Abstract
AIM: This retrospective study was performed to rule out any jeopardizing effect of extraction therapy of four first premolars on airway at any level of its anatomic course. MATERIALS AND METHODS: Lateral cephalograms of 50 adolescent patients divided into two groups of 25 each, based on orthodontic treatment by first premolar extraction as group I and without extraction as group II, were selected for the study. 13 angular and 11 linear measurements were compared pre-and post-treatment via statistical analyses using SPSS (Version 17.5, SPSS, Chicago) software. Paired 't' tests were used to assess the variability. P-value < 0.05 was considered to be statistically significant. RESULTS: Comparison of angular parameters showed that the average percentage (%) change in SNA, SNB, ANB, IMPA, FMA, saddle, articulare, gonial, total angle and hyoid did not differ significantly across two study groups (P > 0.05), but values of UI/LI, UI/NA, LI/NB, differed significantly among both groups. Similarly, linear parameters showed that the average % change in nasopharyngeal airway space (NAS) and width of soft palate differed significantly across two study groups (P-value<0.05), whereas the average % change in posterior airway space (PAS), hypopharyngeal airway space (HAS), hyoid distance and length of tongue did not differ significantly (P-value>0.05). However, no significant differences were observed during intragroup and intergroup comparisons of the combined angular and linear measurements of both groups. CONCLUSIONS: Present study showed no significant change on airway after therapeutic orthodontic tooth movement with or without extraction treatment.