Superior border plating technique in the management of isolated mandibular angle fractures: a retrospective study of 50 consecutive patients.

PURPOSE: To determine the complication rate for patients presenting with isolated mandibular angle fractures treated by open reduction and internal fixation using a single superior border miniplate technique. PATIENTS AND METHODS: This is a retrospective study of consecutive patients with isolated mandibular angle fractures treated using a specific protocol at a Regional Oral and Maxillofacial Department between January 1998 and December 2004. Patient demographics, fracture etiology, length of hospital stay, removal of third molar, and postoperative complications were recorded. Preoperative and postoperative inferior alveolar nerve function was recorded. Objective sensory testing and patient interviews were conducted to determine the incidence of postoperative sensory deficit. RESULTS: The study population included 50 patients presenting with isolated mandibular angle fractures, 6 patients (12%) experienced complications requiring bone plate removal. These complications were minor and occurred after fracture healing as follows: 4 patients (8%) experienced superficial soft tissue infection associated with the bone plate, treated with oral antibiotics, 1 patient (2%) experienced bone plate exposure, and a further patient (2%) presented with a fractured bone plate. All 6 patients (12%) were treated by bone plate removal under general anesthesia as elective day case surgery. Thirty-nine (78%) patients had long-term sensory follow-up, mean 37 months (2 to 84 months). Permanent inferior alveolar sensory deficit (>12 months) was present in 4 (8%). Five of 26 (19%) patients with normal postinjury/preoperative sensory function had a postoperative sensory deficit. All patients in this group reported recovery of normal sensation within 6 months. CONCLUSIONS: The results of this study suggest that the complication rates associated with the treatment of isolated mandibular angle fractures using a superior border plating technique, in this patient population, is relatively low (12%). The complications were all minor in nature. There was a permanent (>12 months) inferior alveolar sensory deficit in 4 (8%) patients.     

Use of straight and curved 3-dimensional titanium miniplates for fracture fixation at the mandibular angle.

PURPOSE: The aim of this follow-up study was to evaluate the clinical usefulness of a new type of 3-dimensional (3D) miniplate for open reduction and monocortical fixation of mandibular angle fractures. PATIENTS AND METHODS: In 20 consecutive patients, noncomminuted mandibular angle fractures were treated with open reduction and fixation using a 2 mm 3D miniplate system in a transoral approach. All patients were systematically monitored until 6 months postoperatively. Among the outcome parameters recorded were infection, hardware failure, wound dehiscence, and sensory disturbance of the inferior alveolar nerve. RESULTS: The mean operation time from incision to wound closure was 65 minutes. Two patients had a mucosal wound dehiscence with no consequences. None developed an infection requiring a plate removal. All but 2 patients had normal sensory function 3 months after surgery. Plate fracture occurred in one patient in whom a preceding surgical removal of the third molar had been the reason for the mandibular fracture. In the absence of clinical symptoms, the patient declined plate removal. On final follow-up, fracture healing was considered clinically complete in all patients. CONCLUSIONS: The 3D plating system described here is suitable for fixation of simple mandibular angle fractures and is an easy-to-use alternative to conventional miniplates. The system may be contraindicated in patients in whom insufficient interfragmentary bone contact causes minor stability of the fracture.     

Fixation of mandibular fractures with 2.0-mm miniplates: review of 191 cases.

PURPOSE: Our goal was to study the use of 2.0-mm miniplates for the fixation of mandibular fractures. Patients and Methods: Records of 191 patients who experienced a total of 280 mandibular fractures that were treated with 2.0-mm miniplates were reviewed. One hundred twelve of those patients, presenting 160 fractures, who attended a late follow-up were also clinically evaluated. Miniplates were used in the same positions described by AO/ASIF. No intermaxillary fixation was used. All patients included had a minimum follow-up of 6 months. Demographic data, procedures, postoperative results, and complications were analyzed. RESULTS: Mandibular fractures occurred mainly in males (mean age, 30.3 years). Mean follow-up was 21.92 months. The main etiology was motor vehicle accident. The most common fracture was the angle fracture (28.21%). Twenty-two fractures developed infection, for an overall incidence of 7.85%. When only angle fractures are considered, that incidence is increased to 18.98%. Although only 1 patient (0.89%) described inferior alveolar nerve paresthesia, objective testing revealed sensitivity alterations in 31.52% of the patients who had fractures in regions related to the inferior alveolar nerve. Temporary mild deficit of the marginal mandibular branch was observed in 2.56% of the extraoral approaches performed and 2.48% presented with hypertrophic scars. Incidence of occlusal alterations was 4.0%. Facial asymmetry was observed in 2.67% of the patients, whereas malunion incidence was 1.78%. Fibrous union, mostly partial, occurred in 2.38% of the fractures, but only 1 of those presented with mobility (0.59%). Condylar resorption developed in 6.25% of the fixated condylar fractures. Mean mouth opening was 42.08 mm. CONCLUSION: The overall incidence of complications, including infections, was similar to those described for more rigid methods of fixation.     

Treatment modalities for mandibular angle fractures.

PURPOSE: Management of mandibular angle fractures is often challenging and results in the highest complication rate among fractures of the mandible. Optimal treatment for angle fractures remains controversial. Historically, treatment of mandible fractures included intraoperative maxillomandibular fixation (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 are examined. MATERIALS AND METHODS: 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 Fisher's exact and chi-square tests. Results were considered significant if P <.05. RESULTS: One hundred ten of 127 potential responses were received (87%). Among 104 surgeons who treat mandible fractures, 86 (83%) treat more than 10 mandibular fractures per year. Preferred techniques for simple, noncomminuted mandibular angle fractures in this group were: single miniplate on the superior border (Champy technique) with or without arch bars (44 surgeons, 51%); tension band plate on the superior border and nonlocking, bicortical screw plate on the inferior border (11 surgeons, 13%); dual miniplates (9 surgeons, 10%); a locking screw plate on the inferior border only (6 surgeons, 7%), and 3-dimensional plates (5 surgeons, 6%). Eleven surgeons (13%) gave multiple answers. Although only 13% of surgeons surveyed primarily use the combination of tension band and nonlocking, bicortical screw plates, many surgeons (73%) continue to use this technique in certain circumstances. Within this group, 32 (51%) place screws in a neutral position, while 31 (49%) place screws in an eccentric position, resulting in compression. For simple noncomminuted angle fractures, the number of surgeons performing internal fixation without MMF were: 14 often (16%); 20 occasionally (23%); 17 seldom (20%); and 35 never (41%). Surgeons treating more than 10 versus those who treat less than 10 fractures per year, International versus North American faculty, and Oral and Maxillofacial surgeons (OMS) versus non-OMS surgeons were compared. Surgeons who treat more than 10 fractures per year favor the Champy technique over the tension band and bicortical plate combination (44 [51%] vs 11 [13%]), while those surgeons who treat less than 10 per year favor the tension band and bicortical plate combination over the Champy technique (9 [50%] vs 3 [17%]; P < .01, Fisher exact test). International faculty are less likely to use intraoperative MMF than North American faculty (29 [81%] vs 31 [43%]; P < .01, Fisher exact test). OMS surgeons are less likely to use the tension band and bicortical plate combination than non-OMS surgeons (22 [56%] vs 42 [90%]; P < .017, Fisher exact test). CONCLUSION: This survey suggests an evolution in the management of mandibular angle fractures. A single miniplate plate 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 favoring neutral rather than eccentric screw placement. Intraoperative MMF is not considered mandatory by some surgeons in certain circumstances.     

口内途径坚强内固定术治疗下颌骨骨折29例报告

目的 :评价口内途径坚强内固定术及术中暂时性小环结扎治疗下颌骨骨折的效果。方法 :对 2 9例 47处下颌骨体部骨折先作两侧磨牙区和切牙区三点式颌间小环结扎 ,骨折线两侧作牙间结扎 ,初步恢复下颌骨的弓形和咬合关系后 ,自下颌前庭沟作切口 ,显露骨折处并复位后进行小型钛板坚强内固定术。术毕拆除颌间结扎 ,恢复下颌运动。分别于术后第 1d和 90d进行临床和X线检查 ,评价其咬合关系、骨折复位及愈合情况。结果 :2 9例47处下颌骨体部骨折均获得良好的复位和骨性愈合 ,咬合关系良好 ,无并发症。结论 :口内途径小型钛板坚强内固定术可对下颌骨体部骨折进行良好的固定 ,获得满意的咬合关系。     

Relationship between the risk of mandibular angle fractures and the status of incompletely erupted mandibular third molars.

BACK GROUND: Several studies have shown the increased risk of mandibular angle fractures associated with incompletely erupted mandibular third molars. But only a few reports analysed in detail the relationship of the status of eruption of this tooth and this type of fracture. OBJECTIVES: The purpose of this study was to clarify the influence of the eruption status of incompletely erupted mandibular third molars on the incidence of mandibular angle fractures. METHODS: Four hundred and thirty-six mandibular halves in 218 patients with mandibular fractures, aged between 15 and 40 years old, were analysed using panoramic radiographs. RESULTS: The incidence of angle fractures in the mandibular halves with incompletely erupted mandibular third molars was 30.8% and this was statistically significantly higher than that in another group (p<0.0001). Deeply located mandibular third molars clearly showed a higher incidence of this fracture when compared with the adjacent second molar (p<0.0001). CONCLUSION: The results of this investigation showed that incompletely erupted mandibular third molars close to the inferior border of the mandible have a high risk of angle fractures.     

Transoral 2.0-mm miniplate fixation of mandibular fractures plus 2 weeks' maxillomandibular fixation: a prospective study.

PURPOSE: We conducted a study to assess the efficacy of intraoral treatment of mandibular fractures using a 2.0-mm miniplate and 2 weeks of maxillomandibular fixation (MMF). PATIENTS AND METHODS: Forty-four mandible fractures in 31 patients with a mean of 15 days of MMF were included in this study. A 2.0-mm miniplate was adapted along Champy's lines of ideal osteosynthesis and secured with four 8.0-mm monocortical screws. All patients were followed for at least 8 weeks after surgery. The incidences of bone or soft tissue infections, wound dehiscence, nonunion, malunion, malocclusion, plate fractures, and iatrogenic neurosensory deficits were prospectively evaluated. RESULTS: Primary bone healing was achieved in 100% of cases. No soft or hard tissue infection, malocclusion, malunion, nonunion, dental injuries, plate fracture, or iatrogenic nerve injuries were observed. Two (4.52%) minor complications-intraoral wound dehiscences-were noted. CONCLUSIONS: The use of a single 2.0-mm miniplate adapted along Champy's line of ideal osteosynthesis and stabilized with 4 monocortical screws plus 2 weeks of MMF was a viable treatment modality for mandibular fractures.     

下颌角骨折张力带固定与下颌骨下缘固定的临床对比研究

目的　探讨下颌角骨折小型接骨板张力带固定的临床可行性。方法　研究组 2 7例 2 8侧下颌角骨折行小型接骨板张力带固定 ,对照组 19例行下颌骨下缘固定 ,两组的不利型骨折比例分别为 82 %和 95 % ,严重移位骨折比例 2 5 %和 85 % ,术前感染比例 0和 2 5 % ,骨折复位同期拔牙比例5 5 %和 33% ,病例复查率 89%和 79% ,平均复查期 36周和 31周 ,经临床及X线检查进行比较分析。结果　研究组和对照组的术后感染率分别为 10 71%和 5 0 0 % ,干扰率 7 40 %和 5 2 6 % ,张口受限率 14 81%和 10 5 3% ,创伤性关节炎发生率 11 11%和 2 1 0 5 %。张力带固定组 2 1 43%的骨折术后出现下颌骨下缘分离或再移位 ,同时伴外骨痂形成 ;下颌下缘固定组 10 %的骨折存在复位固定缺陷 ,分别发生在未设张力带的加压固定和两个小型接骨板并行固定。结论　下颌角骨折采用小型接骨板张力带固定的稳定性不足 ,只适用于有利型和轻度移位的骨折 ,不利型和严重移位的骨折应增加下缘固定。稳定性不足和复位同期拔牙是术后感染的可能原因。     

Comparison of strains produced by titanium and poly D, L-lactide Acid plating systems to in vitro forces.

PURPOSE: To determine if a specific resorbable plating system provides similar fixation, in terms of strain distribution under load, to a titanium system when the Champy technique is applied for the treatment of a mandibular angle fracture. MATERIALS AND METHODS: A formalin-fixed cadaver mandible was harvested just before the study. A bicortical osteotomy was then made using a diamond disc extending in an oblique direction in the area of the angle. It was then passively fixated with a 4-hole 2.0-mm miniplate. Two stacked rosette strain gauges were bonded to the mandible on either side of the fracture. Each rosette had 3 strain gauges arranged in specific degrees relative to each other. The mandible was then placed on a dynanometer and 30 lb loads were delivered on the ipsilateral molar. Static resistance was placed in the condylar neck region to simulate the glenoid fossa. Loading was repeated 10 times with a period of 3 minutes between loads. Measurements were recorded for each strain gauge after loads were in place for 30 seconds. The same process was repeated using a 4-hole 2.1-mm resorbable miniplate. The strains were then used to calculate the maximum and minimum strains for each rosette. Hooke's law was used to calculate the principal stresses. RESULTS: Differences were observed between the strain gauges for each individual plating system. There was variability within the resorbable plate measurements as shown by the standard deviation. Using the REML ANOVA test, a significant difference was found between the 2 materials. CONCLUSION: In this in vitro study, there were significant biomechanical differences observed between a 2.0-mm titanium miniplate and a 2.1-mm resorbable miniplate when used to treat a mandibular angle fracture following Champy's principles. Based on our finding, both systems cannot be used interchangeably for the treatment of mandibular angle fractures under the same clinical conditions.     

Transoral 2.0-mm Locking Miniplate Fixation of Mandibular Fractures Plus 1 Week of Maxillomandibular Fixation: A Prospective Study

PURPOSE: In this study, a 2.0-mm locking miniplate (LMP)/screw system was assessed in the treatment of mandibular fractures with a 1-week period of maxillomandibular fixation (MMF). PATIENTS AND METHODS: Fifty mandibular fractures in 34 patients with a mean of 6.97 days of MMF were included in the study. The 2.0-mm LMPs were adapted along Champy's line of ideal osteosynthesis and secured with four 8.0-mm locking monocortical screws. All patients were followed for a minimum of 6 weeks. The incidence of soft tissue infections, nonunion, malunion, malocclusion, osteomyelitis, nerve injury, and tooth damage was prospectively assessed. RESULTS: Primary bone healing was achieved in 98% of cases. Three complications (6%) were observed. Two minor complications of intraoral wound dehiscence and malocclusion were noted. A fibrous nonunion requiring 3 additional weeks of MMF was noted. No evidence of malunion, osteomyelitis, plate fracture, iatrogenic nerve injuries, or dental injuries was noted. CONCLUSIONS: A single 2.0-mm LMP placed along Champy's line of ideal osteosynthesis with four 8-mm monocortical locking screws plus 1 week of MMF fixation is a reliable and effective treatment modality for mandibular fractures.     

Mandibular angle fracture treated with new three-dimensional grid miniplate

ABSTRACT: Fractures of the mandibular angle deserve particular attention because they represent the highest percentage of mandibular fractures and have the highest postsurgical complication rate, making them the most challenging and unpredictable mandibular fractures to treat. Despite the evolution in the treatment of maxillofacial trauma and fixation methods, no single treatment modality has been revealed to be ideal for mandibular angle fractures. Several methods of internal fixation have been studied with great variation in complications rates, especially postoperative infections. Recently, new studies have shown reduction of postsurgical complications rates using three-dimensional plates to treat mandibular angle fractures. Nevertheless, only few surgeons have used this type of plate for the treatment of mandibular angle fractures. The aim of this clinical report was to describe a case of a patient with a mandibular angle fracture treated by an intraoral approach and a three-dimensional rectangular grid miniplate with 4 holes, which was stabilized with monocortical screws. The authors show a follow-up of 8 months, without infection and with occlusal stability.     

A computer study of biodegradable plates for internal fixation of mandibular angle fractures.

PURPOSE: This computer-based study was performed to determine the suitability of small biodegradable plate systems for mandibular angle fractures. MATERIALS AND METHODS: In a 3-dimensional computer model of the mandible, fracture mobility and plate strain were calculated for bite forces applied on 13 bite points on the dental arch. The angle fracture was fixed with 2 polylactide (PLA) midiplates or with 2 PLA maxiplates. The first plate was positioned buccally on the external oblique ridge. Two positions of the second plate were studied: halfway up the height of the mandible or on the lower border. Maximum fracture mobility was set at a limit of 150 microm to enable undisturbed fracture healing. Maximum plate strain was set at the yield strain of PLA. RESULTS: Fixation with the PLA maxiplates, with the second plate positioned halfway up the height of the mandible, resulted in fracture mobility below the set limit for all bite points. For the other PLA fixation strategies, fracture mobility exceeded the set limit. Fixation with the second plate positioned halfway up the height of the mandible generally resulted in less fracture mobility than with the plate positioned on the lower border. The yield strain of PLA was not exceeded in any of the fixation strategies. CONCLUSIONS: Based on the computer model, 2 PLA maxiplates are suitable for fixation of mandibular angle fractures. One plate should be positioned buccally on the external oblique ridge, and the other should be positioned halfway up the height of the mandible.     

Comparative analysis of the effectiveness of the mandibular angle fracture treatment methods

425 patients with mandibular angle fractures were treated at the Hospital of Kaunas University of Medicine (HKUM) Clinic of Maxillo-Facial Surgery. Treatment included the application of closed fracture fragments fixation methods (wire splint fixation, and Kirschner wire osteosynthesis), and methods of open fixation--osteosynthesis using the supra-periosteal miniplate, and osteosynthesis using supra-osseous Zes Pol plate (the latter method was modified by the authors). Relative computerized densitometry showed that closed fixation methods result in a faster healing of fractures. The findings of the pain threshold testing showed that open fixation methods more severely damage the function of the lower alveolar nerve. Using closed fixation methods, osteomyelitis occurred in 5.3% of cases, while using open fixation methods--in 15.3% of cases. Thus, the authors of the article maintain that when mandibular angle fractures, in the presence of suitable conditions, closed fracture fragments fixation methods should be given a priority.     

Comparative evaluation of 2.0-mm locking plate system vs 2.0-mm nonlocking plate system for mandibular fracture: a prospective randomized study

This study evaluated the efficacy of a 2.0-mm locking plate/screw system compared with a 2.0-mm non-locking plate/screw system in mandibular fractures. A prospective randomized clinical trial was conducted. Patients were randomly assigned to receive 2.0-mm locking plates (group A) or 2.0-mm nonlocking plates (group B). All patients were followed up for 12 weeks postoperatively. Complications were analysed according to the type of plate used and the site of fracture. Fifty patients with 76 fractures met the inclusion criteria. Thirty-six fracture sites were treated with 2.0-mm locking plates and 40 with 2.0-mm nonlocking plates. The number of patients requiring postoperative maxillomandibular fixation was significantly higher in group B (p < 0.01); seven complications occurred representing 9% of the total. Two complications occurred in the locking group and five in the nonlocking group with complication rates equalling 6% and 13%, respectively. When comparing the overall complication rates according to plates used, the χ² test showed no statistically significant difference between the locking and nonlocking plates (p > 0.05). In conclusion, mandible fractures treated with 2.0-mm locking plates and 2.0-mm nonlocking plates present similar short-term complication rates.     

Use of a 2.0-mm locking plate/screw system for mandibular fracture surgery.

PURPOSE: In this study, we examined the use of a 2.0-mm locking bone plate/screw system in mandibular surgery. PATIENTS AND METHODS: All patients who were treated with a 2.0-mm locking bone plate/screw system during an 8-month period for fractures of the mandible or other defects of the mandible were prospectively studied. Ease of use of locking plate/screw system, characteristics of the fractures and defects, and complications were tabulated. RESULTS: A total of 80 fractures in 59 patients were treated with the 2.0-mm locking plate/screw system. One hundred two 2.0-mm locking plates were applied to the 80 fractures; 58 fractures received 1 plate and 22 fractures received 2 plates. There were no intraoperative difficulties associated with their application. Fracture reductions were considered to be excellent in all cases. At the latest follow-up, all fractures had healed, but 2 patients had slight malocclusions. Six patients developed postsurgical infections. Only 1 patient required hospitalization for treatment of the infection; all others were managed in the outpatient clinic. Four patients required removal of their plates for varying reasons. CONCLUSIONS: The use of a 2.0-mm locking plate/screw system was found to be simple and to provide sound fixation in all cases.     

Plate osteosynthesis of condylar fractures: a retrospective study of 45 patients.

OBJECTIVE: This retrospective study presents the type of osteosynthesis used for the fixation of condylar fractures and the postoperative results and complications observed. METHOD AND MATERIALS: Forty-five patients with fractures of the mandibular condyle underwent open reduction and osteosynthesis with plates and screws. The surgical approach was, in most cases, via a submandibular incision. Stabilization was achieved in the majority of the cases with a 2.0-mm single or double miniplate, but 2.0-mm mini dynamic compression plates were also used. RESULTS: The complications were mainly inadequate reduction, screw loosening, and limitation of mouth opening. No plate fractures or infections were observed. CONCLUSION: The use of a single plate (miniplate or dynamic compression plate) often produces inadequate stability and reduction postoperatively. The placement of two 2.0-mm zygomatic dynamic compression plates demands great tissue dissection and detachment and can lead to limitation of mouth opening. The use of two 2.0-mm miniplates seems to produce better stability and fewer complications.     

Sensory abnormalities associated with mandibular fractures: Incidence and natural history

Purpose: The aims of this study were to determine the incidence of inferior alveolar nerve (IAN) abnormalities in patients with mandibular fractures and to document the natural history and spontaneous recovery rate in patients with a sensory disturbance.Patients and Methods: This was a retrospective evaluation of patients (n = 150) with mandibular fractures at risk for IAN injury admitted to the Oral and Maxillofacial Surgery Service between 1985 and 1995. The inclusion criteria were: 1) fractures between the mandibular and mental foramina, 2) availability of the results of a post-injury, preoperative sensory examination, and 3) at least 1 year follow-up. Fracture characteristics, physical examination findings, hospital course, operative treatment, and follow-up were documented. Patient interviews were conducted to determine the incidence of long-term sensory disturbance and associated morbidity. The results were evaluated with cm-square analysis.Results: Fifty-six percent of patients (84 of 150) had a post-injury/pretreatment IAN abnormality. Patients with sensory disturbance had a significantly higher frequency of displaced fractures than those without sensory disturbance (P < .001). Sixteen of 24 patients (66.7%) with an abnormal post-injury/ pretreatment sensory examination reported a permanent sensory deficit (mean follow-up, 74.3 months); 55% of these patients complained of impairment.Conclusions: The incidence of postinjury IAN deficits in patients with mandibular fractures was greater than 50% and was related to fracture displacement. One third of these patients regained normal sensation; the remaining two thirds reported a persistent sensory deficit. A significant number of these patients complained of discomfort and impairment after a mean follow-up of greater than 6 years.     

Outcomes of patients with teeth in the line of mandibular angle fractures treated with stable internal fixation.

PURPOSE: This study examines the relationship between postoperative infection and/or need for plate removal with the presence and management of teeth in the line of mandibular angle fractures. METHODS: Data were collected on patients treated by intraoral open reduction and internal fixation for fractures of the mandibular angle during an 8-year period. Outcome variables were postoperative infection and need for removal of the bone plate(s). The relationships of demographic variables, teeth in the line of fracture, and management of teeth in the line of fracture were analyzed using standard statistical methods. RESULTS: Four hundred two patients had sufficient follow-up for inclusion in the study. A tooth was present in the fracture line 85% of the time. Teeth in the fracture were removed in 75% of the fractures that contained teeth. Postoperative complications occurred in 19% of the sample. Fractures not containing teeth at the time of fracture had a 15.8% rate of postoperative infection compared with 19.1% for patients who had teeth in the fracture (P = NS). For angle fractures associated with a tooth, when the tooth was retained, the incidence of infection was 19.5%. When the tooth was removed, the incidence was 19.0% (P = NS). CONCLUSIONS: There is an increased risk for postoperative complications when a tooth is present, but the increase is not statistically significant. The incidence of postoperative infection and/or the need for plate removal is not affected by whether the tooth in the fracture is removed.     

Effect of third molars in the line of mandibular angle fractures on postoperative complications: systematic review and meta-analysis

The aim of this systematic review was to verify whether the presence of a lower third molar in the mandibular angle fracture line is associated with postoperative complications. An electronic survey was conducted in five databases. Eligibility criteria included observational and experimental studies that evaluated the association between the presence of the lower third molar in the fracture line of mandibular angle fractures and possible postoperative complications, including infection, paresthesia, necessity of plate removal, temporomandibular joint disorders, malocclusion, dehiscence, and non-union. Thirty-four papers were included in the qualitative analysis and 26 of those in the meta-analysis. The risk of bias of observational studies was assessed by Newcastle–Ottawa scale and of the clinical trials by Cochrane Collaboration risk-of-bias tool. Absence of the third molar was associated with a lower chance of postoperative infection in angle fractures compared to presence of the tooth (odds ratio 0.55, 95% confidence interval 0.34–0.88). No statistically significant difference between the groups was found for the other outcomes evaluated. The findings of this systematic review suggest that the absence of the third molar in the mandibular angle fracture line is associated with a lower postoperative infection rate when compared to angle fractures with a third molar present.     

Does plate adaptation affect stability? A biomechanical comparison of locking and nonlocking plates.

PURPOSE: The purpose of this investigation was to determine whether the degree of plate adaptation and effects of locking influenced the mechanical behavior of the plate/screw/substrate system for 2.0-mm monocortical superior border plates and 2.4-mm reconstruction plates secured at the inferior border intended to stabilize simulated mandibular angle fractures. MATERIALS AND METHODS: A total of 130 polyurethane synthetic mandible replicas (Synbone, Landquart, Switzerland) were used in this investigation. Five controls each, for incisal edge and molar loading, as well as 5 samples each for 2.4-mm locking and nonlocking reconstruction plates and 2.0-mm locking and nonlocking monocortical superior border plates, intimately adapted (0.0-mm offset), 1.0-mm offset and 2.0-mm offset were subjected to loading at the incisal edge and molar region with an Instron 1331 (Instron Corp, Canton, MA) servohydraulic mechanical testing unit. Load/displacement data were recorded, and yield load, yield displacement, and stiffness were determined. Mean and standard deviation values were calculated. Statistically significant differences were determined for the effects of locking and degree of plate adaptation using a 1-way analysis of variance (P <.05). For differences within categories and among groups, a Sheffé multiple-comparison test was performed. First-order polynomial best-fit curves were created for each group to further evaluate and compare the mechanical behavior. RESULTS: There were no statistically significant differences (P <.05) for yield load, yield displacement, and stiffness within the 2.4 and the 2.0 locking categories for both molar and incisal edge loading. For the 2.4 nonlocking category, there were statistically significant differences for yield load, yield displacement, and stiffness between the 0.0-mm offset group and both the 1.0-mm and 2.0-mm offset groups for both molar and incisal edge loading but not between the 1.0-mm and 2.0-mm groups. For the 2.0 nonlocking category, there were statistically significant differences for yield load, yield displacement, and stiffness between both the 0.0-mm and 1.0-mm offset groups and the 2.0-mm offset group for both molar and incisal edge loading but not between the 0.0-mm and 1.0-mm groups. CONCLUSIONS: The degree of adaptation (amount of offset) affected the mechanical behavior of the nonlocking systems evaluated. It did not affect the locking systems. Failure occurred as an "all-or-nothing" pattern.