Objective To analyze the effect of oral nursing based on comprehensive assessment on facial appearance satisfaction and oral malodor degree in patients undergoing orthodontics with fixed orthodontic appliances. Methods A total of 70 patients who underwent orthodontics with fixed orthodontic appliances in our hospital from June 2021 to June 2024 were selected as the research subjects. According to the random number table method, they were divided into the control group and the observation group, with 35 patients in each group. The control group received routine nursing, and the observation group received oral nursing based on comprehensive assessment. The facial appearance satisfaction, oral malodor degree, periodontal indexes and quality of life were compared between the two groups. Results After intervention, the facial appearance satisfaction score in the observation group was higher than that in the control group (P <0.05). After intervention, the content of volatile sulfur compounds (VSCs) in the observation group was lower than that in the control group (P <0.05). After intervention, the PLI, SBI and PD in the observation group were lower than those in the control group (P <0.05). After intervention, the salivary pH value in the observation group was higher than that in the control group (P <0.05). After intervention, the quality of life score in the observation group was higher than that in the control group (P <0.05). Conclusion The effect of oral nursing based on comprehensive assessment in patients undergoing orthodontics with fixed orthodontic appliances is definite, which can improve the facial appearance satisfaction, reduce the degree of oral malodor, and is beneficial to improving the periodontal indexes of patients, thereby enhancing their quality of life.