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牙齒的萌出有哪些特點?

Posted By vickong pun     July 13, 2021    

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牙齒的萌出有哪些特點?

  

  牙齒的萌出有哪些特點?

牙齒的發育是一個連續的過程,包括生長、鈣化和萌出。
牙胚是由來自外胚葉的造釉器和來自中胚葉的乳突狀結締組織構成牙濾泡,它們埋於上下頜骨內,隨著頜骨的生長發育,牙胚亦發育化,直至牙冠突破牙囊,穿破牙齦而顯露於口腔。
牙冠破齦而出稱為出齦。

從牙冠出齦到上下牙咬合接觸較易發生異常。
因此時牙根尚未完全形成,牙周附著不牢固,牙槽骨也較疏鬆,易受外力的影響。
若唇、頰舌的壓力大小和方向不正常、不平衡,或有不良的吮指、唇的習慣等都可造成異位畸形。
牙齒萌出的特點是:

①牙齒萌出有一定次序,萌出先後與牙胚發育的先後基本一致。

②牙齒的萌出有一定的時間,但其生理範圍較寬。

③左右同名牙大致同時出齦。

④下頜牙萌出略早於上頜的同名牙。
牙齒的發育全過程與機體內、外環境有著十分密切的關係,與機體的代謝平衡、神經系統的調節以及營養、內分泌等都有關。

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