Mandibular reconstruction using computer-aided design and computer-aided manufacturing: an analysis of surgical results.

PURPOSE: The purpose of this study was to analyze the accuracy of virtual surgical planning in mandibular reconstruction. MATERIALS AND METHODS: This is a retrospective study involving 8 consecutive patients reconstructed with nonvascularized iliac crest bone grafts and free fibula osteomyocutaneous flaps. DICOM data from a maxillofacial skeleton computed tomography (CT) scan were sent to a medical modeling company and used to map the mandibular resection, anatomically place the mandibular reconstruction plate, and create surgical guides. After surgery a postoperative CT compared the virtual plan to the surgical result. Linear measurements [2 transverse and 1 anterior-posterior (A-P)] were performed to determine if the virtual surgical result was achieved. The transverse measurements were made from the condylar head to condylar head and from the gonial angle to gonial angle. The A-P analysis was made by measuring a perpendicular line drawn from the anterior inferior mandibular border to the center point on the condylar head to condylar head measurement. RESULTS: The average surgical error in the A-P dimension for the iliac crest bone grafts and free fibula flap was 0.2 mm (range 0.0 mm to 0.7 mm) and 0.9 mm (range 0.2 mm to 1.9 mm), respectively. In the transverse dimension the average surgical error was 1.6 mm (range 0.7 mm to 2.4 mm) and 2.7 mm (range 1.9 mm to 4.5 mm) from condyle to condyle, and 1.7 mm (range 0.7 mm to 2.7 mm) and 2.5 mm (range 0.4 to 4.8 mm) from gonial angle to gonial angle. CONCLUSION: The use of CAD-CAM (Medical Modeling, Golden, Colorado) technology for the fabrication of surgical resection guides and mandibular reconstruction plates resulted in an accurate surgical result.

Sodium channel expression and localization at demyelinated sites in painful human dental pulp.

UNLABELLED: The expression of sodium channels (NaCh(s)) change after inflammatory and nerve lesions, and this change has been implicated in the generation of pain states. Here we examine NaCh expression within nerve fibers from normal and painful extracted human teeth with special emphasis on their localization within large accumulations, like those seen at nodes of Ranvier. Pulpal tissue sections from normal wisdom teeth and from teeth with large carious lesions associated with severe and spontaneous pain were double-stained with pan-specific NaCh antibody and caspr (paranodal protein used to visualize nodes of Ranvier) antibody, while additional sections were triple-stained with NaCh, caspr and myelin basic protein (MBP) antibodies. Z-series of images were obtained with the confocal microscope and evaluated with NIH ImageJ software to quantify the density and size of NaCh accumulations, and to characterize NaCh localization at caspr-identified typical and atypical nodal sites. Although the results showed variability in the overall density and size of NaCh accumulations in painful samples, a common finding included the remodeling of NaChs at atypical nodal sites. This remodeling of NaChs included prominent NaCh expression within nerve regions that showed a selective loss of MBP staining in a pattern consistent with a demyelinating process. PERSPECTIVE: This study identifies the remodeling of NaChs at demyelinated sites within the painful human dental pulp and suggests that the contribution of NaChs to spontaneous pulpal pain generation may be dependant not only on total NaCh density but may also be related to NaCh expression at atypical nodal sites.