# How Does Allergen Sensitization Affect Orthodontic Tooth Movement-Associated Phenomena? A Systematic Review of Animal Studies

## TL;DR

This review explores how allergen sensitization might affect tooth movement during orthodontic treatment, based on animal studies.

## Contribution

The study systematically reviews animal research to assess the impact of allergen sensitization on orthodontic tooth movement phenomena.

## Key findings

- Periodontal ligament showed increased compression and stretching in sensitized animals during tooth movement.
- Allergen-sensitized animals exhibited greater tooth movement after 14 days of force application.
- Results on root resorption were conflicting across the studies reviewed.

## Abstract

Background: The immune reactions of patients suffering from chronic allergies and asthma are associated with systemic imbalances that may lead to the overexpression of mediators potentially involved in bone remodeling during orthodontic tooth movement. Aim: The aim of this systematic review was to evaluate the existing evidence from animal studies with regard to the effects of allergen sensitization on the phenomena correlated with orthodontically induced tooth movement. Materials and Methods: This systematic review was based on PRISMA 2020 guidelines. A search without restrictions and hand searching were performed from inception to December 2024. The investigation focused on the impact of allergen sensitization on phenomena associated with orthodontic tooth movement. After the retrieval and selection of relevant studies, data extraction was performed, and the data’s risk of bias was evaluated with the SYRCLE’s Risk of Bias Tool. Results: From the detected records, the inclusion criteria were met by only three studies. At the beginning of tooth movement, periodontal ligament was found to be more compressed in the stress area and more stretched in the tension area in sensitized animals. The amount of tooth movement after 14 days of force application was also greater. However, there were conflicting outcomes regarding root resorption. The risk of bias in the retrieved studies was assessed as high overall. Conclusions: Despite the fact that existing evidence is not directly related to human beings and is based on a limited number of animal studies, allergen sensitization could potentially influence the phenomena associated with orthodontic tooth movement, and orthodontists should be aware of the relevant implications.