The dose limits of teeth protection for patients with nasopharyngeal carcinoma undergoing radiotherapy based on the early oral health-related quality of life

Radiation-related teeth damage is a common complication in nasopharyngeal carcinoma (NPC) patients undergoing radiotherapy (RT) that seriously affects their oral health-related quality of life (OHRQoL). However, few studies have focused on protecting teeth function. This study aimed to calculate dental dose limits based on OHRQoL. Analysis was performed on 96 NPC patients who received RT (all received routine pre-radiotherapy dental interventions in our department). Based on the General Oral Health Assessment Index (GOHAI), OHRQoL was assigned into poor (<46) and good condition groups (≥46). The binary logistic regression analysis model was used for single-factor and multivariate analyses to identify the independent factors affecting OHRQoL. The cut-off value of dose received by teeth was obtained by drawing a receiver operating characteristic curve. NPC patients experienced a decline in OHRQoL following RT (P < 0.05). Univariate analysis of GOHAI revealed that the average dose of maxillary anterior teeth, the average dose received by the oral cavity, tumor volume (GTVnx), and liking of the sweet food all affected GOHAI (P < 0.05). Multivariate analysis indicated that the average dose of maxillary anterior teeth and liking sweet food were independent factors that influenced the OHRQoL of NPC patients with RT. When the average dose received by maxillary anterior teeth is greater than 28.78 Gy, and there is a tendency in sweet food, the OHRQoL will deteriorate. NPC patients who received RT had a better OHRQoL if the average dose to maxillary anterior teeth was limited to less than 28.78 Gy and the intake of high-sugar foods was reduced.