A review of mandibular angle fractures

Enhancing the Adaptation of Single Non-compression Miniplate in the Management of Angle Fractures of the Mandible for Better Surgical Outcome-A Technique Modification

The anatomical characteristics and the cortico-cancellous nature of bone disrupted by the presence of teeth make the mandible more vulnerable to fractures during traumatic injuries of the face. Fractures of the angle region constitute about 30% of mandibular fractures due to the change in dentate bone to the lateral flare of ramus, change in grain pattern of the bone, and presence of third molars all weakening the region making it fragile and thus fracture. Several studies corroborated the effectiveness of Champy's technique as to have the lowest complication rate when compared to the other techniques. Though a well-sequenced procedure, fixing an angle fracture is practically challenging and here we describe our experience, with a modification of the sequence to aid in better surgical outcome.

Parameter optimization in a finite element mandibular fracture fixation model using the design of experiments approach

Only a few mandibular bone finite element (FE) models have been validated in literature, making it difficult to assess the credibility of the models. In a comparative study between FE models and biomechanical experiments using a synthetic polyamide 12 (PA12) mandible model, we investigate how material properties and boundary conditions affect the FE model's accuracy using the design of experiments approach. Multiple FE parameters, such as contact definitions and the materials' elastic and plastic deformation characteristics, were systematically analyzed for an intact mandibular model and transferred to the fracture fixation model. In a second step, the contact definitions for the titanium screw and implant (S-I), implant and PA12 mandible (I-M), and interfragmentary (IF) PA12 segments were optimized. Comparing simulated deformations (from 0 to -5 mm) and reaction forces (from 10 to 1'415 N) with experimental results showed a strong sensitivity to FE mechanical properties and contact definitions. The results suggest that using the bonded definition for the screw-implant contact of the fracture plate is ineffective. The contact friction parameter set with the highest agreement was identified: titanium screw and implant μ = 0.2, implant and PA12 mandible μ = 0.2, interfragmentary PA12 mandible μ = 0.1. The simulated reaction force (RMSE = 26.60 N) and surface displacement data (RMSE = 0.19 mm) of the FE analysis showed a strong agreement with the experimental biomechanical data. The results were generated through parameter optimization which means that our findings need to be validated in the event of a new dataset with deviating anatomy. Conclusively, the predictive capability of the FE model can be improved by FE model calibration through experimental testing. Validated preoperative quasi-static FE analysis could allow engineers and surgeons to accurately estimate how the implant's choice and placement suit the patient's biomechanical needs.

Analytical Study of Stress Distributions around Screws in Flat Mandibular Bone under In-Plane Loading

A known complication for mechanically loaded bone implants is the instability due to screw loosening, resulting in infection and the non-union of fractures. To investigate and eventually prevent such bone degradation, it is useful to know the stress state in the bone around the screw. Considering only in-plane loadings and simplifying the mandibular bone into an orthotropic laminated plate, the analysis was reduced to a two-dimensional pin-loaded plate problem. An analytic model, based on the complex stress analysis, was introduced to the bone biomechanics field to obtain the stress distributions around the screw hole in the bone. The dimensionless normalized stresses were found to be relatively insensitive to the locations of the screw hole over the mandible. Parametric analyses were carried out regarding the friction coefficient and load direction. It was found that the load direction had a negligible influence. On the contrary, the friction coefficient had a significant effect on the stress distributions. Whether the screw was well bonded or not thus played an important role. The proposed analytic model could potentially be used to study bone failure together with stress-based failure criteria.

Open Reduction, Internal Fixation of Isolated Mandible Angle Fractures in Growing Children

BACKGROUND

Mandible angle fractures can result in significant, long-term morbidity in children. However, management of this particular mandibular fracture type is not well-characterized in the pediatric population. This study investigated isolated mandibular angle fractures in the pediatric patients.

METHODS

This was a 30-year retrospective, longitudinal cohort study of pediatric patients presenting to a single institution with mandibular angle fractures. Patient data were abstracted from electronic medical records. Subgroup analyses were completed by dentition stage.

RESULTS

Seventeen patients met inclusion criteria, of whom 6 (35.3%) had deciduous, 4 (23.5%) had mixed, and 7 (41.2%) had permanent dentition. Deciduous/mixed dentition patients with mobile, displaced fractures underwent ORIF, whereas those with nondisplaced fractures underwent treatment with soft diet. Among permanent dentition patients, most patients (71.4%) underwent ORIF regardless of fracture severity. The post-ORIF complication rate was 55.6%; no complications were reported after soft diet or closed treatment (Fischer exact: P = 0.05). The most common post-ORIF complication was alveolar nerve paresthesia (17.6%) and post-ORIF complication rates did not vary by age (deciduous: 16.7%, mixed: 25.0%, permanent: 42.9%, Fischer exact: P = 0.80). ORIF patients who received a single upper border miniplate had a lower complication rate (42.9%) than other plating methods (upper and lower miniplates-100%). Fracture severity was predictive of post-ORIF complications (odds ratio: 2.23, 95% confidence interval: 2.22-2.24, P < 0.0001).

CONCLUSIONS

Isolated mandible angle fractures were relatively rare in children, and treatment requirements varied by injury severity and dentition stage. Although isolated angle fractures had substantial associated morbidity, this fracture pattern did not result in notable growth limitations/deformity.

Minimal access fixation of mandibular angle fracture

Angle fractures represent the highest percentage of mandibular fractures. Fixation using a single miniplate ventral to oblique line of buccal cortex of the mandible was described by Champy et al. (1976). Ellis has documented low complication rate with monocortical miniplate fixation as a treatment for angle fractures. Most often used approaches are (a) extraoral approach, (b) intraoral approach, and (c) transbuccal approach. Each of these techniques has its pros and cons. We, in this note, propose an approach which sidelines the drawbacks of these approaches and has the combined advantages of these techniques. This technique results in no external scarring or injury to marginal mandibular nerve, and it also allows direct visualization and confirmation of occlusion during plate placement. This approach is through a contaminated area that poses a risk of infection. This approach of ours is based upon this pioneering works of Forrest. The approach proposed by us can aid an experienced maxillofacial surgeon to provide economical outpatient-based care to patients with minimally displaced/undisplaced angle fracture in a routine dental setup. This technique can be breakthrough for introduction of endoscopic approach for treating angle fracture.

The influence of the mandibular gonial angle on the occurrence of mandibular angle fracture

BACKGROUND/AIMS

Angle fractures represent the largest percentage of mandibular fractures. They pose as a unique entity because of their codependent morphological dynamic factors, rendering the understanding of the mechanism, and treatment challenging. The aim of this study was to analyze the association between the mandibular gonial angle and the risk of mandibular angle fracture while highlighting its clinical relevance.

MATERIALS AND METHODS

A retrospective analysis of radiographs of patients treated for mandibular fractures was done. The factors studied were as follows: the presence of a high gonial angle and an impacted third molar. The outcome was mandibular angle fracture. The gonial angle was measured using Planmeca Digital Software 3.7.0.R. Status of the third molar was also noted. Data obtained were analyzed using SPSS 22 (IBM Corp, Armonk, NY).

RESULTS

The sample comprised 70 mandibular fractures (32 angle fractures and 38 non-angle fractures). The mean gonial angle in the angle fracture group was 128.5 ± 5.4º which was 10.2° larger than in the non-angle group (mean 118.5 ± 4.4º; P = 0.0001). Patients with a high gonial angle were 8.7 times more likely to sustain an angle fracture than those with normal or low gonial angles. A statistically significant relationship between the presence of impacted third molar and patients sustaining mandibular angle fractures was noted (P = 0.0001).

CONCLUSION

Subjects with a high gonial angle and an impacted third molar are at an increased risk for mandibular angle fracture due to direct and indirect morphological factors.

The Influence of the Mandibular Gonial Angle on the Incidence of Mandibular Angle Fracture-A Radiomorphometric Study

PURPOSE

The aim of this radiomorphometric study was to analyze the association between the mandibular gonial angle and the risk of mandibular angle fracture.

MATERIALS AND METHODS

A retrospective analysis of medical records and radiographs of patients treated for mandibular fractures was performed. The exposure studied was the presence of a high gonial angle and the outcome was fracture of the mandibular angle. The mandibular gonial angle and mandibular height at the angle were measured using Facad software (Ilexis AB, Linköping, Sweden). Data obtained were analyzed using SPSS 16 (IBM Corp, Armonk, NY).

RESULTS

The study sample was comprised of 210 mandibular fractures (70 mandibular angle fractures and 140 non-angle fractures). The mean gonial angle in patients with mandibular angle fractures was 126.8 ± 7.9°, which was 4.5° larger than in patients with other mandibular fractures (P = .0001). Patients with a high gonial angle were 11.77 times more likely to sustain an angle fracture than those with normal or low gonial angles (adjusted odds ratio = 11.77; 95% confidence interval, 3.65-37.94; P < .001). There also was a statistically significant decrease in mandibular height at the angle in patients with a high gonial angle (P = .0001).

CONCLUSION

This study shows that people with a high gonial angle are at an increased risk for angle fracture and presents the related clinical implications.

Complications of the use of trans-osseous wire osteosynthesis in the managementof compound, unfavorable and non-comminuted mandibular angle fractures

OBJECTIVE

To analyze cases of compound, unfavorable and non-comminuted mandibular angle fractures treated by trans-osseous wiring, presenting postoperative complications, in a low resource center.

MATERIALS AND METHODS

This was a 13-year retrospective study of 1,324 fractures in 1,317 subjects. The predictor variables were age, gender, aetiology, time lag between injury and treatment, and concomitant mandibular and mid-facial fractures. The outcome variable was the development of complication(s) after treatment. Descriptive and bivariate statistics were computed with EPI INFO 7 version software, and the P value was set at 0.05.

RESULTS

The sample size was composed of 63/1317 (4.8%) of patients with complications. There were 48 males and 15 females with male: female ratio of 3.2:1. The age of the patients ranged from 21 to 62 years (mean 37.4± 5.6 years). The test of significance showed statistically significant association between complications of mandibular angle fractures and increasing age (P<0.002), male gender (P<0.001), road traffic accident (P<0.001), longer time lag between injury and treatment of fractures (P<0.000), and concomitant mandibular fractures (P<0.000). Deranged occlusion (n=19, 28.8%) and limited mouth opening <35mm (n=16, 24.2%) were the common complications. The complications were successfully treated during follow-up.

CONCLUSION

The use of trans-osseous wire osteosynthesis gave good results, and can still be useful in centres that are less well equipped and where access to rigid internal fixation with mini plates is either limited or unavailable.

FUNDING

Self-funded.

Isolated bilateral mandibular angle fractures: an extensive literature review of the rare clinical phenomenon with presentation of a classical clinical model

Bilateral angle fractures are a rare clinical phenomenon in contrast to the incidence of unilateral angle fractures. However, the rarity has garnered less attention in spite of the uniqueness of fracture pattern and distinctive biomechanics. This article is a detailed review on the etiology, clinical presentation, and management of bilateral angle fractures with the presentation of an interesting case. The bilateral angle fracture reported is a untreated, malunited fracture representing an ideal clinical model to study its biomechanics. The clinical features were anterior open bite, increased facial height, and temporomandibular joint tenderness. The management included osteotomy at the malunion and miniplate osteosynthesis. Bilateral angle fracture presents mandible in three independent fragments (left angle, right angle, and intermediate corpus), each with strong muscles acting in different vectors. This makes the fracture vulnerable to severe displacing forces and unfavorable to achieve the optimal reduction, stability, and healing. This necessitates comprehension of the biomechanical forces involved to avoid malunion following fixation. The article details the complex biomechanics of mandibular angle and its clinical implications in the rare event of bilateral angle fractures. It describes the necessity for a systematic approach and ideal osteosynthesis principles to achieve maximal treatment outcomes and minimal complications.

Mandibular trauma treatment: a comparison of two protocols

Objectives: The aim of this study was to evaluate the treatment of mandibular fractures treated in two European centre in 10 years. Study Design: This study is based on 2 systematic computer-assisted databases that have continuously recorded patients hospitalized with maxillofacial fractures in two centers in Turin, Italy and in Amsterdam, the Netherlands for ten years. Only patients who were admitted for mandibular fractures were considered for this study. Results: Between 2001 and 2010, a total of 752 patients were admitted at Turin hospital with a total of 1167 mandibular fractures not associated with further maxillofacial fractures, whereas 245 patients were admitted at Amsterdam hospital with a total of 434 mandibular fractures. At Amsterdam center, a total of 457 plates (1.5 - 2.7 mm) were used for the 434 mandibular fracture lines, whereas at Turin center 1232 plates (1.5 – 2.5 mm) were used for the management of the 1167 mandibular fracture lines. At Turin center, 190 patients were treated primarily with IMF, whereas 35 patients were treated with such treatment option at Amsterdam center. Conclusions: Current protocols for the management of mandibular fractures are quite efficient. It is difficult to obtain a uniform protocol, because of the difference of course of each occurring fracture and because of surgeons’ experiences and preferences. Several techniques can still be used for each peculiar fracture of the mandible.

Key words:Mandibular fracture, facial trauma, maxillofacial, treatment, multicentre, database.

Internal fixation of mandibular angle fractures using one miniplate in Greek children: a 5-year retrospective study

Treatment modalities of mandibular angle fractures (MAFs) have been analyzed in several studies mainly referring to adult populations.

AIM

The aim of this study was to retrospectively present and discuss our experience and literature findings regarding the treatment of MAFs in children.

PATIENTS AND METHODS

Data were retrieved from the files of the Oral and Maxillofacial department, at the Children's Hospital ''P. & A. Kyriakou'' of Athens, during a 5 years period (2009-2013). Demographic features, treatment methods, outcome and follow-up of all patients with mandibular angle fractures were recorded.

RESULTS

6 boys, 5-14 years old (mean age 10 years), were included in the study. They were all treated intraorally with open reduction and fixation via one monocortical titanium plate osteosynthesis at the external oblique line of the mandible, followed by 1 week of intermaxillary fixation (IMF). Plates were removed 3-12 months post-operatively. Follow-up period ranged from 12 to 18 months (mean 14.7 months). All fractures healed uneventfully and the patients tolerated well both the operation and the post-operative period.

CONCLUSION

Osteosynthesis via intraoral approach combined with short duration IMF is adequate in treating MAFs in children.