Study on the effects of periodontal mechanoreceptors on maintenance of the system regulating jaw-movement and the regenerative medicine for the system

为了揭示牙周输入在咀嚼系统发育和维持中的一般作用，我们在出生后30 ~ 360天对ICR小鼠的下牙槽神经（IAN）进行了辣根过氧化酶-小麦胚芽凝集素示踪方法，并在出生后第20天进行了单侧拔牙处理和未处理。出生后第20天提取Toot后，三叉神经感觉核复合体（TSNC）标记的TG、Me5神经元和标记末梢数量减少。此外，一些神经营养因子已被检查以评估其在神经发育以及周围和中枢神经系统（CNS）再生中的功能。在一些实验模型中，酸性和碱性成纤维细胞生长因子（FGF）似乎对神经死亡具有拯救作用。预期，在拔牙窝内单次注射aFGF可以恢复受拔牙影响的Me5、TG神经元和TSNC的初级传入终端。从目前的结果来看，由于缺牙导致的感觉输入减少导致咀嚼系统发育和维持障碍，aFGF可能是挽救这一现象的有效试剂之一

To reveal the general role of the periodontal afferent in the development and maintenance of the masticatory system, the horseradish peroxidase-wheat germ agglutinin tracing method was applied from 30 to 360 days after birth to the inferior alveolar nerve (IAN) of ICR mice with or without treatment of the unilateral extraction of molars on the 20th postnatal day. Toot extraction on the 20th postnatal day decreased the numbers of labeled TG and Me5 neurons and labeled terminals of trigeminal sensory nuclear complex (TSNC}. Furthermore, several neurotrophic factors have been examined for assessing their functions in neural development as well as in the regeneration of peripheral and central nervous system (CNS). Particularly, acidic and basic fibroblast growth factor (FGF)s seem to have rescue effects on neural death in several experimental models. Expectedly, single injection of aFGF into the tooth-extracted socket restored the Me5, TG neurons and the primary afferent terminals of the TSNC affected by the tooth-extraction. From the present results, it is suggested that the decrease in the sensory input due to the tooth-loss cause the disorder of the development and maintenance of the masticatory system and aFGF may be at least one of potent reagents to rescue this phenomenon