Impact of Third Molars on Mandibular Fractures

The mandible is the most frequently fractured facial bone, with the presence and status of lower third molars exerting a decisive influence on fracture patterns. Impacted wisdom teeth diminish bone continuity at the mandibular angle, creating a stress concentration point that predisposes to angle fractures when subjected to traumatic loading. Conversely, the absence or full eruption of these teeth shifts force transmission proximally, heightening susceptibility to condylar fractures. Occlusal support further modulates this relationship by altering the distribution of masticatory and impact forces across the mandibular corpus. Comprehensive radiographic evaluation of third molar position, occlusal architecture and mandibular morphology is therefore essential for accurate risk assessment, informed surgical planning and optimisation of patient outcomes in maxillofacial trauma management.

Research from Nature Portfolio

Recent studies have quantified the relative contributions of occlusal support and third molar characteristics to fracture localisation. A retrospective analysis of 187 mandibular fracture cases found that absence of stable occlusal support elevated the odds of condylar fractures by more than five-fold, independent of third molar presence or angulation. This work underscores the primacy of occlusal architecture in governing mandibular load transfer and suggests that, in the absence of functional cusp-to-cusp contact, stress is preferentially dissipated at the condylar neck rather than the angle region.

Impact of Third Molars on Mandibular Fractures publication trend

The graph below shows the total number of articles in impact of third molars on mandibular fractures across all publications each year (not limited to Nature Index journals).

Technical terms

Impacted third molar: A lower wisdom tooth that fails to erupt fully and remains partially or wholly embedded in the jawbone, often impinging on adjacent structures.

Occlusal support: The stabilising contact between upper and lower teeth during function, which governs the direction and magnitude of forces borne by the mandible.

Mandibular angle fracture: A break in the junction between the mandibular body and ramus, commonly occurring at the site of third molar impaction.

Condylar fracture: A fracture of the condylar process of the mandible, which forms the articulating portion of the temporomandibular joint.

Radiomorphometric indices: Quantitative measurements of mandibular geometry—such as gonial angle and ramus height—derived from imaging to assess bone strength and fracture propensity.

Gonial angle: The angle formed by the intersection of the posterior border of the mandibular ramus and the lower border of the mandibular body, reflecting facial growth pattern and biomechanical loading.

References

1. The influence of wisdom tooth impaction and occlusal support on mandibular angle and condyle fractures. Scientific Reports (2021).
2. Correlation of radiomorphometric indices of the mandible and mandibular angle fractures. Heliyon (2022).
3. Relação de fraturas mandibulares com a presença de terceiros molares inferiores e suas posições. Research Society and Development (2023).