Orofacial Clefts

Page Links: Introduction, Incidence, Distribution of Facial Clefts, Accuracy Prenatal Diagnosis, Low-Risk Population, High-Risk Population, Ultrasound Scanning Technique, 3-D Ultrasound, MRI, Summary Orofacial Clefts, References

 

Introduction

39.CleftLip140.Cleftlip2.fw41.CleftLip3

Above. Types of orofacial clefts (cleft lip). Left. Unilateral incomplete cleft lip. Middle. Unilateral complete cleft lip. Right. Bilateral complete cleft lip. (Graphics: Originally from en.wikipedia; in Public Domain)

36.Cleftpalate1.fw37.Cleftpalate238.Cleftpalate3

Above. Types of orofacial cleft palate. Left. Unilateral complete cleft lip and palate. Middle. Bilateral complete cleft lip and palate. Right. Unilateral incomplete cleft palate. AR = alveolar ridge, HP=hard palate, SP=soft palate. (Graphics: Originally from en.wikipedia; in Public Domain)

Facial clefts are classified as cleft lip (CL), cleft lip and cleft palate (CLP), and cleft palate (CP).

Environmental and genetic factors may be responsible when errors in the developmental process occur, and these include failure to “fuse, merge or interact”. [1]

35.003.fw

Above. Facial clefts may be isolated or they may be associated with malformations, karyotype abnormalities and syndromes.

34.Distribution4

Above. Over 300 syndromes have been described with facial clefts, and the distribution according to the type of cleft is [2]: isolated cleft lip 25%, isolated cleft palate 25%, cleft lip and cleft palate 50%. This distribution has remained relatively constant over 4 decades.

 

Incidence

33.Template4

The incidence of cleft lip and palate is reported as 1.82 per 1000 live births [3] and 1.3 per 1000 live births [4] or approximately 1 in 500 to 1 in 1000 live births.

 

Distribution of Facial Clefts

33.Associas4

Above. In one study of 101 facial clefts among 49,314 deliveries, 57% of the facial clefts were isolated and among the 43% remaining clefts: 10% were associated with chromosomal aberrations, 12% syndromes or sequences, and 21% with structural malformations only. [5]

Associated malformations are more common in cleft lip with palate than with cleft lip alone (34% versus 20%), and there is a 1.7 male to female predominance among those with cleft lip and palate. [6]

32.Associa2s4

In a study of 6 million births, associated malformations were noted in 29.2% of CLP patients. About 27% of CLP patients will demonstrate 1 or more malformations. [7] Among infants with CL or CLP, heart, limb and central nervous system are the most common anomalies. [8] Among those with cleft lip with cleft palate, the left side of the face tends to predominant.

 

Accuracy of Prenatal Diagnosis

Low-Risk Population

31.detection2s4

In a systematic review of 421 studies, the accuracy varied widely with 2-D ultrasound for the prenatal diagnosis of cleft lip with or without cleft palate. Among low-risk populations’, the diagnostic accuracy varied from 9% to 73%, to detect any type of cleft. To detect cleft lip with or without cleft palate the diagnostic accuracy varied from 9% to 100% and to detect cleft palate alone, the diagnostic accuracy was 7%. [9] Cleft palate without the presence of cleft lip was rarely detected in the primary care setting unless there were a combined 2-D and 3-D ultrasound approach.

 

High-Risk Population

30.detection3d4

In that same review, improved rates of detection (60% to 100%) for cleft lip with or without cleft palate occurred when 3-D ultrasound was used in a tertiary care setting.

 

Ultrasound Scanning Technique

29.scan244
27.Parasagittal28.Parasagittal

Above. Planes of view for cleft lip, and cleft palate. Mid-line sagittal.

25.Approx.coronalaxial.view_26.Approx.coronalaxial.view_

Above. Planes of view for cleft lip and cleft palate.

To improve the detection rate of fetal clefts, the face should be viewed in 3 orthogonal planes (coronal, axial and sagittal). The detection rate can be increased from about 20% to 30% when one or two planes are used compared to 90% when all three planes are used. [10]

23.FN.midsagprofile24.FN.midsagprofile

Above. Mid-sagittal 2-D ultrasound view of the fetal head with nasal bone, nose and lips outlined.

21.Coronaluplipnose22.Coron.FN.midsagprofile - Copy

Above. The oblique coronal view demonstrates the visualization plane for the upper lip and nose.

18.FNaxial.midsagprofile - Copy19.FNaxial.midsagprofile - Copy

Above. The approximate axial or transverse view of the fetal maxilla and upper lip allows visualization of the lip, alveolar ridge, tooth buds and part of the hard palate.

Routine visualization of the fetal face and lip should be a part of the mid-trimester scan. Coronal views of the lips, tangential views of the maxillary alveolus and a profile view of the face should be part of the examination. [11],[12]

16.fn.Normal mouth17.fn.Normal mouth

Above. Normal oblique coronal view of the fetal upper lip and nose.

14.Fn.Coronal nose-mouth15.Fn2.Coronal nose-mouth

Above. Normal oblique coronal view of the fetal upper lip and nose.

In a 2-D examination, images are obtained in the anterior coronal plane and the probe is moved from the nose and the mouth to the edge of the lips, thus obtaining the classic nose-mouth view.

12.fn.Axialview cleft lip and palate13..fn.Axialview cleft lip and palate

Above. Axial view of cleft lip and cleft palate demonstrating the alveolar ridge with tooth buds and the hard palate.

Serial axial/transverse views allow visualization of the nose down through the mouth to the lower edge of the mandible, thereby allowing assessment of the upper alveolar ridge, palate, tongue and mandible. [13] Transvaginal ultrasound may be useful prior to 20 weeks.

With training and experience, the detection rate for facial clefts can be improved. [14] A new 2-D marker for the diagnosis of isolated cleft palate is termed the “equal sign” when a transverse plane images the uvula and soft palate, while a mid-sagittal plane assesses the soft palate and uvula. [15]

 

3-D Ultrasound

11.3d.mri

Current strategies suggest that 2-D ultrasound should be employed for screening, and when a cleft lip and/or palate are suspected, 3-D ultrasound should be the next step.

9.ad multiplanar10.3d multiplanar

Above. Note the 3 reference planes for a 3-D sample volume.

As noted previously, increased detection is possible with 3-D which includes the usual surface rendering and the orthogonal display permitting visualization in the three reference planes: sagittal, transverse and coronal. The transverse plane can identify the alveolus and palate by visualizing the front toot buds and alveolar ridge, and when the volume is slightly rotated the symmetry of the palate can be seen. [16] The surface rendering is useful in visually defining the defect.

7.fn3d244

Several techniques for 3-D ultrasound have been described and include the reverse view technique. [17] In the reverse view technique, the frontal plane is used to examine the fetal lips and alveolar ridge followed by a 180 degree rotation of the face on the vertical axis to examine the secondary palate.

5.3dplanesofview6.adplanesofview

Above. The planes in the reverse view technique are shown. The yellow arrow represents the frontal plane to examine the fetal lips and alveolar ridge, while a 180 degree rotation of the face allows the a view posterior to the face allowing views of the secondary plate and soft palate.

4.special3-d44

In the flipped face view [18], a 3-D static volume is acquired, which is rotated 90 degrees so the cut plane is mid-sagittal from the chin to the nose. Scrolling from the chin to the nose allows sequential visualization of the lower lip, mandible, alveolar ridge, tongue, upper lip, maxilla and alveolar ridge as well as the hard and soft palate.

In the oblique face view [19], the secondary palate is insonated at a 45 degree angle in the sagittal plane and 3-D ultrasound is reconstructed in the axial and coronal planes.

All three methods will visualize the upper lip and alveolar ridge [20], but with only 7 patients in a comparison study, it is difficult to render further judgment. A number of other 3-D ultrasound techniques are described, but none of those studies report detection of isolated cleft palate. [21]

 

Facial Clefts MRI

fetal facial clefts MRI

MRI may play a useful role in the evaluation of facial clefts following 2-D ultrasound screening. MRI confirmed the diagnosis of CLP in 16 of 25 fetuses in whom the diagnosis was made by 2-D ultrasound [22], but MRI’s greatest value was to define the extent of the cleft and to improve the morphologic study of the fetal facial bony anatomy. In another study conducted between 24 and 37 weeks, the positive predictive value of MRI for involvement of the palate was 96% and the negative predictive value was 80%. [23] MRI defines the primary and secondary plate and correlates well with postnatal or postmortem findings [24], but most of the studies have been conducted between 24 and 37 weeks and few reports demonstrate fetal examination at or below 20 weeks.

 

Orofacial Clefts:  Summary

 

2.Template3B

1.Summary1c.fw

1. The development of facial clefts is multifactorial.

2. Cleft lip accounts for 25%, cleft palate accounts for 25% and cleft lip with palate account for 50%.

3. The incidence is about 1 in 500 to 1 in 1000 live births.

4. About 57% of the facial clefts are isolated and the remainder are associated with chromosomal aberrations (10%), syndromes or sequences (12%), and structural malformations only (21%).

5. The antenatal 2-D ultrasound detection rate varies widely (9 to 100%) and cleft palate is rarely detected.

6. 3-D ultrasound in a tertiary care setting improves detection (60 to 100%).

7. If facial clefts are suspected on 2-D ultrasound, 3-D should ideally be performed.

8. 3-D includes the usual surface rendering and the orthogonal display permitting visualization in the three reference planes: sagittal, transverse and coronal.

9. A number of specialized techniques for 3-D ultrasound have been reported.

10. MRI at 24 to 37 weeks supports the diagnosis of facial cleft and is better able to define the extent of the defects compared to ultrasound.

 

References

Other topics:

Fetal Heart

Fetal Chest

Fetal Abdomen


 

    1
  1. Abstract: PMID: 11464997

    2
  2. Abstract: PMID: 4950925

    3
  3. Abstract: PMID: 3422598

    4
  4. Abstract: PMID: 11844160

    5
  5. Abstract: PMID: 18381773

    6
  6. Abstract: PMID: 17286264

    7
  7. Abstract: PMID: 11113886

    8
  8. Abstract: PMID: 19441124

    9
  9. Abstract: PMID: 20235140

    10
  10. Abstract: PMID: 8816530

    11
  11. Abstract: PMID: 11844160

    12
  12. Abstract: PMID: 24191520

    13
  13. Abstract: PMID: 22477739

    14
  14. Abstract: PMID: 18381773

    15
  15. Abstract: PMID: 20521240

    16
  16. Abstract: PMID: 22477739

    17
  17. Abstract: PMID: 15619313

    18
  18. Abstract: PMID: 17060428

    19
  19. Abstract: PMID: 17111460

    20
  20. Abstract: PMID: 19109803

    21
  21. Abstract: PMID: 22477739

    22
  22. Abstract: PMID: 21509548

    23
  23. Abstract: PMID: 20509765

    24
  24. Abstract: PMID: 20617504