Complications with intermaxillary fixation screws in the management of fractured mandibles

Embrasure wires for intraoperative maxillomandibular fixation are rapid and effective

PURPOSE

The management of some mandible fractures requires maxillomandibular fixation (MMF) intraoperatively but not postoperatively. Intraoperative MMF with arch bars has significant disadvantages, including duration of application and risk of disease transmission. Some surgeons have sought to minimize these disadvantages, improve efficiency, and decrease cost by omitting formal MMF altogether and manually stabilizing the occlusion. Embrasure wires are a method of intraoperative MMF with significant potential advantages. The purpose of this investigation was to compare embrasure wires with Erich arch bars (Karl Leibinger Co, Mulheim, Germany) for intraoperative stabilization of mandible fractures.

PATIENTS AND METHODS

This retrospective case review comprised 50 patients with a primary diagnosis of mandible fracture requiring open reduction-internal fixation with intraoperative MMF. Patients were categorized into 2 groups: intraoperative MMF using embrasure wires (group A) or intraoperative MMF using arch bars (group B). In each group the time required to place the MMF was recorded in whole minutes. The success or failure of the technique to maintain stable MMF throughout the procedure was assessed.

RESULTS

Intraoperative MMF was used with embrasure wires in 27 of 50 patients (54%) and with arch bars in 23 of 50 (46%). The mean time required for placement of embrasure wire MMF (2.51 minutes) was significantly (P < .001) less than the mean time required for placement of arch bar MMF (25.47 minutes). The quality of MMF was judged to be stable for the duration of fixation in 24 of 27 patients (89%) in the embrasure wire MMF group and 22 of the 23 patients (96%) in the arch bar group. This difference was not significant (P = .61).

CONCLUSION

Embrasure wires can be placed in significantly less time than arch bars, and they provide a reliable form of intraoperative MMF during mandible fracture repair. For intraoperative MMF, embrasure wires offer significant advantages compared with arch bars by reducing application time. In addition, embrasure wires may reduce the risk of disease transmission by decreasing the number of wires required for MMF.

IMF Screw: An Ideal Intermaxillary Fixation Device During Open Reduction of Mandibular Fracture

Intermaxillary fixation (IMF) is conventionally used for treatment of fractures involving maxillomandibular complex both for closed reduction and as an adjuvant to open reduction. To overcome the cumbersome procedure of tooth borne appliances cortical bone screws were introduced in the year of 1989 to achieve IMF which is essentially a bone borne appliance. In our institution we treated 45 cases of mandibular fracture both single and multiple fractures by open reduction over a period of 24 months. IMF screws were used to achieve dental occlusion in all the cases. Various advantages, disadvantages and complications are discussed. In our institutional experience we found that the IMF screws are an ideal device for temporary intermaxillary fixation for the cases having only mandibular fracture.

Transgingival lag-screw osteosynthesis of alveolar process fracture

Fracture of the alveolar process is a common injury. In some cases, traditional fixation may not be possible. The teeth needed for splinting or mandibulo-maxillary fixation may be missing. The fracture line and soft tissue injury may jeopardize the blood supply of the broken bone. In these extreme and rare situations, the best rehabilitation is needed to avoid the loss of hard and soft tissues, and a secondary reconstruction is required. Between January 2003 and December 2006, of 468 cranio-facial trauma patients studied, alveolar process fracture was reported in 28 (6%) cases. In six (1%) cases, the anatomy of the fracture lines, and the position and number of the remaining teeth made splinting and mandibulo-maxillary fixation impossible. Patients were treated with a transgingival lag-screw (TLS) osteosynthesis. All patients healed well with no complications. There was no bone or tooth loss in the surgical area, and broken fragments were not absorbed. The TLS technique is recommended for alveolar fractures when the blood supply is jeopardized and dental splinting or mandibulo-maxillary fixation is not possible. There is no need for flap reflection.

Predictable drill-free screw positioning with a graduated 3-dimensional radiographic-surgical guide: a preliminary report

INTRODUCTION

Mini-implants are placed in restricted sites, requiring an accurate surgical technique. However, no systematic study has quantified technique accuracy to reliably predict the surgical risks. Therefore, a graduated 3-dimensional radiographic-surgical guide (G-RSG) was proposed, and its inaccuracy and risk index (RI) were estimated.

METHODS

The sample consisted of 6 subjects (4 male, 2 female), who used mini-implant anchorage. Ten drill-free screws (DFS) were placed by using the G-RSG. The central point of the mesiodistal septum width (SW) was the selected implant site on the presurgical radiograph. The distances between DFS and the adjacent teeth (5-DFS and 6-DFS) were measured to evaluate screw centralization and inaccuracy degree (ID). These distances were statistically compared by independent t tests, and inaccuracy was determined by the expression ID = (5-DFS - 6-DFS)/2, which represents deviation of the mini-implant's final position regarding the central point initially selected. Then SW, ID, and screw diameter (SØ) were combined to estimate the surgical risk with RI expressed by RI = SØ/SW - ID.

RESULTS

The 5-DFS and 6-DFS distances were not significantly different. The ID of the G-RSG was 0.17 mm. The low ID ensured a safe RI (<1) in spite of the restricted SW.

CONCLUSIONS

The G-RSG accuracy allowed fine prediction of the final DFS position in the interradicular septum, with a low RI, which is a helpful tool to estimate surgical risks.

Effects of intentional damage of the roots and surrounding structures with miniscrew implants

INTRODUCTION

The purposes of the study were to evaluate the immediate damage to roots and periodontal structures after initial miniscrew implant (MSI) placement and the short- and long-term damage after MSIs were left in situ.

METHODS

The roots of the maxillary second, third, and fourth premolars of 7 mature beagle dogs were randomly assigned to undergo immediate, short-term (left for 6 weeks), or long-term (left for 12 weeks) damage. Intentional damage was inflicted with self-tapping screws (1.8 x 8 mm) placed with a stent. Alternating tetracycline and calcein labels were administered at 6-week intervals. Undecalcified sections were stained and evaluated histologically to determine the extent of damage; healing was evaluated by using fluorescence labels.

RESULTS

Histology showed damage to 73.8% of the teeth, ranging from displacement of bone into the periodontal ligament to invasion of the pulp chamber. Displacement of bone into the periodontal ligament and direct damage to the periodontal ligament occurred in 3 (7.2%) instances. Damage was isolated to the cementum of 8 (19.0%) teeth, whereas damage occurred in the dentin of 11 (26.2%) teeth. Loss of bone in the furcation was evident in 3 (7.2%) teeth, and severe damage into the pulp occurred in 6 (14.2%) teeth. No differences in the amounts of damage were evident between the immediate, short-, and long-term groups. Healing often occurred with cementum around the unloaded MSIs.

CONCLUSIONS

Extensive damage can be caused by MSIs, with little to no differences evident over time. Unloaded MSIs that remain in contact with roots of teeth can show varying degrees of healing.

Self-tapping and self-drilling screws for intermaxillary fixation in management of mandibular fractures

The current study evaluated the success and the possible complication of intermaxillary fixation with self-tapping and self-drilling screws (STSDSs) in nondislocated or slightly dislocated mandibular fractures.Forty patients with mandibular fractures, treated with intermaxillary fixation using STSDSs, were clinically assessed by means of a dental vitality test and evaluation of tooth mobility adjacent to the cortical screw holes, and radiologically by means of a panoramic dental radiograph upon removal of the screws.The main complication was screw loss in 4.4% of cases, followed by coverage by oral mucosa in 1.2% of cases. However, no dental root damage, screw breakage, malocclusion, or poor consolidation of mandibular fractures was observed.The use of STSDSs for intermaxillary fixation is a useful alternative to the use of arch bars in the treatment of some types of mandibular fractures. In addition, there is no risk of dental lesions as with self-tapping screws.

Application of Intermaxillary Fixation Screws in Maxillofacial Trauma

PURPOSE

The use of intermaxillary fixation (IMF) in the treatment of maxillofacial trauma represents the cornerstone of fracture reduction and immobilization. Many modalities of IMF have been described; recently IMF screws have been introduced into clinical practice, however, hardware failure can occur. We performed a retrospective study evaluating hardware-associated complications for self-drilling/tapping IMF screws.

MATERIALS AND METHODS

A retrospective study on 49 patients requiring IMF was performed. The diagnosis, duration of IMF, screw site, use of elastic or wire fixation, and associated complications were recorded. IMF screws were used to adjunct open reduction techniques, for definitive closed reduction, or fracture prevention following dentoalveolar surgery. Follow-up examinations were performed until fracture healing was complete (6 to 8 weeks).

RESULTS

A single adverse event occurred in 19 patients (39%) while 4 patients (8%) had more than 1 complication. The most common event was screw loosening; 29% of patients had at least 1 screw dislodged in the treatment period. Of the total number of screws placed (229), 15 (6.5%) became loose, and were equally distributed among the mandible and maxilla. The remaining complications noted were root fracture, 4% (2 of 49); loosened wires, 6% (3 of 49); screw shear, 2% (1 of 49); malocclusion, 2% (1 of 49); and ingested hardware, 2% (1 of 49).

CONCLUSIONS

Overall the IMF self-drilling/tapping screws have been shown to be a useful modality to establish maxillomandibular fixation. It is a safe, and time-sparing technique; however, it is not without limitations or potential consequences which the surgeon must be aware of in order to provide safe and effective treatment.

The Use of an Intermaxillary Fixation Screw for Mandibular Setback Surgery

PURPOSE

To assess skeletal stability after mandibular setback surgery with and without an intermaxillary fixation (IMF) screw.

PATIENTS AND METHODS

The subjects were 40 patients with mandibular prognathism. The subjects underwent sagittal split ramus osteotomy with titanium plate fixation and were divided into 2 groups, 1 with and 1 without an IMF screw. A lateral cephalogram was done preoperatively, immediately after surgery, and 1 month, 3 months, and 6 months postoperatively. The 2 groups were then compared statistically.

RESULTS

In the comparison of the time-course change between the 2 groups with repeated measure analysis of variance, there were significant differences in occlusal plane (between subjects, F = 2.517; df = 4; P = .0437) and convexity (between subjects, F = 4.048; df = 4; P = .0038). However, there was no significant difference in the other measurements.

CONCLUSION

This study suggested that in most measurements, there was no significant difference between 2 groups with and without an IMF screw in time-course skeletal change. However, use of IMF screws was helpful for orthognathic surgery as a rigid anchor of IMF.

Mandibular fractures treated with maxillomandibular fixation screws (MMFS method)

The purpose of the treatment of mandibular fractures is to restore proper dental occlusion and stable temporomandibular joint movement, as well as the reduction of the displaced fracture. Consideration must be given to the selection of the most appropriate surgical and rehabilitation methods in such patients. Typical surgical methods for the treatment of mandibular fractures include the arch bar method or plating at the location of the fracture combined with fixing the mandible to the maxilla using the arch bar method. However arch bars and circumdental wires, which require teeth for fixation, damage teeth and periodontal tissue, and tend to be uncomfortable for patients during the fixation period. Moreover, daily maintenance of oral hygiene is difficult for patients with an arch bar. Surgeons are also exposed to the risk of blood-transmitted diseases through skin punctures by wires when affixing these devices. For these reasons, we chose to study the potential of the MMFS method, which is thought to lessen all of the following problems: tissue damage, operating time, patient discomfort, and possible exposure to percutaneous infectious disease due to puncture of gloves and skin by the wires. We demonstrated the utility of the MMFS method in the present study.

The Use of Microimplants in Orthodontic Anchorage

PURPOSE

Various types of temporary implants have been introduced to serve as orthodontic anchorage. The hypothesis of this study is that microimplants of 1.2 mm diameter can be used as orthodontic anchors, and that their success is related to their length. The aim of this study is to determine the incidence of anchor retention after orthodontic force application for moving teeth, and to determine the relationship of microimplant length to retention rate.

METHODS

Fifty-nine microimplants (diameter: 1.2 mm) were placed in 29 patients as orthodontic anchorages. After 2 weeks of microimplant placement, a force of 100 to 200 g was loaded with an elastometric chain or NiTi coil spring. Risk factors were characterized as to why a microimplant may fail, and Fisher's exact test was used for statistical analysis.

RESULTS

Nine microimplants were removed and the overall success rate was 84.7%. Exploring the causes for failure, we found significant differences between the length of microimplants and success rate; 6 mm was 72.2% and 8 mm was 90.2%.

CONCLUSIONS

The results suggest that microimplants are suited as an alternative orthodontic anchorage. We recommend that 8-mm microimplants are preferable to 6-mm.

The application of mini-implants for orthodontic anchorage

The aim of this study was to explore the use of mini-implants for skeletal anchorage, and to assess their stability and the causes of failure. Forty-five mini-implants were used in orthodontic treatment. The diameter of the implants was 2mm, and their lengths were 8, 10, 12 and 14mm. The drill procedure was directly through the cortical bone without any incision or flap operation. Two weeks later, a force of 100-200g was applied by an elastometric chain or NiTi coil spring. Risk factors for the failure of mini-implants were examined statistically using the Chi-square or Fisher exact test as applicable. The average placement time of a mini-implant was about 10-15min. Four mini-implants loosened after orthodontic force loading. The overall success rate was 91.1%. The location of the implant was the significant factor related to failure. In conclusion, the mini-implants are easy to insert for skeletal anchorage and could be successful in the control of tooth movement.

An audit of mandibular fractures treated by intermaxillary fixation using intraoral cortical bone screws

INTRODUCTION

During the last 10 years, intermaxillary fixation using intraoral cortical bone screws has been introduced for the treatment of mandibular fractures. The aim of this work was to evaluate the indications and possible complications of this method.

MATERIALS AND METHODS

Sixty-two patients with mandibular fractures, treated by intermaxillary fixation using these screws, were evaluated by preoperative and postoperative panoramic radiographs. Clinical testing was carried out for vitality and abnormal mobility of teeth adjacent to the site of screw insertions. To evaluate the efficacy of this method, different factors were considered such as possible iatrogenic dental injuries, loss, breakage or screw cover by oral mucosa and postoperative occlusion.

RESULTS

The most important complication was iatrogenic damage to dental roots (1.5%), 4.9% of the screws were covered by oral mucosa and 1.9% were lost, while none were broken. Malocclusion was observed in one patient (1.6%) and lack of consolidation of a displaced fracture of the mandibular body in another patient.

CONCLUSIONS

Use of intraoral cortical bone screws for intermaxillary fixation is a valid alternative to arch bars in the treatment of mandibular fractures. Iatrogenic injury to dental roots is the most important problem of this procedure, but can be minimized by an experienced surgeon.

Transalveolar screws and the incidence of dental damage: a prospective study

The incidence of screw/tooth contact in the placement of transalveolar screws was prospectively studied. The clinical significance of such contact when it occurred was assessed. Patients with fractures of the mandible requiring intra- or post-operative control of their occlusion with transalveolar screws were entered into the study. Following screw removal, contact was assessed radiographically and all teeth adjacent to screws were tested for vitality. Any contacts were judged to be minor if less than 50% of the diameter of the screw hole impinged on a tooth root or major if this was more than 50%. Fifty-four male and one female patients completed the study. There were 232 screws placed in these patients adjacent to 440 teeth. Twenty-six screws (11.2%) had major contacts and 37 (15.9%) had minor contacts. Seventeen teeth tested as non-vital with electronic pulp testing but of these only 6 showed any impingement by screws. Two screws were associated with complications in two patients. Screw/tooth contact does occur using transalveolar screws, however, the incidence of clinically significant damage appears to be very low.

A drill-free bone screw for intermaxillary fixation in military casualties

Drill-free bone screws are a simple and quick method of establishing intermaxillary fixation requiring a minimum amount of specialist training or equipment. These screws offer significant advantages over other methods of intermaxillary fixation and are well suited for use in military casualties.