Oral health status of southern Chinese following head and neck irradiation therapy for nasopharyngeal carcinoma

Objective: To investigate the oral health status of patients with nasopharyngeal carcinoma (NPC) after completion of radiotherapy. Methods: Thirty-three NPC patients (mean age 53±10 years) who had completed head and neck radiotherapy (3.6±3.1 years post-operation) were examined. Dental caries, periodontal status and oral mucosal lesions were recorded. Stimulated whole saliva (SWS) flow rate, pH, buffer capacity and carriage rate of carcinogenic micro-organisms were assessed. Jaw opening was measured. Results: Xerostomia was present in all patients, while 42% had candidiasis and 21% had limited jaw opening. The mean number of teeth present was 22, mean DMFT was 8.0, mean number of untreated root caries lesions was 1.4. Both saliva pH and buffering capacity were low while Streptococcus mutans and Lactobacillus spp. carriage were high. 52% of the patients had no dental care following radiotherapy. Although few patients expressed direct dissatisfaction, perceived level of information and of post-operative dental care was insufficient. Conclusions: Post-irradiated NPC patients constitute a high-risk group for dental root caries and oral candidiasis. The carriage rate of Streptococcus mutans and Lactobacillus spp. in this NPC patient group was the highest among findings of other similar studies. This may be related to the inadequacy of dental care after radiotherapy. Head and neck radiotherapy was not associated with periodontal disease.