Anatomical preconditions for the palatal sinus floor augmentation—A three-dimensional feasibility study

Classifying Maxillary Sinuses of Polish Patients for Sinus Lift: A Pilot Study

To date, there is no systematic anatomical classification available that could help clinicians in choosing between the lateral and palatal approach in sinus lift procedures. The aim was to provide a simple-to-use and memorable classification of the maxillary sinus concerning the thickness of lateral and palatal walls to facilitate the most adequate choice for the window location during direct sinus floor elevation. Cone beam computed tomography scans were consecutively obtained for 200 maxillary sinuses of patients needing dental implant placement with potential maxillary sinus augmentation. The thickness and height of the alveolar bone of the lateral and palatal walls of the maxillary sinuses were assessed. Four variants were distinguished. Class 0: an adequate sub-sinus residual bone height; without the need for sinus floor augmentation. Classes 1-3 had a reduced sub-sinus residual bone height. Class 1: a thinner lateral than palatal sinus wall. Class 2 (the most frequent; 49%): the comparable thickness of both walls in which either lateral, palatal, or crestal window osteotomies can be applied. Class 3 (the least frequent; 3%): a thinner palatal sinus wall in comparison to the lateral wall. The presented anatomical classification simplifies the decision-making process of choosing the most adequate window location and osteotomy technique.

The Palatal Window for Treating an Incompletely Augmented Maxillary Sinus

Maxillary sinus augmentation through a lateral window is reported as one of the most predictable bone augmentation procedures before implant placement. The elevation of the membrane represents a delicate and crucial step that allows the creation of the space for the bone graft material. If the elevation is not completed, the regenerated bone might be inadequate for the implant placement. In this case, a new intervention will be necessary to complete the bone augmentation. Reaccessing from a lateral window, however, would be challenging due to thickness of the buccal boney wall because of the first grafting procedure; therefore, a different approach has to be used. The aim of this case report is to present the palatal window technique for treating incompletely augmented maxillary sinus. The detailed step-by-step diagnostic and surgical procedures are described, and the advantages and limitations of the technique are discussed through a review of the literature.

Morphometric analysis of sinus depth in the posterior maxilla and proposal of a novel classification

The aim of this study was to analyse the posterior maxillary sinus based on its extension into the alveolar process and to provide a simple clinical classification. A retrospective cohort study was conducted in CT scans of 200 dentate and 200 edentulous patients (100 women and 100 men, respectively). After manual placement of 12 reference points morphometric analysis was performed and sinus depth, residual alveolar ridge height (RH) and the sinus opening angle were calculated. Sinuses were classified according to the quartiles of sinus depth: class I (above the hard palate), class II (0–6 mm below the hard palate) and class III (>6 mm below the hard palate). Sinus depth was found to be a reliable anatomical landmark and did not vary significantly between gender (p = 0.8940) or dentition groups (p = 0.9723). Alveolar height varied significantly between sinus classes (p < 2 × 10⁻¹⁶) and dentition groups (p < 2 × 10⁻¹⁶) but not between genders (p = 0.5178). The sinus opening angle was significantly different between sinus classes (p < 2.2 × 10⁻¹⁶) but not between gender or dentition groups. We propose a novel classification built upon the quartiles of sinus depth, dividing the sinuses into three classes. Our classification is the first one that represents the anatomy of the patient independent of gender and dentition.