Cleft Lip & Palate imaging

CLEFT LIP & PALATE IMAGING

Fetal facial anomalies may be isolated, but most facial abnormalities are associated with more complex fetal malformation syndromes or abnormal karyotypes.

, when a fetal anomaly is detected,or in high-risk

pregnancies a careful ultrasonographic evaluation of the fetal face may also contribute to a specific diagnosis.

• EMBRYOLOGY

• Facial development begins at about four to five menstrual weeks and is almost complete by the end of the embryonic period, at about 10 menstrual weeks .

• the embryo has acquired all its basic morphologic characteristics before the face has attained adequate size to permit ultrasonographic examination.

• Most malformations of the face originate from anomalous development of the branchial apparatus, optic vesicles, pharyngeal pouches, and facial prominences, as listed by days after fertilization

ULTRASONOGRAPHIC APPROACH TO THE FETAL FACE AND NORMAL ANATOMY

identified as early as 11 to12 menstrual weeks; but it is usually not until 14 to16 menstrual weeks that the ultrasonographer can observe more detailed facial

• the following views should be obtained:I. Axial views of the orbits, nose, lips, anterior palate, tongue, and

oropharynxII. Coronal views of the orbits, nose, lips, maxilla, and anterior

portion of the mandibleIII. Profile view of soft tissues and facial bones, including the

nasal bones and mandibleiv. Views of the ears

a targeted ultrasonographic examination of the face may be particularly useful :

• In pregnancies complicated by polyhydramnios, concomitant extrafacial/structural anomalies, a maternal history of teratogen exposure, or a family history of previous craniofacial malformation (e.g., facial cleft)

Visibility may be limited in the presence of oligohydramnios, maternal obesity, or fetal position, especially in the occiput anterior position

• three-dimensional ultrasonography (3DUS) has the potential to offer clearer visualization and understanding of fetal facial anatomy.

• 3DUS offers the potential advantage of improving visualization of anatomic spatial relations, which is particularly important

• Ultrasonographic evaluation also may serve as an indicator of fetal well-being and behavioral changes

• For example, fetal vomiting or regurgitation can be identified by watching the fetal mouth, using colorflow imaging to indicate regurgitation in fetuses with upper gastrointestinal obstruction

• The sensitivity of ultrasound screening for facial defects in unselected populations has not yet been determined

• technologic innovations have improved the accuracy of detecting these abnormalities

• Cleft lip with or without cleft palate is the most common congenital malformation involving the face.

• Although often associated, cleft lip and cleft palate are embryologically and etiologically distinct malformations, originate at different times during development, and involve different developmental processes .

• Cleft lip and cleft palate may be incomplete or complete, unilateral or bilateral,lateral or midline, and symmetric or asymmetric.

• The incidence of cleft lip and palate is about 1 per1000 live births in the white population .

• a higher prevalence among Asians (1.5–2.0 per 1000) and

• Native Americans (3.6 per 1000) and a lower frequency among African-Americans (0.5 per 1000).

• About 80% of infants with cleft lip also have cleft palate

• There is a high incidence of chromosomal abnormalities among fetuses with facial clefts, in particular trisomy 13 and 18 .

• Siblings of patients with cleft lip with or without cleft palate have an increased frequency of cleft lip with or without cleft palate, but not of cleft palate alone;

• whereas siblings of patients with cleft palate alone have an increased frequency of cleft palate but not of cleft lip with or without cleft palate .

• Cleft lip with or without cleft palate affects male fetuses twice as frequently as females;

• , cleft palate alone affects males 25%less than female fetuses.

Recurrent RiskAffected relative Risk in child, percent

Cleft lip with or without cleft palate

Parent 2%

Sibling 4 – 7%

Parent and Sibling 11 – 14%

Two Siblings 10%

Cleft palate only

Parent 7%

Sibling 2 – 5%

Parent and sibling 14 – 17%

EtiologyGenes

• Control cell patterning, cell proliferation, extracellular communication, and differentiation

• Clefting usually represents a genetically complex event• Single Mendelian disorders associated with clefting are

rare• 2 to 20 genes are thought to interact to result in facial

clefting

Some Common Associations, Malformations, and Syndromes Associated with Cleft Lip and Palate

• Familial• Chromosomal abnormalities• Trisomy 13/Trisomy 18/Trisomy 21/Trisomy 22/XXXXY syndrome/Various

translocations/Triploidy• Autosomal-dominant, autosomal-recessive, and x-linked/cleft syndromes• Multiple syndromes

• Nongenetic cleft syndromes• Amniotic band syndrome• Anencephaly• Congenital heart disease• Holoprosencephaly• Encephaloceles• Medial cleft face syndrome• Congenital oral teratoma

Environmental agents

• Several agents that are associated with an increased frequency of midfacial malformation.

• Medications —phenytoin, sodium valproate, methotrexate.

• With corticosteroids there is no evidence of an increase in malformations.

Etiology• Cigarette smoking

• Noted with mothers of children with facial clefting, both CL/P and CP.

• Alcohol • Associated with an increased risk of fetal facial clefting. • Alterations in cell membrane fluidity or reduced activity

of specific enzymes such as superoxide dismutase.• Folate deficiency

• Contributes to a range of birth defects. • Evidence is emerging for a similar association with the

development of CL/P.

classified clefts into one of five categories.• Type I: cleft lip alone• Type II: unilateral cleft lip and palate• Type III: bilateral cleft lip and palate• Type IV: midline cleft lip and palate• Type V: facial defects associated with amniotic bands or

limb–body wall complex

• Cleft lip with or without cleft palate results from failure of fusion of the maxillary prominence with the medial nasal prominence on one or both sides at about the seventh week of development.

• The palate forms from the fusion of the primary and secondary palates between the fifth and the 12th weeks.

• The secondary palate is the primordium of the remainder of the hard and soft palates and contains the remainingb tooth sockets. It consists of two lateral palatine processes that extend medially and that progressively fuse in the midline from anterior to posterior

• . When development is complete, the line of fusion between the primary and thesecondary palates runs in an arch-like configuration.

• Perpendicular to this in the midline, the fusion line of the secondary palate extends from the incisive foramen anteriorly to the uvula posteriorly.

Unilateral incomplete

Unilateral complete

Bilateral complete

Incomplete cleft palate

Unilateral complete lip and palate

Bilateral complete

• Unilateral Cleft Lip/Unilateral Cleft Lip and Palate

• This may reflect the difficulty in diagnosis and the fact that evaluation of the face is not routine in low-risk obstetric ultrasonography

• Most clefts detected prenatally with ultrasound are not subtle and tend to be large.

Typical ultrasound features include :• an anechoic region in the upper lip just lateral to

the midline, which extends to the nares with a unilateral cleft lip and palate).

• a flattened appearance to the affected side, with widening of the nostril and communication between the nostril and the mouth).

• nose with a hooked appearance.• A gap in the maxilla and palate.• can be identified as early as 16 weeks’ gestation,• the incomplete cleft lip may be considerably more

subtle and not as easily visualized until late in the second or third trimester of pregnancy

• The incomplete cleft is visualized best in the coronal view of the lip.

Prenatal Diagnosis

• Bilateral Cleft Lip and Palate• identified ultrasonographically before

16 weeks’ gestation • premaxillary protrusion,,. The

paranasal echogenic mass represents protruding bone and alveolar structures within the premaxillary protrusion. The mass typically is inferior to the nose, irregular in shape, and of similar echogenicity to bone and alveolar structures.

• categorized bilateral cleft lip and palate into those with premaxillary protrusion and those with a hypoplastic midface.

• Premaxillary protrusion is most apparent on midline sagittal views but can also be seen on coronal or transverse views (81).

The differential diagnosis for premaxillary protrusion includes the following:

oAnterior cephalocele• Hemangioma• Teratoma• Enlarged protruding tongue• Proboscis (associated with holoprosencephaly)

Cleft Palate• Isolated cleft palate is much more difficult to observe and

diagnose ultrasonographically and is frequently missed on prenatal sonograms cleft palate may remain difficult.

• These investigators noted that the ability to visualize the anatomy of the hard palate decreased with advancing gestational age;

• ultrasonographic assessment should be made before 24 weeks’ gestation. With advancing gestational age,

• If a cleft lip is detected, coronal frontal scans obtained more posteriorly and axial views may demonstrate

`Features suggestive of cleft palate include:• cleft lip, maxillary interruption, and increased tongue

excursion .• Color Doppler ultrasound evaluation of the study of

nonvascular slow amniotic fluid flow into the nasal andbuccal cavities may be considered a useful diagnostic aid in identification of fetal palate defects

• stomach and polyhydramnios may be ultrasonographic clues that the fetus has cleft palate

Median Cleft Lip• The median cleft lip and palate, or

premaxillary agenesis, is the rare form and occurs

• primarily in association with two syndromes: the median cleft face syndrome (frontonasal dysplasia) and the holoprosencephaly complex

• This 3D image demonstrates midline cleft lip and palate (curved• arrow) with hypotelorism and small or near absent nares in this fetus with• alobar holoprosencephaly. O, orbits.

The ultrasonographic findings:

• a gaping midline cleft lip and palate and a hypoplastic midface characterized by a flattened nose and maxilla

• These fetuses have a poor prognosis;

• More than half of affected fetuses in this series had either trisomy 13 or trisomy 18.

• Amniotic Band Syndrome• also known as the amniotic band

disruption complex or limb–body wall complex

• , is a common, usually sporadic cause of various fetal malformations involving the craniofacial region, limbs, and trunk.

• It is estimated to occur in one in 1200 live births

• ranging from mild deformities to severe anomalies that are incompatible with postnatal life

Ultrasonographic Findings• Detection of bizarre facial clefts in unusual locations

warrants a careful search for other manifestations of the amniotic band syndrome

• These include asymmetric encephalocele, gastropleuroschisis, asymmetric amputations, and focal constrictions with distal lymphedema

• The facial problems can include cleft lip and occasionally cleft palate, asymmetric microphthalmia, and severe nasal deformity

• Sequelae of the amniotic band syndrome may be observed as early as 12 to 13 weeks’ gestation on endovaginal examination

• Identification of a band is not necessary to make the diagnosis, and a diagnosis of amniotic band syndrome• should never be made on observation of these bands in

the absence of fetal deformities because several types of membranes may be seen in normal pregnancies

• . detected as a manifestation of a syndromehe frequency and type of chromosomal abnormality varied with the type of cleft.

• The highest rate of chromosomal abnormalities was found in median clefts, which were dominated by trisomy 13.

• Trisomy 13 is associated with cleft lip and cleft palate or isolated cleft palate in 60% of cases.

• Forty percent of cases with trisomy 18 have cleft lip with or without cleft palate.

• in about 0.5% of cases with trisomy 21 and• , and chromosome analysis should be considered especially

when the clefts are known to be associated with a high risk for chromosome abnormalities (types II to IV).

Associated Findings and Prognosis

• Associated Findings and Prognosis

• Most cases of cleft lip and cleft palate diagnosed prenatally have been detected as a manifestation of a syndrome

• importance of identifying the specific type of facial cleft, owing to the strong correlation between the type of facial cleft and both mortality rate and frequency of additional fetal anatomic and chromosomal

• Kraus et al found a 60% incidence of associated anomalies, most commonly clubfoot and polydactyly.