Australasian Dentist Issue 93

CATEGORY 90 AUSTRALASIAN DENTIST INTRODUCTION Up until now, the endosseous screw implant has dominated the dental implant market. Over the years, multiple dental implant companies have appeared that cater to the growing number of dental implant devices that follow the same basic design principles that rely on adequate jaw bone to accommodate the implant fixtures. As more people are presenting with less alveolar bone, there has been a parallel rise in complimentary products such as synthetic bone grafts, plasma products and barrier membranes as well as a myriad of surface treatments that have emerged to address the challenges of inadequate bone to support the dental implants. Even dimensional extremes of extra short stubby implants and extra long zygomatic implants still rely on the existing endosseous screw technology that fails to make that leap of faith into a completely new way of designing dental implants (1). The subperiosteal frame is an idea that predates the endosseous screw implant (2). Instead of placing the dental implant into the jaw bone, the subperiosteal frame is placed on top of the jaw bone. While there were many reasons why the original subperiosteal frames fell out of favour (3), the 21st century digital technology now available has brought about a resurgence in interest in the concept of subperiosteal frames. The aim of this article is to present examples of Australian made OsseoFrames (4) that were used to provide simple fixed dental implant solutions in the form of a new age subperiosteal implant system that is custom designed and constructed on a digital platform. CASE REPORT 1 – Anterior Maxilla (Figs. 1-3) A 33yo male presented to the author with missing maxillary incisors following a near fatal motorcycle accident 18 months previously. He not only lost the 12,11,21 and 22, but was also missing a significant amount of labial alveolar bone in the anterior maxilla. This left him with a knife edge edentulous alveolar ridge between his maxillary canines. The patient was keen for a fixed dental implant solution and so was given 2 options. The first option was for a conventional staged procedure consisting of initial onlay block bone graft to the anterior maxilla followed 4 – 6 months later by 2 dental implants with the fixed dental bridgework installed two months later. The whole process was estimated to take at least 6 months before he received his final prosthetic teeth. The alternative was an OsseoFrame that was custom designed on Dicom files of his CT scans and 3D printed in Titanium. A set of initial prosthetic teeth would also be provided so that the whole process from implantation of the OsseoFrame and attachment of the prosthetic teeth is undertaken in the one operation. Unsurprisingly, the patient opted for the second choice. Using materialize software, biomedical engineers designed a fully custom subperiosteal frame to support the 4-unit bridge on 2 transmucosal posts. Prosthetic teeth were then made by OSTEON on the finished frame and delivered, together with the OsseoFrame, to the hospital for implantation. Under general anaesthesia, a crestal gingival incision was made along the edentulous alveolar ridge and mucoperiosteal flaps raised with relieving incisions on the labial and palatal aspects to expose the razor thin alveolar bone. The fully customized titanium OsseoFrame was fitted into the preplanned position and secured to the bone with multiple titanium self-tapping bone screws. The gingival flaps were then closed over the frame using dissolving sutures leaving the 2 transmucosal posts exposed through the wound. The 4-unit bridge was then attached to the 2 transmucosal posts with internal M2 screws and after an occlusal adjustment the patient was woken up. The operative procedure took less than 1 hour, and the patient was discharged home about 2 hours later with his new teeth in place. OPG x-ray was taken on discharge and the bridgework removed about 3 weeks later to assess wound healing which was satisfactory with no sign of inflammation, infection or wound dehiscence. LINICAL By George Dimitroulis, Consultant Oral & Maxillofacial Surgeon, Epworth-Freemasons Hospital, East Melbourne Vic OSSEOFRAME: A simple alternative to complex implant dentistry for the Atrophic Edentulous Alveolus Figure 1: Postoperative x-ray showing the OsseoFrame in Case 1 secured to the anterior edentulous maxilla with 2 conical transmucosal posts connecting the 4-unit bridge to the frame. Figure 2: Clinical photo of the anterior maxilla in Case 1 showing the 2 transmucosal conical posts 3 weeks after implantation of the OsseoFrame. The red areas are where the bridge was pressing against attached tissues and so the bridge was appropriately adjusted. Figure 3: The 4-unit bridge in place which was first inserted at the time of initial implantation of the OsseoFrame in Case 1. In all OsseoFrame cases, the initial bridgework is made in acrylic to allow for adjustments. Once the underlying gingival tissues are fully healed and the OsseoFrame is solidly attached/osseointegrated to the alveolus, the patient can then proceed with construction of their permanent final teeth which is usually 3 to 6 months after implantation.