Department of Obstetrics and Gynecology, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
PLoS One. 2022 Jun 1;17(6):e0269095. doi: 10.1371/journal.pone.0269095. eCollection 2022.
To determine the normal distribution of 1) inferior facial angles (IFA), 2) jaw index, 3) mandible width/maxilla width ratio (MD/MX ratio), and 4) mandible length (ML) in second trimester Thai fetuses.
A prospective study was performed between April 1 and October 31, 2020, at the Maternal-Fetal Medicine Unit of Songklanagarind Hospital. Transabdominal ultrasonography was performed on Thai singleton pregnant women at 150/7 to 236/7 weeks of gestation to measure IFA, jaw index, MD/MX ratio and ML. All women received standard antenatal care and were followed up until delivery. The exclusion criteria were multifetal gestation, congenital anomaly, chromosomal abnormality, fetal growth restriction, abnormal amniotic fluid volume, suspected abnormality of fetal mandible, maxilla or jaws based on the proposed criteria from previous studies and suspected neonatal structural or genetic abnormalities postnatally. Quantile regression was used to estimate changes in the median, 5th and 95th percentiles of each parameter across gestational ages and to generate formulas for predicting the 5th percentile value for each parameter.
The results of 291 women were analyzed. Scatter plots and reference ranges of each parameter were generated. IFA, jaw index and ML values significantly increased, while the MD/MX ratio value significantly decreased, with increasing gestational age. The formulas calculated for predicting the 5th percentile value for each parameter were IFA = 55.12 + 0.045*(GA in days-136) jaw index = 37.272 + 0.01693*(GA in days-136) MD/MX ratio = exp(0.027-0.00110*(GA in days-136)) ML = 20.83 + 0.243*(GA in days-136).
The reference ranges and formulas to calculate the 5th percentile values of mandible parameters in Thai fetuses were developed.
This study has been reviewed and approved by the Thai Clinical Trials Registry with identification number TCTR20210602003.
确定 1）下颌角（IFA）、2）颌指数、3）下颌骨宽度/上颌骨宽度比（MD/MX 比）和 4）下颌骨长度（ML）在泰国胎儿中期的正常分布。
这是一项前瞻性研究，于 2020 年 4 月 1 日至 10 月 31 日在宋卡那格欣医院母胎医学科进行。对 150/7 周至 236/7 周妊娠的泰国单胎孕妇进行经腹超声检查，以测量 IFA、颌指数、MD/MX 比和 ML。所有妇女均接受标准产前检查，并随访至分娩。排除标准为多胎妊娠、先天性异常、染色体异常、胎儿生长受限、羊水异常、根据以往研究提出的标准怀疑胎儿下颌、上颌或颌骨异常、怀疑新生儿结构或遗传异常。使用分位数回归估计每个参数的中位数、第 5 百分位和第 95 百分位在不同胎龄的变化，并生成预测每个参数第 5 百分位值的公式。
对 291 名妇女的结果进行了分析。生成了每个参数的散点图和参考范围。IFA、颌指数和 ML 值随着胎龄的增加而显著增加，而 MD/MX 比随着胎龄的增加而显著降低。为预测每个参数的第 5 百分位值而计算的公式为 IFA=55.12+0.045*(GA in days-136)，颌指数=37.272+0.01693*(GA in days-136)，MD/MX 比=exp(0.027-0.00110*(GA in days-136))，ML=20.83+0.243*(GA in days-136)。
制定了泰国胎儿下颌骨参数的参考范围和计算第 5 百分位值的公式。
该研究已由泰国临床试验注册中心审查和批准，注册号为 TCTR20210602003。
