| 释义 |
cementum noun[ U ] anatomy specializeduk /sɪˈmen.təm/ us /səˈmen.təm/ a hard substance that covers the root of a tooth (= the bottom part inside the gum) and fixes the tooth to the jawbone: The root is found below the gum and it is covered by cementum. Cementum is the most popular source for obtaining growth rings in ageing mammals. He found that the toxins generated by the bacteria were able to pass through the cementum. For age determination in adult moose, the first molar of the lower jaw was sectioned and cementum layers counted. For human teeth to have a healthy oral environment, enamel, dentin, cementum, and the periodontium must all develop during appropriate stages of foetal development. SMART Vocabulary: related words and phrases The teeth baby tooth buck-toothed centric cingulum coronal deciduous tooth erupt interdental labially lingually mesially milk tooth molar odontoblast pulpal rictus snaggle-toothed snaggled through clenched teeth wisdom tooth |