PURPOSE: To compare the use of the Glatzel mirror and peak nasal inspiratory flow in the evaluation of mouth-breathing participants and to analyze the correlation between these instruments. METHODS: Sixty-four children were evaluated - 32 mouth breathers and 32 nasal breathers; the children were aged 4 to 12 years. The mouth breathers were subdivided according to the cause of obstruction by a multidisciplinary team. The Glatzel mirror and peak nasal inspiratory flow were used in both groups to evaluate patency and nasal airflow. Data were then subjected for statistical analysis. RESULTS: The Glatzel mirror allowed us to differentiate the breathing mode considering gender, age, weight, height, and body mass index, but it did not help in identifying the cause of mouth breathing. The peak nasal inspiratory flow did not allow differentiation of the breathing mode and identification of the cause of mouth breathing. In our sample, there was no correlation between the instruments used. CONCLUSION: The Glatzel mirror was reliable in identifying participants with and without nasal obstruction, although it was not possible to differentiate subgroups of mouth breathers using this instrument. The peak nasal inspiratory flow showed differences only between nasal breathers and surgical mouth breathers. Low correlation was found between these two instruments.
Speech; Language and Hearing Sciences; Health evaluation; Mouth breathing; Nasal obstruction; Respiration