在≥2 岁的患者中,Bell 面瘫是单侧面瘫最常见的病因。在 15 至 45 岁的人群中最常见。[7]Peitersen E. Bell palsy: the spontaneous course of 2,500 peripheral facial nerve palsies of different etiologies. Acta Otolaryngol Suppl. 2002;549:4-30.http://www.ncbi.nlm.nih.gov/pubmed/12482166?tool=bestpractice.com据报道,每年的发病率为 23 - 32 例/100,000。[7]Peitersen E. Bell palsy: the spontaneous course of 2,500 peripheral facial nerve palsies of different etiologies. Acta Otolaryngol Suppl. 2002;549:4-30.http://www.ncbi.nlm.nih.gov/pubmed/12482166?tool=bestpractice.com[8]Hauser WA, Karnes WE, Annis J, et al. Incidence and prognosis of Bell palsy in the population of Rochester, Minnesota. Mayo Clin Proc. 1971;46:258-264.http://www.ncbi.nlm.nih.gov/pubmed/5573820?tool=bestpractice.com[9]Yanagihara N. Incidence of Bell palsy. Ann Otol Rhinol Laryngol. 1988;97:3-4.http://www.ncbi.nlm.nih.gov/pubmed/3144231?tool=bestpractice.com男女比例和两侧面部比例相等。没有实质性证据表明发病率存在季节或地区差异。