Vestibular bone thickness of the mandible in relation to the mandibular canal-a retrospective CBCT-based study.

BACKGROUND: The aim of this study was to assess vestibular bone thickness of the mandible in relation to the mandibular canal and position of the mental foramen in relation to the neighbouring teeth. Measurements were performed on radiographic cone-beam computed tomography (CBCT) images. METHODS: This retrospective study analysed 314 CBCTs, having been taken at the Clinic of Cranio-Maxillofacial and Oral Surgery, University of Zurich, Switzerland. RESULTS: CBCTs from 168 female and 146 male patients (median age 40.2 years) were analysed. Median bone thickness lateral to the nerve canal to the buccal mandibular cortical plate was ~ 4 mm immediately posterior to the mental foramen, increased to ≤ 6 mm over the next 30 mm, then decreased to ~ 3 mm at the level of the mandibular foramen. In two thirds of cases, both mental foramina were located near the second premolar (66.2% right, 67.7% left). Bone thickness and the position of the mental foramen showed marked intra- and interindividual variance. CONCLUSIONS: A preoperative CBCT is recommended for detailed planning of surgical interventions that may reach the mandibular canal (e.g. wisdom teeth removal, root resection, implant placement, bone block harvesting).

[Risk assessment in patients undergoing osseous antiresorptive therapy in dentistry. An update]. / Risikobeurteilung von Patienten mit ossärer, antiresorptiver Therapie in der zahnärztlichen Praxis. Ein Update.

Antiresorptive therapy is prescribed in particular for the treatment of osteoporosis as well as for the treatment of tumor-induced hypercalcemia and metastatic bone disease. As a consequence, osteopathologies such as bisphosphonate-related osteonecrosis of the jaws (BRONJ) may occur. In 2008, our department reported on BRONJ in a paper that provided dental clinicians with information on diagnostics, therapy, and prevention (Dannemann et al., Schweizer Monatsschrift für Zahnmedizin, Vol. 118, 2/2008). During the last 8 years, new findings have emerged concerning potential etiologies, modes of therapy, and the use of additional antiresorptive therapies. For example, an important point for colleagues in dental practice is the now common intravenous administration of bisphosphonates in osteoporosis patients, which may lead to uncertainty when assessing risk in these patients. For this reason, this article provides an update of the above mentioned publication and gives dental clinicians an updated guideline concerning risk assessment in patients undergoing antiresorptive therapy. In this context, a risk assessment algorithm is presented. The pathogenesis, diagnosis, therapy, and prevention of BRONJ and oral implantation in patients receiving antiresorptive therapy are addressed with regard to the current literature. Finally, we present two example cases.