Neuschulz J, Wilhelm L, Christ H, Braumann B
Department of Orthodontics, University of Cologne Medical School, Kerpener Str. 32, 50931, Cologne, Germany,
J Orofac Orthop. 2015 Jan;76(1):30-40. doi: 10.1007/s00056-014-0257-1. Epub 2015 Jan 22.
Micro- and retrognathia of mandibular origin may lead to life-threatening respiratory problems in connection with glossoptosis immediately after birth. Prenatal screening for this malformation is therefore increasingly important. Today this is accomplished by predominantly subjective standards. Objective criteria have been proposed but have not become established. We therefore made an effort to develop indices that would identify major skeletal discrepancies or micrognathia in as straightforward a fashion as possible during routine prenatal sonography.
Series of fetal jaw sonograms (Toshiba Aplio MX®) were obtained in 313 women with normal pregnancies from weeks 19-29 of gestation. Upper- and lower-jaw landmarks were interactively located on screen and evaluated for reproducibility. Linear parameters representative of maxillary and mandibular length (SpA'-SpP' and Rami-SymMe) were measured and related to femur length and gestational age. Based on these data, indices for maxillary, and mandibular length were derived and analyzed.
High correlations were identified for mandibular length both with gestational age (R = 0.845; R(2) = 0.713) and with femur length (correlation coefficients (R) = 0.839; coefficients of determination (R(2)) = 0.704). For maxillary length, the respective correlation coefficients were 0.691 (R(2) = 0.477) and 0.656 (R(2) = 0.430). Estimates of mandibular and maxillary length based on gestational age and femur length were obtained by regression analysis. The mean bimaxillary length ratio was 0.628 ± 0.043.
Maxillary and mandibular growth can be objectively evaluated via indices. It is conceivable to develop this approach into a sensitive and reliable method of prenatal jaw screening for major skeletal anomalies and congenital malformations.
下颌源性小颌畸形和后缩畸形在出生后可能会立即导致与舌后坠相关的危及生命的呼吸问题。因此，对这种畸形进行产前筛查变得越来越重要。如今，这主要通过主观标准来完成。虽然已经提出了客观标准，但尚未确立。因此，我们努力开发一些指标，以便在常规产前超声检查期间以尽可能直接的方式识别主要的骨骼差异或小颌畸形。
从313名妊娠19 - 29周的正常孕妇中获取一系列胎儿颌部超声图像（东芝Aplio MX®）。上下颌的标志点在屏幕上交互式定位，并评估其可重复性。测量代表上颌和下颌长度的线性参数（SpA'-SpP'和下颌支 - 颏下点），并将其与股骨长度和孕周相关联。基于这些数据，得出并分析上颌和下颌长度的指标。
下颌长度与孕周（R = 0.845；R² = 0.713）以及与股骨长度（相关系数（R）= 0.839；决定系数（R²）= 0.704）之间均存在高度相关性。对于上颌长度，相应的相关系数分别为0.691（R² = 0.477）和0.656（R² = 0.430）。通过回归分析获得基于孕周和股骨长度的下颌和上颌长度估计值。双颌长度的平均比值为0.628±0.043。
上颌和下颌的生长可以通过指标进行客观评估。可以想象，将这种方法发展成为一种用于产前颌部筛查主要骨骼异常和先天性畸形的敏感且可靠的方法。
