An audit into the timing of dental extractions pre-head and neck radiotherapy and the prevalence of osteoradionecrosis.

Objective It is recommended that radiotherapy for head and neck cancer commences ten days post-dental extractions to reduce the risk of osteoradionecrosis (ORN) of the jaw. However, consideration must be given to patients' survival which might be compromised by delaying radiotherapy for these patients. The records of 154 patients receiving radiotherapy to the head and neck were retrospectively reviewed between July 2016 and August 2017, at Queen Alexandra Hospital in Portsmouth, to identify patients who have developed ORN, associated risk factors and the relative timings of dental extractions compared to the guidelines of the Royal College of Surgeons (RCS).

Zygomatic implants: the impact of zygoma bone support on biomechanics.

Maxillectomy and severely resorbed maxilla are challenging to restore with provision of removable prostheses. Dental implants are essential to restore esthetics and function and subsequently quality of life in such group of patients. Zygomatic implants reduce the complications associated with bone grafting procedures and simplify the rehabilitation of atrophic maxilla and maxillectomy.

Extrasinus zygomatic implant placement in the rehabilitation of the atrophic maxilla: three-dimensional finite element stress analysis.

Placement of zygomatic implants lateral to the maxillary sinus, according to the extrasinus protocol, is one of the treatment options in the rehabilitation of severely atrophic maxilla or following maxillectomy surgery in patients with head and neck cancer. The aim of this study was to investigate the mechanical behavior of a full-arch fixed prosthesis supported by 4 zygomatic implants in the atrophic maxilla under occlusal loading. Results indicated that maximum von Mises stresses were significantly higher under lateral loading compared with vertical loading within the prosthesis and its supporting implants.

Marginal bone loss influence on the biomechanics of single implant crowns.

Marginal bone loss, whether it is physiological or pathological, is one of the implant treatment complications. The biomechanical consequences of marginal bone loss could be catastrophic particularly when the abutment screw is at supraosseous level. This study aimed at investigating marginal bone loss influence on the biomechanics of single implant crown using finite element (FE) analysis.

Stress analysis of occlusal forces in canine teeth and their role in the development of non-carious cervical lesions: abfraction.

Non-carious cervical tooth lesions for many decades were attributed to the effects of abrasion and erosion mainly through toothbrush trauma, abrasive toothpaste, and erosive acids. However, though the above may be involved, more recently a biomechanical theory for the formation of these lesions has arisen, and the term abfraction was coined. The aim of this study was to investigate the biomechanics of abfraction lesions in upper canine teeth under axial and lateral loading conditions using a three-dimensional finite element analysis.

The mechanical behaviour of cantilever fixed partial dentures in shortened dental arch therapy: a 2-D finite element analysis.

In the present study two-dimensional finite element models of two- and three-unit cantilever fixed partial dentures were created to simulate the replacement of a maxillary second premolar in a shortened dental arch. The purpose of the study was to investigate the mechanical behaviour of the two designs of fixed partial denture using the finite element method. The results indicate that the mechanical behaviour of the three-unit fixed partial denture was more favourable than that of the two-unit fixed partial denture under similar conditions of occlusal loading.