Most Common Fractured Part of the Mandible
The parasymphysis region is the most common site of mandibular fracture, accounting for 28.4% of all mandibular fractures. 1
Anatomical Distribution of Mandibular Fractures
The mandible's U-shaped ring configuration makes it vulnerable to fractures at predictable locations, with the parasymphysis being the most frequently affected site 1. This vulnerability stems from the mandible's incomplete ring structure that articulates with the calvaria via the temporomandibular joints 2.
Common Fracture Sites in Order of Frequency:
- Parasymphysis region: 28.4% (most common) 1
- Angle (angulus) region: frequently involved, especially in combination fractures 1
- Condylar/subcondylar region: second most common in adults 3, 4
- Body and symphysis: particularly in edentulous areas 5
Critical Clinical Pattern: The Second Fracture
You must always search for a second fracture after identifying the first, as 67% of mandibular fractures occur in pairs due to the ring-like configuration. 2, 6, 7
Most Common Dual Fracture Patterns:
- Angle or subcondylar fracture with contralateral parasymphyseal fracture (most frequent combination: 24.6%) 2, 7, 1
- Flail mandible: bilateral subcondylar fractures with symphyseal fracture 2, 6, 7
Context-Dependent Variations
The most common fracture site varies by mechanism of injury:
- Assaults and ballistic trauma: The mandible becomes the most common maxillofacial fracture site overall 2, 8
- Motor vehicle accidents: Commonly produce fractures through anterior alveolar process, condylar necks, or edentulous areas of body and symphysis 5
- Overall facial trauma: Nasal bones are the most common facial fracture, but within the mandible specifically, parasymphysis predominates 8, 1
Associated Injuries Requiring Evaluation
- Intracranial injury: 39% of mandibular fracture patients 6, 7
- Cervical spine injury: 11% of patients 6, 7
- Inferior alveolar nerve damage: occurs when fractures extend through the mandibular canal 2, 7
- Additional injuries beyond mandible: 20-40% of patients 2, 6, 7
Imaging Recommendation
CT maxillofacial with multiplanar reformations achieves nearly 100% sensitivity and is the gold standard for detecting mandibular fractures, including subtle nondisplaced fractures. 6, 7 This superior sensitivity compared to conventional radiography (which has only 86-92% sensitivity) is critical for identifying the second fracture that occurs in two-thirds of cases 6.