The aim of this study was to evaluate the oral, dental, and craniofacial features of individuals affected by the chronic forms of acid sphingomyelinase deficiency (ASMD). This study comprised a sample of adult and pediatric patients (n = 8) with chronic ASMD. The individuals underwent oral examinations to evaluate the occurrence of caries, as well as full-mouth periodontal examinations, to assess the occurrence and severity of periodontal diseases. Panoramic and profile radiographs were obtained to analyze dental conditions and craniofacial parameters. Participants also answered questionnaires to identify systemic impairment, parafunctional habits, and bruxism. Dental anomalies of size, shape, and number were found, with agenesis and microdontia being the predominant findings. The average of caries experience was 11.75 (±8.1). Only one patient had periodontal health and all adult individuals had periodontitis at different stages and degrees. Bruxism was found in 87.5% of the sample. The convex profile and maxillary and mandibular retrusion were the most relevant findings in the cephalometric analysis. It is concluded that individuals with chronic ASMD, in addition to several systemic manifestations, present significant modifications in their oral health, from a greater occurrence of dental anomalies, caries, periodontal disease, in addition to skeletal changes. K E Y W O R D S acid sphingomyelinase deficiency, caries, craniofacial anomalies, dental anomalies, periodontal disease 1 | INTRODUCTION Acid sphingomyelinase deficiency (ASMD) is a rare autosomal recessive genetic disease that results from mutations in the Sphingomyelinphosphodiesterase 1 (SMPD1) gene located in region p.15.4 of chromosome 11, which causes deficiency of the enzyme acid sphingomyelinase (ASM) (Schuchman & Desnick, 2001; Spence & Callahan, 1989). ASM deficiency results in intracellular toxic accumulation of sphingomyelin, mainly in cells of the mononuclear phagocytic system (Wasserstein et al., 2004; Wasserstein, Godbold, & Mcgovern, 2013). This disease affects adults and children and has a wide spectrum of severity. ASMD is progressive and may reduce life expectancy (Mcgovern, Avetisyan, Sanson, & Lidove, 2017). ASMD is also known as Niemann-Pick disease and is subclassified into an acute neurovisceral form (previously known as Niemann-Pick type A-NPA) and chronic visceral (previously known as Niemann-Pick type B-NPB. A chronic form