@Curve of Spee(史必氏曲) & Curve of Wilson(威爾森曲)－崇愛牙醫診所(資料重建中,歡迎新舊朋友)

curve of spee

深咬的案例,curve of spee在下顎前方會隆起,形成高聳的陡峭形態,上下牙列的對咬關係因為功能性的位移(functional shift),很顯然下顎前牙會無意的去咬在上顎顎側的牙齦上,這是代償作用
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同樣的,暴牙的案例當中,因為上下牙列的水平覆咬(overjet)關係差異大,下顎的前牙區也是為了代償作用,史必氏曲會隆起,造成下顎的curve of spee是concave(凹陷)的形態,上顎牙列則是convex(凸出)的形態
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反咬的戽斗牙列,其 curve of spee顯得較flat(平坦)
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假性的戽斗,因為下顎前方毫無阻擋,curve of spee往往會無意的隆起,臨床上矯正時會整平之,以改善成為正常的咬合

由以上圖例可知,矯正裡頭多少都會碰到需要整平curve of spee的情形,也就是我們所說的打平咬合,一條弓絲擺入牙列後,它會按照牙齒上所黏著的bracket(托槽),裡頭所建置的角度與軸傾度,轉矩度,一一的表現出來,咬合每次的上下牙齒接觸都會產生震盪力,這種震盪頻率必需要有吸震效果的弓絲來做整平的工作,否則,牙齒的牙周韌帶往往因為施力的不同,必須很小心的施力控制力值,否則,有可能會產生牙根的吸收(root resorption)

整平curve of spee的方法很多,此處不多贅述,弓絲是重要的要會選擇使用,反向史必氏曲弓絲(reverse curve of spee,俗稱搖椅弓))形態有多種,使用上必須當心,否則弓型很容易變樣,要重新再以ssw弓絲整好,線的使用對矯正是非常重要的,矯正醫師一定要懂得彎線,這樣才能避開一些可能的不當牙齒位移,也才能逐步把牙列整平排齊,達到矯正的目的

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史必氏曲(curve of Spee,這是前後矢狀向=sagittal)

威爾森曲(curve of Wilson,這是左右向=垂直向=vertical)

Curve of Spee.(史必氏曲)

-The cusp tips and incisal edges align so that there is a smooth, linear curve when viewed from the lateral aspect. The mandibular curve of Spee is concave whereas the maxillary curve is convex.

-It was described by Von Spee as a 4" cylinder(4吋的柱狀體) that engages the occlusal surfaces.

-It is called a compensating curve of the dental arch.(牙弓的補償曲線) Illustration of the Curve of Spee seen from a lateral perspective and the Curve of Willson viewed from the distal end of the lower dentition

-There is another: the Curve of Wilson. Clinically, it relates to the anterior overbite: the deeper the curve, the deeper the overbite. The Curve of Wilson is referred to only infrequently in dental literature.

-If the Curve of Spee is flattened out during orthodontic treatment, it tends to come back. .....

Curve of spee (在字典裡頭的解釋)

In Anatomy, the Curve of Spee (called also von Spee's curve or "Spee's curvature") is defined as the curvature of the mandibular occlusal plane beginning at the tip of the lower cuspid and following the buccal cusps of the posterior teeth, continuing to the terminal molar.

According an another definition c. of Spee is an anatomic curvature of the occlusal alignment of teeth, beginning at the tip of the lower canine, following the buccal cusps of the natural premolars and molars, and continuing to the anterior border of the ramus.

Ferdinand Graf von Spee, German embryologist, (1855–1937) was first to describe anatomic relations of human teeth in the sagittal plane.(在解剖學上 ,史必氏曲被定義為下顎的弧型咬合平面,源自於下顎犬齒的尖端,接著連結下顎後牙的頰側咬頭,持續到大臼齒結束所連成的一條弧線,也可以定義史必氏曲為由牙齒的排列所構成的咬合平面的弧線,開始在下犬齒的尖頭端,持續沿著小臼齒的頰側咬頭到大臼齒,到達ramus的前緣/ Ferdinand Graf von Spee,是一位德國的胚胎學家,他首先定義人類在矢狀平面向的牙齒解剖排列關係)

The pull of the main muscle of mastication the "masseter" is at a perpendicular angle with the curve of Spee to adapt for favorable loading of force on the teeth.(構成咬合咀嚼力的咬肌剛好和史必氏曲成垂直的狀態,提供給牙齒適當的咬合壓力)

occlusion~key to dentistry(A36-A40裡有CURVE OF SPEE&WILSON)(如果您的咬合學不夠好,這裡正是您再充電一次的好地方)