Methods: Eighty lateral cephalometric radiographs of 40 subjects, obtained in two evaluation moments (1 and 2), were used. Among them, 24 subjects were predominantly nasal breathers (N1 and N2 Groups) and 16 ones were predominantly mouth breathers (B1 and B2 Groups). The subjects aged 11 to 14,11 years in the first evaluation, and 13,5 to 17,4 years in the second one. The LAFH values were obtained by the cephalometric combined method, which consists on the association of manual and digital methods.Student t test was used for mean values comparison.
Results: The LAFH mean values (mm) were: 64,52 for the N1 group and 66,58 for B1 group; 67,96 for the N2 group and 69,08 for B2 group. There is no statistically significant difference* between N1¨CB1 groups and between N2¨CB2 groups. Besides, for N1¨CN2 and B1¨CB2 groups, there is statistically significant difference *. The increment rate of the measure among the two evaluation moments is similar for both breathers groups (N and B), and its mean value is 2,98mm (* at p°Ü0,05 level).
Conclusions: The results allow to conclude that there is no difference in LAFH between predominantly mouth and nasal breathing subjects. As the face grows, there is significant increase on LAFH values for both breathing patterns.