Conclusion The larger pleomorphic adenoma predominantly occur at the parotid,submaxillary gland or palate,while the smaller one at lip,bucca,gingiva,frons and nasolabial sulcus.
If the gingiva recedes or plaque forms between the gingiva and the root, bacteria and acids have direct access to the cementum, which is much softer than enamel and dissolves more quickly.
The crown is the visible part of the tooth that protrudes from the gingiva, and it's covered in enamel, which has such a high mineral content that it's the hardest substance in the human body.
，
只要仔细观察、有效护理，是可以降低口腔粘膜炎发生
度的。
化 
是较大多形性腺瘤的好发
,
较小的则易发生在唇、颊、龈、额、鼻唇沟
上面）与
。
，细菌和酸就可以直接侵犯
