|Year : 2017 | Volume
| Issue : 2 | Page : 43-47
Intermaxillary fixation (IMF) Screws in minimally displaced mandibular fractures: A case control study
B Suresh Babu1, Irfan Ali2, S Ravi Raja Kumar3, Mahaboob Shaik3, Sagar A Naidu4, Abdul Qahar Qureshi5, Abhinav Kumar6, Abhishek Singh Nayyar7
1 Department of Oral and Maxillofacial Surgery, Saraswati-Dhanwantari Dental College and Hospital and Post-Graduate Research Institute, Parbhani, Maharashtra, India
2 Consultant Oral and Maxillofacial Surgeon, Hyderabad, Telangana, India
3 Department of Oral and Maxillofacial Surgery, Saint Joseph Dental College, Eluru, Andhra Pradesh, India
4 Department of Oral and Maxillofacial Surgery, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital, Nagpur, Maharashtra, India
5 Department of Dentistry, Government Medical College, Akola, Maharashtra, India
6 Department of Oral and Maxillofacial Surgery, Vyas Dental College & Hospital, Jodhpur, Rajasthan, India
7 Department of Oral Medicine and Radiology, Saraswati-Dhanwantari Dental College and Hospital and Post-Graduate Research Institute, Parbhani, Maharashtra, India
|Date of Web Publication||30-Apr-2018|
Dr. Abhishek Singh Nayyar
44, Behind Singla Nursing Home, New Friends' Colony, Model Town, Panipat - 132 103, Haryana
Source of Support: None, Conflict of Interest: None
Context: Numerous methods have been used for obtaining intermaxillary fixation (IMF) in the treatment of mandibular fractures. Conventional methods such as arch bars and eyelet wires have been the most common methods for achieving IMF, but they have their own disadvantages. During the last two decades, IMF using intraoral, self-tapping IMF screws have been introduced for the treatment of minimally displaced fractures of the mandible. The present case control study evaluated the efficacy and associated complications of self-tapping IMF screws in the treatment of minimally displaced mandibular fractures. Materials and Methods: A total of twenty patients of minimally displaced mandibular fractures were divided into two groups and were treated with open and closed reduction methods using self-tapping IMF screws to evaluate the efficacy of IMF screws and associated complications. Results: The most common complications encountered were pain and edema in almost all patients. In Group I treated with open reduction, damage to the roots of teeth occurred in two patients, which later became nonvital after 6 weeks, while in Group II treated with closed reduction, two patients were seen with tissue overgrowth and screw loosening. In one case, postoperative malocclusion was also observed in Group I. Conclusion: Use of self-tapping IMF screws for IMF is a valid alternative to conventional methods in the treatment of minimally displaced mandibular fractures. Iatrogenic injury to roots of the teeth is the most important complication of the IMF screws but that can be minimized and/or overcome by a careful evaluation and treatment planning of the cases.
Keywords: Intermaxillary fixation, mandibular fractures, self-tapping screws
|How to cite this article:|
Babu B S, Ali I, Kumar S R, Shaik M, Naidu SA, Qureshi AQ, Kumar A, Nayyar AS. Intermaxillary fixation (IMF) Screws in minimally displaced mandibular fractures: A case control study. Arch Med Surg 2017;2:43-7
|How to cite this URL:|
Babu B S, Ali I, Kumar S R, Shaik M, Naidu SA, Qureshi AQ, Kumar A, Nayyar AS. Intermaxillary fixation (IMF) Screws in minimally displaced mandibular fractures: A case control study. Arch Med Surg [serial online] 2017 [cited 2019 Jun 19];2:43-7. Available from: http://www.archms.org/text.asp?2017/2/2/43/231628
| Introduction|| |
In ancient Greek period, Edwin Smith provided a clear documentation for the treatment of mandibular fractures dating back as early as 17th century. Between 25 BC and 11th century AD, surgeons and writers such as Sushruta, Celsus, and Avicenna described conservative means of treating jaw fractures. Sushruta advocated the treatment of maxillofacial fractures with bandages and splinting. Recent methods for the treatment of maxillofacial fractures include open reduction and internal fixation (ORIF) usually requiring control of occlusion with the help of intermaxillary fixation (IMF), a process which is complicated, requiring a close follow-up and being time-consuming at times. Oral and maxillofacial surgery is one of the specialties which have significantly expanded over the last few decades and which includes maxillofacial trauma. Management of maxillofacial trauma presents a plethora of challenges of its own including a need to restore normal occlusion, maintenance of facial symmetry, and complex movement of the temporomandibular joints. Surgery is a discipline based on principles that evolved from both basic research and centuries of trial and error. The treatment of maxillofacial fractures involves different methods from bandages and splinting to recent methods of ORIF and usually requires a control of dental occlusion with the help of IMF which is time-consuming at times. IMF is a basic and fundamental principle in the management and treatment of maxillofacial trauma patients. It serves as a cornerstone of maxillofacial reconstruction. A variety of IMF techniques have been described. In modern practice, however, arch bars and eyelets are considered as the standard. While arch bars provide an effective and versatile means for achieving IMF, their use is not without consequences. The more commonly encountered disadvantages of using arch bars include movement of teeth in lateral and extrusive directions as well as a difficulty in securing arch bars in isolated posterior teeth. The risk of penetrating injury to the surgeon, increased surgical time both in placement and in removal, trauma to the periodontium, and a compromised oral hygiene are all shortcomings of the traditional arch bars. To overcome these problems, IMF screws were introduced. These screws are easy to use and greatly shorten the operating time to achieve IMF. IMF screws were first introduced by Arthur and Berardo  in 1989 and later modified by Jones  with a capstan-shaped head design. He suggested the use of threaded titanium screws of 2 mm diameter and 10–16 mm length. According to him, screws with capstan style head are important as they allow the wires and elastics to be held away from the gingival tissues. These screws were easy to use and greatly shortened the operating time from 1 h to about 15 min to achieve IMF. The advantages of double-headed bicortical screws have been described by several authors. Self-tapping IMF screws, however, have some potential disadvantages, too, which include damage to the nerves, roots, tooth germs, thermal necrosis of the bone, and drill bit breakage. Recently developed drill-free screws avoid these problems although. The present case control study evaluated the efficacy and associated complications of self-tapping IMF screws in the treatment of minimally displaced mandibular fractures.
| Materials and Methods|| |
A total of twenty patients of minimally displaced mandibular fractures were divided into two groups and were treated with open and closed reduction methods using self-tapping IMF screws to evaluate the efficacy of IMF screws and associated complications. The inclusion criteria for the present study included fractures of dentate mandibles, undisplaced, minimally displaced fractures, and age of the patients between 18 and 55 years. The patients who had severely displaced fractures, comminuted fractures, and fractures of edentulous mandibles and pediatric patients in mixed dentition stages were excluded from this study. A preoperative orthopantomograph (OPG) was done to observe the root morphology and place the IMF screws interdentally, preventing trauma to the roots of the teeth. In addition, the course of inferior alveolar nerve canal was taken into consideration. Clinically, the mucogingival junction was kept into consideration to facilitate screw placement sufficiently occlusal to prevent its burial into the vestibule. The selected cases were treated by ORIF in Group I while by closed reduction under local anesthesia in Group II. Self-tapping IMF screws with dimensions of 2.5/2 mm diameter and 8/10 mm length were used in all the cases. The head of the screw was 4 mm in length and 6 mm in diameter. Care was taken not to place the screws too far inferiorly as it might have endangered the inferior alveolar nerve and vessels present in the canal. The patients were divided based on age, gender, etiology, type, and site of fracture. In Group I, the fracture sites were exposed, reduced, and stabilized in position, following which bone plating was done. IMF screws were utilized for securing and immobilizing the fracture fragments before bone plating, while in Group 2, closed reduction was done and IMF with IMF screws was achieved. The screws were passed through the buccal and lingual cortices and inserted until the flat surface of the head fitted snugly against the buccal mucosa. Depending on the severity of occlusal derangement, IMF was achieved using 26G wire and/or elastics. Care was taken that the screws did not penetrate the lingual mucosa where they could have caused soft-tissue injury. The screws were removed after 1 week after evaluating the stability of occlusion. Antibiotic therapy was continued for 5 postoperative days. All patients were then reevaluated after 1 week using a postoperative OPG to evaluate any possible, iatrogenic injury to the teeth. Patients were put in IMF for a period of 3–4 weeks. The patients were kept on regular follow-ups for any needful. All the patients were given the same postoperative instructions including regular brushing with soft bristle brush, use of mouthwash at least four times a day, and a liquid diet. All the patients were, then, eventually evaluated on the basis of following criteria including pain, edema at the site of screws, occlusal stability, screw loosening, screw displacement, tissue overgrowth, root perforations, and secondary infections and associated complications in the form of paresthesia and necrosis of the bone. The patients were, also, evaluated for changes in occlusion over a period of 1 week with any possible iatrogenic injuries caused due to the procedure and later, after 1-and 3-month intervals [Figure 1]a-h, [Figure 2]a-h.
|Figure 1: (a) Preoperative occlusion of patient. (b) Preoperative radiograph of patient. (c) Intermaxillary fixation screws placed. (d) Elastics placed. |
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|Figure 2: (a) Preoperative occlusion of patient. (b) Preoperative radiograph of patient. (c) Intermaxillary fixation screws placed. (d) Elastics placed. |
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| Results|| |
The present case control study evaluated the efficacy and associated complications of self-tapping IMF screws in the treatment of minimally displaced mandibular fractures in both open and closed reduction groups wherein a total of ten patients were selected for inclusion into each group. Patients were divided based on age [Graph 1], gender [Graph 2], etiology [Graph 3], type [Graph 4], and site of fracture [Table 1]. All the patients were then eventually evaluated on the basis of following criteria including pain, edema at the site of screws, occlusal stability, screw loosening, screw displacement, tissue overgrowth, root perforations, and secondary infections and associated complications in the form of paresthesia and necrosis of the bone. The patients were also evaluated for changes in occlusion over a period of 1 week with any possible iatrogenic injuries caused due to the procedure [Table 2]. The most common immediate complications encountered included pain and edema; however, there was no reported pain and edema at the sites of screw placement in all the cases by 7th postoperative day. In Group I treated with open reduction, damage to the roots of teeth occurred in two patients which later became nonvital after a period of 6 weeks, while in Group II treated with closed reduction, two patients were seen with tissue overgrowth and screw loosening who were subsequently treated with removal of the same and placement of screws secured in new positions. In one case, postoperative malocclusion was observed in Group I. None of the cases reported with secondary infections and associated complications in the form of paresthesia and necrosis of the bone.
|Table 1: Distribution of mandibular fractures according to site of fracture|
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| Discussion|| |
Farr DR et al reported a case of fracture of screws at the junction of screw head and threaded portion whereas no such case of screw fracture was encountered in the present study. Coburn DG et al, also, observed a similar complication and they recommended a careful drilling of bur hole with slow bur speed and copious irrigation with sterile saline. They, further, suggested the insertion of screw at an even speed and no application of force if resistance is encountered. Holmes S et al, also, reported similar complications and advocated caution while the use of bicortical screws and suggested the technique of two forward turns followed by one backward turn while placement of the screws. The next complication mentioned with IMF screws was injury to the roots of teeth adjacent to screw fixation site, although, only two cases of iatrogenic injury to the roots was reported in the present study. Steven K et al recommended a thorough clinical and radiographic assessment of the adjacent teeth in the site of screw placement. Another complication associated with this method was loosening of the screws which was seen in 2 patients in group II treated with closed reduction who presented with tissue overgrowth and screw loosening and who were subsequently treated with removal of the same and placement of screws secured in new positions. Busch RF, also, reported this complication and recommended the use of greater diameter screws. Win KKS used horizontal stabs incisions before using drill to make the pilot hole for the placement of self tapping IMF screws of diameter 3.5mm and with 12mm/16mm length in three partially edentulous patients with dentures. In the present study, no incisions were used before placing the self drilling screws. Bush RF had, also, used self tapping IMF screws in 67 patients in his 2-year study and reported one case each of a periodontal abscess and cellulitis around the screw and one screw that was displaced into the maxillary sinus. In the present study, no such complications were observed. Bush RF, also, reported loss of fixation in 6 patients while in the present study, no case of loss of fixation was observed either. Another complication associated with self tapping IMF screws is that they become embedded in the soft tissues over a period of time and their removal necessitates use of stab incisions under local anesthesia. This complication, although, was encountered in two patients in the present study. The controversy over whether to treat fractures by open or, closed method has remained a subject of debate for over 200 years. The advent of refined aseptic techniques to minimize chances of post-operative infections and effective antibiotics have made open reduction method of fracture management justified and popular. Roccia F et al used IMF screws in 62 patients and suggested that these screws were not indicated where the function of tension band and post-operative directional traction were required as in multiple comminuted mandibular fractures. Contraindications to IMF screws, also, include pediatric patients with multiple unerupted teeth and patients with severe osteoporosis. Self tapping IMF screws provided good intra-operative fixation in all the 20 cases in the present study. Also, none of the cases reported with secondary infections and associated complications in the form of paresthesia and necrosis of the bone post-operatively. There was no reported pain and edema at the sites of screw placement in all the cases by 7th post-operative day. Thus, the use of this method seems to be ideal in cases with relatively favorable, undisplaced mandibular fractures. In cases with multiple and unfavorable fractures of mandible, although, where pre-operative elastic traction is necessary, self tapping IMF screws may not be an ideal option to meet intermaxillary fixation. In the present study, post-operative occlusal discrepancy was noted only in one case similar to the findings of other studies conducted in the past. Elastic traction given with the help of arch bars was used to correct malocclusion that resulted with treatment in that case.
| Conclusion|| |
Intermaxillary fixation with self-tapping IMF screws is a valid alternative to conventional methods in the treatment of minimally displaced fractures of the mandible. Self-tapping IMF screws offer good temporary fixation intraoperatively to check occlusion and postoperatively for intermaxillary fixation. Self-tapping IMF screws reduce operating time, damage to the periodontal tissues, and offer an ease of handling. The present case control study revealed a low percentage of iatrogenic injury to the teeth and postoperative malocclusion within acceptable limits similar to that reported in the literature. Considering the results, IMF screws would be advantageous in the treatment of minimally displaced fractures of the maxillofacial skeleton, and their use could well be extended to the management of other facial fractures.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2]