Application of computer-assisted design and manufacture technique in the treatment of condylar osteochondroma combined with jaw bone deformities: Report of a case

Protection of Inferior Alveolar Neurovascular Bundle in Alveolar Bone Operation

PURPOSE

The aim of this study was to investigate the protection of the inferior alveolar neurovascular bundle in alveolar bone operation in conditions such as chronic osteomyelitis and cementoma.

PATIENTS AND METHODS

The study enrolled 7 cases, 4 with chronic osteomyelitis and 3 with cementoma with pain. Computed tomography scan and 3-dimensional reconstruction were performed for the diseases. Data were processed by ProPlan CMF 1.3 software. The edge of lesion was defined and the inferior alveolar nerve was marked. Template was designed to guide the osteotomy line. Piezosurgery was used for osteotomy, with the avoidance of nerve canal. Current perception threshold (CPT) was performed to evaluate the nerve function after operation.

RESULTS

The CPT difference of the affected side before and after operation showed no statistically significant differences compared with that of the unaffected side (P = 0.0556).

CONCLUSIONS

Digital template protects the inferior alveolar neurovascular bundle with the aid of piezosurgery during alveolar bone resection, which obtained satisfying clinical results. As powerful assistive tools of functional surgery, digital template and piezosurgery achieve both the purposes of treatment and function.

Preservation of the inferior alveolar neurovascular bundle in the osteotomy of benign lesions of the mandible using a digital template

Our aim was to evaluate the effect of a digital template in the preservation of the inferior alveolar neurovascular bundle during osteotomy for benign lesions of the mandible in 6 patients who were treated with mandibular osteotomies during 2013. Computed tomographic (CT) data were imported into ProPlan CMF 1.4 software. The borders of the lesion and the inferior alveolar canal were marked, and a digital template designed to mark the borders, outline the canal, and guide the osteotomy. A mirror image of the unaffected mandible was used to make a stereolithographic model by a rapid prototyping technique to prefabricate the reconstruction plate for the bone graft. The accuracy of the designs and the templates was evaluated during operation and postoperatively by CT. The sensation of the skin was tested using a Neurometer® CPT (current perception threshold) sensory detector (Neurotron Inc, Baltimore USA) to evaluate the function of the preserved inferior alveolar neurovascular bundle during follow up. With the digital template it was possible to guide removal of the bony lesion while accurately protecting the neurovascular bundle. Follow up for a mean of 8 months (range 5 -12) showed good facial symmetry, a stable occlusion, and recovery of sensation in the lower lip on the affected side. We conclude that a digital template can successfully help the resection of benign lesions of the mandible while preserving the function of the inferior alveolar neurovascular bundle.