Post-radiotherapy head and neck cancer patients are at increased risk of dental caries due to radiotherapy-induced salivary gland hypofunction and radiation damage to tooth structure. Dental caries causes pain and discomfort and is likely to have a detrimental impact on patients' quality of life. This systematic review appraised and synthesised best available evidence regarding the incidence and severity of post-radiotherapy dental caries in head and neck cancer patients. Six databases and two trial registries were searched from their inception to May 2019. A total of 22 papers met the inclusion criteria. The pooled percentage of patients that developed dental caries postradiotherapy was 29% (n=15 studies; 95% CI 21%, 39%; I 2 =88.0%). Excluding studies with longer than two years follow-up, the pooled percentage was 37% (n=9 studies; 95% CI 25%, 51%; I 2 =88.6%). Meta-regression analysis revealed that studies with a higher mean/median radiotherapy dose exposure had an increased incidence of dental caries (p=0.02). Furthermore, studies with a higher proportion of patients treated with chemotherapy had an increased incidence of dental caries (p=0.02) after the exclusion of an outlier. It is important to be mindful of the high degree of observed heterogeneity and the inclusion of a large number of non-randomised studies. Data regarding the number of carious teeth, the number of carious tooth surfaces, and the number of carious lesions that developed post-radiotherapy were unsuitable for meta-analysis. There is a need for well-designed studies to improve understanding about dental cariesrisk in post-radiotherapy head and neck cancer patients. Highlights This review summarised the incidence of post-radiotherapy dental caries. Pooled estimates for post-radiotherapy caries ranged from 29-37%. A narrative review of the severity of post-radiotherapy caries is also presented. Comprehensive oral care is needed for head and neck cancer patients. Keywords Head and neck neoplasms Radiotherapy Dental caries Chemotherapy Oral health Abbreviations: CI-confidence intervals CM-Ciaran Moore (reviewer) CML-Conor McLister (reviewer) DMFS-decayed, missing, or filled tooth surfaces DMFT-decayed, missing, or filled teeth DNA-deoxyribonucleic acid GMK-Gerry McKenna (reviewer) HANC-head and neck cancer IMRT-intensity modulated radiation therapy *Manuscript (without author details) Click here to view linked References ORN-osteoradionecrosis PRISMA-Preferred Reporting Items for Systematic Reviews and Meta-Analyses PROSPERO-International Prospective Register of Systematic Reviews SD-standard deviation Author Type of study Year of Publication Number of patients Follow-up (months) Caries (outcome) data Caries assessment Site of head and neck cancer Age (years) Gendermale (%)

Background Many factors determine dietary intake in older adults, including physical health, psychological well-being and socio-economic status. Dental status may also be important. The aim was to examine how dental status impacts perceived ability to eat to certain foods, nutrient intake and nutritional status in UK older adults. Methods Data collected by the National Diet and Nutrition Survey Rolling Programme was analysed. A 4-day food diary assessed dietary intake, while a Computer Assisted Personal Interview collected socio-demographic, health behaviour and oral health information. Participants aged 65 years and over ( n = 1053) were categorised into three groups according to their dental status: edentate with dentures (E-DEN, n = 292), dentate with dentures (D-DEN, n = 305) or dentate with no dentures (DEN, n = 456). A total of 515 participants provided a blood sample that was used to assess nutrient concentrations including vitamin B12, vitamin C, ferritin, vitamin B6 (pyridoxal-5-phosphate, PLP), retinol, β-carotene and 25-hydroxyvitamin D (25-OH-D). Multiple regression methods were performed to examine cross-sectional associations between dental status, food selection, nutrient intake and nutritional status. Results Both E-DEN and D-DEN groups, compared with the DEN group, were more likely to report difficulty eating apples, raw carrots, lettuce, nuts, well-cooked steak and crusty bread ( P < 0.01). No group differences were observed in perceived ability to eat sliced bread, sliced cooked meats and cheese. The E-DEN group compared with the DEN group had lower mean daily intakes of omega 3 fatty acids ( P = 0.006), non-starch polysaccharides ( P = 0.001), β-carotene ( P = 0.001), folate ( P = 0.001), vitamin C ( P = 0.008), magnesium ( P < 0.001) and potassium (P < 0.001), and had lower plasma vitamin B6 PLP ( P = 0.001), vitamin C ( P = 0.009) and β-carotene ( P = 0.015) concentrations, after adjusting for socio-demographic and health behavioural factors. Compared with the DEN group, the D-DEN group did not have lower nutrient intakes or lower blood nutrient concentrations. Conclusions Within this sample of older adults, impaired dental status appears to influence food selection, and intake of important nutrients. Future research should focus on developing dental interventions coupled with dietary counselling to encourage the adoption of healthy eating habits in this high-risk population group.

As natural teeth are lost, many older adults choose softer foods lacking in essential micronutrients and fiber, yet replacing missing teeth alone does not positively influence diet. Dietary intervention in combination with treatment to replace missing teeth is increasing, though understanding of effective intervention components is limited. This systematic review synthesized literature relating to oral rehabilitation coupled with dietary intervention in adults. The primary outcome was dietary intake; secondary outcomes pertained to oral health and dietary intervention characteristics including: theoretical basis and behavior change techniques (BCTs). MEDLINE, Web of Science, PubMed and CENTRAL were searched. Nine studies were included. Study designs were heterogeneous involving 526 participants. Narrative synthesis identified improvements in at least one aspect of participants' oral health (i.e. biting/chewing) alongside at least one positive diet/nutrition outcome post-intervention for all studies. F/V results were pooled for three studies using meta-analysis techniques resulting in a standardized mean difference (SMD) of 0.29 [CI À0.54, 1.12], p ¼ 0.49, but with marked heterogeneity (p ¼ 0.0007). Few interventions were theory-based and intervention components were poorly described. Overall, narrative synthesis indicated support for dietary intervention coupled with oral rehabilitation on diet. Meta-analysis was only possible with three studies highlighting limitations. Large-scale, appropriately described trial methodologies are needed. Trial registry: This review was prospectively registered with PROSPERO on the 11 July 2017 [CRD42017071075].

ObjectiveThis randomised clinical trial aimed to compare the impact of two different tooth replacement strategies for partially dentate older patients namely; removable partial dentures (RPDs) and functionally orientated treatment based on the shortened dental arch (SDA) concept, on Oral Health-related Quality of Life (OHrQOL).Methods89 patients completed a randomised clinical trial. Patients were recruited in two centres: Cork University Dental Hospital (CUDH) and a Geriatric Day Hospital (SFDH). 44 patients were randomly allocated to the RPD group and 45 to the SDA group where adhesive bridgework was used to provide 10 pairs of occluding contacts. The impact of treatment on OHrQOL was used as the primary outcome measure. Each patient completed the Oral Health Impact Profile (OHIP-14) at baseline, 1, 6, 12 and 24 months after treatment.ResultsBoth treatment groups reported improvements in OHIP-14 scores at 24 months (p<0.05). For the SDA group OHIP-14 scores improved by 8.0 scale points at 12 months (p<0.001) and 5.9 scale points at 24 months (p<0.05). For the RPD group OHIP-14 scores improved by 5.7 scale points at 12 months (p<0.05) and 4.2 scale points at 24 months (p<0.05). Analysis using ANCOVA showed that there were significant between group differences recorded in both treatment centres. 24 months after intervention the SDA group recorded better OHIP-14 scores by an average of 2.9 points in CUDH (p<0.0001) and by an average of 7.9 points in SFDH (p<0.0001) compared to the RPD group.ConclusionsPatients in the SDA group maintained their improvements in OHrQOL scores throughout the 24 month study period. For the RPD group the initial improvement in OHrQOL score began to diminish after 6 months, particularly for those treated in SFDH. Thus, the benefits of functionally orientated treatment increased over time, particularly for the older, more systemically unwell cohort in SFDH.