The Role of Bone Grafts in Preventing Medication-Related Osteonecrosis of the Jaw: Histomorphometric, Immunohistochemical, and Clinical Evaluation in Animal Model.

Objective: To evaluate the effects of inorganic bovine bone graft (Lumina Bone, Criteria, Brazil) and beta-tricalcium phosphate (ß-TCP) graft (ChronOS, Synthes, Brazil) in rats with the risk of developing post-extraction medication-related osteonecrosis of the jaw (MRONJ). Methods: Eighteen male Wistar rats weighing 350 to 450 g were induced to develop MRONJ using zoledronic acid for 5 weeks. In the sixth week, the right maxillary first molar was extracted. The animals in Group I (G1) did not receive bone grafts after tooth extraction, while Group II (G2) animals received inorganic bovine bone grafts, and Group III (G3) animals received beta-tricalcium phosphate (ß-TCP) grafts. Clinical evaluation and histomorphometric and immunohistochemical analyses were performed. ANOVA and Tukey's statistical tests were used and a level of significance was considered to be 5%. Results: In the clinical evaluation, animals from G2 and G3 did not present clinical manifestations of osteonecrosis, unlike the control group (G1) animals, which presented necrotic bone tissue exposure in all samples. In the histomorphometric evaluation, animals in G3 showed greater formation of bone tissue (66%) and less formation of bone lacuna (18%) than animals in G1 (58%/32%) and in G2 (59%/27%) (P < 0.05). Moderate (++) immunostaining was observed in G2 and G3 for RANKL, TRAP, and OC, while G1 showed moderate (++) labeling for OC and mild (+) immunostaining for TRAP and RANKL. Conclusions: Greater formation of bone tissue and fewer bone lacunae were found in animals treated with ß-TCP. In clinical evaluation, bone graft groups presented with the clinical manifestation of MRONJ and showed higher intensity of immunostaining for TRAP and RANKL. Despite the limitations of experimental animal studies, the results of this work may assist in the development of future clinical research for the prevention of MRONJ.

Lower third molar displaced to lateral pharyngeal space after mandibular angle fracture: a case report.

The removal of displaced dental elements from deep anatomical spaces is a condition that requires the knowledge of the region and skills to perform the procedure. The lateral pharyngeal space contains important structures such as the internal carotid artery and close proximity with the cranium basis. The aim of this paper is to report a clinical case of a lower third molar displaced to the lateral pharyngeal space after a mandibular angle fracture and its treatment by surgical intervention. The tooth was removed under general anesthesia by direct approach and the fracture was reduced and fixed with a plate and screws. This case report illustrates the importance of an immediate procedure to avoiding severe complications and further damage to important anatomical structures.

Unusual Horizontal Root Fracture in a Mandibular Second Molar after Lower Wisdom Teeth Removal.

Dental trauma is a common injury observed at dental practices that normally occurs in young patients. It especially affects the anterior teeth, although trauma to the posterior teeth can also be observed frequently when caused by high-impact trauma and masticatory forces. Horizontal root fracture in the posterior teeth is even more rare and involves a more specific type of trauma. This article reports the case of a second molar root fracture that happened during the removal of an impacted wisdom tooth. The patient had no discomfort associated with the event, and the tooth had no change in sensibility or mobility during follow-up. Seven months after the fracture, there was complete radicular healing even though no treatment was given.