abnormal skeleton development abnormal osteoblast morphology abnormal cell differentiation abnormal osteoblast differentiation MP:0008395 abnormal osteoblast formation MPheno.ontology abnormal osteoplast formation atypical production of or inability to produce skeletogenic cells that secrete osteoid, are capable of producing mineralized (hydroxyapatite) matrix, are located adjacent to or within osteoid tissue, and arise from the transformation of a preosteoblast cell MP:0005008