Influence of habitual mouth breathing on taste sensation

Purpose

Although habitual mouth breathing is recognized to cause various disorders of orofacial growth and function, including taste sensation, the relationship between habitual mouth breathing and taste disorders has not been investigated sufficiently. This study aimed to examine the influence of habitual mouth breathing on taste sensitivity and relevant factors such as salivation, oral moisture, and olfactory function.

Materials and methods

Thirty volunteers (male, 18; female, 12) aged 22–35 years participated in this study. On the basis of their responses to a questionnaire regarding habitual breathing, 15 subjects each were assigned to the mouth-breathing (MB) and control groups. Recognition thresholds for sweet, salty, sour, bitter, and umami tastes at the tip and root of the tongue were measured using the filter-paper disk method. Salivary flow and spinnbarkeit (viscosity), oral moisture, and olfactory function were also measured as factors related to taste sensitivity. Additionally, a questionnaire about dry mouth, nasal obstruction, snoring, and olfaction was implemented.

Results

The MB group exhibited significantly higher recognition thresholds for sweetness and sourness at the tip and for bitterness and sourness at the root of the tongue compared with the control group. However, there was no significant intergroup difference in the threshold for salty or umami taste, salivary flow or spinnbarkeit, oral moisture, or olfactory function. The MB group exhibited a significantly higher subjective feeling of dry mouth, nasal obstruction, and snoring than the control group.

Conclusions

Mouth breathing habit poses a risk for taste deterioration without affecting salivary secretion and olfactory function.