Steven M. Roser

The Accuracy of Virtual Surgical Planning in Free Fibula Mandibular Reconstruction: Comparison of Planned and Final Results

PURPOSE The concept of virtual surgery uses surgical simulation rather than relying exclusively on intraoperative manual approximation of facial reconstruction. The purpose of this study was to evaluate the degree to which surgical outcomes in free fibula mandibular reconstructions planned with virtual surgery and carried out with prefabricated surgical plate templates and cutting guides correlated to the virtual surgical plan in a series of 11 patients. MATERIALS AND METHODS This retrospective study evaluated 11 consecutive patients (6 males and 5 females) with an average age of 50.73 years (range, 23-72 years) who required mandibular reconstruction for aggressive benign or malignant disease with a free fibula osseomyocutaneous flap at Emory University Hospital (Atlanta, GA) between January 1, 2009 and December 31, 2009. In each case, a high-resolution helical computed tomography (CT) scan of the maxillofacial region and mandible was obtained prior to surgery. The CT data was sent on a CD to a modeling company (Medical Modeling Inc, Golden, CO). The scans were then converted into 3-dimensional models of the maxillofacial skeleton utilizing both automatic and manual segmentation techniques in the SurgiCase CMF software (Materialise NV, Leuven, Belgium). A virtual surgery planning session was held via a Web meeting between the surgeons and the modeling company, at which the resection planes of the mandible, positioning of the plate, and fibula lengths/osteotomy angles were established. The surgery was then carried out using prefabricated cutting guides and manual bending of a reconstruction plate using a prefabricated plate template. A postoperative CT scan of each patient was obtained within the first 7 postoperative days on the same scanner. Three-dimensional computer models of the final reconstruction were obtained for comparison with the preoperative virtual plan. To make the desired comparisons, the 3-dimensional objects representing the postoperative surgical outcome were superimposed onto the preoperative virtual plan using manual alignment techniques. These objects were then compared by 1-to-1 magnification for measurements of fibular bone volume, location of mandibular osteotomies, location of fibular osteotomies, plate contour, plate position on fibula, and plate position on mandible. Comparison was made between the virtual and final plates with regard to contour and position through superimposition overlays of the 3-dimensional models that are registered in the same coordinate system. RESULTS A total of 19 mandibular osteotomies were carried out. The mean distance of the actual mandibular osteotomy when compared to the virtual mandibular osteotomy was 2.00 ± 1.12 mm. The mean volume determined by the software program of the 11 virtual fibulas was 13,669.45 ± 3,874.15 mm(3) (range, 9,568 to 22,860 mm(3)), and the mean volume of the 11 actual postoperative fibulas was 12,361.09 ± 4,161.80 mm(3) (range, 7,142 to 22,294 mm(3)). The mean percentage volumes of the actual postoperative fibula compared to the planned fibula were 90.93 ± 18.03%. A total of 22 fibular segments were involved in the study created by 44 separate fibula osteotomies. The mean distance of the actual fibula osteotomy when compared to the virtual fibula osteotomy was 1.30 ± 0.59 mm. The mean percentage overlap of the actual plate to the virtual plate was 58.73% ± 8.96%. CONCLUSIONS Virtual surgical planning appears to have a positive impact on the reconstruction of major mandibular defects through the provision of accuracy difficult to achieve through manual placement of the graft, even in the hands of experienced surgeons. Although a reasonably high level of accuracy was achieved in the mandibular and fibula osteotomies through use of the surgical cutting guides, the limited ability to correctly contour the plate by hand to replicate the plate template is reflected in our findings.

Pediatric Tumors of the Temporomandibular Joint

The incidence of tumors and pseudotumors of the temporomandibular joint (TMJ) in the pediatric population is low. They are often challenging to recognize unless associated with signs and symptoms that may erroneously be interpreted as TMJ dysfunction. Tumors of the TMJ can be divided into 3 categories based on the nature and type of precursor cell involved in the tumor: benign tumors, malignant tumors, and pseudotumors. This article discusses the most common entities in these categories.

Quality Improvement and Reporting Systems : What the Oral and Maxillofacial Surgeon Should Know

Health care is an inherently dangerous environment, and patient safety should be an explicit goal of oral and maxillofacial surgery. Important components of a safety program include a nonpunitive safety culture, the implementation of patient safety practices, standardized incident reporting and adverse event analysis, regular self-assessment, and internal and external benchmarking. Implementation of a safety program requires the strong commitment of leadership and the engagement and empowerment of all employees. Oral and maxillofacial surgery can become the model dental specialty by implementing patient safety programs for office-based surgery. The programs could then be used by all dental practitioners performing oral surgery in the office.

Medical Management of Patients Undergoing Dentoalveolar Surgery

The oral and maxillofacial surgeon (OMS) should have an understanding of common medical comorbidities. This understanding allows for risk stratification and thus prevention of potential problems. Remaining knowledgeable regarding diseases, diagnosis, treatment strategies, and pharmacology ultimately improves patient care. This article provides an update on some of the most common medical diseases for the patient undergoing dentoalveolar surgery.