title: Craniocervical posture and hyoid bone position in children with mild and moderate asthma and mouth breathing.
abstract: BACKGROUND
  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.
authors.affiliation: Traumatology and Rehabilitation Program, Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus, Ribeirão Preto School of Medicine, University of São Paulo, Brazil. thaiscchaves@hotmail.com
authors.forename: Thaís Cristina
authors.initials: TC
authors.lastname: Chaves
authors.forename: Tatiana Simões
authors.initials: TS
authors.lastname: de Andrade e Silva
authors.forename: Solange Aparecida Caldeira
authors.initials: SA
authors.lastname: Monteiro
authors.forename: Plauto Christopher Aranha
authors.initials: PC
authors.lastname: Watanabe
authors.forename: Anamaria Siriani
authors.initials: AS
authors.lastname: Oliveira
authors.forename: Débora Bevilaqua
authors.initials: DB
authors.lastname: Grossi
mesh_terms: D001249:Asthma / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002508:Cephalometry; D002648:Child; D005260:Female; D006257:Head; D006801:Humans; D006928:Hyoid Bone / Q000000981:diagnostic imaging*; D008297:Male; D009058:Mouth Breathing / Q000000981:diagnostic imaging*; D009333:Neck; D011187:Posture; D011859:Radiography