Osteopontin and osteocalcin in maxilla tissue of skeletal Class III patients

Abstract

Bone extracellular matrix proteins osteopontin and osteonectin have important function during embryonic osteogenesis and are active in bone remodeling process. Knowledge about bone extracellular matrix proteins explores the mechanisms of craniofacial development and helps to understand better morphopathogenesis of severe dentofacial anomalies. Aim of the current study was to investigate an expression of osteopontin and osteocalcin in maxilla tissue in skeletal Class III patients. The study group included 10 skeletal Class III patients to whom combined orthodontic and surgical treatment was recommended. Samples of tuber maxillae tissue from ten skeletal Class III malocclusion patients were collected due the orthognatic surgery procedure. The routine histological method was followed and samples were stained by hematoxyline-eosine. Tissue samples were stained according the standard immunohistochemical methods and expression of osteocalcin and osteopontin in maxilla tissue was examined. Distribution of these factors was evaluated semiquantitetively by counting the positive structures in visual field. The trabecules of bone contained parallel located collagen fibers and irregular bone mineralization. Connective tissue proliferation in osteon channels was observed. Quantity of cells positive to osteopontin was higher than quantity of cells containing osteocalcin in all patterns extracted of maxilla tissue in patients with skeletal Class III. In few cases osteocalcin positive cells were located near the border with soft tissue - close to osteogenic cells zone, but no osteocalcin was observed deeper in bone. The intensity of osteocalcin expression was variable, and differs individually despite the relatively regular osteopontin distribution in all patterns. There were pronounced osteopontin, but not osteocalcin-containing cells with approximately similar intensity of protein expression in tuber maxillae in skeletal Class III patients.