Clear aligner therapy has become increasingly popular as an esthetic alternative to conventional braces in orthodontic treatment. While clear aligners are traditionally manufactured by commercial laboratories using a thermoforming technique, recent advances in 3D printing technology now allow clinicians to produce aligners directly in their own clinic, either by printing the aligner itself (direct method) or by printing a model and then thermoforming the aligner over it (indirect method)." "This study compares three approaches to orthodontic treatment in patients with mild to moderate dental crowding who do not require tooth extraction: clear aligners produced directly in-house using 3D printing with a shape-memory resin, clear aligners produced indirectly in-house using a 3D-printed model and thermoforming, and conventional fixed orthodontic treatment with metal brackets and wires." "A total of 36 patients aged 12 to 30 years were randomly assigned to one of these three treatment groups, and 33 patients completed the study. Treatment quality was evaluated using the American Board of Orthodontics Objective Grading System (ABO-OGS), an objective scoring method based on dental models obtained at the end of treatment. The total duration of treatment, from the start of active treatment to its completion, was also compared among the three groups." "The findings of this study may help clinicians and patients better understand the advantages and limitations of in-house clear aligner production compared to conventional fixed appliances, particularly regarding treatment efficiency and duration.