Objective: To investigate the effect of minocycline hydrochloride ointment as an adjunctive treatment on gingival esthetics and oral health in orthodontic patients. Methods: A total of 80 patients undergoing fixed orthodontic treatment between January 2023 and January 2025 were selected and divided into a control group and an observation group using a random number table method, with 40 patients in each group. The control group received conventional basic periodontal treatment and oral hygiene instructions, while the observation group additionally received topical minocycline hydrochloride ointment. The modified Pink Esthetic Score (mPES), Plaque Index (PLI), Gingival Index (GI), Sulcus Bleeding Index (SBI), probing depth (PD), and Oral Health Impact Profile-14 (OHIP-14) scores were compared between the two groups before and after treatment. Adverse reactions were also recorded. Results: Before treatment, no statistically significant differences were found between the two groups in mPES, PLI, GI, SBI, PD, or OHIP-14 scores (P>0.05). After treatment, the observation group had a higher mPES and lower PLI, GI, SBI, PD, and OHIP-14 scores than the control group (P<0.05). There was no statistically significant difference in the incidence of adverse reactions between the two groups (P>0.05). Conclusion: Minocycline hydrochloride ointment as an adjunctive treatment can improve gingival morphology and esthetics, alleviate gingival inflammation, and maintain periodontal and oral health in orthodontic patients, with favorable safety, and is worthy of clinical application.