The effect of orthodontic tooth movement on the sensitivity of dental pulp: A systematic review and meta-analysis.

Objectives: Orthodontic tooth movement (OTM) is a process that's initiated by orthodontic forces. As a consequence, the forces could restrict pulpal blood supply, possibly affecting dental pulp. The study aimed to review the available evidence on the short and long-term effects of orthodontic tooth movement on dental pulp sensitivity and to identify clinically relevant risk factors. Sources: PubMed, Embase, Scopus, and Web of Science were searched for papers from 1990 to the end of December 2021. Study selection: The studies that evaluated dental pulp sensitivity of teeth undergoing OTM were included in the systematic review. Randomized, nonrandomized and case-controlled studies were included in the analysis. Risk of bias in each study was assessed using the ROBINS-I tool. Data: The systematic search yielded an initial sample of 1110 studies, 17 were included in qualitative analysis. Most studies were classified as moderate risk of bias, however only limited long-term evidence with a higher risk of bias exists. Electric pulp test (EPT) sensitivity threshold during active OTM was increased by 4.25 SD (P < 0.001) and the relative risk (RR) of pulpal non-sensitivity was 13.27 (P < 0.001) higher compared to pre-orthodontic baseline status. Significant differences were between subgroups associated with the type of OTM. A positive relationship between pulpal non-sensitivity and mean patient age was discovered (P = 0.041). After OTM the risk of pulpal non-sensitivity remained 5.76 times higher (P < 0.001) in the long term. Conclusions: Evidence showed that OTM could affect dental pulp sensitivity. The type of OTM and patients' age were identified as clinically relevant risk factors. Clinical significance: Orthodontic tooth movement negatively impacts the sensitivity of dental pulp during active treatment and to a lesser degree in the long term. Pulpal sensitivity tests during active OTM should therefore be interpreted with caution. Data indicates younger patients have a lower risk of negative pulpal sensitivity during orthodontic treatment.