Cone-Beam Computed Tomographic Evaluation of Maxillary Tuberosity after the Extraction of Maxillary Third Molars.

Maxillary tuberosity is still one of the most important parts in the posterior maxilla, because of its role in the field of prosthetic dentistry, in particular in the improvement of the stability of upper dentures especially in the absence of abatement maxillary molars. The importance of the maxillary tuberosity to receive dental implants as in the case of the amount and the density of bone is critical in the posterior maxilla. In addition, the insertion of orthodontic mini screws in the maxillary tuberosity enables a good anchorage for the orthodontic movement of teeth to get the required space in the orthodontic treatment. The study aimed to evaluate the maxillary tuberosity status on CBCT images after the extraction of maxillary third molars. METHODSThe cross-sectional comparative study included seventy patients aged between 25 and 45 years (regardless of gender). The patients were divided into group A and group B. Group A consisted of 35 patients who were found with absence of upper third molars which are missing congenitally. Group B consisted of 35 patients who were found with absence of upper-third molars, but due to the previous extraction for the period between one to three years after the extraction. A total of 120 CBCT maxillary tuberosity images (for both sides) were obtained from the two study groups. Evaluation of each maxillary tuberosity was done by linear measurement of length, width, and height of the maxillary tuberosity on these CBCT images. RESULTSThe results showed that the mean dimensions of the maxillary tuberosity (width, length, and height) in Group A were 11.87 mm width, 10.17 mm length, and 11.22 mm height, while in Group B they were 9.93 mm width, 8.85 mm length and 8.78 mm height. Statistical analysis showed that the difference was significant for width and height measurements between the two groups, but it was not significant for the length measurements. CONCLUSIONSExtraction of the maxillary third molars leads to a significant reduction in most dimensions of the maxillary tuberosity.

Implantes retrosinusales como alternativa al levantamiento del piso del seno maxilar / Angled retrosinusal implants as an alternative to maxillary sinus floor lifting

En maxilares superiores edéntulos con senos neumatizados, que presenten tejido óseo retro sinusal aceptable, es posible la colocación de implantesen posición angulada con la técnica mínimamente invasiva (flapless) como alternativa al levantamiento del piso del seno maxilar. En los casos de patologías sinusales que desaconsejanla invasión de los mismos para la colocación de implantes, esta alternativa sería la más indicadapara solucionar el problema protético del pilar distal. Si bien se requiere experiencia y habilidad en la técnica,no cabe duda de los beneficios en costos y en postoperatorios para el paciente.

A possible choice for implant rehabilitationin the toothless maxila with neumatized sinus,is to use the pre and retro sinusal zones,whenever the bone volume allows doingso in order to avoid the sinus bottom liftingtechnique, which, even though it has goodpredictability and success, it is a much moretraumatic and expensive surgical procedurethan the mere placing of angled retrosinusalimplants that, with the help of ComputerizedAxial Tomography, could be installed witha minimumly invasive technique (flapless).

Maxillary sinus augmentation with bovine bone mineral (bio-oss.) and the maxillary tuberosity

The aim of this study was to evaluate implant stability placed in the maxillary sinus which was augmented with bovine bone mineral (Bio-Oss.) mixed with autogenous bone from the maxillary tuberosity. Maxillary sinus floor augmentation with the mixture of bovine bone mineral and autogenous maxillary tuberosity bone was performed in 30 maxillary sinuses, and 68 implants were placed at the time of sinus graft. After 6 months of implant placement abutments were connected and implant stability quotient (ISQ) was measured by radio frequency analysis (RFA). In addition, bone level changes was evaluated by taking periapical radiograph. During surgical procedures, no complication was observed, and all patients healed uneventfully. At 6 months the implant showed stable ISQ values. The marginal bone level changes around the fixtures was stably maintained through out the follow up period. This study confirmed that maxillary sinus floor augmentation with mixture of bovine bone mineral and maxillary tuberosity bone could be reliable for bone regeneration in subantral space.