Inhibitory Effect of Short-Term Ketogenic Diet on Cytokine Expression During Orthodontic Movement in a Rat Model

Purpose: To compare the change of IL-1 beta and TNF-alpha expression during orthodontic tooth movement in rats, which were under regular diet and ketogenic diet (KD). Materials and Methods: The maxillary right first molars of 3-month-old male Sprague-Dawley rats were subjected to mesial movement by 50 g of force for 14 days under ketogenic diet. A control group was also established in which rats were subjected to the same tooth movement conditions but under a regular diet. The distance of tooth movement was measured by using precision electronic calipers. After 14 days, the rats were sacrificed and the mesial surface of the palatal root of the right first molar was analysed to determine the expression levels of IL-1 beta and TNF-alpha through immunohistochemical staining. The images obtained were then quantified using ImageJ program. Results: After 14 days of orthodontic tooth movement, the amount of tooth movement in the ketogenic group was lesser by approximately half the distance compared to that of the control group. Moreover, the expression of IL-1 beta and TNF-alpha was also lower. Conclusions: Consuming ketogenic diet reduces the expected amount of tooth movement which was evidently shown by a significant lower cytokine expression of IL-1 beta and TNF-alpha than the group under regular diet. This suggests that ketogenic diet is a contributing factor in delaying the tooth movement during orthodontic treatment.