Orthodontic Intrusion: CIA Vs CNA Intrusion Arch

The purpose of this study was to evaluate clinical efficacy of CIA and CNA intrusion arches. Methods: Tracings recorded from pre and post-treatment lateral cephalograms of 25 patients treated by CIA (Group I) and another 25 patients treated by CNA (Group II) intrusion arches in deep bite cases after four months of treatment were analyzed and findings were recorded. Paired t-test was used to compare pre and post-treatment changes within Groups I and II and unpaired t-test was used to compare treatment changes between Group I and Group II. A 'P' value of < 0.05 was set for statistical significance. Results: Findings of this study demonstrate that an average of 1mm of intrusion takes place with CIA intrusion arch and 1.3mm with CNA intrusion arch in a period of 4 months. Both intrusion arches do not affect the position of molar in vertical or anteroposterior plane. Although there is some amount of retraction of lower incisors seen with both the arches. Interpretation & Conclusion: Both CIA and CNA intrusion arches are effective in bringing about intrusion of lower incisors.