New Clinical Protocol to Evaluate Craniomaxillofacial Deformity and Plan Surgical Correction

Abstract

Cranio-Maxillofacial Surgery (CMF) involves the correction of congenital and acquired conditions of the head and face. In the United States, a significant number of patients require surgery for these types of conditions. They include patients with of congenital and developmental deformities of the CMF region (17 million) 1-7, defects after tumor ablation (28,000 new patients per year)8, post-traumatic defects (200,000 per year)9, 10 and deformities of the temporomandibular joint (6000 patients per year require prosthetic and autogenous TMJ reconstruction)11, 12. The latest figures indicate that 33,000 US servicemen and women have been wounded in action in both Operation Iraqi Freedom and Operation Enduring Freedom.13 It is estimated the one fourth to one third of them suffered head and neck injuries.14 The surgical correction of CMF deformities is among the most challenging. The success of these surgeries depends not only on the technical aspects of the operation, but also, to a larger extent, on the formulation of a precise surgical plan.15-24 Over the last 50 years, there have been significant improvements in the technical aspects of surgery, i.e. rigid fixation, resorbable materials, distraction osteogenesis, minimally invasive approaches, etc. However, the planning methods have mostly remained unchanged.17, 18, 20, 24 It is clear that many of the unwanted surgical outcomes are the result of deficient planning. The need to improve the traditional surgical planning methods has led our group to develop a 3D computer-aided surgical simulation (CASS) system to plan CMF surgery. We have utilized this system in maxillofacial surgery23, 25-27, craniofacial surgery28, trauma, distraction osteogenesis28-30 and TMJ reconstruction31. Using this system, a doctor can perform “virtual surgery” and create a 3D prediction of the patient's surgical outcomes, as if they are performing surgery in the operating room. We have documented the clinical feasibility18, 24, the accuracy32 and cost-effectiveness33 of this system. Our CASS system incorporates 3 distinctive features and innovations: 1) multiple imaging modalities are used to create an accurate model of the craniofacial skeleton; 2) special techniques are employed to orient the computerized bone model in the natural head position (NHP); and 3) Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) techniques are used to fabricate accurate surgical splints and templates to transfer the surgical plan to the operating room. The purpose of this article is to present our CASS planning protocol.