Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Orthod Craniofac Res. 2020 Aug;23(3):342-350. doi: 10.1111/ocr.12376. Epub 2020 Apr 12.
The role of oestrogen in craniofacial growth still remains unclear. Therefore, the present study aimed to assess the effect of oestrogen deficiency on maxilla and mandible dimensions.
The study was conducted at the Department of Pediatric Dentistry at the School of Dentistry of Ribeirão Preto, University of São Paulo, and used forty female Wistar rats.
Ovariectomy (OVX) and placebo surgery (Sham) were performed when animals were twenty-one days old (prepubertal stage). Dimensions of the maxilla and mandible were assessed by craniometric analysis using radiographs, during and after puberty of the animals (45 and 63 days old, respectively). Quantitative real-time PCR and immunohistochemical analyses were performed to determine the expression and localization, respectively, of oestrogen receptor alpha (ERα) and oestrogen receptor beta (ERβ) in different growth sites of the evaluated structures at puberty. The differences between the groups for each outcome were evaluated using the t test with an established alpha error of 5%.
There were significant differences between the OVX and Sham groups for horizontal and vertical linear measurements in the maxilla and the mandible at both pubertal and post-pubertal stages (P < .05). The ovariectomized rats showed significantly greater measures for all dimensions assessed. No differences in gene expression of ERα and ERβ were identified at the different growth sites between the OVX and Sham groups (P > .05). Immunohistochemical analyses revealed the presence of both oestrogen receptors in osteoblasts and chondrocytes in the midpalatal suture and mandibular condyle, respectively, in the OVX and Sham groups.
Our results suggest that oestrogen deficiency from the prepubertal stage might increase the growth of the maxilla and mandible in female rats.
雌激素在颅面生长中的作用仍不清楚。因此，本研究旨在评估雌激素缺乏对上颌骨和下颌骨尺寸的影响。
该研究在圣保罗大学里贝朗普雷托牙科学院儿科牙科系进行，使用了四十只雌性 Wistar 大鼠。
当动物 21 天时（青春期前阶段）进行卵巢切除术（OVX）和安慰剂手术（Sham）。通过在动物青春期（分别为 45 和 63 天）期间和之后的放射影像学颅测分析评估上颌骨和下颌骨的尺寸。进行定量实时 PCR 和免疫组织化学分析，以确定青春期时评估结构的不同生长部位中雌激素受体 alpha（ERα）和雌激素受体 beta（ERβ）的表达和定位。使用 t 检验比较每组的差异，设定 5%的 α 错误。
在青春期和青春期后阶段，OVX 和 Sham 组之间上颌骨和下颌骨的水平和垂直线性测量均存在显著差异（P<.05）。去卵巢大鼠的所有评估维度的测量值均显著更大。在 OVX 和 Sham 组之间，不同生长部位的 ERα 和 ERβ 基因表达没有差异（P>.05）。免疫组织化学分析显示，OVX 和 Sham 组的中缝骨和下颌骨髁突的成骨细胞和软骨细胞中均存在两种雌激素受体。
我们的结果表明，青春期前阶段的雌激素缺乏可能会增加雌性大鼠上颌骨和下颌骨的生长。
