Is the growth pattern in mouth breathers comparable with the counterclockwise mandibular rotation of nasal breathers?

INTRODUCTION

The aim of this longitudinal study was to investigate mandibular rotation and angular remodeling in mouth-breathing children compared with nasal-breathing children.

METHODS

The sample included 55 severely obstructed mouth-breathing children (mean age, 6.1 years) and 55 nasal-breathing children (mean age, 7.3 years). The cephalograms at baseline and after 1 year were traced and measured, and superimpositions were made to determine true mandibular rotation, apparent rotation, and angular remodeling. The significance level was set at 5%.

RESULTS

The mouth-breathing children had a longer face cephalometric pattern compared with nasal-breathing children. No cranial deflection differences were observed. No changes in the vertical growth pattern were observed during the 1-year period in either group. There were no statistically significant differences between the groups regarding apparent rotation (mouth breathing, -0.54°, vs nasal breathing, -0.41°). In comparison with the nasal breathers, the mouth breathers showed statistically significant lower yearly rates of counterclockwise true rotation (mouth breathing, -0.60°, vs nasal breathing, -1.31°) and angular remodeling (mouth breathing, 0.06°, vs nasal breathing, 0.87°).

CONCLUSIONS

Mouth-breathing children had a hyperdivergent cephalometric pattern, but against all expectations, counterclockwise true mandibular and apparent rotations were the average observations. Mouth-breathing children showed less true rotation and angular remodeling than did nasal breathers; however, apparent rotations were similar.