[A PhD completed. Pre-surgical assessment of the mandibular body and canal using CBCT imaging.] / Serie: Hora est. Prechirurgisch onderzoek van mandibula en canalis mandibularis met CBCT-scans.

The aim of this study was to determine the accuracy of the pre-surgical assessment of the mandible using cone beam computed tomography (CBCT) images. For surgical procedures in the mandible, it is important to determine the position of the mandibular canal in order to avoid damage to the inferior alveolar nerve (IAN). The best method to investigate this nerve is with the help of panoramic reconstructed images combined with cross-sectional reconstructed images. To protect the IAN during treatment, this research indicates that a minimal safety zone of 1.13 mm is advisable. When distances were being measured, a larger exaggeration of reality was observed with small distances. It appears that (semi)automatic tracing methods of the mandibular canal still cannot be used in clinical practice. When a CBCT scan reveals a lingual position of the mandibular canal in combination with a narrowing of the mandibular canal at the contact point with the root of a third molar the risk of damaging the IAN increases. CBCT imaging should only be applied in specific cases.

Clinical relevance of cone beam computed tomography in mandibular third molar removal: A multicentre, randomised, controlled trial.

PURPOSE: The aims of this study were to investigate the effectiveness of cone beam computed tomography (CBCT) compared to panoramic radiography (PR), prior to mandibular third molar removal, in reducing patient morbidity, and to identify risk factors associated with inferior alveolar nerve (IAN) injury. MATERIAL AND METHODS: This multicentre, randomised, controlled trial was performed at three centres in the Netherlands. Adults with an increased risk for IAN injury, as diagnosed from PR, were included in the study. In one arm of the study, patients underwent an additional CBCT prior to third molar surgery. In a second arm of the study, no additional radiographs were acquired. The primary outcome measure was the number of patient-reported altered sensations 1 week after surgery. As secondary outcome measures, the number of patients with objective IAN injury, with long-term (>6 months) IAN injury, the occurrence of other postoperative complications, the Oral Health Related Quality of Life-14 (OHIP-14) questionnaire responses, postoperative pain (visual analogue scale score), duration of surgery, number of emergency visits, and number of missed days of work or study were scored. RESULTS: A total of 268 patients with 320 mandibular third molars were analysed according to the intention-to-treat principle. The overall incidence of IAN injury 1 week after surgery was 6.3%. No significant differences between CBCT and PR for temporary IAN injury (p = 0.64) and all other secondary outcomes were registered. A lingual position of the mandibular canal (MC) and narrowing, in which the diameter of the MC lumen was decreased at the contact area between the MC and the roots, were significant risk factors for temporary IAN injury. CONCLUSION: Although CBCT is a valuable diagnostic adjunct for identification of an increased risk for IAN injury, the use of CBCT does not translate into a reduction of IAN injury and other postoperative complications, after removal of the complete mandibular third molar. In these selected cases of a high risk for IAN injury, an alternative strategy, such as monitoring or a coronectomy, might be more appropriate. (http://clinicaltrials.gov, NCT02071030).

The effect of hyperbaric oxygen therapy on quality of life in oral and oropharyngeal cancer patients treated with radiotherapy.

Radiotherapy is used in the setting of curative treatment for head and neck cancer. Xerostomia and related problems occur when major salivary glands are included in the irradiation fields. This reduces quality of life (QOL). Hyperbaric oxygen therapy (HBOT) is a well accepted treatment or prevention modality for osteoradionecrosis of the jawbones and soft-tissue necrosis. It is unknown if and to what extent HBOT influences xerostomia and xerostomia-related QOL. To address this, a prospective study was conducted. Twenty-one patients who underwent radiotherapy for an oral or oropharyngeal carcinoma completed a European Organization for Research and Treatment of Cancer QOL questionnaire before HBOT, as part of the treatment/prevention of osteoradionecrosis, and 1 and 2 years after HBOT. Swallowing-related problems significantly decreased in time, and there was a reported subjective increase in saliva quantity and an improvement in sense of taste. The results suggest that HBOT may positively influence these long-term radiotherapy sequelae.