Fetal Face and Neck

OB2

Branchial apparatus

characteristic external features of the head and neck area in the form of a series of branchial arches, pouches, grooves and membranes

resembles gills

separated by branchial grooves and composed of mesenchymal cells

How many branchial arches are there?

6 but 4 are visible externally

The mesenchyme forms the:

cartilages

bones

muscles

blood vessels

First branchial arch

aka mandibular arch

forms the jaw, zygomatic bone, ear, and temporal bone

The second branchial arch contributes to:

the hyoid bone

What does the neural crest cells form?

skeletal parts of the face

By the fifth week of development, five prominences are identified:

frontal nasal prominence

paired maxillary prominences of the first branchial arch

paired mandibular prominences

Maxillary prominences grow medially between what weeks?

fifth and eighth weeks

These two prominences fuse to form the upper lip

two medial nasal prominences and two maxillary prominences

Until 24-26 weeks gestation, stomodeum is:

separated from the pharynx by membrane that then ruptures to place the primitive gut in communication with the amniotic fluid

The nose is formed in these three parts

bridge of nose originates from the frontal prominence

two medial nasal prominences form crest and tip of nose

lateral nasal prominences form sides, or alae

The mandibular prominences merge at the end of these weeks to form the:

fourth to fifth weeks

lower lip

chin

mandible

Anomalies of the face affect:

1:600 births

The long view of the face demonstrates:

nasal bones

soft tissue

mandible

What is the long view of the face good to rule out?

micrognathia

anterior encephalocele

nasal bridge defects

examine the upper lip

The transverse view of the face demonstrates:

orbital anomalies

intraorbital distances

The transverse views of the face is good to evaluate

maxilla

mandible

tongue

Many fetuses with a facial defect also have:

chromosomal abnormalities

Extensive facial screening may be hindered by:

bone shadowing

poor fetal positioning

oligohydramnios

maternal obesity

Orbital fusion and a proboscis indicates:

alobar holoprosencephaly

Dysmorphology

the study of human congenital malformations and syndromes

Malformation sequence

process of poor formation of tissue allows for a chain reaction of defects to occur, as normal tissue is not a foundation

Deformation sequence

gives way to normal tissue development, however external factors contribute to secondary distortion or deformation

Disruption sequence

occurs when embryogenesis is disrupted by tissue breakdown or injury from a possible broad spectrum of opportunities including infectious, mechanical, vascular, or metabolic in origin

Questions to as when evaluating the face

are the orbits normally spaced?

are the nose and nasal bridge clearly imaged?

is a proboscis or cebocephaly present?

is the upper lip intact?

is the tongue normal size?

is the chin abnormally small?

are the ears normal size and position?

An anterior cephalocele may cause

hypertelorism

Frontal bossing

prominent forehead or heavy brow ridge and may be associated with a depression of the nasal bridge

Encephaocele

rare neural tube defects characterized by a protrusion of the brain and membranes that cover it through an opening or defect of the skull

often accompanied by other craniofacial abnormalities

Hemangiomas are MOST COMMONLY found where

the head and face (80%)

Craniofacial microsomia

refers to the underdevelopment or the lack of full development of the anatomical structures on one side of the head and face

Craniosynostosis

premature fusion of any or all six of the cranial structures

Cloverleaf skull

aka Kleeblattschadel skull

appears as a misshapen skull and is associated with skeletal dysplasias (dwarfism) and ventriculomegaly

MOST COMMON abnormality that is noted with trisomy 21

small or absent nasal bone

Nuchal area

association of first trimester nuchal lucency with aneuploidy and is well established

fetuses with diffuse fetal nuchal fluid and hydrops involving the torso have a high prevalence of abnormalities and poor outcomes

To exclude a cleft lip and palate look for:

nostril symmetry

nasal septum integrity

continuity of the upper lip

Tumors that may disrupt facial contours

epignathus

teratoma

Agnathia

absence of the mandible

If the fetus has an abnormally small chin, why could polyhydramnios occur?

the inability to swallow

Jaw index

AP mandibular length / BPD x 100

3 categories mandible pathology fits into

chromosomal abnormalities (trisomy 18)

skeletal dysplasias

primary disorders (Pierre Robin syndrome)

Primary mandible disorders

Pierre Robin Syndrome

Treacher Collins syndrome

Goldenhar syndrome

anopthalmia and hemifacial microsomia

Eye and orbit masses

lacrimal duct cysts

dermoids

congenital teratomas

hemangiomas

Hypotelorism is associated with

holoprosencephaly

microcephaly

craniosynostoses

Phenylketonuria (PKU)

ethmocephaly

cebocephaly

cyclopia

Ethmocephaly

proboscis separating narrow-set eyes with an absent nose and micropthalmia

Cebocephaly

two separate eyes set close together and a small flat nose with a single nostril

Hypertelorism is found with

frontal cephaloceles

Pfeiffer syndrome

apert syndrome

frontonasal dysplasia

Crouzon syndrome

dephalosyndactyly

acrocephalopolysyndactyly

Modified coronal view of the mid-face demonstrates the

nostrils

nasal septum

Evaluation of the nasal triad should assess

nostril symmetry

nasal septum integrity

continuity of the upper lip to exclude cleft lip and palate

Midface hypoplasia

results from an underdevelopment or maldevelopment of the middle structures of the face

Binder syndrome

maxilla- nasal dysplasia that affects the anterior aspect of the maxilla and nasal complex

Sono appearance of Binder syndrome

flattened and retruded nose

half-moon shaped nostrils

short, columella, an acute nasolabial angle, resulting in a concave midfacial profile

MOST COMMON congenital anomaly of the cranioface

cleft lip with or without cleft palate

Cleft lip with or without cleft palate is MORE COMMON in

males

Cleft palate isolated is MORE COMMON in

females

Contributing actors to orofacial clefting predispositions

geographic factors

race, family history

sex

exposure to risk factors during pregnancy

viral infections

drugs and presence of teratogens at the workplace or home

Which side is cleft lip MORE COMMON to appear on?

left side

HIghest prevalence of cleft lip is in this ethnicity

Native Americans and Asian populations

Frontonasal dysplasia

median - cleft face syndrome consisting of a range of midline facial defects involving the eyes, forehead, and nose

Frontal dysplasia abnormalities

ocular hypertelorism

variable bifid nose

brood nasal bridge

midline defect of frontal bone

extension of frontal hairline to form the widow’s peak

Tongue protrusion is associated with

Trisomy 21

Beckwith-Wiedmann syndrome

Congenital ranulas

rare retention cystic masses caused by mucous retention which originates at the base of the oral cavity located within the sublingual and submandibular ducts

Epignathus

teratoma located at the oropharynx

swallowing may be impaired

MOST COMMON neck mass

cystic hygroma colli

Other rare neck lesions

cervical meningomyocele

hemangiomas

teratomas

goiter

sarcoma

metastatic adenopathy

When maternal thyroid disease is present

check fetal thyroid

Graves disease MOST COMMON cause

MOST COMMON location for a cystic hygroma

posterior

Fetal heart failure COMMONLY results in

intrauterine death

Cystic hygroma differential diagnosis

meningomyocele

encephalocele

nuchal edema

branchial cleft cyst

cystic teratoma

hemangioma

thyroglossal duct cyst