Late Oral Complications Caused by Head and Neck Radiotherapy: Clinical and Laboratory Study.

OBJECTIVES: The aim of presented cross-sectional and observational study was to determine the prevalence of late oral complications of patients with head and neck cancer who underwent radiotherapy, by clinical and laboratory analyses. MATERIAL AND METHODS: Fifty-five patients, 43 (78.2%) men and 12 (21.8%) women, mean age 60; range 38 to 87 years, who have completed radiotherapy for head and neck cancer for at least 6 months were enrolled. The presence of xerostomia, hyposalivation, oral candidiasis, and type of oral yeasts were correlated with post-radiotherapy period. A control group, age and gender matched, was used for comparisons. The Pearson's Chi-square or Fischer's exact test was used at a significance level of 5%. RESULTS: The mean post-radiotherapy period was 32 months. The oral complications found were xerostomia (45/55, [81.8%]), hyposalivation (44/55 [80%]) and oral candidiasis (15/55 [27.2%]). Xerostomia and hyposalivation was statistically higher in the study group when compared to the control group (P < 0.05). The presence of yeast occurred in 39 (70.9%) of the patients in the study group, and Candida albicans was the most prevalent etiological agent in 25 (64.1%) of those patients (P < 0.05). CONCLUSIONS: Xerostomia and hyposalivation were the more prevalent late oral complications related to radiotherapy. Oral candidiasis was also observed, although its prevalence was lower. The need for long-term dental follow-up of patients who underwent radiotherapy of the head and neck cancer is mandatory.

Diabetes mellitus and corticotherapy as risk factors for alendronate-related osteonecrosis of the jaws: a study in Wistar rats.

BACKGROUND: The purpose of this study was to investigate the influence of diabetes and corticotherapy on the development of osteonecrosis of the jaws associated with sodium alendronate. METHODS: Rats were allocated into 4 groups of 11 animals each, representing different treatments: (1) alendronate; (2) alendronate and corticotherapy; (3) alendronate and diabetes; and (4) control. Tooth extractions were performed in all animals, and histological analysis was performed by hematoxylin and eosin staining and immunohistochemistry using anti-bone morphogenetic protein (BMP)-4 and anti-matrix metalloproteinase (MMP)-13 antibodies. RESULTS: On hematoxylin and eosin analysis, proportions of inflammatory infiltrate, microbial colonies, and osteonecrosis were significantly greater in the diabetes group. BMP-4 expression in connective tissue was higher in the corticosteroid group than the alendronate group. There were no significant differences between the other groups. MMP-13 expression did not differ between the groups analyzed. CONCLUSION: Diabetes but not corticotherapy is associated with jaw osteonecrosis in rats undergoing alendronate therapy and subjected to tooth extractions.

Comparison of effects of clodronate and zoledronic acid on the repair of maxilla surgical wounds - histomorphometric, receptor activator of nuclear factor-kB ligand, osteoprotegerin, von Willebrand factor, and caspase-3 evaluation.

BACKGROUND: The aim of this study was to compare clodronate and zoledronic acid regarding their influence on the repair of surgical wounds in maxillae (soft tissue wound and tooth extraction) and their relation to osteonecrosis. MATERIAL AND METHODS: Thirty-four Wistar rats were allocated into three groups according to the treatment received: (i) 12 animals treated with zoledronic acid, (ii) 12 animals treated with clodronate and (iii) 10 animals that were given saline solution. All animals were subjected to tooth extractions and surgically induced soft tissue injury. Histological analysis of the wound sites was performed by means of hematoxylin-eosin (H&E) staining and immunohistochemical staining for receptor activator of nuclear factor-kB ligand (RANKL), osteoprotegerin (OPG), von Willebrand factor, and caspase-3. RESULTS: The zoledronic acid group showed higher incidence of non-vital bone than did the clodronate group at the tooth extraction site. At the soft tissue wound site, there were no significant differences in non-vital bone between the test groups. RANKL, OPG, von Willebrand factor, and caspase-3 did not show significant differences between the groups for both sites of surgical procedures. CONCLUSION: Both of the bisphosphonates zoledronic acid and clodronate are capable of inducing maxillary osteonecrosis. Immunohistochemical analysis suggests that the involvement of soft tissues as the initiator of osteonecrosis development is less probable than has been pointed out.