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

A finite element analysis on the indication for extracting partially impacted mandibular third molars considering mandibular trauma

BACKGROUND

Patients presenting with partially impacted lower third molars (M3) have a higher likelihood of experiencing angle fractures while simultaneously decreasing the risk of condylar fractures. However, the specific biomechanical mechanism responsible for this occurrence remains unclear. Moreover, there is an ongoing debate regarding whether the removal of M3s might actually increase the risk of condylar fractures. This study aimed to evaluate how the presence of M3s influences mandibular fractures resulting from blows to the symphysis and lateral mandibular body, and to determine the indication for extracting M3s in such cases.

METHODS

Models of the mandible with a partially M3-impacted model (M3I), M3-extracted model (M3E), and M3-absent model (M3A) were generated using a computer. A traumatic blown force of 2000 N was applied to the symphysis and the right body of the mandible. Von Mises and principal stresses were analyzed, and failure indexes were determined. Two cases of mandibular linear fractures were chosen for model verification and interpretation.

RESULTS

When force was applied to the symphysis, the condylar region exhibited the highest stress levels, while stress in the mandibular angle region was much less regardless of the M3 state. On applying the force to the right mandibular body, stress in the condylar region decreased while stress in the mandibular body increased, especially in the blown regions. Impacted tooth or cavity formation post-M3 extraction led to uneven stress distribution on the blown side of the mandible, increasing the risk of mandibular angle fractures. In cases where M3 was absent or the extraction socket had healed, stress from lateral traumatic blown force was evenly distributed along both the inner and outer oblique lines of the mandible, thereby reducing the risk of mandibular fractures.

CONCLUSIONS

The reduced risk of condylar fractures in patients with partially impacted lower M3s and mandibular angle fractures is mainly due to lateral blows on the mandible, which generate less stress in the condylar region than blows on the mandibular symphysis, rather than being caused by the M3 itself. Extraction of the lower M3 can decrease the risk of mandibular fractures, with a minor influence on condylar fractures.

Use of Patient-Specific Titanium Plates to Prevent Iatrogenic Mandibular Fracture During the Surgical Removal of Dentigerous Cysts: A Two-Case Series

Dentigerous cysts, if left untreated, can grow significantly and weaken the mandible, posing risks of pathological or iatrogenic fracture. Treatment options may include decompression, marsupialization, and enucleation, which are available, with the choice being multifactorial and tailored to each case. This article describes the management of two complex dentigerous cysts at risk of fracture, one about an 84-year-old woman and the second about a 41-year-old man. The cysts and associated teeth were surgically removed, and simultaneously custom-made titanium osteosynthesis plates were placed to prevent per- and postoperative fracture risks. This approach appears to be indicated in cases where marsupialization or decompression is impossible and when there is a high risk of iatrogenic fracture.

Evidence-Based Medicine for Mandible Fracture Repair: Current Controversies and Future Opportunities

Mandibular fractures are among the most common facial fractures resulting from trauma. The nature of the injury, involved facial structures, presence of associated injuries, the dental status of the patient, comorbid conditions, and psychosocial context all must be considered by the surgeon when planning the optimal treatment for these patients. While consensus exists for many aspects of the management of mandibular trauma, some elements remain controversial. Three such topics-antibiotic therapy, treatment of subcondylar fractures, and management of the third molar-remain particularly controversial, with significant heterogeneity in practice patterns and without widely accepted evidence-based guidelines to standardize care. The goals of this work are to (1) review the historical perspective underlying these controversies, (2) summarize recent evidence shaping the current debate, and (3) highlight opportunities for continued efforts to identify best practices.

Correlation of radiomorphometric indices of the mandible and mandibular angle fractures

This study assessed the correlation of radiomorphometric indices of the mandible and mandibular angle fractures (MAFs) in an Iranian population. This retrospective study was conducted on 3D computed tomography (CT) scans of 118 patients between 18 to 60 years. The images were divided into two groups with MAFs and other types of mandibular fractures (non-MAF). The gonial angle, ramus height, condylar neck width, minimum ramus width, and mandibular length were all measured using MARCO PACS software. Age, gender, and presence and eruption status of third molar at the fracture side were all recorded. The correlation between these parameters and MAF was analyzed using R software (alpha = 0.05). Of all patients, 41 samples had MAF. The two groups were not significantly different regarding the mean age and gender (P > 0.05). The mean size of gonial angle and ramus height in the MAF group were significantly larger, and smaller than the corresponding values in the non-MAF group, respectively (P < 0.001). The median minimum ramus width in the MAF group was significantly smaller than that in the non-MAF group (P = 0.001). Patients with a large gonial angle had 6.6 times higher odds of MAF compared with other fracture types (P = 0.046). Condylar neck width, mandibular length, and erupted third molars had no significant correlation with type of fracture. Presence of impacted third molar increased the odds of MAF by 5.55 times.

Patients with a large gonial angle, short ramus height, minimum ramus width, and impacted third molar are more susceptible to MAF. Surgeons can use these indices to predict the risk of MAF in trauma patients with such facial characteristics, and make a diagnosis by radiographic modalities.

Photoelastic analysis of conventional and locking system for treatment of mandibular angle fractures with a single plate

Background

This photoelastic analysis evaluated stress distribution in different osteosynthesis systems, conventional and locking, used for treatment of mandibular angle fractures with a single plate.

Material and Methods

Angle fractures were simulated in mandibles made of photoelastic resin. Following Champy’s method, plate osteosynthesis was performed. The samples were divided into five groups: Group 1, non-fractured mandible; Group 2, two screws were installed in each segment using a conventional system; Group 3, two screws were installed in each segment using a locking system; Group 4, three screws were installed in the proximal segment and four screws in the distal segment using a conventional plate; Group 5, three screws were installed in the proximal segment and four screws in the distal segment using a locking plate. In an universal testing machine coupled to a polariscope, a load was applied to the first molar 10 times. The 50 images were randomly numbered and analyzed qualitatively and quantitatively by two raters.

Results

The locking system promoted better stress distribution along the osteosynthesis. The locking system reduced stress magnitude in the distal segment, with a significant between-group difference (P≤ 0.001).

Conclusions

The locking plate/screw system can distribute stress more evenly throughout the osteosynthesis, especially when long seven-hole plates are used.

Key words:Internal fracture fixation, osteosynthesis, mandibular fracture, bone plates.

Surgical Management of Mandibular Angle Fractures: Does the Extraction of the Third Molar Lead to a Change in the Fixation Pattern? A European Multicenter Survey

PURPOSE

The authors conducted a retrospective, multicenter study to investigate the differences in the fixation patterns, in terms of number and thickness of plates, between patients in whom a third molar (3M) was maintained or removed in the line of mandibular angle fractures.

MATERIALS AND METHODS

The study was conducted in 6 European level I and II maxillofacial trauma centers. Data were collected on patients ≥ 16 years of age who underwent open reduction internal fixation (ORIF) for mandibular angle fractures (MAF) from 2008 to 2018, in whom a 3M in the fracture line was present and who had a follow-up duration of 6 months. The study population was divided into 2 groups: patients treated with ORIF in whom the 3M was maintained (group 1) and those treated with ORIF in whom the 3M was extracted (group 2) during treatment. The 2 groups were compared for differences in the internal fixation pattern, specifically in terms of the number and thickness of the plates.

RESULTS

A total of 749 patients with 774 MAF were collected. A total of 1,050 plates were placed: 849 were ≤ 1.4 mm thick (80.9%) and 201 plates ≥ 1.5 mm thick (19.1%). 548 patients were treated with ORIF and 3M maintained (group 1), and 201 treated with ORIF and 3M extracted (group 2). Statistically significant differences were seen in the number of ≤1.4 mm plates between the 2 groups for single undisplaced/displaced MAF(P value ≤ 0.5) and for undisplaced/displaced angle + parasymphysis/body fractures (P-value ≤ 0.5).

CONCLUSIONS

Analyses of data collected from 6 European maxillofacial centers indicated that the majority of surgeons of our sample perceived the MAF as being more unstable when removing the 3M during ORIF leading them to perform a rigid fixation in the angular region.

Surgical Management of Bilateral Mandibular Angle Fractures With a Third Molar in Line of Fracture: A European Multicenter Survey

PURPOSE

The aim of this survey was to investigate the surgical management of bilateral mandibular angle fracture (BMAF) in Europe.

METHODS

Data were collected from 2008 to 2018 on patients ≥ 16 years of age who underwent open reduction internal fixation (ORIF) for BMAF with a third molar in the fracture line. The study was conducted at 6 European trauma centers. The following data were recorded: sex, age, cause of the fracture, type of fracture (nondisplaced, displaced, comminuted), type of approach (intraoral, transbuccal, or extraoral), thickness of the plate (≤1.4 mm or ≥1.5 mm), number of plates, cause of plate removal, and third molar extraction status.

RESULTS

25 patients with BMAF (24 males, 1 female, 17 to 83 years old [mean: 28.2 years]) were collected. The main cause of BMAF was assault, and the main surgical approach was intraoral. The most common types of BMAF were displaced + undisplaced (11 patients), displaced + displaced (7 patients), undisplaced + undisplaced (6 patients), and comminuted + comminuted (1 patient). Osteosynthesis was performed with 2 ≤1.4 mm plates on 1 angular fracture and 1 ≤1.4 mm plate on the other fracture in 11 patients, 1 ≤1.4 mm plate on both angular fractures in 6 patients, 1 ≥1.5 mm plate on both fractures in 5 patients, and 2 ≤1.4 mm plates on both fractures in the remaining 3 patients. Out of 25 patients with BMAF, 7 third molars were extracted during ORIF. Among these patients, angular fracture fixation was performed in 3 cases with 1 ≥1.5 mm plate and in 4 patients with 2 ≤1.4 mm plates.

CONCLUSIONS

This retrospective multicenter survey indicates a trend of treating with open reduction and rigid internal fixation at least 1 angular fracture of BMAF and those cases requiring extraction of the third molar in the line of fracture.

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.

In vitro precision evaluation of blue light scanning of abutment teeth made with impressions and dental stone casts according to different 3D superimposition methods

PURPOSE

The purpose of this in vitro study was to determine the precision evaluation of blue light scanning of abutment teeth impressions and dental stone casts according to different 3D superimposition methods.

METHODS

Impressions and dental stone casts of the maxillary canine, 1st premolar, and 1st molar were fixed; they were repeatedly scanned 11 times, (6 types, total n = 66). Stereolithography (STL) files were superimposed one by one, and used to obtain 10 root mean square (RMS) values with the 2 superimposition methods (best-fit-alignment, no control). Statistical analysis included the independent t test and one-way ANOVA with Tukey honest significant differences (α = 0.05).

RESULTS

RMS ± Standard Deviation (SD) values for the best-fit-alignment method of the abutment teeth impressions of the maxillary canine, 1st premolar, and 1st molar was 8.07 ± 0.76, 5.03 ± 0.23, and 6.59 ± 0.24, respectively, and those of the no control method were 9.36 ± 0.82, 7.10 ± 1.14, and 8.17 ± 0.36 respectively. RMS ± SD values for the best-fit-alignment method for the dental stone casts were 4.07 ± 0.27, 3.39 ± 0.07, and 3.29 ± 0.07, respectively, and those for the no control method were 6.26 ± 2.50, 4.98 ± 1.16, and 4.55± 0.74, respectively.

CONCLUSIONS

Using different 3D superimposition methods, blue light scanning of abutment teeth impressions and dental stone casts shows high precision. The no control method showed lower precision best-fit-alignment. However, the results may help advance the digital dental CAD/CAM research and the clinical field of Prosthodontics.

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.

Classification of the journal category "oral surgery" in the Scopus and the Science Citation Index Expanded: flaws and suggestions

Objectives

The aim of this study was to evaluate the journal category “oral surgery” in Scopus and in the Science Citation Index Expanded (SCIE).

Materials and Methods

The Journal of Oral and Maxillofacial Surgery (JOMS), The Journal of the Korean Association of Oral and Maxillofacial Surgeons (JKAOMS), and The Journal of Prosthodontic Research (JPR) were selected from the Scopus list of journals as oral surgery journals. Maxillofacial Plastic and Reconstructive Surgery (MPRS) was selected from PubMed as a Scopus oral surgery title. From these titles, 10 recently published articles were collected and used for reference analysis.

Results

The percentage of citations from oral surgery journals was 26.7%, 24.5%, and 40.1% for JKAOMS, MPRS, and JOMS, respectively. In total, 1.1% of JPR's citations were from oral surgery journals and significantly fewer from other journals (P<0.001). The percentage of citations from dentistry journals excluding oral surgery journals was 11.9%, 34.4%, and 15.8% for JKAOMS, MPRS, and JOMS, respectively. For JPR, 80.6% of citations were from dentistry journals and significantly more were from other journals (P<0.001).

Conclusion

Selected samples revealed that JPR is incorrectly classified as an oral surgery journal in Scopus. In addition, the scientific interaction among JKAOMS, MPRS, and JOMS was different to JPR in the reference analysis.

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.