Sinus Floor Cortication: Classification and Prevalence.

PURPOSE: To present a classification and assess the presence and degree of cortication of the sinus floor utilizing Computerized Tomography (CT) scan images. MATERIALS AND METHODS: One hundred CT scans, of patient who required a sinus augmentation procedure (SAP), were evaluated and classified according to the Type of sinus floor cortication (SFC). Type 1: sinus floor showing similar or higher density than the surrounding cortical areas. Type 2: sinus floor showing less density than the surrounding cortical areas. Type 3: sinus floor showing no cortical bone. Type 4: sinus floor showing the fusion of sinus floor bone and native crestal bone. RESULTS: The SFC were present in 31, 41, 18, and 10 cases in Type 1, 2, 3, and 4, respectively. CONCLUSIONS: This classification based on the level of cortication of the sinus floor is clinically useful as a method of determining if the dental implant can be placed simultaneously or not with the SAP, or can be placed even without a SAP.

Trifactorial classification system for osteotome sinus floor elevation based on an observational retrospective analysis of 926 implants followed up to 10 years.

OBJECTIVE: A novel osteotome trifactorial classification system is proposed for transcrestal osteotome-mediated sinus floor elevation (OSFE) sites that includes residual bone height (RBH), sinus floor anatomy (contour), and multiple versus single sites OSFE (tenting). METHOD AND MATERIALS: An analysis of RBH, contour, and tenting was retrospectively applied to a cohort of 926 implants placed using OSFE without added bone graft and followed up to 10 years. RBH was divided into three groups: high (RBH > 6 mm), mid (RBH = 4.1 to 6 mm), and low (RBH = 2 to 4 mm). The sinus "contour" was divided into four groups: flat, concave, angle, and septa. For "tenting", single versus multiple adjacent OSFE sites were compared. RESULTS: The prevalence of flat sinus floors increased as RBH decreased. RBH was a significant predictor of failure with rates as follows: low- RBH = 5.1%, mid-RBH = 1.5%, and high-RBH = 0.4%. Flat sinus floors and single sites as compared to multiple sites had higher observed failure rates but neither achieved statistical significance; however, the power of the study was limited by low numbers of failures. CONCLUSION: The osteotome trifactorial classification system as proposed can assist planning OSFE cases and may allow better comparison of future OSFE studies.

Classification and management of antral septa for maxillary sinus augmentation.

The antral septum, a commonly found anatomical variation, has been related to the occurrence of membrane perforation during sinus augmentation. The aims of this study were to review features of antral septa and to propose a classification system and options for managing antral septa during sinus augmentation. A literature search of the PubMed database was performed to identify articles investigating antral septa. Manuscripts using three-dimensional computed tomography, providing direct measurements of human subjects or cadavers, and reporting features of antral septa besides the prevalence were included. Antral septa presented in approximately 20% to 35% of maxillary sinuses. Single septum was much more common than multiple septa. Mediolaterally (transversely) oriented septa were more frequently found than anteroposteriorly (sagittally) oriented septa. Their size varies and commonly increases from the lateral to medial segment within one septum. The proposed classification consists of three categories--easy (E), moderate (M), and difficult (D)--based on the location, number, orientation, and size of antral septa. Corresponding treatment approaches were suggested for each category. Sinus augmentation is complicated by the presence of antral septa, the features of which determine the degree of surgical difficulty. Based on the results of the included studies and clinical experiences, a classification system and treatment strategies of antral septa were proposed and may assist surgeons in managing antral septa during sinus augmentation.