Introduction: The investigators aimed to evaluate the effectiveness of non-extraction orthodontic treatment for Angle class I malocclusion.

Many people are also concerned about their oral health. When social communication is more important, aesthetic concerns also receive a lot of attention. A beautiful smile can boost self-assurance and empathy. Angle class I malocclusion is prevalent, and dental malocclusion is a significant percentage of the population at all ages . Tooth extraction is a controversial topic in orthodontics, with the general view being against it. Angle and his students argued against it, but Charles Tweed saw recurrence in the 1930s after retreatment without extraction and retreatment with extraction. The use of tooth extraction therapy increased in the 1960s but has become less common since the late 20th century. The science of orthodontics has made significant advancements under the principle of least invasiveness, but the debate remains about whether to consider tooth extraction. The contemporary view believes that the majority of patients may and should be treated without tooth extraction, but in rare circumstances, extraction is necessary to make up for crowding and excessive incisor protrusion that harm the beauty. In truth, each individual must be thoroughly evaluated in light of their bite, cosmetic condition, and stability in the wake of therapy before any course of action is recommended. The investigators aimed to evaluate the effectiveness of non-extraction orthodontic treatment for Angle class I malocclusion.

Inclusion Criteria:

• Patients (≥ 15 years) with indicated Angle class I malocclusion and missing space ≤9mm
• Cervical vertebral maturation stages 5, 6, (CS5, CS6): cervical vertebrae 2, 3, and 4 have a concave curved lower border and have at least one rectangle C3, C4 cervical vertebra upright or at least square
• No prior orthodontic treatment
• Fully erupted permanent teeth (except third molars)
• Voluntary research participation

Exclusion Criteria:

Face soft tissue surgical procedures, periodontal disease, and maxillofacial congenital anomalies