Abstract
Objective To determine behavioral testing after experimental tooth movement in rats and to explore the role of nociceptin/orphanin FQ and its receptor (the N/OFQ-NOP system) in pain induced by experimental tooth movement. Design The mouth-wiping behavior of rats was assessed by studying behavioral responses after experimental tooth movement. The distribution of N/OFQ in the periodontal ligament, the trigeminal ganglion (TG), and the caudal one-third of the trigeminal subnucleus caudalis (Vc) was assessed by immunohistochemistry. The variations in N/OFQ expression in the TG and Vc were measured by Western blotting. The ongoing changes in the gene expression of the prepronociceptin gene and opioid receptor-like 1 receptor were assessed in the TG and Vc by real-time polymerase chain reaction (RT-PCR). Results Overall, the mouth-wiping behavior increased significantly. The behavior first increased and then gradually decreased to a low level, showing cyclical variation. N/OFQ immunoreactivity increased in the periodontal ligament after tooth movement. ppN/OFQ mRNA and protein levels showed a time-dependent increase in the TG and were positively correlated with pain stimulus. NOP gene levels showed large fluctuations. In the Vc, the expression and changes in the N/OFQ-NOP system showed the opposite trend as those noted in TG and the periodontal membrane. Conclusion The N/OFQ system may have a complex regulatory function in the pain induced by tooth movement and may be related to inflammation caused by orthodontic tooth movement and periodontal damage. The specific mechanism remains to be further studied.
Highlights
Orthodontic treatment is based upon the application of an orthodontic force to correct the dislocation of teeth, dental arch, or jaws
MRNA levels of the nociceptin receptor nociceptin/orphanin peptide receptor (NOP) showed an immediate decrease at 4 h (p < 0.05) followed by a slow increase until the 3rd day and a second decrease (p < 0.05), and the processing side of the control group showed similar changes (Figure 9). e changes in the nociceptin/orphanin FQ (N/OFQ) system in the Vc, which are inconsistent with those in the trigeminal ganglia and periodontal ligament after experimental tooth movement and periodontal injury, prompted a complex regulatory function of the N/OFQ system on pain. is process exerted a specific effect in the early stages after orthodontic tooth movement and periodontal inflammatory injury
Our study found that a limited amount of N/OFQ was positively expressed in the periodontal ligament and apical roots, which started to increase 1 day after tooth movement and gradually decreased after a week. is trend was possibly due to increased adaptation of local tissues to external stimulation
Summary
To determine behavioral testing after experimental tooth movement in rats and to explore the role of nociceptin/orphanin FQ and its receptor (the N/OFQ-NOP system) in pain induced by experimental tooth movement. E mouth-wiping behavior of rats was assessed by studying behavioral responses after experimental tooth movement. E behavior first increased and gradually decreased to a low level, showing cyclical variation. N/OFQ immunoreactivity increased in the periodontal ligament after tooth movement. PpN/OFQ mRNA and protein levels showed a time-dependent increase in the TG and were positively correlated with pain stimulus. In the Vc, the expression and changes in the N/OFQ-NOP system showed the opposite trend as those noted in TG and the periodontal membrane. E N/OFQ system may have a complex regulatory function in the pain induced by tooth movement and may be related to inflammation caused by orthodontic tooth movement and periodontal damage. Conclusion. e N/OFQ system may have a complex regulatory function in the pain induced by tooth movement and may be related to inflammation caused by orthodontic tooth movement and periodontal damage. e specific mechanism remains to be further studied
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
