Introduction. Retention is necessary for three major reasons: 1) periodontal and gingival tissues are influenced by orthodontic tooth movement and require time for reorganization when the orthodontic appliance is removed; 2) teeth may be in an inherently unstable position after the treatment, so that soft tissue pressure constantly produce a relapse tendency; 3) changes produced by growth may alter the orthodontic treatment result. Material and methods. 12 patients, who were in a period of fixed and mixed contention. Of which fixed contention was applied to 7 patients and mixed contention to 5 patients. The patients were subjected to clinical and paraclinical examination. The patients were subjected to clinical and paraclinical examination: analysis of study models, photographic examination, panoramic radiography, teleradiography. Results. Out of 7 patients who had fixed retention, relapse was observed in 3 patients with detached retainers. Out of 5 patients who had mixed contention, relapse was only detected in one patient because he did not wear the Hawley device, the retainer was detached or the patient did not go to the doctor in time. Other patients are under observation, stable and without changes. Conclusion. In the study we found, how much influence the application of a correct diagnosis and treatment. An advantage of retainers is attributed to the correction of minor dental deviations, thus these devices have the possibility to combine both: prophylactic and curative methods.