Objective To compare the effects of extraction fixed orthodontics treatment and non-extraction arch expansion with distalization therapy on oral spatial structure and oral function recovery in adolescent patients with malocclusion. Methods A total of 100 adolescent patients with malocclusion who received orthodontics treatment in the Department of Stomatology of our hospital from April 2024 to August 2025 were selected as the research subjects, and they were divided into group A and group B by the random number table method, with 50 patients in each group. Group A received extraction ffxed orthodontics treatment, and group B received non-extraction arch expansion with distalization therapy. The oral spatial structure, oral function recovery and facial aesthetic indicators were compared between the two groups. Results The sagittal linear variation value of group B was lower than that of group A, and the transverse linear variation value was higher than that of group A (P<0.05). There was no statistically signiffcant difference in vertical linear variation value between the two groups (P>0.05). After treatment, There was no statistically signiffcant difference in masticatory efffciency score between the two groups (P>0.05). The speech intelligibility score in group B was higher than that in group A, and the incidence of tongue biting was lower than that in group A (P<0.05). The soft tissue proffle variation value of group B was lower than that of group A, and the smile width score was higher than that of group A (P<0.05). There was no signiffcant difference in aesthetic satisfaction score between the two groups (P>0.05). Conclusion Both orthodontics protocols can improve oral spatial structure and oral function in adolescents with malocclusion. Extraction ffxed orthodontics treatment shows more prominent advantages in sagittal jaw space adjustment and soft tissue proffle improvement, yet accompanied by inferior speech function and higher risk of tongue biting. Non-extraction arch expansion with distalization therapy can widen transverse dental arch space and help to maintain favorable smile width. The two methods achieve equivalent aesthetic satisfaction. Clinicians should select appropriate therapy individually based on oral conditions and personal demands.