Normal Range of Inferior Facial Angle (IFA) During the First Trimester to the Diagnosis of Micrognathia

Author(s):

Ladan Younesi Asl, Ayda Roostaee*, Samaneh Azimi Souteh, Ghazaleh Amjad and Zeinab Safarpour Lima

Introduction: Fetal facial malformations such as micrognathia, maxillary dysplasia, cleft lip and palate, as well as absence of nasal bone have been defined to be associated with some chromosomal abnormalities or genetic syndrome. Ultrasonography can show these parameters exactly. Proper imaging allows medical staff and radiologists to better examine the anatomy of the fetal face and make a more accurate diagnosis. The current study aimed at establishing the reference range for IFA and analyzing its association with fetal micrognathia during the first trimester.

Materials & Methods: This cross-sectional study was performed on pregnant women with a gestational age of 18 to 28 weeks referred to Shahid Akbarabadi Hospital in Tehran. After visiting, informations including age of mother and gestational age was recorded. Then results of ultrasonography test was registered. After childbirth, infants were examed and assigned in to one of the 2 groups. After that, records of IFA were analyzed in both groups.

Results: In the present study, 329 eligible mothers included in the study. We recorded their information and IFA of their fetus. Average age of mothers was determined 30/996/20. Furthermore, gestational age ranged from 17 w+3 d to 27 w. Moreovere, minimum and maximum of IFA were 48 and 79, respectively. Average of IFA was also recorded to be 60/865/69. 2 of the fetuses had abnormality after birth (IFAs 48 and 49). This study showed a significant association of IFA with abnormality of mandible after birth and abnormality of mandible in fetus with lower IFA was found to be more probable.

Conclusion: Our results showed an average of 60/865/69 for IFA, indicating that average of IFA in Iranian fetuses is less than most of the world. This study also revealed a significant association of IFA with abnormality of mandible after birth, Howevere, comprehensive studies with large abnormal samples are nedeed to assess fetuses with lower IFA.