Feitosa D S, Marques M R, Casati M Z, Sallum E A, Nociti F H, de Toledo S
Department of Prosthodontics, Division of Periodontics, School of Dentistry at Piracicaba, State University of Campinas, Piracicaba, Brazil.
J Periodontal Res. 2009 Aug;44(4):472-8. doi: 10.1111/j.1600-0765.2008.01144.x. Epub 2009 Oct 22.
Recent studies have pointed to potentially periodontal risk indicators, however no information is available on the impact of changes in thyroid hormone levels on the progression of periodontitis and on the quality of alveolar bone. Thus, the aim of the present study was to evaluate histologically, in rats, the influence of thyroid hormones on the rate of periodontal bone loss resulting from ligature placement and on the quality of tooth-supporting alveolar bone.
Thirty-six male Wistar rats were randomly assigned to the following groups: healthy (control, n = 12), hypothyroidism (n = 12) and hyperthyroidism (n = 12). Once alterations were confirmed by total serum levels of triiodothyronine and thyroxine, ligatures were randomly placed around one of the first mandibular molars. Thirty days later, the animals were killed and specimens routinely processed for serial decalcified sections. The parameters assessed were periodontitis-related bone loss, quality of tooth-supporting alveolar bone and the number of cells positive for tartrate-resistant acid phosphatase (TRAP), a marker of bone resorption.
At the ligated sites, intergroup analysis revealed that hypothyroidism significantly increased the bone loss resulting from ligature-induced periodontitis (p = 0.02) and the number of TRAP-positive cells on the linear surface of bone crest (p = 0.01). In addition, no significant differences were detected regarding the quality of the bone (p = 0.24) or the number of TRAP-positive cells in the area of the interradicular bone for ligated teeth among the groups (p = 0.17).
It may be concluded that decreased serum levels of thyroid hormones may enhance periodontitis-related bone loss, as a function of an increased number of resorbing cells, whereas the tooth-supporting alveolar bone seems to be less sensitive to alterations in hormone levels.
近期研究指出了潜在的牙周风险指标，但关于甲状腺激素水平变化对牙周炎进展及牙槽骨质量的影响尚无相关信息。因此，本研究旨在通过组织学方法评估大鼠体内甲状腺激素对结扎所致牙周骨丧失速率以及牙齿支持性牙槽骨质量的影响。
36只雄性Wistar大鼠被随机分为以下几组：健康组（对照组，n = 12）、甲状腺功能减退组（n = 12）和甲状腺功能亢进组（n = 12）。通过血清总三碘甲状腺原氨酸和甲状腺素水平确认发生改变后，随机在下颌第一磨牙之一周围放置结扎线。30天后，处死动物并对标本进行常规处理以制作系列脱钙切片。评估的参数包括与牙周炎相关的骨丧失、牙齿支持性牙槽骨质量以及抗酒石酸酸性磷酸酶（TRAP）阳性细胞数量，TRAP是骨吸收的标志物。
在结扎部位，组间分析显示甲状腺功能减退显著增加了结扎诱导的牙周炎所致的骨丧失（p = 0.02）以及牙槽嵴线性表面TRAP阳性细胞数量（p = 0.01）。此外，各组间在骨质量（p = 0.24）或结扎牙齿根间骨区域TRAP阳性细胞数量方面未检测到显著差异（p = 0.17）。
可以得出结论，甲状腺激素血清水平降低可能会因吸收细胞数量增加而加剧与牙周炎相关的骨丧失，而牙齿支持性牙槽骨似乎对激素水平变化不太敏感。
