Objective To investigate the condition of the oral mucosae in Xinjiang Uygur centenarians and explore some related factors Methods The oral mucosae and mucosal exfoliative cells of 140 Xinjiang Uygur centenarians were examined Saliva and blood were collected from some centenarians Salivary immunoglobulins (IgA, IgM, IgG), complements (C 3 and C 4), nitrous oxide (NO), 10 trace elements, serum sex hormones, thyroid hormones and osteocalcin (OST) were analysed using immunoglobulin, complement and NO kits, an ionochromatophotometer, and the kits for sex hormones and thyroid hormones, and fluorescence enzyme linked immunosorbent assay, respectively Results Most centenarians (64 29%) had normal labial, buccal, palatal and gingival mucosae The abnormal changes in mucosae were mainly vascular nevus patches and senile plaques Their mucosal exfoliative cells showed similar characteristics to those in elderly Han The centenarians who had normal mucosae had higher level of the trace element molybdenum (Mo) in their saliva than who had abnormal mucosae ( P <0 01) Conclusion The oral mucosal condition of Uygur centenarians was generally good The abnormal changes in oral mucosae of the centenarians were lesions not harmful to health and may be related to the lower level of Mo in their saliva Objective To investigate the condition of the oral mucosae in Xinjiang Uygur centenarians and explore some related factors Methods The oral mucosae and mucosal exfoliative cells of 140 Xinjiang Uygur centenarians were examined Saliva and blood were collected from some centenarians Salivary immunoglobulins (IgA, IgM, IgG) , complements (C3 and C4), nitrous oxide (NO), 10 trace elements, serum sex hormones, thyroid hormones and osteocalcin (OST) were analysed using immunoglobulin, complement and NO kits, an ionochromatophotometer, and the kits for sex hormones and thyroid hormones, and fluorescence enzyme linked immunosorbent assay respectively, respectively. Most of centenarians (64 29%) had normal labial, buccal, palatal and gingival mucosae The abnormal changes in mucosae were mainly vascular nevus patches and senile plaques Their mucosal exfoliative cells was similar similar to those in elderly Han The centenarians who had normal mucosae had higher level o The trace element molybdenum (Mo) in their saliva than who had abnormal mucosae (P <0 01) Conclusion The oral mucosal condition of Uygur centenarians was generally good The abnormal changes in oral mucosae of the centenarians were lesions not harmful to health and may be related to the lower level of Mo in their saliva