Mandibular angle fractures: a clinical challenge decrypted over 10 years

Mandibular angle fractures represent approximately 20% to 30% of mandibular traumas. This area is particularly vulnerable due to a reduced bone section, the frequent presence of impacted third molars, and the forces exerted by the masticatory muscles. Despite this prevalence, surgical management remains complex, marked by high rates of postoperative complications such as infections, malocclusions, or hardware failures.

The primary objective of this monocentric study conducted at Kepler University Hospital (Linz, Austria) was to characterize the anatomical, morphological, and clinical factors influencing the behavior of these fractures. The authors analyzed a retrospective cohort of 115 patients treated over a 10-year period, between January 2015 and December 2025, to identify variables associated with fracture patterns, treatment complexity, and complications.

The study is based on the hypothesis that craniofacial morphology, the state of the dentition (notably the position of third molars according to the Gregory-Pell classification) and demographic characteristics interact significantly with fracture severity. By correlating these clinical and radiological data (CT scans), researchers aim to refine preoperative risk assessment for more personalized surgical planning.

Study methodology

This retrospective single-center cohort study covers a ten-year period, from January 1, 2015, to December 17, 2025. The team screened 632 mandibular fracture records at the Kepler University Hospital (Linz), ultimately selecting 115 patients meeting the single inclusion criterion: the presence of a mandibular angle fracture confirmed by CT scan.

To evaluate the surgical stabilization needs, the authors defined two complexity groups based on the osteosynthesis material:

• Simple fixation: use of 1 to 2 plates.
• Complex fixation: use of 3 or more plates.

The analysis protocol utilizes data from preoperative scans (parameters: 100 kV, 413 mAs). Researchers measured precise morphometric variables, including the heights and widths of the ascending ramus, gonial and ante-gonial angles, as well as anterior (AFH) and posterior (PFH) facial heights. The study also documents dental status, the presence of third molars (Gregory-Pell classification), and the mechanism of the accident.

Statistical analysis compares variables via Student's t-tests or Mann-Whitney tests, after verifying distribution using the Shapiro-Wilk test. Researchers also applied age stratification, setting a threshold at 30 years to explore the impact of skeletal maturity on fracture patterns.

Cohort composition and prevalence

Analysis of 10-year data reveals that mandibular angle fractures account for 18.2% of the total mandibular trauma cohort (115 patients included out of 632 screened). All included patients underwent evaluation by standardized CT scan (100 kV, 413 mAs).

Anatomical and morphometric variables

The study systematically quantified the following parameters for each case:

• Ramus dimensions: Measurements of height (lower border to the articular process) and width (minimum and maximum).
• Angular analysis: Evaluation of gonial angles (tangent to the posterior and inferior border) and antegonial angles.
• Cephalometric proportions: Measurement of the anterior facial height (Nasion-Menton) and posterior facial height (Sella-Gonion), as well as their ratio (PFH/AFH).

Surgical complexity factors

The complexity classification allowed for the segmentation of the cohort according to material stabilization requirements:

The analysis integrated the influence of third molars (position and class according to Pell & Gregory) located in the fracture line, as well as the presence of associated ipsilateral or contralateral fractures.

Analysis of surgical complexity determinants

This study's approach emphasizes the importance of a preoperative evaluation that goes beyond simple fracture localization. By using the number of osteosynthesis plates as an indicator of complexity, the authors highlight the biomechanical challenge posed by the mandibular angle. This area, subject to the powerful forces of the masticatory muscles, requires a fixation strategy adapted to individual craniofacial morphology.

The systematic inclusion of anterior and posterior facial height measurements (AFH, PFH) and gonial angles suggests that the overall skeletal configuration influences stress distribution during trauma. In clinical practice, this means that the practitioner must anticipate increased instability in patients presenting specific morphological characteristics or third molars in unfavorable Gregory-Pell positions.

The study nevertheless presents limitations: its retrospective and monocentric nature limits the generalization of the data. Furthermore, the definition of complexity based on the number of plates is a pragmatic methodological choice but not validated by a standardized clinical scale. Finally, all radiological measurements were performed by a single examiner, which excludes the evaluation of inter-observer variability.

In concrete terms, for the practitioner:

• Systematically assess the risk associated with the wisdom tooth: The Pell-Gregory classification is a key indicator of mandibular angle fragility; its inclusion in the fracture line should lead to the anticipation of increased instability.
• Refine your planning with CT-Scan: Do not settle for panoramic imaging; precise 3D measurement of the gonial angle and ramus dimensions is essential to predict the number of fixation plates required.
• Adapt your surgical tray: In the presence of unfavorable morphological factors (narrow ramus, marked angle), plan from the outset a strategy with 3 plates or more to prevent healing complications and hardware failures.

Technical lexicon of the study

Gonial angle: Morphometric parameter defined as the angle between the tangent to the posterior border of the ramus and the tangent to the lower border of the mandibular body.

Antegonial angle: Measurement performed at the level of the antegonial notch using tangential lines along the lower mandibular border.

Gregory-Pell Classification: Grading system used to assess the depth and position of impacted or partially erupted third molars in relation to the ramus and the occlusal plane.

Anterior Facial Height (AFH): Linear distance measured between the Nasion and the Menton on frontal computed tomography (CT) reconstructions.

Posterior Facial Height (PFH): Distance measured between the Sella turcica and the Gonion on sagittal reconstructions, used to calculate the PFH/AFH ratio.

Complex fixation: Specific operational definition for this study characterizing the need for surgical stabilization through the use of three or more osteosynthesis plates.

Transbuccal technique: Surgical approach mentioned for the placement of osteosynthesis material, allowing perpendicular access to the operative field for screwing.

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