Histological and Biochemical Analysis after Posterior Mandibular Displacement in Rats

SIMPLE SUMMARY: The lower jaw has a particular contribution to the human appearance, and so it is not uncommon for people to seek treatment in cases of its extreme growth. The orthodontist often selects to place intraoral devices in order to address the problem. This study used healthy young rats to guide their lower jaws backward. Measurements of biochemical molecules in blood that are related to bone metabolism did not reveal any statistically significant differences. However, noteworthy local microscopic alterations of the condyle were evidenced. They involved histological changes in bone structure and the thickness of cartilage. In conclusion, it seems that the procedure under study might not cause any severe organic disturbance in the lab animals under the conditions of the experiment. Only minor histological effects on condylar morphology were observed. ABSTRACT: The present study aimed to investigate any biochemical and histological changes of the rat condyle and mandible in animals that had sustained mandibular growth restriction. Seventy-two male Wistar rats were divided into two equal groups, experimental and control. Each group consisted of three equal subgroups. The animals were sacrificed 30, 60, and 90 days after the start of the experiment. Blood samples were collected from the eye, and the osteoprotegerin (OPG), Receptor Activator of Nuclear Factor Kappa B Ligand (RANKL), and Macrophage Colony-Stimulating factor (MCSF)concentrations were measured by using enzyme-linked immunosorbent assay (ELISA) kits. A histological analysis was performed on the mandibular condyles. The blood serum values of OPG, RANKL, and MCSF did not exhibit any statistically significant difference between groups or subgroups. However, significant histological changes became evident after a histomorphometric condylar examination was performed. The Bone Surface/Total Surface ratio appeared reduced in the anterior and posterior regions of the condyle. In addition, the Posterior Condylar Cartilage Thickness was measured and determined to be significantly diminished. The present intervention that employed orthodontic/orthopedic devices did not prove to have any significant effect on the circulating proteins under study. Posterior displacement of the mandible may culminate only in local histological alterations in condylar cartilage thickness and its osseous microarchitecture.