Changes in respiratory and cardiac functions of mandibular deficient patients after treatment with a removable functional appliance

There is no study on respiratory or cardiac function of mandibular deficient patients before or after treatment. This preliminary trial was conducted for the first time to assess respiratory/cardiac parameters of such patients before and after treatment (compared to healthy controls) with a removable functional appliance. This before-after clinical trial was performed on 20 patients with Class II division 1 malocclusion (mandibular deficiency with normal maxilla) and 20 matched control subjects at the peak of the mandibular growth spurt. Bionator removable functional appliance was used for 9 months to treat Class II cases. Capnography and pulse oximetry were used to record respiratory parameters (end-tidal carbon dioxide (PETCO2)), respiration rate (RR), oxygen saturation (SPO2), and pulse rate (PR)). Groups were compared using paired and unpaired t tests (α=0.05). CO2 and O2 did not change significantly after treatment (P>0.5, paired t-test). However, respiratory rate and pulse rate reduced significantly after the treatment (P0.1). O2 in healthy subjects was not different from pre-treatment or post-treatment values in Cl II patients (P>0.2, independent-samples t-test). The respiratory rate in healthy controls differed from pre-treatment (P