Prediction of the Growth of Upper Airway in Normal Children

Objectives: The aim of this study is to predict the normal growth of the upper airway by using serial lateral cephalograms. Methods: Cephalograms of 23 normal Japanese children were selected at the age T1 (4.96 yr.±0.74) and the age T2 (9.47 yr.±1.33). 10 landmarks were used as references to construct 14 linear and 1 angular measurements for the upper airway measurement. 14 linear and 18 angular measurements were chosen for other maxillofacial measurements. The data were analyzed by multiple linear regression analysis. Results:1.The equation for the annual growth change of the height from the nasopharyngeal airway to the oropharyngeal airway (MPW⊥PNS-ANS) is YA=-22.753+0.207X₁+0.047X₂+0.042X₃, where YA is the annual growth change of MPW⊥PNS-ANS, X₁ is the angle N-Pog to SN at T1, X₂ is the angle L1 to mandibular plane at T1, and X₃ is the angle Ramus plane to SN at T1. The combination of the three angles at T1 can explain the variability of YA by 69%(R²=0.692, P<0.05). 2.The equation for the annual growth change of the height from the nasopharyngeal airway to the posterior airway (MLPW⊥PNS-ANS) is YB=17.025-0.075X₄-0.047X₅-0.075X₆,where YB is the annual growth change of MLPW⊥PNS-ANS, X₄ is the angle NSAr at T1, X₅ is the angle ArGoMe at T1, and X₆ is the angle Nasal floor to SN at T1. The combination of the three angles at T1 can explain the variability of YB by 77%(R²=0.773, P<0.05). Conclusion: The findings could present an effective model for predicting the growth of the upper airway, that would be more helpful in the clinical evaluation and practice.