Anatomical aspects of sinus floor elevations

Abstract

Inadequate bone height in the lateral part of the maxilla forms a contra-indication for implant surgery. This condition can be treated with an internal augmentation of the maxillary sinus floor. This sinus floor elevation, formerly called sinus lifting, consists of a surgical procedure in which a top hinge door in the lateral maxillary sinus wall is prepared and internally rotated to a horizontal position. The new elevated sinus floor, together with the inner maxillary mucosa, will create a space that can be filled with graft material. Sinus lift procedures depend greatly on fragile structures and anatomical variations. The variety of anatomical modalities in shape of the inner aspect of the maxillary sinus defines the surgical approach. Conditions such as sinus floor convolutions, sinus septum, transient mucosa swelling and narrow sinus may form a (usually relative) contra-indication for sinus floor elevation. Absolute contra-indications are maxillary sinus diseases (tumors) and destructive former sinus surgery (like the Caldwell-Luc operation). The lateral sinus wall is usually a thin bone plate, which is easily penetrated with rotating or sharp instruments. The fragile Schneiderian membrane plays an important role for the containment of the bonegraft. The surgical procedure of preparing the trap door and luxating it, together with the preparation of the sinus mucosa, may cause a mucosa tear. Usually, when these perforations are not too large, they will fold together when turning the trap door inward and upward, or they can be glued with a fibrin sealant, or they can be covered with a resorbable membrane. If the perforation is too large, a cortico-spongious block graft can be considered. However, in most cases the sinus floor elevation will be deleted. Perforations may also occur due to irregularities in the sinus floor or even due to immediate contact of sinus mucosa with oral mucosa. Obstruction of the antro-nasal foramen is, due to its high location, not a likely complication, nor is the occurrence of severe haemorrhages since the trap door is in the periphery of the supplying vessels. Apart from these two aspects, a number of anatomical considerations are described in connection with sinus floor elevation.

Evaluation of the posterior superior alveolar artery and the maxillary sinus with CBCT

“…15 CBCT provides accurate and reliable linear measurements for reconstruction and imaging of dental and maxillofacial structures. [7][8][9] According to Kim et al, 16 the prevalence of the PSAA differs significantly between males (64%) and females (40%). In the present study, no significant correlation was found between gender and presence of the artery.…”

“…maxillary sinus. 8,9 Any imaging technique that subjects the patient to ionizing radiation must yield as much pertinent information as possible, and it is important that the physician collect all the useful information possible. Cone beam computed tomography (CBCT) may be recommended as a dose-sparing technique compared with standard medical computed tomography (MDCT) scans for dentomaxillofacial imaging.…”

Avaliação histológica de hidroxiapatita sintética associada a fosfato de cálcio (?-TCP) utilizados em levantamento de assoalho de seio maxilar

“…Dentre essas condições, pode-se destacar a pneumatização do seio maxilar. 3,6 Nesta circunstância, alguns procedimentos de elevação do seio maxilar, visando à correção desta deficiência e à possibilidade de colocação de implantes osseointegráveis na região, são necessários, sendo inclusive muito bem descritos há muito tempo na literatura 1,2 .…”

“…Hematoxilina -Eosina, aumento original de 100. b -Fotomicroscopia, (Grupo EA) em maior aumento, ilustrando a presença de osteócitos viáveis (setas) nas trabéculas ósseas. Hematoxilina -Eosina, aumento original de 400. maxilar é tido como uma técnica cirúrgica segura, confiável e com excelentes índices de sucesso, comprovados por estudos com controles superiores a 10 anos [6][7][8] . Porém, devido à necessidade de um sítio doador e à sua morbidade, gradualmente outros biomateriais vêm sendo usados, apresentando índices de sucesso convincentes.…”

Observation of maxillary sinus septa and bony bridges using dry skulls between Hellman's dental age of IA and IIIC

“…Also, modified techniques, such as the double window technique, were proposed in maxillary sinus lift procedures involving the septa 17,18) . The diagnosis of septum presence was important in the presurgical imaging of sinus floor elevation techniques.…”