PURPOSE:
to characterize the breathing function of subjects with dentofacial deformity in relation to the upper and lower airways and to the aspect of breathing regarding phonation.
METHODS:
40 adult subjects, divided into three groups: control group, dentofacial deformity II and dentofacial deformity III; the two last were in orthodontic treatment for orthognathic surgery. We carried out the MBGR Protocol clinical exam for breathing mode and type, nasal airflow, possibility of nasal use and obtainment of the protocol score; spirometry for assessing the breathing capacity. We also verified the expiratory airflow using a graded mirror to calculate the haze area and the extent of phonation time of /s/.
RESULTS:
There was a higher incidence of medium/upper breathing type for all groups. There was a statistical difference for the breathing mode, most patients with dentofacial deformity were oronasal or oral breathers; for the nasal expiratory flow, the subjects with dentofacial deformities had unilaterally reduced flow; for the possibility of nasal use, the dentofacial deformity II group had a greater number of subjects with impairment; for the score, the dentofacial deformity II group had the worst results. Individuals with a lower possibility of nasal use showed a lower haze area and lower phonation time of /s/. Mouth breathers showed lower phonation time of /s/. The statistical analysis did not show difference between the groups in the objective exams.
CONCLUSIONS:
Individuals with dentofacial deformity showed medium/upper breathing type, oral or oronasal mode, reduced expiratory nasal flow and respiratory support for phonation; the impairments in the possibility of the nasal use and the oral breathing affected the use of expiratory air for speech.
Breathing; Spirometry; Maxillofacial Abnormalities
