Purpose: The purpose of this study was to evaluate endoscopic assisted mandibular distraction.
Methods: A total of twelve mandibular distraction cases were performed utilizing endoscopic assist technique. These included six intraoral internal mandibular distraction procedures and six removal of distraction devices. All cases were performed between January 2006 and Febuary 2007. All cases underwent mandibular distraction through intraoral approach with percutaneous placement of screws. All cases had the distraction arm brought out through a percutaneous incision. On the six mandibular distraction cases, the seventy degree endoscope was inserted through the intraoral incision and used to visualize the anatomy, place the distraction devices, mark and place the osteotomy, and confirm distraction of the segments. On removal of device cases, the endoscope was again used to visualize these screws, assist with removal of bone in the interstices of the screw head, and accurately seat the screwdriver. It was also used to visualize the quality of bony regenerate.
Two cases were performed on patients with Treacher Collins syndrome. Both cases underwent bilateral mandibular distraction procedures. Both children had severe obstructive sleep apnea (OSA), one had undergone prior, failed mandibular distraction and had a tracheotomy. One case was performed on a patient with hemifacial microsomia who also had OSA. One case was performed on a patient with jaw asymmetry with right sided benign mandibular hypertrophy confirmed by SPECT scanning and a diminutive mandible on the left. This patient underwent combined LeFort I and mandibular osteotomy with MMF and simultaneous mandibular and maxillary distraction with a single left mandibular device.
Results: In all cases, mandibular osteotomies and placement of distraction devices was successfully completed with endoscopic assist. The endoscope proved valuable for visualization of the anatomy and placement of the distraction device. Furthermore, visualization of the distraction device and placement of screw percutaneously was greatly facilitated by visualization afforded with the endoscope. In no patient was a Risdon incision necessary. In the patient who had undergone prior distraction, there was preoperative lip insensibility. In the patients who underwent primary osteotomy, there were no permanent lip sensory changes.
Removal of distraction devices were greatly simplified with the use of endoscope. This allowed for removal of bone from the interstices of the screws with ease. Furthermore, it allowed for accurate seeing of the screwdriver into the screw head. In no patient was a Risdon incision necessary.
Overall, the time required for placement of the distraction device and removal of the distraction device was decrease compared to similar cases performed without endoscopic assist. The visualization was felt to be greatly enhanced with the endoscopic technique.
Conclusions: The use of the endoscope allowed for easier placement and removal of the distraction device, more accurate osteotomy placement, avoidance of a Risdon incision, and avoidance of injury to the inferior alveolar nerve by allowing more proximal device placement and osteotomy.