Operative Technique for External Approach to Simple Angle of Mandible Fracture
The external (extraoral) approach for simple angle fractures utilizes a Risdon's submandibular incision, allowing direct visualization and fixation with a single 2.5mm non-compression miniplate using monocortical screws, with the primary advantage being superior accessibility for anatomic reduction compared to transoral approaches. 1, 2
Surgical Approach and Incision
Make a Risdon's submandibular incision approximately 2-3 cm below and parallel to the inferior border of the mandible, extending from the angle region anteriorly. 1
The incision provides excellent exposure for fractures where the fracture line starts posterior or distal to the third molar, extends to the angle of the mandible, or runs high into the ramus. 2
Dissect through subcutaneous tissue and platysma, identifying and preserving the marginal mandibular branch of the facial nerve by staying below the inferior border of the mandible. 1
Fracture Reduction
Establish intermaxillary fixation (IMF) intraoperatively using upper and lower Erich's arch bars to achieve proper occlusion before plating. 1
Expose the fracture site by elevating the masseter muscle from the lateral surface of the mandible. 1
Reduce the fracture segments anatomically under direct visualization—the extraoral approach provides 86.7% "good" accessibility compared to 53.3% with transoral approaches. 2
Fixation Technique
Fix the reduced fracture with a single 2.5mm, 4-hole non-compression stainless steel miniplate placed along Champy's ideal line of osteosynthesis (along the external oblique ridge). 1
Use 6-8mm monocortical screws for fixation—two screws on each side of the fracture line. 1
This single miniplate technique is reliable for simple, non-comminuted angle fractures with low major complication rates. 1
Key Advantages of External Approach
Superior accessibility (86.7% rated as "good") allows easier anatomic reduction, particularly for fractures posterior to the third molar or extending high into the ramus. 2
Direct visualization reduces the risk of inadequate exposure—7 of 42 transoral cases required conversion to extraoral approach due to poor access. 3
Better suited for difficult cases including edentulous/atrophic mandibles, comminuted fractures, or infected fractures. 3
Expected Complications and Management
Temporary facial nerve paresthesia occurs but typically resolves spontaneously within 15 days with conservative management; permanent paralysis is rare with proper technique. 4
Infection rates average 20%, managed with antibiotics and/or incision and drainage; rarely requires plate removal. 1
Mild to moderate occlusal discrepancies (36.7%) may require 1-2 weeks of postoperative IMF with elastics. 1
Sensory changes to lower lip/chin from inferior alveolar nerve involvement occur in 26.7% initially but improve to 3.3% by one month. 1
Visible scar is the primary disadvantage compared to transoral approaches, though proper incision placement in a skin crease minimizes this. 2
Critical Pitfalls to Avoid
Always search for a second fracture—67% of mandibular fractures occur in pairs due to the U-shaped ring configuration, with common patterns including contralateral parasymphyseal fractures. 5, 6
Screen for associated injuries: 39% have intracranial injuries and 11% have cervical spine injuries requiring evaluation. 5, 6
Avoid damage to the marginal mandibular nerve by maintaining dissection below the inferior border of the mandible. 1
The extraoral approach takes longer (mean 73.4 minutes vs 49.7 minutes for transoral), but provides better exposure and avoids conversion to external approach mid-procedure. 2, 3