Photogrammetric analysis of postextraction space closure

Introduction. When planning orthodontic treatment, it is sometimes necessary to apply the extraction of individual teeth, in order to achieve proper occlusion and an acceptable aesthetic appearance. Clinicians give the greatest advantage to elastic chains as a method for post-extraction space closure during treatment with fixed orthodontic appliances. When closing post-extraction spaces, it is necessary to measure them in order to adjust the treatment plan. One of the most acceptable methods is photogrammetry. The aim of this study was to analyze, using a photogrammetric method, the efficacy of post-extraction space closure with elastic chains during orthodontic treatment with fixed orthodontic appliances. Material and Methods. The total sample in study consisted of 38 post-extraction spaces in 19 patients who were indicated for first premolars extraction and use of fixed orthodontic appliances in order to achieve treatment goal. Elastic chains were used to close post-extraction spaces. Post-extraction sites were monitored for 6 months with follow-up examinations every 4 weeks. Mechanisms were activated at controlled examinations, and measurements of the width of post-extraction spaces were performed by photogrammetry and digital caliper. Results. The results showed that average reduction of post-extraction space width was 1.00 mm per month by photogrammetric measurement, while the average values of measurements with a digital caliper were 1.02 mm. The average values were measured in six time intervals and a statistically significant change in average intervals of post-extraction spaces during 6 months was determined. Conclusion. The elastic chain has proven to be a very effective mechanism for closing post-extraction space, and photogrammetry as a simple and precise method for monitoring results of treatment. Since the difference in relation to measurements with a digital caliper is minimal, photogrammetry can be routinely applied in everyday practice.