The effect of posterior tooth loss on the expression of type II collagen, IL-1β and VEGF in the condylar cartilage of growing rats

ObjectiveThe aim of this study was to evaluate the effect of unilateral and bilateral loss of posterior occlusal support on the expression of type II collagen, interleukin-1β and VEGF in the condylar cartilage of growing rats.DesignThirty female Wistar rats (5 weeks old) were randomized into three groups: control, unilateral extraction of mandibular molar teeth, bilateral extraction of mandibular molar teeth. Animals were sacrificed 8 weeks after tooth extraction and the temporomandibular joints were prepared for immunohistochemical analysis.ResultsBilateral molar extraction increased the expression of interleukin-1β (P < 0.01) and VEGF (P < 0.01), while unilateral extraction increased the expression of interleukin-1β (P < 0.05) and type II collagen (P < 0.01). The expression of VEGF was higher on the extracted than on the non-extracted side (P < 0.01) after unilateral extraction.ConclusionLoss of posterior occlusal support alters the expression of type II collagen, interleukin-1β and VEGF in the condylar cartilage of rats. The expression pattern of these proteins is different when loss of occlusal support was bilateral or unilateral, including differences between extracted and non-extracted sides.