Open reduction and internal fixation with 2.0 mm monocortical miniplate in mandibular fracture: a retrospective study

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Introduction

A variety of treatments for mandibular fractures have been introduced. Such recent methods include Barton’s bandage, gunning splints, intermaxillary fixation, and methods using plates and screws [1]. It is important to maintain the original occlusion of the patient. At the same time, it is necessary to make an effort to reduce changes in appearance. Recently, rigid fixation methods with plates and screws have frequently

been used for early union and functional recovery [2]. When rigid fixation is performed, stable maintenance of the bone segment enables bone union at an early stage. As functions are implemented early, it is possible to prevent temporomandibular joint ankylosis, which is attributable to a long period of intermaxillary fixation. Therefore rigid fixation method is needed [3].

Compression plates, lag screws, and bicortical plates have been used mainly for rigid fixation [4-6]. However, the use of such fixation devices may require an extraoral approach [1,7]. When a compression plate is used, there is a possibility of infection that is attributable to compression force on the surrounding bone caused by rigid fixation [8,9]. As a result, the use of a monocortical plate in an intraoral approach has been introduced. The use of a monocortical plate has the benefit that it is possible to avoid exterior scarring because of the intraoral ORAL BIOLOGY RESEARCH 2014; 38(2): 69-72

Open reduction and internal fixation with 2.0 mm monocortical miniplate in mandibular fracture: a retrospective study

Hyun-Chun Park, Kyung-Seop Lim, Cheol-Man Kim, Kyung-In Jeong, Jae-Seek You, Ji-Su Oh, Seung-Min Shin, Seong-Su Yang, Su-Gwan Kim*

Department of Oral and Maxillofacial Surgery, School of Dentistry, Chosun University, Gwangju, Korea

ABSTRACT

Purpose: An intraoral approach is effective in treating mandible fractures without complications, such as extraoral scar formation and damage to the mandibular branch of the facial nerve. The aim of this study was to report possible complications as well as their incidence rates after open reduction and internal fixation using 2.0 mm monocortical miniplate fixation to treat mandible fractures via an intraoral approach.

Materials and Methods: The subjects were selected from patients who visited Chosun University Dental Hospital with mandible fractures as their chief complaint, and they underwent open reduction and internal fixation with a 2.0 mm miniplate through an intraoral approach from 2010 to 2012.

Results: A total of 101 patients and 169 miniplates were included. The period of intermaxillary fixation varied from zero to more than 2 weeks. Intermaxillary fixation was performed for more than 2 weeks in five patients, accompanied by a subcondylar fracture. Seven patients in total, representing a notably low rate, experienced complications such as irritation, nerve damage, infection, screw loosening, and malocclusion.

Conclusion: Open reduction and internal fixation with a 2.0 mm monocortical miniplate via an intraoral approach is a valuable method for treating mandible fractures and exhibits a low rate of complications as well as high stability.

Key Words: Bone plates, Fracture fixation, Mandible Original Article

Received Mar 28, 2014; Revised version received May 22, 2014 Accepted Jun 9, 2014

Corresponding author: Su-Gwan Kim

Department of Oral and Maxillofacial Surgery, School of Dentistry, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju 501- 759, Korea

Tel: 82-62-220-3815, Fax: 82-82-62-228-7316 E-mail: sgckim@chosun.ac.kr

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Open reduction and internal fixation with miniplate in mandibular fracture

approach and prevent facial nerve damage caused by the incision of facial skin [1,10]. This study examines complications that may occur after open reduction and internal fixation (ORIF) using monocortical plates through intraoral approach and intermaxillary fixation over a short period of less than two weeks. Based on the results of examination, this study intends to compare the bicortical fixation with the previous extraoral approach to investigate the usefulness of such a method.

Materials and Methods

Patients

We followed Helsinki Declaration in this study. We got approval (CDMDIRB-1320-104) of Chosun University Dental Hospital Clinical Trial Center Institutional Review Board (IRB).

This study targeted patients who visited Chosun University Dental Hospital for treatment of mandibular fractures over approximately three years from 2010 to 2012. Of these patients, the authors selected 101 patients who underwent ORIF using a monocortical plate (Leforte; Jeil Med Corps, Seoul, Korea) through intraoral approach. The number of monocortical miniplates were 169 in 101 patients. The age and gender, underlying disease of patients were not considered and the cases of maxillary fracture were excluded. All of Condylar head and neck fractures treated with conservative method were excluded.

In subcondyle fractures, cases treated with conservative method were excluded and only treated with ORIF using endoscope via intraoral approach were selected.

Surgical method

Prior to the procedure, antibiotics were administered through intravenous injection. Next, nasotracheal intubation was used to perform general anesthesia. An intraoral incision was made to approach the fracture. After confirmation of the fracture, rubber bands were used to perform intermaxillary fixation. The patient’s occlusion was induced to turn to a

centric occlusion before the occlusion was confirmed. Next, a miniplate of 2.0 mm (Leforte; Jeil Med Corps) was placed and fixed along Champy’s line. Subcondyle fracture sites were secured a clear view using endoscope and were reducted through extraoral passage made by trocar. A drill was used to form a hole before installing a monocortical screw after fixation of the miniplate. The patient’s occlusion was checked aposition of centric occlusion in a passive way. After the patient recovered completely from the anesthesia, rubber bands were used again to perform intermaxillary fixation, which was the case with a great number of patients.

Most of the patients were hospitalized approximately one week. The patients were allowed to take intravenous or oral antibiotics for seven to 14 days. Afterwards, patients continued to visit the hospital at one-week intervals until approximately four weeks. The arch bar and wire were removed after approximately four weeks.

Results

This study targeted a total of 101 patients, 87 men and 14 women, who had mandibular fractures. The average age of the study subjects was 29.54 years. The simple fracture region was found in 73 patients. A fracture of the mandibular angle was found in 29 patients (28.71%), a fracture of the symphysis was found in 21 patients (20.79%), and a fracture of the parasymphysis was found in 14 patients (14.85%). There were multiple fractures in 28 patients, including 14 patients (13.86%) who had simultaneous fractures of the parasymphysis and mandibular angle and 5 patients (4.95%) who had fractures of the symphysis and mandibular angle (Table 1). The period of intermaxillary fixation varied from one week or less in 34 patients, more than one week and less than two weeks in 62 patients, and more than two weeks in 5 patients (Table 2).

In particular, 20 patients who had intermaxillary fixation of one week or less did not receive intermaxillary fixation after

Table 1. Sites of Mandibular Fractures

Site

S P A B S+A P+A B+A S+SC P+SC Total

Distribution (n) 21 15 29 8 5 14 2 3 4 101

S: symphysis, P: parasymphysis, A: angle, B: body, SC: subcondyle.

Hyun-Chun Park et al.

71 the procedure. When intermaxillary fixation was performed

for more than two weeks, most of the cases had a fracture accompanied by a subcondylar fracture. Complications included two patients who had irritation, two patients who experienced severe nerve damage sign, one patient who had an infection, one patient who experienced screw loosening, and one patient who had malocclusion (Table 3). Of the 101 patients, seven patients in total experienced complications, representing a notably low rate of 6.93%. Particularly, it was observed that the rates of miniplate infection and screw loosening were 0.99% each, which was very low.

Discussion

In cases of mandibular fracture, one strength of rigid fixation based on open bone reduction is that such fixation enables the early removal of intermaxillary fixation and is conducive to fast bone union and early recovery of mandibular bonemovement [7]. To perform such rigid fixation, it is possible to use comp- ression plates, lag screws, or reconstruction plates [11]. How- ever in most cases, it is difficult to use such devices in an intra- oral approach. Therefore, it is inevitable that scars will be left in the facial area. As a way to replace this method, the use of a 2.0-mm monocortical plate in an intraoral approach has been introduced. A benefit of this new method is that proper fixation can be secured without any scars on the face [1,10].

A previous study reported that when only a 2.0-mm monocortical plate was used to perform rigid fixation, it was impossible to secure sufficient fixation force, which resulted in movement of the bone segments. This failure of fixation increased the frequency of infection [12]. In addition, it was also reported that the monocortical plate itself did not have sufficient strength, which increased the possibility of fractures in cases of early mobilization. However, there was another report that when intermaxillary fixation was performed for less than two weeks to restrict movement during the period

of callus formation, it was possible to obtain excellent results.

Moreover titanium monocortical plates with sufficient strength have recently been used. Also, in this study, when intermaxillary fixation was conducted for less than two weeks using monocortical plate for fixation, rates of infection or plate fracture were notably low. Furthermore, in cases of simple fractures, such as fractures of the parasymphysis or symphysis, two monocortical plates were used for fixation.

Although intermaxillary fixation was not performed, there were no cases of nonunion, plate fracture or infection. These results demonstrate that the 2.0-mm monocortical plate has sufficient strength. Infection or screw loosening took place most frequently when the plate was used for fixation of the mandibular angle. However, such cases occurred in only two patients. After the miniplate was removed, the same miniplate was used for fixation. When intermaxillary fixation was performed for two weeks, no particular complications occurred.

Consequently, it is believed that use of a 2.0-mm monocortical plate in an intraoral approach provides sufficient stability to treat patients with mandibular fractures.

When a 2.0-mm monocortical plate was applied to Champy’s line [13] in an intraoral approach, many studies reported no significant differences in rates of infection or fractures compared to cases where compression plates were applied [14,15]. In addition, when 2.0-mm monocortical plates were used along with a soft diet, many studies reported no significant differences in stability compared to cases where compression plates were used, even though intermaxillary fixation was not performed over a long period [16]. Also, in this study, patients who received intermaxillary fixation within two weeks were prescribed a liquid and soft diet for four weeks and were warned to be careful of mastication.

Nonunion or infection was not observed even after intermaxillary fixation was removed.

According to another study, when only compression plates Table 2. Duration of Intermaxillary Fixation

Duration

0 Week ≤1 Week 1-2 Weeks >2 Week Total

Number 20 14 62 5 101

Table 3. Complications of Monocortical Plate Fixation in an Intra- oral Approach

Type

Malocclusion Infection Irritation Screw loosening

Nerve damage

Number 1 1 2 1 2

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Open reduction and internal fixation with miniplate in mandibular fracture

were used to perform rigid fixation without intermaxillary fixation, approximately 15% of 59 patients were reported to have infection or miniplate fracture [17]. The previous result was not significantly different from the results of this study.

Rather, when intermaxillary fixation was performed over a short period of less than two weeks, and a monocortical plate was used, the prevalence of complications was lower at 6.93%.

Therefore, it is believed that it may be necessary to perform intermaxillary fixation for two weeks, even when a compression plate is used.

It can be concluded that sufficient stability for treatment of a mandibular fracture is provided when a 2.0-mm monocortical plate is applied to Champy’s line using an intraoral approach, and intermaxillary fixation is performed for less than two weeks. In particular, when two miniplates are used to treat simple fractures of the parasymphysis and symphysis, it seems that sufficient stability is secured if intermaxillary fixation is not performed, and instead, the patient is warned to be careful.

Therefore, it is believed that use of a 2.0-mm monocortical plate in an intraoral approach can be a useful method for ORIF of mandibular fractures.

Acknowledgements

This study was supported by research fund from Chosun University, 2014.

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