1 Professor at Orthodontics Department, School of Dentistry, Tehran University of Medical sciences, Tehran, Iran

2 Postgraduate Student of Pedodontics. School of Dentistry, Shahed university of medical sciences, Tehran, Iran



OBJECTIVE: as regards to prevalence of mouth breathing and its complications, The panoramic view of children with mouth breathing as a routine initial accessible radiographic examination, was assessed in the present study; considering Confounding factors such as the magnification, dimensional changes, type of the x-ray machine and head position during imaging. We tried to innovate new standardization of nasal cavity analysis in panoramic radiography, in addition to creating specified and reliable new parameters, and investigate if there are significant differences between these parameters in mouth breathing patients than in those with nasal breathing. 
METHODS: This wasa control and analytical study which assessed 30 patients with Mouth breathing and 30 patients with nasal breathing, in the range of 9-12 years old with equal numbers of both sexes, in both groups. After tracing panoramic radiographs, five angular and proportional variables was created and measured, T-test was performed and the level of significance was evaluated. For investigation of nasal septum deviation, we used Chi-square test.
RESULT: "NL" and "NL/B" parameters and unclear irregular view ofnasal cavity ininternal structures, showed significant differences in mouth breathing group (P.Value < 0.5). Right and left nasal cavity width in each patient, separately in two groups- mouth breathing and normal breathing- showed no significant differences. 
CONCLUSION: Due to availability and benefits of panoramic radiography,the proportional and angular parameters used, were reliable for assessment of nasal cavity in mouth breathing children and could be developed in future studies for diagnosis of mouth breathing children.