Background.  Coffin–Lowry syndrome (CLS) is a rare genetic disorder. The syndrome presents with psychomotor retardation, short stature, skeletal deformations, digit abnormalities, and distinctive facial features. Oral and dental findings in CLS are common and they include thick prominent lips, high palate, midline lingual furrow, hypodontia, microdontia, delayed eruption, and early tooth loss. Only one earlier case suggesting hypoplastic root cementum as cause for primary loss of teeth in CLS has been published.

Case Report.  This case describes a 3-year-old boy with premature loss of primary incisors without preceding root resorption. In addition to the dental findings, the boy had several general signs and symptoms and the dental findings together with the other characteristics led to the clinical diagnosis of CLS, which later was genetically verified. Histological analysis of an extracted primary incisor showed hypoplastic root cementum.

Conclusion.  Hypoplastic root cementum may explain early tooth loss in CLS. As early loss of primary teeth is rare, especially when there is no previous root resorption, the individual is likely to seek dental care. Thus, the dentist may play an important role in assisting in the diagnosing of CLS.