Improvement in early detection of orofacial clefts using the axial view of the maxilla

An effective ultrasound fetal palate screening software based on the "sequential sector scan through the oral fissure" and three-dimensional ultrasound

BACKGROUND

Orofacial clefts are one of the most common congenital malformations of the fetal face and ultrasound is mainly responsible for its diagnosis. It is difficult to view the fetal palate, so there is currently no unified standard for fetal palate screening, and the diagnosis of cleft palate is not included in the relevant prenatal ultrasound screening guidelines. Many prenatal diagnoses for cleft palate are missed due to the lack of effective screening methods. Therefore, it is imperative to increase the display rate of the fetal palate, which would improve the detection rate and diagnostic accuracy for cleft palate. We aim to introduce a fetal palate screening software based on the "sequential sector scan though the oral fissure", an effective method for fetal palate screening which was verified by our follow up results and three-dimensional ultrasound and to evaluate its feasibility and clinical practicability.

METHODS

A software was designed and programmed based on "sequential sector scan through the oral fissure" and three-dimensional ultrasound. The three-dimensional ultrasound volume data of the fetal face were imported into the software. Then, the median sagittal plane was taken as the reference interface, the anterior upper margin of the mandibular alveolar bone was selected as the fulcrum, the interval angles, and the number of layers of the sector scan were set, after which the automatic scan was performed. Thus, the sector scan sequential planes of the mandibular alveolar bone, pharynx, soft palate, hard palate, and maxillary alveolar bone were obtained in sequence to display and evaluate the palate. In addition, the feasibility and accuracy of the software in fetal palate displaying and screening was evaluated by actual clinical cases.

RESULTS

Full views of the normal fetal palates and the defective parts of the cleft palates were displayed, and relatively clear sequential tomographic images and continuous dynamic videos were formed after the three-dimensional volume data of 10 normal fetal palates and 10 cleft palates were imported into the software.

CONCLUSIONS

The software can display fetal palates more directly which might allow for a new method of fetal palate screening and cleft palate diagnosis.

Cleft Lip and Cleft Palate: Time to Include Orofacial Ultrasound Markers Into the First-Trimester Anatomy Scan?

Orofacial clefts are one of the most common congenital malformations. The prenatal diagnosis is often made in the second trimester of pregnancy as result of ultrasound examination of the midface on coronal and axial planes. However, the diagnosis in the first trimester is elusive due to the small size of the facial structures and technical limitations present at this early gestational age. In this Commentary, we suggest the routine systematic ultrasound identification of easy-to-obtain landmarks to improve the detection of cleft lip and cleft palate in the first trimester. These include, but are not limited to, visualization of the primary palate using the coronal plane of the face looking for disruption at the base of the retronasal triangle, and visualization of the palate using the sagittal plane looking for the maxillary gap and loss of the superimposed line. Early prenatal detection of orofacial clefts would allow a more detailed search for associated chromosomal anomalies or genetic syndromes.

The performance of first-trimester ultrasound in diagnosing fetal cleft palate: Meta-analysis and systematic review

OBJECTIVE

This system review and meta-analysis was aim to evaluate the accuracy of prenatal ultrasound in diagnosing cleft palates (CPs) during first trimester.

DATA SOURCE

We systematically searched the databases of PubMed, Embase, and Cochrane Library for the articles, which assessed the accuracy of CPs diagnosed by ultrasound during first trimester.

REVIEW METHOD

The characteristics of the included studies were recorded. The quality of included studies was assessed by QUADAS-2. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under the curve (AUC) were calculated using Meta-Disc software version 1.4. The publication bias was assessed by Stata software version 12.0.

RESULTS

This meta-analysis included 13 studies with 39 806 fetuses. The pooled sensitivity, specificity, PLR, NLR were 0.874, 0.999, 689.84, and 0.161, respectively. The DOR and AUC were 6651.3 and 0.9084, respectively.

CONCLUSION

The overall detection rate was 0.874, which indicated high value of first trimester ultrasound in diagnosing CPs.

A feasible method to evaluate fetal palate: sequential sector-scan through oral fissure

BACKGROUND

Prenatal diagnosis of cleft palate is still challenging. To describe a practical and efficient method, sequential sector-scan through oral fissure (SSTOF), to evaluate palate.

METHODS

According to the characteristics of the fetal oral anatomy and ultrasonic directivity, we designed a practical method, sequential sector-scan through oral fissure, to evaluate the fetal palate, and the approach was verified efficiently by following up results of those fetuses with orofacial cleft who were induced because of their accompanied lethal malformations. Then, the 7098 fetuses were evaluated using sequential sector-scan through oral fissure. Fetuses were followed up after birth or induction to validate and analyze prenatal diagnosis.

RESULT

According to the scanning design, sequential sector-scan through oral fissure was performed successfully from the soft palate to the upper alveolar ridge in induced labor fetuses, and the structures were displayed clearly. Among 7098 fetuses, satisfactory images were obtained for 6885 fetuses and the remaining 213 fetuses' images were unsatisfactory because of fetuses' positions and pregnant women with high BMI. Among 6885 fetuses, 31cases were diagnosed CLP or CP, which were confirmed after delivery or termination. There were no missing cases.

CONCLUSIONS

SSTOF is a practical and efficient method to diagnose cleft palate, which might be applied to evaluate the fetal palate in prenatal diagnosis.

Absent 'superimposed-line' sign: novel marker in early diagnosis of cleft of fetal secondary palate

OBJECTIVES

To describe a novel sign, the 'superimposed-line' sign, for early diagnosis of cleft of the fetal secondary palate on two-dimensional imaging of the vomeromaxillary junction in the midsagittal view.

METHODS

This was a prospective evaluation of the superimposed-line sign using two-dimensional sonography (midsagittal view) in 9576 singleton fetuses referred for routine screening between 12 and 20 weeks of gestation. In this view, the vomer bone appears as a line superimposed on the distal two-thirds of the maxillary line, as the vomer fuses with the secondary palate in the midline. If there is a midline cleft of the secondary palate, the line formed by the palate is absent and hence only the vomer bone is visualized, creating a single line instead of the normal superimposed double line. Multiplanar three-dimensional (3D) views were assessed in cases in which the superimposed-line sign was absent.

RESULTS

The superimposed line was absent in 17 fetuses with a cleft of the secondary palate that was confirmed by 3D evaluation. Of these, 13 had defects involving the premaxilla and four had an isolated cleft of the secondary palate. Postnatal confirmation was available in all cases. The sign was useful in ruling out cleft of the fetal secondary palate in 32 high-risk cases with a family history of cleft palate. The superimposed-line sign had a sensitivity of 89.5% in detecting cleft of the secondary palate.

CONCLUSIONS

The superimposed-line sign is a new sonographic marker for evaluation of cleft of the fetal secondary palate; documentation of this sign proves the presence of both the palate and vomer in the midline. This marker can be demonstrated clearly in the late first trimester, allowing early diagnosis of secondary palatine cleft. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.