OP02.05: The nasofrontal angle can help to identify palate involvement in fetuses with facial clefts

Abstract

It is often difficult to differentiate between a facial cleft with and without palate involvement. We measured the nasofrontal angle (NFA) in fetuses with facial clefts in order to investigate usability of this angle to diagnose cleft palate. We measured the NFA (angle between the nasal and the frontal bones in the midsagittal plane) in volumes of second and third trimester fetuses with facial clefts. EJP and MH measured the NFA twice, blinded for each other's results. The mean of the 4 measurements was used for analysis and compared with a reference range derived from 109 normal fetuses in an earlier study (EJP et al. UOG 2017;50:297). In these normal fetuses the NFA did not change significantly with gestational age with a mean of 117° (10th and 90th centile, were 105° and 129° respectively). In the present study we excluded fetuses with a midline, atypical or isolated palate cleft, a genetic condition or suspicion for a forehead anomaly. Fetuses with a facial cleft were divided in a cleft lip group (CL), a unilateral cleft lip-alveolus group (UCLA), a unilateral cleft lip-alveolus-palate group (UCLAP) and a bilateral cleft lip-alveolus-palate group (BCLAP). We used Student's T-test and Mann-Whitney U tests and considered P < 0.05 statistically significant. 34 volumes were suitable for analysis (mean gestational age: 24.4 wks, range: 18-41 wks). In 9 UCL, 4 UCLA, 11 UCLAP and 10 BCLAP fetuses the mean NFA was 123.4°(SD 4.4), 120.2°(SD 8.8), 128,8°(SD 4.8) and 128.2°(SD 4.5) respectively. In all groups the NFA was larger than in the normal group, however only in the UCLAP and BCLAP group the differences were significant. The NFA in UCLAP + BCLAP fetuses was also significant larger than the NFA in CL + UCLA fetuses. When a facial cleft includes the palate the NFA is significantly larger than when the palate is intact. NFA measurement can increase confidence in the diagnosis of a cleft palate in fetuses with facial clefts. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.