Objective To explore the application effect of orthodontics combined with repair treatment in patients with malocclusion and first molar loss. Methods A total of 90 patients with malocclusion and first molar loss who were treated in our hospital from January 2021 to January 2023 were selected as the research objects. According to different treatment methods, they were divided into control group and experimental group, with 45 patients in each group. The control group was treated with traditional tooth repair, and the experimental group was treated with orthodontics combined with repair treatment. The masticatory function, periodontal health index, oral repair effect and incidence of adverse reactions were compared between the two groups. Results The masticatory efficiency and bite force of the two groups after treatment were higher than those before treatment, and those of the experimental group was higher than those of the control group (P <0.05). After treatment, the gingival index (GI), bleeding index (BI) and probing depth (PD) in the two groups decreased, and those of the experimental group were lower than those in the control group (P <0.05). The excellent and good rate of oral repair in the experimental group was 95.56%, which was higher than 77.78% in the control group (P <0.05). There was no significant difference in the incidence of adverse reactions between the two groups (P >0.05). Conclusion Orthodontic combined with repair treatment can improve masticatory efficiency and bite force for patients with malocclusion and first molar loss, improve periodontal health index, reduce the incidence of adverse reactions, and improve the excellent and good rate of oral repair, which is worthy of clinical application.