6.2 REVIEW OF LITERATURE:
Claude Guimond et al (2005)8 In a retrospective evaluation concluded that fixation of non-comminuted mandibular angle fractures with a 2.0-mm curved angle strut plate was predictable. This was a retrospective evaluation of 37 patients with noncomminuted mandibular angle fractures fixated with a transorally placed curved 2.0mm strut plate. Postoperative intermaxillary fixation was used in 5 patients for a mean period of 22 days. A non chewing diet was prescribed for 6 weeks. Records were reviewed for demographic information, medical history, fracture characteristics, operative management, and complications. Two patients developed infections requiring plate removal and re application of fixation. Both of these patients had a molar in the fracture line that was left in place during the first operation. One patient developed a mucosal wound dehiscence without consequence. After a mean follow up period of 10 weeks, 39.4% of patients with a post injury /pre-treatment inferior alveolar nerve deficit reported a return to normal sensation. All patients who developed a sensory deficit as a result of surgery reported full recovery of sensation. A persistent sensory deficit appeared to be related to fracture displacement. This plate is low in profile, strong yet malleable, facilitating reduction and stabilization at both the superior and inferior borders. Because the design of the strut plate is conceptually that of 2 linear plates connected by reinforcing vertical struts, strut plates may therefore provide greater resistance against gap opening at the inferior border with biting forces compared with that of a single plate is fixed at the external oblique ridge or superolateral border.
Alper Alkan et al (2007)9 conducted a study to evaluate the biomechanical behaviours of different miniplate fixation techniques for treatment of fractures of mandibular angle. Twenty sheep hemi mandibles were used to evaluate 4 different plating techniques. The groups were fixated with champys technique, biplanar plate placement, monoplanar plate placement, and 3 dimensional (3D) curved angle strut plate. A custom made 3 point biomechanical test model was used for samples. Each group was tested with compression forces by an instron Lloyd LRX machine. The biomechanical behaviour of the groups for the forces (N) that caused displacement of 1.75 mm was compared using the instron software program and displacement graphics. The variance analyses showed that biplanar plate placement had more favourable biomechanical behaviour than champy technique and monoplanar plate placement (p<.05).In addition, the 3D curved angle strut plate technique had more favourable biomechanical behaviour than the champy technique(p<.05) but was not significantly different from biplanar or monoplanar plate placement techniques (p>.05).In their study they evaluated the biomechanical behaviour of different miniplate plate fixation techniques for treatment of fractures of the mandibular angle and the study demonstrated that 3-D strut plates or dual miniplate techniques had greater resistance to compression loads than the champy technique. They concluded that biplanar plate orientation may provide a more favourable biomechanical behaviour than monoplanar plate placement.
Peter Bui et al (2009)10 conducted a study to determine the rate of postoperative infection and the efficacy of removing teeth in the line of mandibular angle fracture treated with 2.0mm 8-hole titanium curved strut plates. A retrospective review of mandibular angle fractures treated with a 2.0mm 8-hole strut plate during a 4-year period. Postoperative antibiotics were given for 1 week. Follow up appointments were 4 weeks or longer. A non chewing (soft) diet was instructed for 6 weeks. Data for all selected patients include the information such as age, gender, etiology of injuries, medical history, concurrent injuries, nerve deficits, pre and postoperative antibiotic administration, postoperative infection, a presence or absence of teeth in the line of fractures, and whether these teeth were removed. Four patients (4 or 49 or 8.2%) developed infections. Two of those patients had a tooth in the line of fracture that was retained (2 or 14 or 14%).The third had a tooth in the line of a fracture that was extracted (1 or 18 or 5.6%).The fourth patient was 1 of the 17 patients who did not have teeth in the line of fracture and developed infection (1 of 17 or 5.9%).None of the patients developed failed hardware, malunion, non-union, malocclusion, or iatrogenic nerve injury. They concluded that there is a low complication rate (8.2%) associated with the use of a 3D 2.0-mm 8-hole curved strut plate in the treatment of uncomplicated mandibular angle fracture. Although the infection rate seemed significantly increased in the group with retained teeth in the line of fracture, the size of the patients samples and the presence of other factors such as noncompliance with postoperative instructions, do not allow recommending blanket extraction of teeth in the line of fracture.
Andrew J.L.Gear et al (2005)11 studied the current trends in the management of simple, non-comminuted mandibular angle fractures. Preferred techniques were single miniplate on the superior border (Champy technique); dual miniplates; a locking screw plate on the inferior border only, and 3-dimensional plates. A single miniplate on the superior border of the mandible has become the preferred method of treatment among AO faculty. When using large, inferiorly based plates more surgeons are now favouring neutral rather than eccentric screw placement. Intraoperative maxillomandibular fixation (MMF) is not considered mandatory by some surgeons in certain circumstances. Management of mandibular fractures is often challenging and results in the highest complication rate among fractures of mandible. Optimal treatment for angle fractures remains controversial. Historically, treatment of mandible fractures included intraoperative MMF along with rigid internal fixation. More recently, noncompression plates, miniplates, which produce only relative stability, have gained popularity. The absolute necessity of intraoperative MMF as an adjunct to internal fixation has also become controversial. The current trends in the management of simple, noncomminuted mandibular angle fractures were examined. A survey was submitted to North American and European AO ASIF (Arbeits-gemeinschaft fur osteosynthesefragen Association for the study of internal fixation) faculty in July 2001. Statistical analysis of results included both Fishers exact and chi-square tests. Results were considered significant if p <0.05.
Edward Ellis III and John Grahm (2002)2 carried out a study to examine the use of a 2.0 mm locking bone plate/screw system in mandibular surgery of 80 fractures in 59 patients. 58 fractures received 1 plate and 22 fractures received 2 plates. The methodology showed that there were no intraoperative difficulties in placement of 2.0 mm locking bone plate/screw system and fracture reduction were considered to be excellent in all cases. Thus the authors concluded that the use of a 2.0 mm locking bone plate/screw system in mandibular fractures found to be simple and provided sound fixation in all cases.
Chad P. Collins et al (2004)12 carried out a prospective randomized clinical trial to compare standard 2.0 mm monocortical plates to 2.0 mm locking plates in the treatment of mandibular fractures in ninety patients with 122 fractures at Harboview Medical Centre in Sattle,WA. 64 fractures were treated with locking plates and 58 with standard plates respectively. Complications were divided into minor and major categories. Each complication was analyzed according to which plate was used and where the fracture occurred. The number of days from injury to operation, average age, gender, American Society of Anaesthesiologists`(ASA) classification , compliance, and social habits were all reviewed. Results were statistically analyzed and showed no significant difference between two plate systems which had similar short - term complication rates.
Gary J Nishioka et al (1988)13 Transbuccal fixation of angle fractures involves transoral incision made over the external oblique ridge, beginning midway up the anterior border of the ascending ramus, and is carried into vestibule just lateral to first molar. Small stab incision is also made just through the cutaneous surface approximately 1cm above the inferior border of mandible through which fixation is carried out using trocar instrumentation.
Advantages of transoral approach includes,
a) No significant cutaneous surgical scar.
b) Direct visualization of the occlusion during placement of the bone plate.
c) Less potential surgical morbidity.
Documented complication rates ranges from 5.4% to 28%.
6.3 OBJECTIVES OF THE STUDY:
The objective of this study is to evaluate the treatment outcome of fixation of mandibular angle fracture with 3-dimensional curved angle strut plate through transoral approach with a follow up interval of 1 week, 4 weeks and 8 weeks.
The patients are evaluated for,
The operative time.
Tooth in the line of fracture.
Ease of fixation of plate (access, reduction and fixation of fractured segments)
Stability (hardware failure)
Neurosensory deficits (paresthesia of the area involved)
Ten patients will be randomly selected and subjects will undergo Open Reduction and Internal Fixation under general anesthesia. Fixation will be done using 2 mm titanium self locking 3-dimensional curved angle strut plate and 2x6mm titanium locking screws through transoral approach.
Single or multiple fractures of mandible requiring open reduction with rigid internal fixation for treatment.
Subject willing to participate in this study.
Patient medically fit for general anesthesia.
Patients with systemic disease contraindicated for general anesthesia.
Patients with comminuted fracture.
SAMPLE SIZE: 10 patients
7.4 DOES THE STUDY REQUIRE ANY INVESTIGATIONS OR INTERVENTIONSTO BE CONDUCTED ON PATIENTS OR OTHER HUMANS OR ANIMALS? IF SO PLEASE DESCRIBE BRIEFLY.
1. Routine blood investigations
2. Pre-operative and post-operative orthopantamogram
7.5HAS ETHICAL CLEARANCE BEEN OBTAINED FROM YOUR INSTITUTION IN CASE OF 7.4?
8. LIST OF REFERENCES
Michelet FX, Deymes J, Dessus B: Osteosynthesis with miniaturized screwed plates in maxillo-facial surgery. J Maxillofac Surg 1: 79, 1973
Ellis E, Graham J: Use of a 2.0-mm locking plate/ screw system for mandibular fracture surgery. J Oral Maxillofac Surg 60:645, 2002
Farmand M, Dupoirieux L: The value of 3-dimensional plates in maxillofacial surgery. Rev Stomatol Chir Maxillofac 93:353, 1992
Coward KA, Smith BR, Kruse RN, et al: A biomechanical study of mandibular fractures fixation plates in a bovine rib model. Unpublished document from the Departments of Orthopedic Surgery and Oral and Maxillofacial Surgery, Louisiana State University Medical School, Shreveport, LA
Toma V S, Mathog R H, Toma R S and Maleca R J: Transoral versus extraoral reduction of mandible fractures: A comparison of complication rates and other factors. Otolaryngology-Head and Neck Surgery. Feb 2003; 128:215-219.
Marciani D.R, Anderson E .G, Gonty A.A: Treatment of mandibular angle fractures:Transoral internal wire fixation. J Oral Maxillofac Surg 1994 ;52:752-756.
Claude Guimond , James V. Johnson and Jose M. Marchena : “Fixation of mandibular angle fractures with a 2.0-mm 3-dimensional curved angle strut plate” J Oral Maxillofac Surg 2005; 63 : 209-214.
Alper Alkan, Nukhet Celebi, Bora Ozden, Burcu Bas and Samet Inal: Biomechanical comparison of different plating techniques in repair of mandibular angle fractures. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007; 104:752-6
Peter Bui, Nagi Demian and Patrick Beetar: Infection rate in mandibular angle fractures treated with a 2.0-mm 8-hole curved strut plate. J Oral Maxillofac Surg 67:804-808, 2009
Andrew J.L. Gear, Elena Apasova, John P. Schmitz and Warren Schubert: Treatment modalities for mandibular angle fractures. J Oral Maxillofac Surg 63:655-663, 2005
Chad P. Collins, Galia Pirinjian-Leonard, Andrew Tolas and Rafael Alcalde: A prospective randomized clinical trial comparing 2.0-mm locking plates to 2.0-mm standard plates in treatment of mandible fractures. J Oral Maxillofac Surg 62: 1392-1395, 2004
Nishioka G J , Joseph Sickels J. E.V: “Transoral plating of mandibular angle fracture: A technique”. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1988; 66: 531-535.