A rare disease, also referred to as an orphan disease, is defined as the disease with a low prevalence or that affects a small percentage of the population. It is a well model of human disease, which can facilitate the in-depth study and understanding of related diseases. Therefore, five Chinese governmental authorities, including the National Health Commission of the People's Republic of China, jointly issued the "First National Directory of Rare Diseases" (the First List) on May 11, 2018. The First List covers 121 rare indications. In the analysis of the directory, we found that among the 121 diseases, there are 51 (42.2%) with oral characterization. Oral manifestations mainly include craniofacial abnormalities, dentition (dental) abnormalities, oral soft tissue lesions, jaw bone lesions, salivary gland related diseases, etc., even some of them are the first, earliest and inevitable clinical manifestations of some patients with rare diseases. In order to strengthen the understanding of stomatological counterparts on the importance of the national directory of rare diseases and deeply understand the important and irreplaceable role of stomatologists in the diagnosis and treatment of rare diseases, the present review article is specifically written to introduce the oral characterization of the rare diseases listed in the catalogue, aiming at improving the diagnosis and treatment capabilities of these diseases by peers and benefiting the public.
罕见病（rare diseases）又称"孤病"（orphan diseases），是指发病率极低、患病人数少的疾病或病变，是人类良好的疾病模型，可促进对相关疾病的深入研究与认识。因此，2018年5月11日国家卫生健康委等五部委联合制定公布了我国《第一批罕见病目录》，共涉及121种疾病，其中具有口腔表征的疾病51种，占42.2%。包括颅面部异常、牙列（齿）异常、口腔软组织病变、颌骨病变、唾液腺相关疾病等，甚至部分为罕见病的首发、早发和必发表现。为强化口腔同行对罕见病目录重要性的认识，阐明口腔医师在罕见病诊治中的重要作用，本文详细阐述了该目录中部分疾病的口腔表征，旨在提高同行对这些疾病的诊治水平，造福患者。.
Keywords: Oral manifestations; Rare diseases; Rare diseases directory.