# Comparative Analysis of Halitosis in Adolescents and Young Adults with Removable Retainers, Fixed Retainers, or No Orthodontic Treatment: A Cross-Sectional Study with Salivary pH Subgroup Analyses

## TL;DR

Young people with fixed orthodontic retainers experience more bad breath and lower quality of life compared to those with removable retainers or no appliances, with low saliva pH worsening the issue.

## Contribution

This study identifies fixed retainers and low salivary pH as significant contributors to halitosis in adolescents and young adults.

## Key findings

- Fixed retainer users had higher halitosis severity and lower quality of life compared to removable retainer users and non-users.
- Low salivary pH (<6.8) was associated with increased malodor across all groups.
- A moderate positive correlation was found between halitosis-related quality of life and overall oral health impact.

## Abstract

Background and Objectives: Halitosis is a persistent oral health issue that can undermine self-esteem and social interactions, particularly in younger populations who may be more vulnerable to peer judgment. Orthodontic retainers—both removable and fixed—can alter oral microbiota and salivary parameters, potentially influencing malodor development. This study aimed to compare halitosis severity and oral-health-related quality of life (OHRQoL) in adolescents and young adults (aged 12–25) wearing removable retainers, fixed retainers, or no orthodontic appliances, with an additional focus on salivary pH as a possible modifying factor. Methods: A total of 88 participants were allocated into three groups: removable retainer (n = 28), fixed retainer (n = 30), and no orthodontic treatment (n = 30). Halitosis severity was measured via organoleptic evaluation (0–5 scale) and the Halitosis Associated Life-Quality Test (HALT, 0–100). Salivary pH was determined using a digital pH meter. OHRQoL was assessed through the Oral Health Impact Profile–14 (OHIP-14, 0–56). One-way ANOVA with Tukey’s post hoc test and chi-square analyses were employed to compare outcomes among groups. Spearman’s correlation explored relationships among HALT, organoleptic scores, OHIP-14, and salivary pH. Results: Fixed retainer wearers exhibited higher mean organoleptic scores (2.2 ± 0.6) compared to removable retainer users (1.7 ± 0.5, p = 0.003). HALT results similarly showed that the fixed retainer group (35.6 ± 6.4) reported more halitosis-related burdens than the removable group (31.4 ± 5.9, p = 0.015). Low salivary pH (<6.8) was linked to greater malodor indices in all cohorts (p < 0.05). Correlations revealed moderate positive associations between HALT and OHIP-14 (r = +0.52, p < 0.001). Conclusions: Adolescents and young adults wearing fixed orthodontic retainers reported more severe halitosis and a correspondingly lower oral-health-related quality of life than those with removable retainers or no orthodontic appliances. Salivary pH emerged as an influential factor, indicating that maintaining a neutral oral environment could mitigate malodor. Targeted interventions emphasizing hygiene and saliva management may improve overall well-being in this vulnerable age group.