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

https://doi.org/10.1016/j.joms.2017.06.008Get rights and content

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.

Section snippets

Study Design

To address the research objectives, we designed and implemented a systematic review and meta-analysis according to the Cochrane Collaboration guidelines10 for systematic reviews and the PRISMA statement11 (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The review protocol was registered at the PROSPERO database (registration no. CRD42016047057). The systematic review was structured according to the recommendations by Dodson.12

The present review included all reports of the

Results

The search strategies resulted in 411 studies. After the initial screening, 204 duplicate results were eliminated, and 207 studies remained for the reading of the titles and abstracts. From these, 116 articles were outside the objective of the study, 36 were literature reviews, 28 were case reports, and 2 were letters to the editor. The full text of the 25 remaining studies were analyzed, with 3 excluded because they had not enumerated or included patients without lower third molars and/or

Discussion

The main objective of the present study was to verify, through the comparison meta-analysis, the association between the presence of lower third molars and the risk of mandibular angle fractures in adults. The hypothesis was that the presence of the lower third molar would predispose to a greater risk of mandibular angle fracture. The secondary outcome evaluated in our study was the relationship of mandibular fractures with the position of the third molar, studied using a proportion

References (33)

  • S. Iida et al.

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

    J Craniomaxillofac Surg

    (2005)
  • D.H. Duan et al.

    Does the presence of mandibular third molars increase the risk of angle fracture and simultaneously decrease the risk of condylar fracture?

    Int J Oral Maxillofac Surg

    (2008)
  • S. Naghipur et al.

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

    J Oral Maxillofac Surg

    (2014)
  • T. Baykul et al.

    Incidence of cystic changes in radiologically normal impacted lower third molar follicles

    Oral Surg Oral Med Oral Pathol Oral Radiol Endod

    (2005)
  • D.E. Kelly et al.

    A survey of facial fractures related to teeth and edentulous regions

    J Oral Surg

    (1975)
  • B.P. Hanson et al.

    The association of third molars with mandibular angle fractures: A meta-analysis

    J Can Dent Assoc

    (2004)
  • Cited by (18)

    • Correlation of radiomorphometric indices of the mandible and mandibular angle fractures

      2022, Heliyon
      Citation Excerpt :

      Management of MAFs is difficult due to complex mechanics of the mandibular angle such as thin cross-section, abrupt change in the path of curvature, presence of third molars, and attachment of the muscles of mastication applying loads along different vectors [19]. A number of studies have reported a positive association between third molar impaction and MAF [12,20,21]. However, studies on the correlation of morphometric indices of the mandible and MAF are limited.

    • Titanium versus magnesium plates for unilateral mandibular angle fracture fixation: biomechanical evaluation using 3-dimensional finite element analysis

      2022, Journal of Materials Research and Technology
      Citation Excerpt :

      In order to avoid non-union and mal-union in the outcome, this fracture must be fixed for proper union of the segments. The treatment of mandibular angle fractures is highly challenging due to its unique pathophysiology and associated complications [7,8]. There are various factors to be considered while treating mandibular angle fractures, like the anatomy and physiology of the angle because of the attachment of various masticatory muscles, the location of the erupted or impacted third molar teeth, the amount of masticatory load acting on the angle and the thickness of the surrounding outer cortical bone covering the inner medullary complex [9–13].

    • 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

      2021, Journal of Oral and Maxillofacial Surgery
      Citation Excerpt :

      The mandibular angle is one of the most frequent sites of mandibular fractures because of the complex biomechanics of this region, its thin cross-sectional area, and the presence of the third molar.1-7 Two recent meta-analyses showed that the presence of an impacted third molar (3M) increased the risk of mandibular angle fractures (MAFs) in adults by 2-fold8 to 3.16-fold.9 However, despite consensus on the indications for the removal of a 3M in the fracture line,6,10-15 the optimal surgical management of MAF remains a matter of debate.7,16-21

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

      2020, Journal of Prosthodontic Research
      Citation Excerpt :

      The cervical margins of the teeth were set to the deep chamfer margin; labial (buccal) and lingual axial surface were reduced to about 1.2 mm; incisal and occlusal surfaces were reduced to about 1.7 mm. Buccal, lingual, mesial, and distal surfaces of teeth were fabricated at 6° of an angle; the margins and point angles were rounded. [19–21] After the maxillary canine, the 1st premolar, the 1st molar abutment teeth were made with acrylic resin.

    View all citing articles on Scopus

    Conflict of Interest Disclosures: None of the authors have any relevant financial relationship(s) with a commercial interest.

    View full text