Objectives Dental assessment remains a key intervention for head and neck cancer (HNC) patients pre-radiotherapy (RT). The purpose of this study was to identify the variation in dental status of patients pre-treatment, with respect to population and oncological demographics.

Materials and methods The study reviewed dental panoramic radiographs of HNC patients seen on a dedicated pre-RT dental clinic from 2011-2017. Only patients who had undergone intensity-modulated radiotherapy treatment were included within this study. Relevant dental and oncological data were collected.

Results A total of 886 patients were included in this study, with oropharyngeal cancer constituting 36% of the cohort. The average number of teeth in HNC patients was <21 at the pre-RT phase, which is below the recognised threshold for a functional dentition. Smoking status has a significant impact on overall DMFT (decay/missing/filled teeth), severity of horizontal bone loss and the number of third molars present (p <0.001). In the latter, males had a higher mean number of third molars compared to females (p <0.005). Comparing dental status of patients based on their tumour sub-site identified significant (p <0.0005) variation in all aforementioned categories.

Conclusion There are distinct differences in the dental health of HNC patients due to commence RT, compared to the general population. It varies by cancer sub-site and this should be taken into consideration at dental assessment to tailor a dental care plan to the needs of the individual. Consideration should be given to balancing masticatory function against the risks of osteoradionecrosis on the background of increasingly extended survivorship.

目的牙科评估仍然是头颈癌（HNC）患者放疗前（RT）的关键干预措施。这项研究的目的是确定就人群和肿瘤学人口统计而言，治疗前患者牙齿状况的变化。

材料和方法这项研究回顾了2011-2017年在专门的RT前牙科诊所看到的HNC患者的牙科全景X射线照片。本研究仅包括接受过调强放疗的患者。收集了相关的牙科和肿瘤学数据。

结果本研究共纳入886例患者，其中口咽癌占该队列的36％。在RT前阶段，HNC患者的平均牙齿数量<21，低于公认的功能性牙列阈值。吸烟状况对总体DMFT（蛀牙/缺失/缺牙），水平骨丢失的严重程度和存在的第三磨牙的数量有显着影响（p <0.001）。在后者中，男性的第三磨牙平均数高于女性（p <0.005）。根据患者的肿瘤亚部位比较患者的牙齿状况，发现在所有上述类别中均存在显着（p <0.0005）变化。

结论与普通人群相比，开始放疗的HNC患者的牙齿健康状况存在明显差异。它因癌症子站点而异，在进行牙科评估时应考虑到这一点，以根据个人需要制定牙科护理计划。在生存期延长的背景下，应考虑平衡咀嚼功能与骨坏死的风险。