牙齒周圍支持骨與矯正治療的相關性研究

Abstract

研究背景與目的： 隨著矯正治療技術與骨性錨定裝置（如迷你骨釘、骨板）的廣泛應用，針對牙周狀況不佳患者執行全面性矯正治療逐漸成為臨床常態。然而，關於矯正治療是否會影響牙齒周圍支持骨的變化，文獻仍缺乏針對大臼齒三維移動方向的分析。本研究旨在探討：一、矯正治療是否增加「骨水平」（bone level）惡化與「根叉侵犯」的風險；二、不同矯正移動方式對牙周穩定性的影響； 三、對咬牙之移動是否與牙齒周圍支持骨變化具關聯性。 研究程序及方法： 本研究為回顧性研究，篩選 2009 至 2020 年間於臺大醫療體系接受完整牙周及矯正治療之成人患者，共納入 70 位受試者與 394 顆大臼齒。利用數位模型、 X光影像及測顱疊圖進行大臼齒移動方向分析，評估矯正治療前後之牙齒支持周圍支持骨變化。 評估骨質垂直缺損狀況主要觀察骨水平、 根叉侵犯程度。 其他指標亦分析測顱分析數值的變化，並進行單變項與多變項對數迴歸分析。 研究結果： 骨水平惡化風險與術前骨支持狀況不良、根叉區中重度侵犯、曾接受再生手術、矯正性突出及後牙未扶正等因子顯著相關。 牙齒軸向扶正則與骨水平保護效果具正相關。根叉惡化則與術前中重度根叉侵犯、對咬牙下壓型移動具關聯。整體臼齒於追蹤期拔牙率僅 1.69 %，但事件數偏低，限制了部分統計檢定力。 結論： 在牙周穩定控制下施以適當矯正治療，多數臼齒可維持穩定預後。但對於基期條件不佳或曾接受牙周再生手術者，特定移動型態（如突出）仍可能導致牙齒周圍支持骨惡化。建議臨床治療應於矯正計畫擬定時充分評估牙周條件、移動方向與對咬牙因素，並針對高風險牙齒採取個別化力學策略與定期監測。

Background and Objectives: With the advancement of orthodontic techniques and the widespread application of skeletal anchorage systems (such as mini-screws and bone plates), comprehensive orthodontic treatment in periodontally compromised patients has become increasingly common in clinical practice. However, evidence regarding the impact of orthodontic therapy on the surrounding alveolar bone remains limited, particularly in terms of analyzing the three-dimensional movement of molars. This study aimed to investigate: (1) whether orthodontic treatment increases the risk of deterioration in bone level and furcation involvement; (2) how different types of tooth movement influence periodontal stability; and (3) whether the movement pattern of opposing teeth is associated with changes in alveolar bone support. Materials and Methods: This retrospective study included 70 adult patients who received comprehensive periodontal and orthodontic treatment between 2009 and 2020 at the National Taiwan University healthcare system. A total of 394 molars were analyzed. Digital models, radiographs, and cephalometric superimpositions were used to assess molar movement vectors and changes in alveolar bone support before and after treatment. The primary periodontal outcome measures included vertical bone loss (bone level) and the degree of furcation involvement. Changes in cephalometric parameters were also analyzed. Both univariate and multivariate logistic regression analyses were performed. Results: Deterioration in bone level was significantly associated with poor initial bone support, moderate-to-severe furcation involvement, a history of periodontal regenerative surgery, extrusion-type tooth movement, and the absence of molar uprighting. In contrast, molar uprighting was positively correlated with preservation of bone support. Furcation deterioration was associated with baseline moderate-to-severe furcation and vertical intrusion of opposing teeth. The overall molar extraction rate during the follow-up period was low (1.69%), but the limited number of events reduced the statistical power for some analyses. Conclusion: With stable periodontal control, most molars maintained a favorable prognosis following appropriately planned orthodontic treatment. However, in patients with poor initial periodontal conditions or those who had received regenerative therapy, certain types of tooth movement—such as extrusion—may still pose a risk of alveolar bone deterioration. Clinical treatment planning should carefully evaluate baseline periodontal condition, direction of tooth movement, and opposing occlusion. High-risk teeth may benefit from individualized biomechanics and close periodontal monitoring.