Craniocervical posture and hyoid bone position in children with mild and moderate asthma and mouth breathing.

INTRODUCTION: The objective of the present study was to assess the craniocervical posture and the positioning of the hyoid bone in children with asthma who are mouth breathers compared to non-asthma controls.
METHODS: The study was conducted on 56 children, 28 of them with mild (n=15) and moderate (n=13) asthma (14 girls aged 10.79+/-1.31 years and 14 boys aged 9.79+/-1.12 years), matched for sex, height, weight and age with 28 non-asthma children who are not mouth breathers. The sample size was calculated considering a confidence interval of 95% and a prevalence of 4% of asthma in Latin America. Eighteen variables were analyzed in two radiographs (latero-lateral teleradiography and lateral cervical spine radiography), both obtained with the head in a natural position. The independent t-test was used to compare means values and the chi-square test to compare percentage values (p<0.05). Intraclass correlation coefficient (ICC) was used to verify reliability.
RESULTS: The Craniovertebral Angle (CVA) was found to be significantly smaller in asthma than in control children (106.38+/-7.66 vs. 111.21+/-7.40, p=0.02) and the frequency of asthma children with an absent or inverted hyoid triangle was found to be significantly higher compared to non-asthma children (36% vs. 7%, p=0.0001). The values of the inclination angles of the superior cervical spine in relation to the horizontal plane were significantly higher in moderate than in mild asthma children (CVT/Hor: 85.10+/-7.25 vs. 90.92+/-6.69, p=0.04 and C1/Hor: 80.93+/-5.56 vs. 85.00+/-4.20, p=0.04).
CONCLUSIONS: These findings revealed that asthma children presented higher head extension and a higher frequency of changes in hyoid bone position compared to non-asthma children and that greater the asthma severity greater the extension of the upper cervical spine. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.