Three-dimensional （3D） digital technologies such as X-ray computer tomography, laser scanners, CAD/CAM, and 3D printers have been developing rapidly and are now widely used in prosthetic dentistry and maxillofacial reconstruction. In order to develop such technologies in dentistry properly, we need to recognize their principles and characteristics, and especially the relationships among accuracy, data size, time for processing and manufacturing needed for producing targets of different sizes.
Recently there has been remarkable progress in regenerative medicine, and almost all disorders in the oral and maxillofacial region fall within the scope of research on regenerative medicine. Treatments in this region have been well established using biomaterials, prostheses and microsurgery. To improve upon conventional approaches, regenerative medicine as an alternative should adopt a less invasive and/or more effective approach. In this report, we present our basic and clinical research on bone regenerative medicine in the oral and maxillofacial region.
Recently, in situ tissue engineering such as distraction osteogenesis and transplantation of particulate cancellous bone and marrow （PCBM） has been applied in mandibular reconstruction. This approach takes advantage of the natural process of bone formation in humans. We have tried to develop artificial bone that maximizes bone formation at the transplanted site, but is subsequently replaced by autologous bone. We have made custom-made artificial bone based on CT （CT-Bone） using α-TCP particles and an ink-jet printer, and have conducted clinical research and trials on 30 patients. In each case, improvement of maxillofacial morphology has been observed with no major complications thus far.
Three-dimensional measurement, analysis and simulation are important for the rehabilitation treatment of patients after resection of the jaw and teeth due to trauma, malignant tumor and congenital anomaly. Treatments with dental implants or facial prostheses are useful and necessary for both elderly and growing patients. In such procedures, we must consider and analyze three-dimensionally the location of the grafted bone and the symmetry of the maxillofacial morphology.
Three-dimensional digital data obtained by laser scanner, computer tomography or digital cameras has been used in dentistry since the early 1990s. In the field of maxillofacial prosthodontics, 3D technologies with sophisticated computer software have been used for simulation and fabrication of prostheses. Although 3D technologies have many advantages over conventional methods, there are still some limiting factors which affect accuracy in particular. This review discusses the advantages and limiting factors of 3D technologies related to maxillofacial prostheses.
The Maxillofacial Prosthetic Clinic in Aichi Gakuin University Hospital is in charge of caring for special patients who have maxillofacial defects and require prosthetic treatment. Since 1981, for 31 years, we have treated over 1,700 patients. In this study, a clinical survey was conducted to access the patient population change for maxillofacial prosthetic treatment. The patient numbers, gender, age distribution, referring departments, diagnostic cases and treatment options were investigated. Results revealed that a total of 1,718 patients were examined and there were no gender differences in number; the average age was 43.5 years old. The age distribution showed a larger peak of patients in their teens and twenties, and a smaller peak of patients over 60. Almost half of the referring departments involves oral surgery departments in our university, following Aichi Cancer Institute （13％）, and other medical hospitals （11％）. Diagnostic cases were classified into the groups of maxillary and mandibular defects, the jaw deformities group and the cleft palate group. Those involved had similar percentages and the total of the three groups was 90％. Major treatments are fabricating maxillofacial prostheses and following auxiliary devices. The cases of malignant tumors increased, reaching 76％ in 2011. As for referring departments, patients from oral surgery departments are decreasing, whereas patients from cancer institutes are increasing.