Australasian Dentist Issue 93

CATEGORY AUSTRALASIAN DENTIST 91 CASE REPORT 2 – Posterior Maxilla (Figs. 4-7) A 76 year old male was referred to the author for provision of a fixed prosthetic solution in the right posteriormaxilla where teeth 13,14,15,16 and 17 were missing. The patient could not tolerate the existing partial denture which was constructed 6 months previously and he had hardly worn it. The confounding problem was the very low maxillary sinus floor of only 2-3mm in width which necessitated sinus lift bone graft before dental implant fixtures could be placed. He was given the conventional option of a staged procedure consisting of a maxillary sinus lift using a combination of autogenous and xenogeneic /synthetic bone grafts followed 6 to 9 months later by insertion of 3 dental implants with a further 2 to 3 months delay before prosthetic teeth could be placed. The whole treatment would, in effect, take about 9 to 12 months before he could realise his new teeth – and that is if all went well with no problems. The alternative was a combination of pterygoid and zygomatic buttress implants which the patient declined. Like case 1 already described, the patient opted for the simpler and quicker OsseoFrame solution that provided him with immediate teeth without the need for sinus lift bone grafting. The 1 hour procedure to install both the 3-post OsseoFrame and connect the 5-unit bridge left the patient wondering why anyone would opt for conventional treatment when such a quick and simpler solution is available. DISCUSSION The difference between existing dental implant systems and the OsseoFrame is that conventional dental implants rely on adequate bone mass to accommodate the fixtures. Subperiosteal implants, on the other hand, are placed on top of the alveolar bone and hence may be used in cases of extremely atrophic alveolar bone without the need for bone grafts or fixation to distant anatomical sites such as zygomatic or pterygoid bones. The OsseoFrame is a new generation of subperiosteal dental implants that takes advantage of computer aided design and manufacture (CAD- CAM) as well as materials science and engineering advances (4) that were not available when subperiosteal implants were first introduced in the 1940’s (2). The osseointegration capabilities of titanium make it the ideal material for subperiosteal implants. Furthermore, the fully customized devices are designed for close adaptation to the underlying bony anatomy with further three-dimensional stability provided by numerous bone screws. The ideal placement and parallel positioning of the transmucosal posts help simplify the design and construction of the dental prosthesis which can be pre-made and delivered at the time of surgery. While the OsseoFrame is an Australian product (4), there are many centres around the world that are also rediscovering the benefits of subperiosteal implants and are working hard to commercialize their own brands (5). The OsseoFrame has been around since 2015 and, as a TGA approved medical device, is gaining traction here in Australia whilst interest from overseas is also gathering momentum (4). CONCLUSION In one simple procedure, the OsseoFrame eliminates the need for conventional multi- staged treatments in cases of atrophic bone that would span over many months before the final delivery of prosthetic teeth. As shown in the 2 cases described, the OsseoFrame is a significant paradigm shift in the way we deliver fixed dental prosthetic solutions to patients with atrophic edentulous alveolus and jaws. u NOTE: The OsseoFrame is a TGA approved Dental Implant System device (ARTG-286266) which is designed and manufactured by MAXONIQ, an ISO13485 certified MedTech company based in Melbourne. www. maxoniq.com DECLARATION: Dr George Dimitroulis is a practicing Oral & Maxillofacial Surgeon and Founder of MAXONIQ Pty Ltd, (www.maxoniq.com ) a Melbourne based Medtech Company which developed and manufactures the Subperiosteal implant device, otherwise known as the OsseoFrame TM , described in this article. For a full list of references please email gapmagazines@gmail.com All Correspondence: Dr George Dimitroulis, Suite 1, Ground Floor 124 Grey Street, East Melbourne Vic 3002 Tel: +61 03 9654 3799 Fax: +61 03 9650 3845 Mob: +61 0409 505 146 e-mail: geodim25@gmail.com LINICAL Figure 7: Postoperative x-ray of Case 2 showing the OsseoFrame fixed to the atrophic edentulous right posterior maxilla with multiple bone screws. The 3 conical transmucosal posts are clearly visible but the acrylic bridge attached to the posts remains invisible. Figure 6: Clinical photo of Case 2 showing the attachment of the acrylic bridgework while the patient is still under general anaesthesia. Initial occlusal adjustment is made before the patient wakes up and further adjustments are made in the days following his surgery. Eventually the initial acrylic bridge will be replaced by a permanent bridge about 3-6 months later when soft tissue and bone healing is complete. Figure 4: Biomodel of the patient described in Case 2 showing the closely adapted custom printed OsseoFrame with the initial temporary acrylic bridgework attached. Figure 5: Intra-operative view of the implanted OsseoFrame in the posterior maxilla of the patient described in Case 2. Note the close adaptation of the frame to the atrophic bone which is secured with multiple titanium bone screws.