Experimental fractures of monkey mandibles

Iatrogenic Mandibular Ramus Fracture Following Surgical Removal of Impacted Third Molar

Surgical removal of an impacted tooth is considered to be one of the most frequently performed minor oral surgical procedures due to the plethora of indications associated with it. Like any other surgical intervention, the surgical removal of impacted third molars is also associated with numerous complications. Lot of emphasis has been laid to prevent the complications associated with the surgical removal of impacted third molars. However, at times in spite of delivering the utmost caution, complications occur as a consequence of surgical removal of impacted third molars. We report a rare case in which iatrogenic mandibular ramus fracture occurred in an attempt to surgically removal of an impacted third molar.

Does the Impacted Mandibular Third Molar Increase the Risk of Angle Fracture to Prevent the Incidence of Condylar Fracture? - A Retrospective Analysis

Introduction

This study aimed to retrospectively analyse the influence of the presence or absence of third molars and its position on the incidence of angle and condylar fractures of mandible.

Methodology

A retrospective cross-sectional analysis of 148 patients with mandibular fractures was done. A complete analysis of their clinical records and their radiological data was done. The primary predictor variable was the presence or absence of third molars and their positional status (Pell and Gregory's classification) if present. The outcome variable was the type of fracture and other predictor variables included age, gender and fracture aetiology. Data were subjected to statistical analysis.

Results

We observed that out of 48 patients with angle fractures, third molar was present in 67.34% and in 51.35% of 37 patients with condylar fractures, and there existed a positive correlation between the both. A significant association between the position of the teeth (Class II, III and Position B), angle fractures and (Class I, II, Position A) and condylar fractures was observed.

Conclusion

Angular fractures were associated with superficial and deep impactions and condylar fractures were associated with superficial impactions. No association was observed with the age, gender or mechanism of injury to the pattern of fractures. Impacted mandibular molars increase the risk of angle fracture, thereby preventing the force transmission to the condyle, and the absence or a fully erupted tooth increases the risk of condylar fractures.

Iatrogenic Fracture of the Lower Jaw: A Rare Complication of Lower Molar Extraction

Iatrogenic mandible fracture is a rare complication of a tooth extraction with an incidence between 0.0033-0.0034%. This study retrospectively analyzes a total of 8 patients who underwent lower molar extraction associated with mandible fracture during tooth removal in the period from April 2006 to March 2019. The assessed parameters were age and sex of patients, method of tooth extraction, side distribution of fracture, type of extracted tooth, the position of a lower third molar, presence of bone pathological lesion formed in connection with a tooth, displacement of bone fragments, and sensory impairment in the innervation area of the mental nerve. The position and impaction of the lower third molars were evaluated according to Pell and Gregory's classification and Winter's classification. One fracture was left-sided, and 7 fractures were right-sided. In 6 cases, Winter's extraction elevator was used. In 7 patients, the mandible fracture was treated surgically by performing stable osteosynthesis with the plates and screws. One patient was treated conservatively. This work analyzes the causes of iatrogenic mandible fractures and provides recommendations to reduce the risk of their occurrence.

Horizontal fracture of anterior mandible

A 33-year-old male patient reported to us with the history of assault. The patient was cooperative and oriented, with no sign of head injury. He was assaulted with an axe over the mandible. The patient is having posteroanterior view radiographs of the mandible suggesting isolated horizontal fracture of the anterior mandible. Under general anaesthesia, this unusual fracture was treated by open reduction and internal fixation with a three-dimensional plate and miniplates. The case was managed successfully without any postoperative complications.

Impact of mandibular third molars on angle fractures: A retrospective study

BACKGROUND

Previous studies have shown that the position and presence of mandibular third molars is associated with a high risk of mandibular angle fractures. The aim of this study was to assess the relationship between the position and presence of mandibular third molars and mandibular angle fractures.

MATERIAL AND METHODS

A retrospective study consisting of 256 patients who were admitted for treatment of mandibular fractures between January 2016 and January 2018 was undertaken. Patients' data and orthopantomogram radiographs were obtained from their medical record. The predictor variable was the presence and position of mandibular third molars. The position of the third molars was grouped based on the Pell and Gregory classification. The outcome variable was the presence of an angle fracture. Other study variables included age, gender, mechanism of injury, and fracture location.

RESULTS

Patients with mandibular third molars had a 2.7 times greater chance of an angle fracture than patients without third molars. Patients with their third molars present at occlusal position C and ramus position level 3 had a higher risk of angle fracture in comparison with other groups. There was a statistically significant variation in the risk of an angle fracture, depending on mandibular third molar position (P < .001).

CONCLUSION

Patients with mandibular third molars have an increased risk of angle fractures. The risk for an angle fracture varied depending on the third molar position.

An Anatomic Predisposition to Mandibular Angle Fractures

PURPOSE

To investigate a predisposition to mandibular angle fractures, a retrospective study was performed in which fractured mandibles were compared with healthy mandibles with no history of fracture. Other investigations of angle fracture risk have exclusively studied patients with existing fractures. In addition, the risk has not been comprehensively explained in conjunction with the specific features of mandibular anatomy. We sought to characterize any anatomic variations between the jaws that had fractured and those that had never fractured.

MATERIALS AND METHODS

Healthy mandibles with no history of fracture were physically measured at the William M. Bass Skeletal Collection at the University of Tennessee, Knoxville and compared with fractured mandibles from computed tomography (CT) scans at the Dartmouth Hitchcock Medical Center. A total of 52 healthy mandibles and 44 CT scans were evaluated. MATLAB machine learning algorithms (MathWorks, Natick, MA) were used to compare the study populations and isolate those anatomic features that differed between healthy and fractured mandibles.

RESULTS

Machine learning classifiers were able to differentiate between male and female jaws, with the condylion-gnathion distance the most distinguishing feature. The 6 most common anatomic features that differed between healthy and fractured mandibles were the 1) retromolar space, 2) perimeter of the cross-section just proximal to the second molar, 3) breadth of the ramal cross-section, 4) thickness of the oblique ridge, 5) transgonial angle, and 6) location of the ipsilateral mental foramen. The presence of third molars was also related to fracture risk, with third molars present in 72.7% of the fractured mandibles versus 26.9% of unfractured mandibles. Of the fractured mandibles with third molars present, 87.5% had the fracture running directly through the tooth or its socket.

CONCLUSIONS

The results from the present study have provided evidence that anatomic differences exist between mandibles that sustain angle fractures and those that do not. Although much of the morphology was found to be interdependent, the fracture risk could be accurately predicted using 6 anatomic features. Understanding these mandibular variations and identifying patients vulnerable to mandibular fracture could provide clinicians with additional objective information. Furthermore, using the methods demonstrated in our study, future research could focus on developing an algorithm that includes these unique anatomic features in the hope of assisting surgeons in providing tailored treatment for mandibular angle fractures according to patient-specific morphology.

Transbuccal Approach in Management of Mandible Angle Fracture

With expanding dimensions and an eminent member of trauma team many Ear Nose Throat specialists are exposed to Oro-maxillofacial trauma. Mandibular angle is a difficult region to operate owing to its unique anatomy. Anglefractures form around 30-40% of the mandibular fracture. Open reduction and internal plating is the management of choice in most angle fractures and various approaches have been described in literature. We conducted a study of trans-buccal approach for management of mandibular angle fractures. It was a non-randomised observational study. 57 patients of mandible angle fractures were included in the study. The ORIF was done in these pts under general anaesthesia after careful surgical planning using trans-buccal approach. This approach included an intraoral exposure with stab incision for the trans-buccal passage of drill and screw diver. Out of 57 cases in our study 33 were males and 24 were females. 23/57 patients were in age group 25-35 years whereas 19/57 patients were in age group 15-25 years All 57 patients had good fracture healing. Occlusion dysfunction was seen in only 1 case. Infection was seen 3 cases while intraoral exposure of plates occurred in 2 cases. Average mouth opening was 43.3 mm at 6 weeks with progressive improvement on follow up. Extraoral scar healed well with very good cosmesis in all cases. We strongly suggest the use of transbuccal approach for ORIF in mandibular angle fractures owing to the ease of procedure, comfort of surgeon and less complication rate.

Association Between Third Molar Impaction Status and Angle or Condylar Fractures of the Mandible: A Retrospective Analysis

PURPOSE

The aim of our study was to evaluate the correlations between mandibular third molar impaction status and mandibular angle and condylar fractures.

MATERIALS AND METHODS

This retrospective cross-sectional study included patients with unilateral and isolated angle or condylar fractures. Patient records and panoramic radiographs were evaluated. The predictor variables included the presence, impaction status (Pell and Gregory [P&G] classification), and angulation (Winter classification) of the third molar. The outcome variable was the type of fracture, whereas other predictor variables included demographic factors such as age, gender, and fracture etiology. Bivariate (χ² test) and logistic regression analyses were conducted to estimate the associations between variables and the outcome.

RESULTS

The sample was composed of 164 angle fracture (mean age, 31.6 ± 12.3 years; 83.5% male) and 115 condylar fracture (mean age, 41.9 ± 16.8 years; 76.5% male) patients. A third molar was present in 72.6% of the angle fracture group and 54.8% of the condylar fracture group (P = .002). Deep impactions (classes IC, IIC, IIIB, and IIIC) exhibited an odds ratio (OR) of 3.60 for angle fractures (P < .001). No association was found between tooth angulations and the type of fracture. According to logistic regression analysis, older age (adjusted OR, 1.05; 95% confidence interval [CI], 1.03 to 1.07), P&G class I impaction (OR, 1.86; 95% CI, 1.09 to 3.20), and P&G class A impaction (OR, 1.91; 95% CI, 1.12 to 3.24) were significantly associated with condylar fractures whereas the presence of a third molar (OR, 0.46; 95% CI, 0.28 to 0.76) or P&G class B impaction (OR, 0.287; 95% CI, 0.12 to 0.69) was associated with angular fractures.

CONCLUSIONS

P&G class II or III and class B impaction status was significantly associated with angle fractures, whereas missing or fully erupted (class IA) third molars significantly correlated with condylar fractures.

Relationship between mandible fractures and third molars

Background

This study was conducted to determine the relationship between third molar (M3) and mandibular fracture.

Methods

Patients with unilateral mandibular angle or condyle fractures between 2008 and 2018 were evaluated retrospectively. Medical records were reviewed regarding the location of fractures, and panoramic radiographs were reviewed to discern the presence and position of ipsilateral mandibular third molars (M3). We measured the bony area of the mandibular angle (area A) and the bony area occupied by the M3 (area B) to calculate the true mandibular angle bony area ratio (area A–B/area A× 100).

Results

The study consisted of 129 patients, of which 60 (46.5%) had angle fractures and 69 (53.5%) had condyle fractures. The risk of angle fracture was higher in the presence of M3 (odds ratio [OR], 2.2; p< 0.05) and the risk of condyle fracture was lower in the presence of M3 (OR, 0.45; p< 0.05), than in the absence of M3. The risk of angle fracture was higher in the presence of an impacted M3 (OR, 0.3; p< 0.001) and the risk of condyle fracture was lower in the presence of an impacted M3 (OR, 3.32; p< 0.001), than in the presence of a fully erupted M3. True mandibular angle bony area ratio was significantly lower in the angle fractures than in the condyle fractures (p= 0.003).

Conclusion

Angle fractures had significantly lower true mandibular angle bony area ratios than condyle fractures. True mandibular angle bony area ratio, a simple and inexpensive method, could be an option to predict the mandibular fracture patterns.

Impacted Mandibular Third Molars and Their Influence on Mandibular Angle and Condyle Fractures

The aim of this study is to retrospectively analyze the effect unerupted or partially erupted third molars have on the angle and condyle fracture patterns of the mandible. It also focuses on evaluating the type of impaction that causes angle fracture and the level at which the condyle most commonly fractures. The study involves all the patients who had undergone treatment for condylar and angle of the mandible fractures from 2010 to 2017 in our craniofacial center. The case records and orthopantomograms of each patient were taken into consideration and a correlation was established based on gender, age, etiology, presence of third molars, position of third molars, angulation, and root development of third molars. Of the 150 angle fracture patients, 146 had third molars and 4 did not, whereas of the 130 condyle fractures, third molar was present in 54 patients and absent in 76. The prevalence of angle fractures was statistically significant when a third molar was present, whereas the prevalence of condyle fractures was higher when third molar was absent. The results of age, etiology, angulation, position, and root development of third molars were also statistically significant. However, sex of the patient did not influence the fracture pattern. The presence of an impacted third molar or a completely erupted one has a definite influence on the fracture pattern of the mandible. The occurrence of angle and condyle fractures was mostly affected by the continuity of the cortical bone at the angle of the mandible. Hence, prophylactic removal of mandibular third molars does increase the risk of condyle fractures.

Assessment of the Role of the Mandibular First Molar Tooth in Mandibular Fracture Patterns of 29 Dogs

Mandibular fractures at the level of the first molar tooth (M1) were assessed in 29 dogs. Patients included in this study demonstrated fractures involving the M1 tooth, tooth bud, or alveolus (if tooth was absent). Diagnostic imaging evaluation included intraoral dental radiography and/or computed tomography (CT) with 3D reconstruction. The distal root was involved in 55.2% of cases, mesial root involvement in 34.5% of cases, and the tooth was absent in 10.3% of cases. Fractures were described in the rostral-to-caudal direction. Fractures tended to occur in the caudoventral direction ( P = .057). Cases with CT imaging were also evaluated in the buccolingual direction. Fractures were found to occur significantly more frequently in the caudolingual direction ( P = .022). When classifying fracture patterns along M1 according to a previously published fracture classification system, it was noted that fractures occurred significantly more frequently in either the mesial ( P < .001) or distal ( P < .001) roots by coursing along the periodontal ligament space and communicating with the periapical region. Active or nonworsening periodontitis was described as radiographic or tomographic evidence of (>25%) bone loss in the vertical or horizontal direction. Periodontitis was associated with 7 (24.1%) cases. These results help frame the challenges associated with fracture repair at the M1 location. Treatment planning considerations should include limited structural support caudal to fractures involving the distal root, more frequent involvement of the distal root over the mesial root, risk for poor endodontic prognosis, and the predilection for unfavorable fracture patterns to occur.

Is prophylactic removal of impacted mandibular third molar justified in all patients? A prospective clinical study of patients 50 years and above

BACKGROUND

The prophylactic extraction of asymptomatic impacted mandibular third molar is a contentious issue in dental practice.

OBJECTIVE

To evaluate symptomatic impacted mandibular third molars in patients 50 years and above, and determine the burden of the impaction on the adjacent second molar.

METHODS

This was a prospective clinical study over a three-year period. The diagnosis of impacted mandibular third molar and their associated pathology was made by clinical and radiological examination. The data obtained were age, sex, type of impaction, reason for surgical extraction, and the clinical condition of the adjacent second molar.

RESULTS

Patients 50 years and above were 33.4%, and those with impaction 22.8%, while the symptomatic cases were in 18.4% patients. The age of the patients ranged from 52 to 84 years with male: female ratio, 2.3:1. In all the asymptomatic impactions, the adjacent second molars were disease-free, whereas 73.6% of the adjacent second molar related to symptomatic cases were asymptomatic (P=0.001).

CONCLUSION

This study showed that 15.9% of impactions in 18.4% of patients were symptomatic and required surgical extraction, whereas the burden of impaction on the adjacent second molar was 26.4%, and these required only preventive and restorative treatments.

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.

Anatomical and Radiological Investigation of Dry Bone Adult Mandibles Having Impacted Third Molar Teeth

OBJECTIVE

To investigate the incidence of the impacted mandibular third molars in dry bones adult mandibles.

METHODS

The 198 dry bones adult mandibles gathered from the bone collections in Laboratory of the Anatomy Department of Dokuz Eylul University School of Medicine were macroscopically examined for the presence of impacted mandibular third molars. The genders of the adult bones were unknown. The adult mandibles having impacted third molars were photographed with Canon 400B (55 mm objective). The mandibles having impacted third molars were also radiographically examined with orthopantomography (a dental radiographic technique, kV 60, mA 2.0) in radiology unit of Faculty of Dentistry, Ege University. The impacted teeth were grouped according to their position and degree of impaction.

RESULTS

The each of 2 of 198 adult mandibles (2/198; 1.01%) was having an impacted 3rd molar teeth. These 2 molar teeth were belonged to class 1, B and partially buried, vertically oriented. The first impacted 3rd molar teeth was located on the left side of the one mandible and the second one on the right side of the other mandible.

CONCLUSION

The present study provides information about impacted mandibular 3rd molar in dry bones.

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 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.

Relation of Lower Last Molar Teeth With Mandibular Fractures

OBJECTIVES

The objectives of this study were to study and investigate the relation between the state of the lower last molar teeth eruption and the site of the mandibular fractures.

METHODS

Adult patients with traumatic mandibular fractures were included in this study. Panorama and computed tomography was performed for all patients. The relation between the state of the lower last molar eruption and criteria of the fracture was analyzed.

RESULTS

In 106 patients who had 168 mandibular fractures, impacted lower third molar teeth were found to significantly increase the incidence of mandibular angle fracture while they had nonsignificant effect on incidence of other sites of mandibular fractures.

CONCLUSION

Impacted lower third molar teeth significantly increase the incidence of mandibular angle fracture but did not have the same effect on other sites of mandibular fractures.

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.

Mechanics in the Production of Mandibular Fractures: A Clinical, Retrospective Case-Control Study

As the mandible is susceptible to fracture, the aim of this study was to use multivariate logistic regression analysis to identify and distinguish various internal factors that may influence the location of mandibular fractures. The study included 1131 patients with maxillofacial fractures during the period from January 2000 to December 2009 to evaluate the association of mandibular fracture location (unilateral symphysis, body, angle, condylar, or bilateral condylar fractures) with various internal factors. Among the 1131 patients, 869 had mandibular fractures. Data on age, sex, soft tissue injuries, dental trauma, and maxillofacial fracture type were collected and analyzed using multivariate logistic regression. In total, 387, 210, 139, 319, and 172 patients were diagnosed with unilateral symphysis, body, angle, unilateral, or bilateral condylar fractures, respectively. The dental trauma in patients with bilateral condylar fractures differed from that in patients with unilateral condylar fractures. Patients with mandibular fracture (unilateral symphysis, body, unilateral or bilateral condylar) possessed an approximately equal risk of soft tissue injuries in the mandible. Patients with either unilateral or bilateral condylar fractures were associated with a low risk of mandibular angle fracture (OR < 1). Similarly, patients with mandibular angle fracture were associated with a low risk of unilateral or bilateral condylar fractures (OR < 1). Moreover, patients with symphysis fracture were associated with a low risk of bilateral condylar fractures (90 of 387 [23.3%], OR 0.899). By contrast, patients with bilateral condylar fractures were associated with a high risk of symphysis fracture (90 of 172 [52.3%], OR 17.38). Patients with condylar fractures, particularly those with bilateral condylar fractures, were infrequently associated with secondary mandibular fractures. Mandibular fractures tended to have less of an association with midfacial fractures. The occurrence of mandibular fractures is strongly correlated with age, sex, soft tissue injuries, dental trauma, and the pattern and position of the maxillofacial fractures in patients.

Relationship between fracture of mandibular condyle and absence of unerupted mandibular third molar-a retrospective study

PURPOSE

The purpose of the present study was to find, if there exists, a co-relation between presence of unerupted mandibular third molar and fracture of mandibular condyle.

METHODS

A retrospective, multicenter study was done collecting the data of all mandibular condyle fractures treated from November 2006 till August 2015. Data was collected from the patient's records and radiographs for the following information: age, sex, etiology of fracture, presence and state of lower third molars, and associated fracture. The results were subjected to statistical analysis.

RESULTS

Out of 180 patients of condylar fracture, unerupted third molars were present in 35 (19.44 %) cases compared to 145 (80.55 %) cases of condylar fracture where the unerupted third molars were not present. The difference was statistically significant (p < 0.05). In the unerupted third molar present group, isolated bilateral condylar fracture was seen in 4 (11.4 %) cases, bilateral condylar fracture associated with other mandibular fractures in 9 (25.7 %) cases, isolated unilateral condylar fracture in 0 (0.0 %) cases, and unilateral condylar fracture associated with other mandibular fractures in 17 (48.5 %) cases and condylar fracture associated with mid face fractures in 5 (14.2 %) cases. In the unerupted third molar absent group, isolated bilateral condylar fracture was seen in 5 (3.4 %) cases, bilateral condylar fracture associated with other mandibular fractures in 30 (20.6 %) cases, isolated unilateral condylar fracture in 24 (16.5 %) cases, unilateral condylar fracture associated with other mandibular fractures in 73 (50.34 %) cases, and condylar fracture associated with mid face fractures in 13(8.96 %) cases. The difference between the groups was statistically significant (p = 0.032).

CONCLUSION

This study suggests that the fractures of mandibular condylar region have a significantly higher incidence in patients without an unerupted mandibular third molar.

Impact of the lower third molar and injury mechanism on the risk of mandibular angle and condylar fractures

BACKGROUND

Previous studies have shown the influence of the mandibular third molar on mandibular angle and condylar fractures, but have not comparatively analyzed the impact of the injury mechanism on these fractures. The purpose of this study was to evaluate the influence of the lower third molar (M3) and injury-related factors (fracture etiology and site of impact of the traumatic force) on the risk of mandibular angle and condylar fractures.

MATERIAL AND METHODS

The study included 615 patients who sustained a mandibular fracture in a 13-year period (from January 2000 to December 2013). The independent variables were presence, position and the root number of the M3, fracture etiology, and site of impact of the force. The outcome variables were mandibular angle and condylar fractures. Other variables included in the study were patients' gender and age. The data were analyzed using the chi-square test. Univariate and multivariate binary logistic regression analyses were used to evaluate the relationship between angle and condylar fractures and to show potential determinants.

RESULTS

Angle fractures were significantly influenced by the M3, site of impact, and age, but the main predictors were the eruption status and vertical position of the M3 (classified by Pell and Gregory) and site of impact of the force. Condylar fractures were significantly influenced by the M3 and site of impact of the force, but only the last showed as a predictor.

CONCLUSIONS

Factors related to the M3 showed more significant influence on angle fractures than on condylar fractures.

Influence of the impacted mandibular third molars on fractures of the mandibular angle and condyle - A prospective clinical study

AIMS

This study was set out to evaluate the relationship between the presence and absence of unerupted mandibular third molar and fracture of mandibular angle/condyle, and to analyse if prophylactic removal of symptom-free unerupted mandibular third molar is beneficial.

METHODS

Hundred patients of mandible fracture were selected randomly irrespective of age, sex, caste, creed and socio-economic status. Data were collected from the patients on the basis of history, clinical examination and radiographs for the following information: age, sex, aetiology of fracture, presence and status of the mandibular third molar and location of mandible fracture.

RESULTS

In group A (partially/completely unerupted mandibular 3rd molar), the incidence of angle and condylar fracture was 44.44% and 13.33%, respectively, whereas in group B (fully erupted/missing mandibular third molar), the incidence of angle fracture was 14.45% and the incidence of condylar fractures was 31.77%.

CONCLUSION

Practice of prophylactic removal of mandibular third molar and resultant strengthening of angle region should be reconsidered, as it increases the risk of fracture at condylar region which is difficult to treat and associated with more morbidity.

Impact of the lower third molar presence and position on the fragility of mandibular angle and condyle: A Three-dimensional finite element study

The aim of the present study was to investigate the influences of the presence and position of a lower third molar (M3) on the fragility of mandibular angle and condyle, using finite element analysis. From computed tomographic scans of a human mandible with normally erupted M3, two additional virtual models were generated: a mandibular model with partially impacted M3 and a model without M3. Two cases of impact were considered: a frontal and a lateral blow. The results are based on the chromatic analysis of the distributed von Mises and principal stresses, and calculation of their failure indices. In the frontal blow, the angle region showed the highest stress in the case with partially impacted M3, and the condylar region in the case without M3. Compressive stresses were dominant but caused no failure. Tensile stresses were recorded in the retromolar areas, but caused failure only in the case with partially impacted M3. In the lateral blow, the stress concentrated at the point of impact, in the ipsilateral and contralateral angle and condylar regions. The highest stresses were recorded in the case with partially impacted M3. Tensile stresses caused the failure on the ipsilateral side, whereas compressive stresses on the contralateral side.

Mandibular Third Molar Position Influencing the Condylar and Angular Fracture Patterns

PURPOSE

The aim of this study was to assess the influence of position of mandibular 3rd molar on angle and condylar fractures.

MATERIALS AND METHODS

Panoramic radiographs were used to determine the mandibular fracture patterns based on the presence or absence of the third molar.

RESULTS

Of the 64 patients with mandibular fractures, condyle and angle fractures were found to be 67 and 33 % respectively. The greatest percentage (75 %) of condylar fractures were associated with erupted third molar teeth, and 25 % had impacted teeth. Subcondylar region was found to be the most common site that predisposes to fracture. Moderate force lead to condylar fracture when third molar is erupted or absent and mild force showed angle fracture when third molar is impacted. Increased incidence of angle fracture was observed when tooth is in mesioangular and distoangular position.

CONCLUSION

Impacted mandibular 3rd molar leads to an increased risk of angle fracture and decreased risk of condylar fracture especially when they are more deeply seated.

Does the presence of an unerupted lower third molar influence the risk of mandibular angle and condylar fractures?

It has been suggested that unerupted lower third molars (M3) increase the fragility of the mandibular angle and simultaneously decrease the risk of condylar fracture. However, it is unknown whether this applies regardless of the direction and point of impact of the traumatic force. The aim of this study was to investigate the impact of an unerupted M3 on the fragility of the angle and condyle in terms of a force acting from different directions and affecting different regions of the mandible. Computed tomography scans of a human mandible and finite element methodology were used to obtain two three-dimensional models: a model with, and the other without an unerupted M3. A force of 2000N was applied to three different regions of the models: the symphysis, ipsilateral body, and contralateral body, respectively. When the force was applied to the mandibular body, the results revealed increased angle fragility in cases with unerupted M3. When the force was applied to the symphysis, the condyle region showed higher fragility, irrespective of the presence of an unerupted M3. In summary, fragility of the angle and condyle regions depends on the presence of an unerupted M3 and on the direction and point of impact of the force.

A Clinical Study of Mandibular Angle Fracture

PURPOSE

To establish management protocol for mandibular angle fracture, we describe pertinent factors including cause, impacted third molar and recent treatment tendency.

METHODS

We examined the records of 62 patients who had unilateral mandibular angle fracture. Sixty patients who had open reduction surgery were examined at postoperative weeks 1, 4, 8, 12, and 28.

RESULTS

Left mandibular angle fracture is frequent in younger males. Presence of the mandibular third molar can increase fracture risk. Because of attached muscle, favorable fractures occurred primarily in the mandibular angle area.

CONCLUSION

Extracting the mandibular third molar can prevent angle fractures, and open reduction with only one plate adaptation is generally the proper treatment method for mandibular angle fracture.

Qualitative and quantitative assessment of relationship between mandibular third molar and angle fracture on North Indian population: A clinico-radiographic study

Objective:

To assess the relationship between impacted mandibular third molar presence and the risk for mandibular angle fracture with the effect of various positions of mandibular third molar and the risk of mandibular angle fracture.

Materials and Methods:

In the North Indian territory, a total of 289 patients with mandibular angle fractures were studied and evaluated for the possible relationship with impacted third molar on the basis of clinical and panoramic radiographical findings.

Results:

Results that confirmed the highest risk for mandibular angle fracture was associated with mesioangular angulations (45.42%) followed by vertical (26.34%), distoangular in sequence and least risk was found with bucco-version angulations (2.67%) according to Winter's classification. Additionally, the highest risk of mandibular angle fracture was reported with partially erupted third molar (47.75%), followed by erupted (23.53%) and unerupted third molar (19.38%).

Conclusion:

The risk for mandibular angle fracture is not only affected by status of eruption, angulations, position, number of roots present in third molar but also by the distance of mandibular third molar from inferior border of mandible and the percentage of remaining amount of bone at the mandibular angle region.

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.

Eruption status of third molar and its possible influence on the location of mandibular angle fracture: a retrospective analysis

INTRODUCTION

This study was designed to evaluate the influence of eruption status of mandibular third molars on the location of mandibular angle fracture. We also aimed to evaluate the incidence of damage to mandibular third molar teeth (M3) and its roots.

MATERIALS AND METHODS

Medical records and panoramic radiographs of 142 patient cohorts with mandibular angle fractures with third molars present were retrospectively reviewed.

RESULTS

Revealed that incidence of angle fracture were high in patients with fully erupted M3 when compared to unerupted group. Out of 142 patients, 108 fractures were found involving the M3 socket and 14.1 % had damage to M3.

CONCLUSION

The presence of erupted mandibular third molar increases the chances of angle fracture when compared to impacted M3. Involvement of the M3 socket often resulted in increased operative time and complexity of the surgical procedure with possible removal of the damaged M3.

Biangular fractures of the mandible

INTRODUCTION

Bifocal fractures of the mandible often associate the angle and condyle or symphysis. Little data is available on biangular fractures. The authors had for aim to study their characteristics and to suggest an adapted management.

MATERIAL AND METHODS

We retrospectively reviewed the records of patients operated on for a biangular fracture from January 2005 to December 2009. The impact of a third molar was evaluated using Pell and Gregory's and Shiller's classifications.

RESULTS

Six hundred and forty patients underwent surgery for a mandibular fracture, seven of whom (1.1%) for biangular fractures. The patients' mean age was 27.6 years. Patients were predominantly men (85.7%). Assaults or brawls were the most frequent etiology (85.7%). The mechanism was direct impact in every case. The inferior alveolar nerve was injured in 57.1% of cases. There was an impacted third molar in 71.4% of cases. Most of the time, a single miniplate was sufficient for each angle. Two cases of postoperative infection were noted. The mean follow-up was 52.2months. The occlusion was restored in every case. Three patients presented with neurological sequels in the V3 area.

DISCUSSION

Biangular fractures are rare and present a high risk of infection and neurological sequels. The presence of a mesioangular impacted third molar seems to be a predisposing factor. The risk of neurological sequels requires performing surgery rapidly.

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.

A review of mandibular angle fractures

AFTER STUDYING THIS ARTICLE, THE READER WILL BE ABLE TO: (1) review the incidence and etiology of mandibular angle fractures; (2) gain an understanding of patient evaluation and general management principles; and (3) discuss indications and available techniques for management of mandibular angle fractures. Angle fractures represent the highest percentage of mandibular fractures. Two of the most common causes of mandibular angle fractures are motor vehicle accidents and assaults or altercations. With any patient who has sustained facial trauma, a thorough history and comprehensive physical examination centering on the head and neck region as well as proper radiological assessment are essential. These elements are fundamental in establishing a diagnosis and developing an appropriate treatment plan for any mandibular fracture.

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

PURPOSE

Numerous previous studies already have proven that mandibles with a third molar are significantly more susceptible to angle fracture by external force. Similarly, other data suggest that the absence of a third molar increases the risk of condylar fracture, while concurrently decreasing the risk of angular fracture. We attempt to characterize the effect of a third molar on the incidence of mandibular angle and condylar fractures.

METHODS

This retrospective study reviews data from 385 patients, all of whom were seen in our clinics between February 2006 and November 2009. All data were collected from clinical examination notes and panoramic radiographs, with third-molar state evaluated by the Pell and Gregory classification system.

RESULTS

Our results mirror those of previous studies. The incidence of mandibular angle fracture was significantly greater on sides with a third molar, whereas the condylar fracture rate significantly increased in mandibles lacking a third molar or without a fully erupted third molar. The rate of symphysis and mandibular angle fracture was also high in cases of multiple comorbid fractures.

CONCLUSIONS

Both the presence and the state of the lower third molar affect the risk of future mandibular angle and condylar fracture.

Considerations of mandibular angle fractures during and after surgery for removal of third molars: a review of the literature

BACKGROUND

Angle fractures are quite common considering that the angle of the mandible forms an area of lower resistance which contains a thicker upper border, a thin basilar bone, and the presence of an impacted mandibular third molar. Common complications of mandibular third molar surgery include alveolar osteitis (dry socket), secondary infection, nerve dysfunction, and hemorrhage. Reports of mandibular fracture during and after third molar removal are uncommon.

PURPOSE

The purpose of this paper is to discuss the risk and predisposing factors that should be analyzed regarding the possibility of immediate and late mandibular angle fractures and their need for surgical treatment as a means through which to remove impacted molars. This study is based on a thorough review of the literature as well as on one immediate and one late mandibular angle fracture as described by the authors' own personal experience.

CONCLUSIONS

The danger of an immediate jaw fracture can be avoided by means of proper instrumentation and by refraining from excessive force on the bone. The tooth should be sectioned in such a way as to minimize the extent of bone removal and force caused by instrumentation. The danger of a late jaw fracture can be avoided by precise diagnosis in cases of patients over 25 years of age, particularly men, whose tooth roots are superimposed on or adjacent to the inferior alveolar canal on a panoramic image, any local pathology and systemic disease or medications which may impair bone strength, and patients who present bruxism and are active athletes.

Assessment of the risk of perforation of the mandibular canal by implant drill using density and thickness parameters

OBJECTIVE

The objective of this study was to investigate whether the resistance of the bone surrounding the mandibular canal had sufficient density and thickness to avoid perforation by drills when preparing the bed of the implant.

BACKGROUND

 Damage to the inferior alveolar nerve (IAN) is more common than expected. This injury may lead to serious complications ranging from mild paresthesia to total anaesthesia of the lower jaw.

MATERIALS AND METHODS

  The CT images of 99 patients, whose ages ranged between 20 and 79years, and who applied for an implant application to the posterior aspect of the mandible were included in this study.

RESULTS

The overall average bone thickness in the premolar and molar regions was 0.8717±0.1818 and 0.8556±0.1756mm, respectively, whereas the bone density in the premolar and molar regions was 649.18±241.42 and 584.44±222.73 Hounsfield Units (HU), respectively (p<0.001).

CONCLUSION

It was determined that the average density and thickness of the bone that surrounds the mandibular canal was not sufficient to resist the implant drill. It can be concluded that the risk of injury to the IAN may be minimised by accurately determining the bone mass on the canal prior to the implant procedure, and avoiding excessive force when approaching the canal.

Mandibular third molars as a risk factor for angle fractures: a retrospective study

INTRODUCTION

Anecdotal reports suggest that the presence of mandibular third molars predispose the mandible to angle fractures. The purpose of this study was to evaluate the presence of mandibular third molars as a risk factor for angle fractures in patients with fractured mandibles.

MATERIALS AND METHOD

A retrospective study was designed comprising of patients admitted for treatment of mandibular fractures between January 2006 and January 2009. Data sources were the patients' medical records and radiographs. The predictor variables were the presence and position of third molar. Third molar position was grouped into 9 categories based on the Winter's and Pell & Gregory classification. The outcome variable was the presence of an angle fracture. Other study variables included age, sex, race and mechanism of injury, associated fractures and fracture location.

RESULTS

Of the 136 patients with mandibular third molars, 49 cases had angle fractures. Of the 18 patients without mandibular third molars, 03 had angle fractures.

CONCLUSION

The results of this study demonstrate that patients with fractured mandibles and mandibular third molars are nearly 2.2 times more likely to have an angle fracture than patients without mandibular third molars.

A study on the impact of mandibular third molars on angle fractures

PURPOSE

This study evaluated the relationship between the status and position of mandibular third molars and angle fractures.

MATERIALS AND METHODS

In a total of 2,033 patients with a mandibular fracture, 532 (26%) had angle fractures, and 1,466 (72%) had retained their lower third molars. The most frequent cause for mandibular fracture was road traffic accident (64%), followed by assault (19%).

RESULTS

Of 341 patients with an unerupted third molar, mandibular angle fracture was evident in 249 patients (73%). Only 62 patients (9.4%) with a completely erupted third molar had angle fractures, whereas 83 patients (17.6%) with partially erupted third molars had angle fractures.

CONCLUSIONS

Our study confirmed an increased risk of angle fractures in the presence of a lower third molar, as well as a variable risk for angle fracture, depending on the third molar's position.

Do pathologies associated with impacted lower third molars justify prophylactic removal? A critical review of the literature

Surgical removal of impacted lower third molars is widely carried out in general dental practice and in many institutional clinics. Despite the fact that there are well established indications for the removal of impacted lower third molars, prophylactic removal of these teeth is still being universally practiced. Some reports have estimated that the proportion of impacted third molars that are removed when no clinically sound justification for surgery is present is between 18% and 50.7%. Justifications for prophylactic surgery include the need to minimize the risk of disease (cysts and tumors) development, reduction of the risk of mandibular angle fracture, increased difficulty of surgery with age, and that third molars have no definite role in the mouth. This article critically examines the literature regarding the relationship between impacted lower wisdom teeth, cysts and tumor development, and mandibular fractures.

Three-dimensional bone microstructures of the mandibular angle using micro-CT and finite element analysis: relationship between partially impacted mandibular third molars and angle fractures

The mandibular angle is one of the areas of the mandible that are prone to bone fractures, and the presence of an impacted third molar has been found to be associated with increased risk of angle fractures. The factors involved in bone fractures are the amount and direction of load, and the biomechanical and anatomical properties of bone. In the present study, micro-focused X-ray computed tomography was performed to observe and analyze the three-dimensional (3D) bone microstructure of the mandibular angle, and finite element analysis was conducted to examine the relationship between angle fractures and the presence or absence of mandibular third molars. 3D bone microstructure showed no marked difference between mandibles with and without third molars. Finite element analysis showed that, in the mandible with a third molar, stress was concentrated around the root apex of the third molar, and was transmitted in a direction matching the clinical findings of angle fractures. The results obtained in this study suggest that the presence of an impacted third molar changes the concentration and transmission of stress in the mandible, thus increasing the risk of an angle fracture.