Correlation between pain and hyalinization during tooth movement induced by different types of force

Abstract

Objectives: To evaluate the correlation between pain and tissue reactions during induced tooth movement (ITM). Materials and Methods: Forty-two male Wistar rats (Rattus norvegicus; ∼90 days of age, 300 g) were used. The animals were divided into seven groups of six rats each: one control group and six experimental groups subjected to ITM by continuous force (CF) or interrupted continuous force (ICF) for 1, 3, and 5 days. Hyalinization of the periodontal ligament (PL) and occurrence of pain were observed. Animal behavior (walking, climbing, immobile posture, resting/sleeping, and directed face grooming) and the presence of chemical mediators associated with nociception, cyclooxygenase-2 (COX-2), and interleukin-1 beta (IL-1β) in the PL were analyzed. Results: There was a moderate positive correlation between hyalinization and the presence of COX-2 (rs = 0.404; P < .05) and IL-1β (rs = 0.429; P < .05). There was a moderate negative correlation between hyalinization and exploratory behaviors (walking, r = −0.586, P < .01; climbing, r = −0.573, P < .01), and a moderate positive correlation between hyalinization and resting/sleeping (r = 0.467; P < .01). Conclusions: The results suggest a correlation between pain and undesirable tissue reactions in ITM.

Orthodontic debonding and tooth sensitivity of anterior and posterior teeth:

“…A positive correlation was found in rats between hyalinization and chemical mediators associated with periodontal nociception. 3 Up to 95% of patients experience unpleasant sensations during orthodontic treatment, 4 including simple discomfort, dull pain, or tooth hypersensitivity. 2 Cold stimuli are reported to be the most common triggers 5 of tooth hypersensitivity but dentin exposure resulting from dental wear is necessary for it to occur.…”

Hyalinization and Molecular Pathways Involved in Orthodontic Tooth Movement: A Systematic Review and Meta-Analysis

“…The overall results presented in Table 1 are summarized as follows [7,[21][22][23][24]: In 4 out of the five selected articles, the experiments had been carried out in rats [7,21,22,24]. As well, the animals included in the experiments were a total number of 177, and the experimental interval had been between 1 and 56 days.…”

“…The emergence of the necrotic tissue, known as hyalinization, has been taken into account as a vital element within the tooth movement procedure [7][8][9]. Primarily established on histological investigations, pressure, and a tension side have also been recognized during the OTM procedure [7,8,10].…”

“…The emergence of the necrotic tissue, known as hyalinization, has been taken into account as a vital element within the tooth movement procedure [7][8][9]. Primarily established on histological investigations, pressure, and a tension side have also been recognized during the OTM procedure [7,8,10]. Hyalinization can be accordingly sterile necrosis at the pressure region of PDL observed amid the early phases of the OTM, and broad hyaline zones can thus result in imperative delay within the tooth movement procedure [7,11,12].…”

“…Primarily established on histological investigations, pressure, and a tension side have also been recognized during the OTM procedure [7,8,10]. Hyalinization can be accordingly sterile necrosis at the pressure region of PDL observed amid the early phases of the OTM, and broad hyaline zones can thus result in imperative delay within the tooth movement procedure [7,11,12]. In related studies, hyalinization has been seemingly found within the initial phase of OTM, and small hyalinized patches have been additionally observed within the afterward phases [13,14].…”