Hypocalcified

Hypocalcified is an adjective used in medical and dental contexts to describe tissue that has not undergone normal calcification or mineralization. The term is most commonly applied to enamel, but it can refer to other tissues in which mineral deposition is incomplete during development. Hypocalcification can occur as a primary developmental defect or as part of a broader metabolic or genetic disorder.

In dentistry, hypocalcified enamel is enamel that is present but under-mineralized relative to normal enamel. This yields a softer, more porous, and chalky-looking surface that wears rapidly and is more sensitive to stimuli. Hypocalcified enamel is a hallmark of certain forms of amelogenesis imperfecta (AI), particularly the hypocalcified type, which results from disturbances in enamel mineralization after the enamel matrix has formed. Genetic causes include mutations in genes such as FAM83H (an autosomal-dominant form associated with hypocalcified AI) and others involved in enamel formation. Clinically, affected teeth may erupt with normal shape but show rapid attrition, surface roughness, and increased caries risk. Radiographic findings can show relatively thin or poorly mineralized enamel compared with dentin.

Beyond dentistry, hypocalcified bone or osteoid refers to insufficient mineral deposition in bone, seen in systemic conditions like osteomalacia or rickets due to disruptions in calcium, phosphate, or vitamin D metabolism. These conditions produce bone pain, deformities, and higher fracture risk, and require treatment of the underlying metabolic disturbance.

Diagnosis is based on clinical features, imaging, family history, and, when indicated, genetic testing. Management in dental cases emphasizes protection of dentin, restoration, and preventive care, while systemic cases address the metabolic cause with appropriate supplementation and monitoring.