Subapical Osteotomy: Technique, Indications, and Surgical Considerations
A subapical osteotomy is a dentoalveolar surgical procedure used to reposition a segment of the anterior mandible while preserving the integrity of the basal bone and inferior alveolar nerve. This technique is most commonly indicated for the correction of dentoalveolar deformities that cannot be adequately managed with orthodontics alone and where full orthognathic surgery is unnecessary or undesirable.
When performed correctly, subapical osteotomy allows precise movement of the tooth-bearing segment with predictable healing and minimal morbidity.
Anatomical Considerations
The osteotomy is performed anterior to the mental foramen, ensuring protection of the mental nerve and inferior alveolar neurovascular bundle. Accurate identification of the mental foramen preoperatively—using clinical landmarks and imaging—is essential to avoid nerve injury.
Because the procedure involves mobilization of a tooth-bearing segment, maintaining continuity and blood supply to the segment is critical throughout the surgery.
Surgical Technique Overview
The subapical osteotomy is typically designed using two vertical osteotomies, connected by a horizontal subapical cut that resembles the configuration of a genioplasty incision. This design allows controlled mobilization of the dentoalveolar segment while maintaining stability.
The procedure begins by scoring the cortical bone, which helps guide the osteotomy and reduces the risk of unfavorable fractures. Once the cortex is scored, a piezoelectric device such as the Sonopet is used to complete the osteotomy in a controlled and precise manner. Piezoelectric instrumentation allows for selective cutting of bone while minimizing trauma to adjacent soft tissues and neurovascular structures.
The vertical osteotomies are performed using an oscillating saw, which provides clean, accurate cuts and facilitates controlled segment mobilization. In some cases, completion of the osteotomy may require the use of a chisel.
When a chisel is needed, gentle, controlled pressure is essential. Rather than forceful malleting, torque can be applied using the handle of a hemostat to carefully advance the chisel through the remaining bone. This technique allows for gradual separation of the segment while minimizing the risk of fracture or devascularization.
Mobilization and Stabilization
Once the dentoalveolar segment is fully mobilized, it can be repositioned according to the planned correction. During this phase, care must be taken to preserve soft tissue attachments and avoid excessive manipulation.
In certain cases, ligature wires may be required to maintain continuity and stabilize the segment during healing. These wires help ensure proper alignment and reduce micromotion until bony union occurs. Additional fixation methods may be selected based on surgeon preference and case complexity.
Postoperative Considerations
Maintaining segment stability and vascularity is essential for successful healing. Patients are typically managed with appropriate postoperative instructions, including soft diet, limited function, and close follow-up to monitor healing and occlusion.
Complications are uncommon when proper technique is used but may include segment instability, delayed union, or neurosensory disturbances if anatomical boundaries are not respected.
Conclusion
Subapical osteotomy is a valuable surgical technique for correcting dentoalveolar discrepancies in the anterior mandible while avoiding more extensive orthognathic procedures. By placing the osteotomy anterior to the mental foramen, using controlled instrumentation such as piezoelectric devices and oscillating saws, and applying gentle mobilization techniques, surgeons can achieve predictable outcomes with minimal morbidity.
Careful planning, precise execution, and thoughtful stabilization are the keys to success in subapical osteotomy procedures.
