RESUMO
Guided bone regeneration (GBR) is a well-established and generally predictable method for repairing alveolar ridge defects and preparing edentulous sites for implant placement. Standard GBR involves filling the space underneath a membrane with autogenous bone or a mixture composed of autogenous bone particles and allogeneic bone tissue or heterologous biomaterials. The use of a barrier membrane for GBR has sometimes been associated with complications, however - reportedly involving exposure, infection, and collapse - and the non-resorbable types of membrane seem to be involved more often than the resorbable solutions. Such complications may be severe enough to defeat the object of the GBR procedure. A non-resorbable high-density polytetrafluoroethylene (d-PTFE) membrane has recently been designed specifically for use in bone-augmentation procedures that seems to assure a good bone regeneration process even when the membrane is exposed to the oral cavity. This case report describes an exposure of a d-PTFE membrane occurring after a maxillary GBR procedure and how it was overcome successfully, enabling implants insertion.
RESUMO
BACKGROUND: When considering dental implant rehabilitation in atrophic posterior sectors, the maxillary sinuses must be evaluated in detail. Knowledge of the anatomical variations and of the potential lesions found in these structures conditions the outcome of sinus lift procedures and therefore of the dental implants. A systematic review is made to determine the frequency of anatomical variations and pathological findings in maxillary sinuses among patients subjected to cone beam computed tomography (CBCT). MATERIAL AND METHODS: A PubMed (MEDLINE) literature search was made of articles published up until 20 December 2015. The systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). The quality of the studies included in the review was assessed using the Methodological Index for Nonrandomized Studies (MINORS). RESULTS: The combinations of search terms resulted in a list of 3482 titles. Twenty-three studies finally met the inclusion criteria and were entered in the systematic review, comprising a total of 11,971 patients. The most common anatomical variations were pneumatization and sinus septa. The prevalence of maxillary sinus disease ranged from 7.5% to 66%. The most common pathological findings of the maxillary sinus were mucosal thickening, sinusitis and sinus opacification. CONCLUSIONS: Although the main indication of CBCT of the maxillary sinus in dentistry is sinus floor elevation/treatment planning and evaluation prior to dental implant placement, this imaging modality is increasingly also used for endodontic and periodontal purposes. There is no consensus regarding the cutoff point beyond which mucosal thickening of the maxillary sinus should be regarded as pathological, and the definition of maxillary sinusitis moreover varies greatly in the scientific literature. In this regard, international consensus is required in relation to these concepts, with a clear distinction between healthy and diseased maxillary sinuses.
