畸形舌侧沟（PGG）是一种先天性牙体发育缺陷，通过解剖性菌斑滞留区与复杂牙周袋加速局部牙周组织破坏。本文报道1例30岁男性广泛型Ⅲ期C级牙周炎患者，合并12牙PGG及安氏Ⅰ类错畸形，经4个阶段多学科联合治疗：（1）牙周基础治疗（龈上洁治与龈下刮治等）控制炎症；（2）13-21翻瓣术彻底清创，同期以流动树脂充填12牙PGG，阻断感染通道；（3）正畸治疗关闭上前牙散隙、重建功能性关系；（4）长期牙周支持治疗（每6个月复查）。2年随访显示，全口探诊深度（PD）≥3.4 mm位点占比从基线48%下降至27%，12牙腭侧见局限性角形骨吸收，但根尖区骨密度增高，咬合功能及美学外观显著改善。本病例证实，翻瓣术联合树脂充填可有效清除感染源并封闭解剖缺陷，牙周-正畸协同治疗能同步控制炎症、改善咬合关系，为复杂牙周炎的序列化多阶段管理提供了一种可推广的方案。

Palatogingival groove (PGG), a congenital developmental defect, accelerates localized periodontal destruction by creating anatomic plaque-retentive niches and complex periodontal pockets. This case report describes a 30-year-old male with generalized stage Ⅲ grade C periodontitis, combined with PGG on tooth #12 and Angle Class Ⅰ malocclusion. Multidisciplinary management involved four phases: (1) Initial periodontal therapy (scaling and root planing with oral hygiene reinforcement) to suppress active inflammation; (2) Surgical intervention (open flap debridement from #13 to #21 with concomitant flowable resin sealing of the PGG on #12) to eliminate microbial reservoirs; (3) Orthodontic treatment (diastema closure and functional occlusal reconstruction) to remove traumatic occlusal forces; (4) Long-term supportive periodontal care (6-month recall visits). At 2-year follow-up, the percentage of sites with probing depth (PD) ≥4 mm decreased from 48% (baseline) to 27%. Tooth #12 exhibited localized angular bone loss palatally but increased radiodensity apically, with significant functional and aesthetic improvements. The key findings of this article were as follows. (1) Flap surgery combined with PGG sealing effectively eradicated infection and blocked anatomic pathways. (2) Periodontal-orthodontic synergy simultaneously controlled inflammation and corrected occlusal trauma. (3) Staged multidisciplinary sequencing provided a replicable framework for managing complex periodontitis.