Effect of lower third molars on the incidence of mandibular angle and condylar fractures

The Evaluation of Objective and Subjective Fate of Teeth in the Mandible Fracture Line and the Management-A Center's Experience

OBJECTIVE

The decision to retain or extract teeth in the line of mandibular fractures has been a subject of debate in much of the scientific literature, and there is a need for further evidence to clear this issue. Thus, the aim of this study was to investigate both the positive and negative effects of teeth in the line of mandibular fractures provide more evidence in this field, as well as take into consideration patients' quality of life after the surgery.

METHODS

Patients after trauma with teeth in the line of mandibular fractures were included in this study. Open reduction and rigid internal fixation, elastic intermaxillary reduction were expected to achieve a satisfactory occlusion and/or anatomical reduction in the fragments as assessed by orthopantomogram, computed tomography scans, and clinical examination. The remaining cases had maxillomandibular fixation (MMF) with an arch bar and bridle wire. All the patients included in this study will take the Visual Analog Scale score evaluation before and after surgery subjectively to further verify the impact on their life qualify, as well as the further treatment needed.

RESULTS

A total of 78 patients with teeth in the line of mandibular fractures were included in this study. Open reduction and rigid internal fixation was used in 37 patients, whereas another 35 patients accepted elastic intermaxillary reduction. Six cases underwent MMF. The number of involved teeth was 83. Three of the 83 teeth involved in the fracture lines healed with complications. In the cases where the teeth had been removed before fracture treatment, or in cases of delayed extractions, no complications were noted. The majority of the patients felt good about the whole treatment, however, 4 in the MMF group complained about worry about their oral health due to MMF leading to mouth open limitation.

CONCLUSION

The factors that should be considered for removal include the condition of the teeth and alveolar bone, the timing and the type of treatment, as well as the patients' desire, if possible. This is an individual-based decision that needs to consider more objective and subjective potential risks to avoid complications.

The influence of wisdom tooth impaction and occlusal support on mandibular angle and condyle fractures

This study aimed to analyze the relationship of the occlusal support together with the lower third molars to the mandibular fractures of the angle and condyle among patients in our medical institutions. This was a retrospective study that reviewed the medical records and radiographs of all patients treated for mandibular fractures from 2015 to 2019. The data collected by using picture archiving and communicating system. Only records with mandibular angle or condyle fractures were included. The dependent variable was the presence of the fractures of the mandibular angle or condyle. The independent variables were epidemiological data, third molar characteristics, existence or absence of occlusal support. The data was analyzed through Univariate logistic regression and multivariate logistic regression. From a total of 187 mandibular fractures, 44 presented mandibular angle fracture and 29 shown condyle fractures. The average age was 40.34 ± 13.47 years. The absence of occlusal support increased the chance of condyle fractures by 5.1 times (95% CI 1.61-17.29). The lack of occlusal support is more associated with condyle fractures than the presence of occlusal support, regardless of third molar presence and characteristics and other variables evaluated.

Does the Presence of Impacted Mandibular Third Molars Increase the Risk of Bad Split Incidence During Bilateral Sagittal Split Osteotomy?

BACKGROUND

The possibility of mandibular bad spilt might happen during bilateral sagittal split osteotomy (BSSO). This study investigated the effect of impacted mandibular third molars on bad spilt incidence during BSSO.

METHODS

Totally, 140 patients under 40 years old who were candidates for BSSO surgery due to class 3 skeletal discrepancy were divided randomly into two equal groups. The impacted mandibular third molars were presented in one group during BSSO (Exposed), and the third molars were removed at least six months before surgery for the other group (Unexposed). All cases underwent BSSO using the same technique by a single surgeon. A bad split was diagnosed by inter-operative clinical examination and postoperative panoramic radiography.

RESULTS

Four bad split occurrences were observed including three patients in the group which impacted mandibular third molars were presented and one patient in the group without impacted mandibular third molars. The incidence of bad fracture in the exposed group was 3.7 times more than the unexposed group. The incidence of the bad fracture in exposed group was 3.7 times more than unexposed group. The chance of fractures in females was 1.7 times higher than males. With one year addition to the patient's age, chance of fracture increased 0.985 times more.

CONCLUSION

Overall incidence of bad split fracture in presence of mandibular third molars in females and at older ages increased during BSSO. The extraction of impacted mandibular third molars, six months before the BSSO is recommended to prevent the bad split incidence during the operation.

Mandible fractures and dental injuries related to road traffic accidents over a 12-year period-Retrospective multicentre study

BACKGROUND/AIM

Road traffic accidents (RTAs) are a common cause of maxillofacial injuries. The aim of this retrospective multicentre study was to investigate the characteristics of maxillofacial fractures and dental injuries that occurred in RTAs in Miyagi, Japan.

MATERIALS AND METHODS

The records of 404 patients with maxillofacial injuries treated at the Oral and Maxillofacial Surgery Departments of four different institutions over a period of 12 years were analysed. Ninety-nine of these patients had suffered these injuries in an RTA. RTA-related cases were divided according to age, gender, presentation month, presentation day of the week, transportation mode, time of accident, fracture sites and fracture mechanism.

RESULTS

There were 72 males and 27 females who suffered injuries as the result of an RTA, for a male-to-female ratio of 2.7:1.0, with a mean age of 35.3 years (range, 1-86 years old). Most of the accidents occurred in June and on a Wednesday, and most of the affected patients were riding a bicycle at the time. The number of patients with maxillofacial injuries related to bicycle riding showed an increasing trend in recent years. Mandible fractures were the most prevalent, followed by dental injuries and maxilla fractures. In cases with a single fracture of the mandible, the symphysis was the most frequent site, while in those with multiple fractures, the association of symphysis and bi-lateral condyle fractures was the greatest. For bicycle-related accidents, a single fracture in the mandible occurred more often than multiple fractures.

CONCLUSIONS

The number of RTA-related injuries while bicycle riding showed an increasing trend with mandible fractures commonly seen in those cases. Efforts to reduce maxillofacial injuries related to bicycle accidents are needed.

Do Mandibular Third Molars Play a Role in Fractures of the Mandibular Angle and Condyle?

INTRODUCTION

The relationship between impacted mandibular third molars with angle and condylar fractures is subject of many publications, yet their conclusions differ widely, hence the authors wanted to investigate this topic in their patients.

METHODS

The authors designed a retrospective study including 241 patients who presented with angle and/or mandibular condyle fractures over a 13-year period at the authors' institution. The study variable was the presence/absence of third molars. The authors used the Pell and Gregory system to classify their position, whereas the angulation was classified using Archer classification. The outcome variables were the presence of angle and condylar fractures. Other study variables included fracture etiology.

RESULTS

Assaults were the most frequent cause of angle fractures (62.7%), whereas falls were mostly responsible for condylar fractures (79.6%). Angle fractures were mostly isolated (66.3%), whereas condylar fractures were mostly associated with other fractures (62.6%). The majority of the angle fractures occurred in patients with third molars (63.6%), on the contrary the majority of the condylar fractures occurred in patients without mandibular third molars (78.3%). Angle fractures were mostly associated with fully erupted or superficially impacted third molars (90,9%). Finally in the presence of mesioangulated third molars, condylar fractures did not happen in 83.8% of patients.

CONCLUSIONS

According to the authors' findings, fully erupted or superficially impacted mandibular third molars are a risk factor for angle fractures but at the same time a protective factor for the condyle. On the contrary, the absence of mandibular third molars "strengthens" the angle and represents a risk factor for condylar fractures.

Does the angulation of the mandibular third molar influence the fragility of the mandibular angle after trauma to the mandibular body? A three-dimensional finite-element study

The relationship between mandibular third molar (M3) angulation and mandibular angle fragility is not well established. The aim of this study was to evaluate the impact of M3 angulation on the mandibular angle fragility when submitted to a trauma to the mandibular body region. A three-dimensional (3D) mandibular model without M3 (Model 0) was obtained by means of finite-element analysis (FEA). Four models were generated from the initial model, representing distoangular (Model D), horizontal (Model H), mesioangular (Model M) and vertical (Model V) angulations. A blunt trauma with a magnitude of 2000 N was applied perpendicularly to the sagittal plane in the mandibular body. Maximum principal stress (P_max) (tensile stress) values were calculated in the bone. The lowest P_max stress values were noted in Model 0. When the M3 was present extra stress fields were found around marginal bone of second molar and M3. Comparative analysis of the models with M3 revealed that the highest level of stress was found in Model V, whereas Model D showed the lowest stress values. The angulation of M3 affects the stress levels in the mandibular angle and has an impact on mandibular fragility. The mandibular angle becomes more fragile in case of vertical impaction when submitted to a trauma to the mandibular body region.

Does an Association Exist Between the Presence of Lower Third Molar and Mandibular Angle Fractures?: A Meta-Analysis

PURPOSE

The current data suggest that the presence of lower third molars predisposes the patient to a greater risk of mandibular angle fracture. Thus, the present review sought to determine whether an association exists between the presence of a lower third molar and the occurrence of a mandibular angle fracture in adults and to assess the influence of third molar position according to the Pell and Gregory classification.

MATERIALS AND METHODS

The present study was a systematic review and meta-analysis of analytical observational studies. The present review included all reports of the relationship between mandibular angle fractures and lower third molars. No restriction regarding year, language, or publication status was used. The review protocol was registered at the PROSPERO database (registration no. CRD42016047057). Electronic searches unrestricted for publication period and language were performed in the PubMed, Scopus, SciELO, and Latin American and Caribbean Health Sciences databases. Google Scholar and OpenGrey databases were used to search the "gray literature," avoiding selection and publication biases. The entire search was performed by 2 eligibility reviewers. Association and proportion meta-analyses were planned for the studies with sufficient data. The primary predictor variable was the relationship between the presence of a lower third molar and the development of mandibular angle fractures. The secondary outcome variables were the vertical and horizontal positions of the lower third molar, according to the Pell and Gregory classification and their relationship to the susceptibility to developing a mandibular angle fracture.

RESULTS

The search strategies resulted in 411 studies, from which 16 were selected for qualitative and quantitative review. The association meta-analysis included all the selected studies and showed that patients with lower third molars are 3.16 times more likely to develop mandibular angle fractures. The proportion meta-analysis included 5 studies and showed that the overall rate of mandibular angle fractures was 51.58% and that positions III and C are more likely to result in fracture, with a rate of 59.84 and 63.67%, respectively.

CONCLUSIONS

The results of the present study have shown that the presence of impacted third molars increases by 3.16 times the risk of mandibular angle fractures in adults, with the greatest risk present when third molars are classified as IIIC according to Pell and Gregory. The available evidence is not sufficiently robust to determine whether third molar presence or the level of impaction is the main causative factor for the occurrence of mandibular angle fractures.

How Is Third Molar Status Associated With the Occurrence of Mandibular Angle and Condyle Fractures?

PURPOSE

Third molars (M3s) have been hypothesized to be associated with the risk of mandibular angle fracture and mandibular condylar fracture. The authors systematically estimated the relative risk (RR) of M3 status for the development of mandibular angle fracture and mandibular condylar fracture through a meta-analysis of cohort studies.

MATERIALS AND METHODS

In this systematic review, the PubMed, EMBASE, and Cochrane Library databases were searched from inception to October 2016. The predictor of risk was the presence or absence of M3s. The primary outcome was the RR of mandibular angle or condylar fracture. A fixed- or a random-effects model was applied to evaluate the pooled risk estimates. Sensitivity analysis also was performed to identify the potential sources of heterogeneity. Publication bias was assessed by the Begg and Egger tests.

RESULTS

Overall, 13 retrospective cohort studies were included. Of these, 13 reported the association between M3s and mandibular angle fracture, and 5 reported the association with mandibular condylar fracture. Patients with M3s had an increased risk of mandibular angle fractures (RR = 2.63; 95% confidence interval [CI], 2.15-3.21) but a decreased risk of mandibular condylar fractures (RR = 0.47; 95% CI, 0.25-0.86). Substantial heterogeneity in the risk estimates was found. No evidence of publication bias was found.

CONCLUSION

The present meta-analysis provides further evidence associating the presence of M3s with an increased risk of mandibular angle fractures and a simultaneously decreased risk of mandibular condylar fracture. Because of potentially more serious complications associated with condylar fracture, clinicians should carefully consider the decision to remove M3s to decrease the risk of mandibular angle fracture.

Influence of third molars in mandibular fractures. Part 1: mandibular angle-a meta-analysis

The aim of this systematic review was to investigate the influence of the presence and position of mandibular third molars on angle fractures. An electronic search was conducted in the PubMed, Scopus, Web of Science, Cochrane Library, and VHL databases, through January 2016. The eligibility criteria included observational studies. The search strategy resulted in 704 articles. Following the selection process, 35 studies were included in the systematic review and 28 in the meta-analysis. Twenty studies presented a score of ≤6 stars in the Newcastle-Ottawa scale assessment, indicating a risk of bias in the analysis. The presence of a mandibular third molar increases the chance of an angle fracture (case-control and cross-sectional studies: odds ratio (OR) 3.83, 95% confidence interval (CI) 3.02-4.85, I²=83.1%; case-control studies: OR 3.27, 95% CI 2.57-4.16, I²=81.3%). The third molar positions most favourable to angle fracture according to the Pell and Gregory classification are class B (OR 1.44, 95% CI 1.06-1.96, I²=87.2%) and class II (OR 1.67, 95% CI 1.36-2.04, I²=72.4%). Class A (OR 0.60, 95% CI 0.45-0.81, I²=87.1%) and class I (OR 0.51, 95% CI 0.37-0.71, I²=89.4%) act as protective factors for angle fracture. The results suggest that the presence of the third molar increases the chance of angle fracture by 3.27 times and that the most favourable positions of the third molar for angle fracture are classes B and II, whilst classes A and I act as protective factors.

Influence of third molars in mandibular fractures. Part 2: mandibular condyle-a meta-analysis

The aim of this systematic review was to investigate the influence of the presence and position of mandibular third molars in mandibular condyle fractures. An electronic search was conducted in PubMed, Scopus, Web of Science, Cochrane Library, and VHL, through January 2016. The eligibility criteria included observational studies. The search strategy resulted in 704 articles. Following the selection process, 13 studies were included in the systematic review and 11 in the meta-analysis. In terms of the risk of bias analysis, six studies presented ≤6 stars in the Newcastle-Ottawa scale assessment. The presence of a mandibular third molar decreased the probability of condylar fracture (cross-sectional and case-control studies: odds ratio (OR) 0.26, 95% confidence interval (CI) 0.17-0.40, I²=87.8%; case-control studies: OR 0.30, 95% CI 0.16-0.58, I²=91.6%). The third molar positions most favourable to condylar fracture according to the Pell and Gregory classification are class A (OR 1.32, 95% CI 1.09-1.61, I²=0%) and class I (OR 1.37, 95% CI 1.05-1.77, I²=32.8%). Class B (OR 0.69, 95% CI 0.49-0.97, I²=56.0%) and class II (OR 0.71, 95% CI 0.57-0.87, I²=0%) act as protective factors for condylar fracture. The results suggest that the presence of a mandibular third molar decreases the chance of condylar fracture and that the positions of the third molar most favourable for condylar fracture are classes A and I, with classes B and II acting as protective factors.

Correlation of Third Molar Status with Incidence of Condylar and Angle Fractures

The mandibular angle and condylar regions are most prone to fractures and this has been attributed to the presence/absence or the position of the third molars. This retrospective study was undertaken to analyze the correlation between the third molars and incidence of condylar and angle fractures in 104 patients treated for these fractures during the period from June 2009 to December 2013. Clinical and radiographic records of these patients were studied to look for the presence and position of third molars and their relation to incidence of condylar or angle fractures. There was a definite positive relation to impacted third molars and increased incidence of angle fractures. The condylar fractures were more commonly seen when the third molars were fully erupted or missing. Third molar impactions predispose to angle fractures and missing or fully erupted third molars predispose to condylar fractures.

A multi-centre retrospective study of mandibular fractures: do occlusal support and the mandibular third molar affect mandibular angle and condylar fractures?

This retrospective study was performed to investigate the influence of occlusal support and the presence, state, and position of mandibular third molars on the incidence of mandibular angle and condylar fractures. The following variables were investigated: age, sex, cause of fracture, presence and state (impaction, angulation, and the number of roots) of the mandibular third molars, site of the mandibular fracture, presence of occlusal support, duration of intermaxillary fixation, and postoperative complications. Various risk factors for mandibular angle and condylar fractures were investigated by univariate analysis. The risk of mandibular angle fracture was significantly higher in patients with occlusal support and mandibular third molars. The risk of condylar fracture was significantly higher in patients without occlusal support or mandibular third molars. The position and angulation of the mandibular third molars were not significant risk factors in mandibular angle and condylar fractures. This study demonstrated the influence of occlusal support and the presence of mandibular third molars on the incidence of mandibular angle and condylar fractures. The presence of occlusal support may be a more important factor affecting mandibular angle or condylar fractures than the position of the mandibular third molars.

Does the presence or position of lower third molars alter the risk of mandibular angle or condylar fractures?

PURPOSE

The purpose of this study was to determine whether a relation exists between the presence of mandibular third molars (M3s) and mandibular angle and condylar fractures and whether the risk of these fractures varies with M3 position.

MATERIALS AND METHODS

A retrospective cohort study was conducted in patients with mandibular fractures presenting to the oral and maxillofacial surgery service from April 2007 to March 2012. Data sources were patients' hospital charts and panoramic radiographs. Predictor variables were the presence and position of M3s. M3 position was based on the Pell and Gregory classification and angulation was determined by measuring the angle between the long axis of the M3 and the mandibular occlusal plane. Outcome variables were the presence of angle and condylar fractures. Other study variables included age, gender, and fracture etiology. Data were analyzed using the χ(2) test and Student t test.

RESULTS

The study sample consisted of 446 patients with 731 mandibular fractures. Results showed that the risk of mandibular angle fracture was significantly higher in patients and mandible sides with impacted M3s (P < .001), whereas the risk of condylar fracture was significantly higher in patients and mandible sides lacking impacted M3s (P < .001). A relation between the position of M3s to angle or condylar fractures could not be found (P > .05).

CONCLUSION

The presence of impacted M3s increased the risk of angle fracture and simultaneously decreased the risk of condylar fracture. However, no relation appeared to exist between M3 position and fracture pattern.

Do erupted third molars weaken the mandibular angle after trauma to the chin region? A 3D finite element study

It has been suggested that third molars increase mandibular fragility because they do not contribute to its strength. For ethical reasons, a human study design that would permit the elucidation of this interference is not possible. This study evaluated the impact of the presence of erupted third molars on the mandibular angle of resistance when submitted to trauma. A three-dimensional (3D) mandibular model was obtained through finite element methodology using computed tomography (CT) with the geometry and mechanical properties to reproduce a normal mandibular structure. Human mandibles with no, one or two erupted third molars were evaluated. Whenever the third molar was present there was a greater concentration of tensions around the cervical part of its alveolus. Approximated Von Mises equivalent stress of the third molar region was 107.035 MPa in the mandible with teeth and 64.6948 MPa in the mandible without teeth. In the condylar region it was 151.65 MPa when the third molar was present and 184.496 MPa when it was absent. The digital models created proved that the mandibular angle becomes more fragile in the presence of third molars. When they are absent the energy concentrates on the lateral e posterior aspect of the condylar neck.

Fractures of angle of mandible - A retrospective study

AIMS

This retrospective study was done to evaluate the efficacy of single miniplate osteosynthesis at superior border of angle of mandible.

MATERIAL AND METHODS

In this study 50 patients were treated by single miniplate osteosynthesis according to Champy's principle. Bite force generated was used as a parameter for judging the efficacy of internal fixation. In this article we present our experience over the years in the management of the fractures of angle of mandible based on this model.

RESULTS

Most patients were of 21-30 yrs of age with unilateral angle fracture of mandible except one patient who had isolated bilateral angle fracture. The patients were treated successfully according to Champy's principle of osteosynthesis. There was a progressive improvement in the bite force generated after osteosynthesis.

CONCLUSIONS

The angle of the mandible is an anatomically weak and an area susceptible to fracture. The presence of an impacted or partially erupted third molar tooth further weakens it. Angle of mandible is the most common site for fracture however, bilateral angle fracture is very rare and uncommon. Osteosynthesis according to Champy's model led to an early functional improvement as demonstrated by the bite force generated.