Document Type



This item is available under a Creative Commons License for non-commercial use only


Biophysics, Dentistry, oral surgery and medicine

Publication Details

“Retention systems for extraoral maxillofacial prosthetic implants: a critical review”, Marcus Vinicius Cobein, Neide Pena Coto, Oswaldo Crivello Junior, José Benedito Dias Lemos, Livia Morelli Vieira, Marina Leite Pimentel, Hugh James Byrne, Reinaldo Brito Dias, British Journal of Oral and Maxillofacial Surgery, 55, 763–769 (2017)


Objectives: The purpose of this literature review is to provide information on the different available techniques for implant-supported prosthetic retention, which are bar-clip, o-ring or magnets. Through presenting the practitioner preferences reported in literature, although limited from strict comparison due to the heterogeneity of methodologies and studied individuals, this review aims to identify the choices for maxillofacial prosthesis implant retention systems, regarding patient comfort and good aesthetic outcome, as an aid to surgical and prosthetic planning for implant-supported extraoral maxillofacial prosthetics. With proper knowledge of each implant retention system, a practitioner can design a treatment plan which allows for a more natural and comfortable prosthetic. Methods and Materials: Papers were searched through the PubMed and Scopus databases. The literature search was restricted to papers published from 2001-2013 although patient studies may have been conducted prior to 2001. MeSH terms for the searches were “Maxillofacial Prosthesis” and “Craniofacial Prosthesis OR Craniofacial Prostheses”. Overall, 2630 papers were returned. After eliminating duplicates, titles and abstracts were analyzed, 25 papers were filtered and reviewed. Of these, 12 papers were excluded, because they were case reports or non-systematic literature reviews. Of the remaining 13, 10 papers presented group analysis and were deemed appropriate to access practitioner’s choices, as cited in the abstract. These papers refer to 1611 prosthesis. Three papers do not mention the type of prosthetic connection chosen, so they were not counted for this purpose. Results: The most popular choices of retention system for different patient conditions were analysed, even though the sites and corresponding retention systems were not specified in all of the 10 papers based on group analysis. The bar-clip system was the most used in auricular (6 papers out of 10) and nasal prosthesis (4 papers out of 10). For the orbital region, 6 out of the 10 favored magnets. Conclusions and relevance: Non-osseointegrated mechanical or adhesive retention techniques are the least expensive and have no contraindication. When osseointegrated implants are possible, there is a more commonly used system for each facial region. The choice of implant retention system is mostly determined by two factors: standard practice and maxillofacial surgeon and maxillofacial prosthetist abilities.