Effects of fixed orthodontic treatment on taste perception: a randomized controlled trial

This study aimed to evaluate whether fixed orthodontic treatment leads to measurable changes in taste perception. The primary objective was to assess alterations in the perception of sweet, salty, sour, and bitter tastes before and after treatment initiation.

A total of 128 patients aged 10-19 from the Orthodontics Clinic of Biruni University were randomly assigned to either a fixed orthodontic treatment group (n = 64) or a control group (n = 64). Taste perception was evaluated using nine solutions (two concentrations each of sweet, salty, sour, and bitter, plus a neutral control) administered before treatment and again six weeks later. Perceived taste intensity was measured using a Visual Analog Scale (VAS). Statistical comparisons were performed using the Mann-Whitney U test, Wilcoxon Signed-Rank test, and Pearson Chi-Square test.

Significant changes were observed within the experimental group: sweet taste scores (low concentration) decreased, and bitter taste scores (high concentration) increased from the first to the second session (p < 0.05). However, no significant differences were found between the experimental and control groups across all taste modalities and time points (p > 0.05).

Fixed orthodontic appliances may cause minor, short-term alterations in taste perception, specifically for sweet and bitter tastes. These changes are likely influenced by salivary flow and are not clinically significant when compared to untreated individuals.

Clinicians should inform patients that mild and temporary changes in taste may occur during the initial phase of fixed orthodontic treatment. These effects are manageable and typically resolve with good oral hygiene and adaptation to the appliance.

This study was retrospectively registered at ClinicalTrials.gov (NCT06989736) on May 23, 2025.