Anatomy of the Maxillary Sinus and the Role of CT Scans in Maxillary Sinus Augmentation Surgery

Background: Detailed knowledge of sinus anatomy as well as timely identification through CT scans of the anatomic structures inherent to the maxillary sinus is required to avoid unnecessary surgical complications. Purpose: To investigate sinus homeostasis, physiology, and anatomy; to review all anatomical-related risk factors for sinus membrane perforation; and to analyze the significance of preoperative and postoperative sinus CT scan imaging. Materials and MethodsData from the recent literature on the above topics were explored. Results: Thinner membranes may not have sufficient mechanical strength to resist force during elevation or bone grafting, and thicker membranes may be associated with the presence of subclinical sinusitis. Increased thickness of an unhealthy membrane generally indicates a weaker membrane with a gelatinous texture, whereas thickening of a healthy membrane occurs at the periosteal layer level and can enhance its strength. Sinus membrane thickness, sinus septa, type of edentulism, and root position relative to the sinus cavity, residual bone height, sinus width, palatonasal recess angle, buccal wall thickness, zygomatic arch location, alveolar antral artery, and bone dehiscence may influence the clinical complexity of the surgery. There is no clear evidence of systematic negative outcomes related to sinus perforations. In patients with severely atrophic posterior maxillas, the possibility of lacerating the alveolar antral artery and/or detecting antral septa must be considered, especially when the residual ridge height is < 3 mm high. Transient edema and thickening of the sinus mucosal membrane typically resolve spontaneously. In cases of graft extrusion, conservative management could be considered for asymptomatic patients with healthy sinus and open ostium at the time of surgery. On the other hand, patients with symptoms should be referred. Radiographic evidence of implant protrusion into the sinuses is not always associated with complications. Conclusions: Investigating sinus homeostasis and physiology, exploring the vascular anatomy within the maxillary sinus, identifying anatomical risk factors for sinus membrane perforation, and analyzing the significance of preoperative and postoperative sinus CT imaging provide a systematic and comprehensive framework for evaluating the complexity of maxillary sinus augmentation using a lateral approach.