Based on the present histological and previous molecular biological studies, the special structure at the apical end is obviously different from the cervical loop giving rise to Hertwig's epithelial root sheath, in human, mouse and rat molar tooth germs.
作者所作的组织学和分子生物学实验结果表明，人类、大鼠及小鼠磨牙牙胚中这种根尖末端特殊的结构与颈环区Hertwig上皮根鞘结构明显不同。
Periodontosis is one of middle-aged and elderly people's common diseases, its causes as follows, bacteria infection, damaging periodontosis, tooth damaging periodontosis etc, it can cause the hot toothache of wind, the stomach fire toothache, the empty fire toothache, pulpitis, apical periodontitis, tooth trough abscess, honeycomb inflammation, maxilla or mandibular osteomyelitis, tooth carbuncle, wisdom pericoronitis, noma, So investigating to epidemiology of periodontosis, prevent and cure positive meaning to health and medicine of human oral cavity.
牙周病是中老年人常见的疾病之一，它的患病原因有：细菌感染性牙周病，牙周损伤性牙周病，牙齿损伤性牙周病等，它可以引起风热牙痛、胃火牙痛、虚火牙痛、牙髓炎、牙周炎、牙槽脓肿、蜂窝组织炎、颌骨骨髓炎、牙痈、智齿冠周炎、牙疳、牙宣、根面口糜、口疮等。因此对牙周病的流行病学统计和调查，对人体口腔健康和药物防治有着积极的意义。牙周病；药物防治
Caries, pulpitis, and apical periodontitis increase health care costs and attendant loss of economic productivity. They ultimately result in premature tooth loss and therefore diminishing the quality of life.
龋病、牙髓炎和根尖周炎使维护健康的费用增高及其效用降低，并最终导致牙齿早期缺失降低生活质量。
Stem shallowly grooved, densely retrorse puberulent; leaves very broadly ovate to oblate-ovate, apex rounded, margin crenate-serrate, apical tooth acute; corolla reddish purple or white
茎具浅槽，浓密被微柔毛；卵形，先端圆形的叶宽卵形到扁球形的，边缘具圆齿有锯齿，锐尖的顶端齿；花冠红紫色或白色 71 Isodon latifolius 宽叶香茶菜
In present study, a large animal model, miniature pig was used, and we tested regeneration of periodontal bone defects and tooth root mediated by tooth related stem cells including periodontal ligament stem cells and stem cells from apical papilla.
本研究利用与人类牙颌系统相似的小型猪作为大型动物模型，首先分离培养小型猪牙周膜干细胞及根尖牙乳头干细胞，研究其生物学特性，并建立稳定可靠的牙周炎骨缺损模型，探讨牙周膜干细胞修复实验性牙周炎骨缺损的能力；同时利用牙周膜干细胞及根尖牙乳头干细胞复合生物支架材料进行生物牙根再生。
Shows the pathologic structure of decayed tooth, pulpitis, apical putrescence, paradentitis and apical abscess.
并显示正常牙、龋齿、牙髓炎、根尖坏死、牙周炎和根尖脓肿等病理过程。
Objective: To evaluate the capability of the apical tissue of rat molar to grow tooth root and periodontal tissue.
目的：探讨大鼠磨牙牙根根端组织发育牙根和牙周组织的能力。
Conclusion: Stem cells or dental epithelial progenitor cells might reside in the cervical loop of the apical end of the rat lower incisor. The present study may provide an excellent cell source for study on the differentiation of dental epithelial cells and tooth regeneration.
结论：鼠切牙唇侧颈环处可能存在牙源性上皮干细胞或前体细胞，为进一步研究牙源性上皮分化和牙组织工程提供细胞来源。
The discovery would possibly be beneficial to continuous development of the root of young permanent tooth with dental pulp necrosis and apical periodontitis after appropriate treatment.
这一发现可能有利于根尖未发育完成的年轻恒牙发生牙髓坏死以及由此引起的根尖周炎经适当的治疗后牙根的继续发育。
The effects of unilateral hyper-erupted third molar tooth on apical stress distribution of mandibular teeth by photoelastic analysis
第三磨牙伸长对下颌各牙根尖应力分布规律影响的光弹实验研究
[Objective] To investigate the Metergasis of physiology of mastication after loss of tooth for finding out the relation among sensory nerve, motor nerve of masseter muscle and central nerve around apical ligament.
目的：探讨牙齿丧失后，口腔咀嚼生理功能的变化，了解牙齿根尖周膜感觉神经与咀嚼肌运动神经，中枢神经的关系。
RESULTS: During tooth root patterning, expression of MSX1 was found not only in dental papilla of the apical area, dental sac and odontoblasts, but also in dental attachment apparatus such as cementoblast, periodontal supporting tissues and alveolar bone.
结果：在牙根发育不同时期内，MSX1mRNA不仅在牙乳头、牙囊组织及成牙本质细胞中有阳性表达，而且在牙附着组织，如成牙骨质细胞、上皮根鞘、牙周组织及根周牙槽骨组织中也有表达。
In the mandible, when the alveolar bone resorption reaches the apical 1/3 of canine (root length 4, 5 mm), if part of the tooth crown was removed, to make an acceptable crown/root ratio, so the canine can be used as the abutment of an overdenture.
下颌根周牙槽骨吸收至根尖1/3(根长约4～5 mm)的尖牙，在行截冠术和完善的牙体治疗后，如能保持合理的冠根比，即可用做覆盖义齿的基牙。
Developing apical complex is the growth regulating center of tooth root and periodontium development
发育期根端复合体是牙根牙周发育的生长调控中心
The magnitude of apical main stress also altered evidently with the change of tooth position and the difference mainly came from asymmetrical occlusion.
另外，随牙位的变化根尖主应力的大小也会发生显著变化，而且这种差异主要来自于不对称性咬合类型。