BGDB Face and Ear - Abnormalities

From Embryology
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Practical 6: Trilaminar Embryo | Early Embryo | Late Embryo | Fetal | Postnatal | Abnormalities | Quiz


Pharyngeal Abnormalities

There are terms for the different types of pharyngeal abnormalities, all of these except clefting are relatively rare.

  • Sinuses - a pharyngeal groove defect, when a portion of the groove persists and opens to the skin surface, located laterally on the neck.
  • Fistula - a pharyngeal membrane defect, a tract extends from pharynx (tonsillar fossa) beween the carotid arteries (internal and external) to open on side of neck.
  • Cysts -a cervical sinus defect, remants of the cervical sinus remains as a fluid-filled cyst lined by an epithelium.
  • Vestiges - a cartilaginous or bony developmental remnants that lie under the skin on side of neck.
  • Clefting - the way in which the upper jaw forms from fusion of the smaller upper prominence of the first pharyngeal arch leads to a common congenital defect in this region called "clefting", which may involve either the upper lip, the palate or both structures.

Embryo Cleft Lip and Palate

Embryonic clefting, ventral view (stage16)

Cleft lip and palate develop between the 4th and 8th week of gestation and is dominated by changes resulting in the formation of the nose. Palatal development occurs between the 7th and 12th week of gestation and is divided into the formation of the primary palate (prolabium), premaxilla and cartilaginous septum) and formation of the secondary palate (hard and soft palate).

300+ different abnormalities different cleft forms and extent upper lip and ant. maxilla hard and soft palate

These are listed as two separate abnormalities as they occur at different developmental times and two processes of patale formation.

Embryonic

Primary palate, fusion in the human embryo between week 6-7 (GA Week 8-9, stage 17 and 18), maxillary component of the first pharyngeal arch and the frontonasal prominence (philtrum) fuse from an epithelial seam to the mesenchymal bridge.

Fetal

Secondary palate, fusion in the human embryo in week 9-10 (GA week 11-12). Maxillary component of the first pharyngeal arch form lateral palatal shelves in the oral cavity that grow, elevation and fuse during this early fetal period. The fusion event is to both each other and the primary palate.

Fetal Cleft Ultrasound Movies

Cleft lip 01.jpg

Cleft lip 02.jpg
 ‎‎Cleft Lip 15 Week
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Cleft lip 01.jpg
 ‎‎Cleft Lip 18 Week
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Movie shows a cleft lip in an 13 week (GA 15 weeks) fetus. Movie shows a cleft lip in an 18 week fetus. Fetal facial clefting can be detected by ultrasound scans. A common form of facial abnormality is that of cleft lip and palate. This is associated with the way in which the maxillary processes of the first pharyngeal arch must grow and fuse.

A measurement of the facial cleft of 4.8 mm (between the 2 plus marks + +)

Clefting

Cleft Palate - Australia (1981-1992)[1]

The way in which the upper jaw forms from fusion of the smaller upper prominence of the first pharyngeal arch leads to a common congenital defect in this region called "clefting", which may involve either the upper lip, the palate or both structures. Most clefting can be surgically repaired postnatally, though cleft lip and palate generates feeding and nutrition issues related to the inability of forming a "liquid seal" and separation of the respiratory space from the oral space. There are specially developed feeding devices for babies with cleft lip and palate.

Cleft Lip and Palate Classification

unilateral incomplete - cleft on one side of the lip that does not extend into the nose. unilateral complete - cleft on one side of the lip that extends into the nose. bilateral complete - cleft that involves both sides of the lip and extends into and involves the nose.

Stage16 cleft palate

Cleft Lip

Australian Palate Abnormalities (2002-2003)[2]

Bilateral cleft lip and palate.
Cleft lip with or without cleft palate (9.2 per 10,000 births) ICD-10 Q36.0, Q36.1, Q36.9, Q37.0–Q37.5, Q37.8, Q37.9
A congenital anomaly characterised by a partial or complete clefting of the upper lip, with or without clefting of the alveolar ridge or the hard palate. Excludes a midline cleft of the upper or lower lip and an oblique facial fissure (going towards the eye).
  • 17% of the affected pregnancies were terminated in early pregnancy or resulted in fetal deaths. Most of the fetal deaths or terminations of pregnancy (95%) had multiple abnormalities.
  • more commonly seen in males than in females.
  • babies born before 25 weeks of gestation, 150 per 10,000 births had this anomaly. Most babies (80.0%) were born at term with a birthweight of 2,500 grams or more.
  • Maternal age group was not associated with the anomaly.
  • Rates significantly higher among Indigenous women than non Indigenous women.
Australian Palate Abnormalities (2002-2003)  
Cleft lip with or without cleft palate (9.2 per 10,000 births) ICD-10 Q36.0, Q36.1, Q36.9, Q37.0–Q37.5, Q37.8, Q37.9
A congenital anomaly characterised by a partial or complete clefting of the upper lip, with or without clefting of the alveolar ridge or the hard palate. Excludes a midline cleft of the upper or lower lip and an oblique facial fissure (going towards the eye).
  • 17% of the affected pregnancies were terminated in early pregnancy or resulted in fetal deaths. Most of the fetal deaths or terminations of pregnancy (95%) had multiple abnormalities.
  • more commonly seen in males than in females.
  • babies born before 25 weeks of gestation, 150 per 10,000 births had this anomaly. Most babies (80.0%) were born at term with a birthweight of 2,500 grams or more.
  • Maternal age group was not associated with the anomaly.
  • Rates significantly higher among Indigenous women than non Indigenous women.
Cleft palate without cleft lip (8.1 per 10,000 births) ICD-10 Q35.0–Q35.9
A congenital anomaly characterised by a closure defect of the hard and/or soft palate behind the foramen incisivum without a cleft lip. This anomaly includes sub-mucous cleft palate, but excludes cleft palate with a cleft lip, a functional short palate and high narrow palate.
  • overall rate has increased to 9.1 when the rate was estimated using data from the four states that include TOP data. The reported number of fetal deaths or early terminations of pregnancy with this anomaly was small and these deaths or terminations could be due to other associated anomalies.
  • proportion of females with this anomaly was higher (56.9%) than males.
  • 52.7 per 10,000 babies born before 25 weeks of gestation.
  • 83.0% were born at term and most of the babies (82.7%) had a birthweight of 2,500 grams or more.
  • Women aged 40 years or older and women born in South Central America or the Caribbean region had the highest rates of affected births.
  • Multiple births had a significantly higher rate of affected babies than singleton births.
  • Rates did not differ significantly by Indigenous status or areas of residence.
Links: Palate Development | Head Development | Gastrointestinal Tract - Abnormalities | ICD-10 GIT | Australian Statistics
Reference: Abeywardana S & Sullivan EA 2008. Congenital Anomalies in Australia 2002-2003. Birth anomalies series no. 3 Cat. no. PER 41. Sydney: AIHW National Perinatal Statistics Unit.

Cleft Palate

Cleft palate
Cleft palate feeder
Cleft palate without cleft lip (8.1 per 10,000 births) ICD-10 Q35.0–Q35.9
A congenital anomaly characterised by a closure defect of the hard and/or soft palate behind the foramen incisivum without a cleft lip. This anomaly includes sub-mucous cleft palate, but excludes cleft palate with a cleft lip, a functional short palate and high narrow palate.
  • overall rate has increased to 9.1 when the rate was estimated using data from the four states that include TOP data. The reported number of fetal deaths or early terminations of pregnancy with this anomaly was small and these deaths or terminations could be due to other associated anomalies.
  • proportion of females with this anomaly was higher (56.9%) than males.
  • 52.7 per 10,000 babies born before 25 weeks of gestation.
  • 83.0% were born at term and most of the babies (82.7%) had a birthweight of 2,500 grams or more.
  • Women aged 40 years or older and women born in South Central America or the Caribbean region had the highest rates of affected births.
  • Multiple births had a significantly higher rate of affected babies than singleton births.
  • Rates did not differ significantly by Indigenous status or areas of residence.
Incomplete Cleft Palate Complete Cleft Palate
Cleft palate 001.jpg Cleft palate 002.jpg
Involving only the soft palate and uvula Completely involving the secondary palate


Palate Links: palate | cleft lip and palate | cleft palate | head | Category:Palate

Genetic - First Arch Syndrome

Pierre Robin sequence

There are 2 major types of genetic first arch syndrome, Treacher Collins and Pierre Robin, both result in extensive facial abnormalites.

Treacher Collins syndrome (TCS)

  • a rare autosomal dominant craniofacial disorder (1:50.000)
  • caused by frameshift deletions or duplications in the TCOF1 gene.
  • hypoplasia of the mandible and zygomatic complex
  • down-slanting palpebral fissures
  • coloboma of the lower eyelid
  • absence of eyelashes medial to the defect
  • external and middle ear malformation
  • conductive hearing loss
Links: Medline Plus - Pierre Robin Syndrome | Medline Plus - Treacher Collins Syndrome

Environmental - Fetal Alcohol Syndrome (FAS)

FASface.jpg

The following facial features may be associated with FAS

  • Microcephaly - leads to small head circumference
  • Palpebral fissure - short opening of eye
  • Epicanthal folds - fold of skin at inside of corner of eye
  • Midface - flat
  • Nasal Bridge - low
  • Philtrum - Indistinct, vertical grooves between nose and mouth
  • Upper Lip - thin
  • Micrognathia - small jaw
  • Ears - curve at top part of outer ear is underdeveloped and folded over parallel to curve beneath. Gives the appearance of a "railroad track"
Fetal Alcohol Syndrome face appearance

Environmental - Infections

A range of prenatal and perinatal viral and bacterial infections can seriously impact upon development of sensory systems, including both hearing and vision. In addition, some medications have been shown to be ototoxic, particularly for the newborn.


Links: Rubella Virus | Cytomegalovirus | TORCH Infections

Auricular Abnormalities

Pre-auricular fistulae and appendage locations.jpg


Additional Information

Additional Information - Content shown under this heading is not part of the material covered in this class. It is provided for those students who would like to know about some concepts or current research in topics related to the current class page.

Branchial Anomalies

Branchial anomalies in children: A report of 105 surgical cases[3] "Branchial anomalies (BAs) account for 20% of all congenital masses in children. We sought to review the incidence of involvement of individual anomalies, diagnostic methods, surgical treatment, and complications of BAs in children. ...A total of 33 (31.4%) cases presented with first BAs, 13 (12.4%) presented with second BAs, and 59 (56.2%) presented with third and fourth BAs, including 6 cases of congenital lower neck cutaneous fistula."

Mid-facial Developmental Defects

Mid-facial Defects[4] "Despite the advances in human genome sequencing technology, the causes of nearly 70% of all birth defects, which include midfacial development defects, remain unknown."

Hearing Loss

Mammalian auditory hair cells do not spontaneously regenerate, once damaged or lost they are not replaced. Hearing loss due to the loss of hair cells is permanent.


Global Orofacial Cleft Rate (1950 - 2015)
This data is from a study of the published data (1950 - 2015)[5]
Continent Orofacial cleft rate /1,000 live births (95% confidence interval)
Asia 1.57 (1.54-1.60)
North America 1.56 (1.53-1.59)
Europe 1.55 (1.52-1.58)
Oceania 1.33 (1.30-1.36)
0.99 (0.96-1.02)
Africa 0.57 (0.54-0.60)
  • American Indians 2.62 per 1,000 live births (highest prevalence rates)
  • Japanese 1.73
  • Chinese 1.56
  • Whites 1.55
  • Blacks 0.58 (lowest prevalence rates)


Cephalic Disorders

Cephalic (Greek, kephale = head) are a group of abnormalities that relate to a wide range of skeletal (skull) and neural (brain) associated defects. Listed below are some selected skull defects.

  • Acephaly (absence of head)
  • Exencephaly (brain outside skull)
  • Macrocephaly (large head)
  • Micrencephaly (small brain)
  • Otocephaly (absence of lower jaw)
  • Brachycephaly (premature fusion of coronal suture)
  • Oxycephaly, also known as turricephaly (premature fusion of coronal suture + other)
  • Plagiocephaly (premature unilateral fusion of coronal or lambdoid sutures)
  • Scaphocephaly, also known as dolichocephaly (premature fusion of sagittal suture)
  • Trigonocephaly (premature fusion of metopic suture)
Abnormal Neonatal Skull (CT)
Skull CT abnormal 01.jpg

Scaphocephaly (Dolichocephaly)

Skull CT abnormal 02.jpg

Coronal Synostosis

Skull CT abnormal 03.jpg

Anterior Plagiocephaly

Skull CT abnormal 04.jpg

Oxycephaly (Turricephaly)

Skull CT abnormal 05.jpg

Posterior Plagiocephaly

Skull CT abnormal 06.jpg

Deformational Plagiocepahly

Skull CT abnormal 07.jpg

Trigonocephaly

Skull CT abnormal 08.jpg

Oxycephaly

Skull CT Images: Normal overview | Normal vertex and lateral | Normal endocranial and vertex | Normal Vertex - Fontanels | Dolichocephaly and Scaphocephaly | Coronal Synostosis | Anterior Plagiocephaly | Turricephaly | Posterior Plagiocephaly | Deformational Plagiocepahly | Trigonocephaly | Oxycephaly | Computed Tomography
Links: head abnormalities | Skull Abnormal Synostosis | hearing abnormalities | vision abnormalities

Surgical Cleft Repairs

Palatoplasty Cheiloplasty
Surgical repair of the palate Surgical repair of the lip
Cleft palate 003.jpg Cleft lip 007.jpg
Cleft Palate Cleft Lip and Palate
Palate Links: palate | cleft lip and palate | cleft palate | head | Category:Palate

Adult skull cleft palate


Ventral view of adult skull showing cleft palate.

Adult Skull Cleft Palate Images: skull unlabeled | skull with labeled excerpt | skull overlaying excerpt

References

  1. P. Lancaster and E. Pedisich, Congenital Malformations Australia 1981-1992, ISSN 1321-835.
  2. Abeywardana S & Sullivan EA 2008. Congenital Anomalies in Australia 2002-2003. Birth anomalies series no. 3 Cat. no. PER 41. Sydney: AIHW National Perinatal Statistics Unit.
  3. Li W, Xu H, Zhao L & Li X. (2018). Branchial anomalies in children: A report of 105 surgical cases. Int. J. Pediatr. Otorhinolaryngol. , 104, 14-18. PMID: 29287855 DOI.
  4. Suzuki A, Sangani DR, Ansari A & Iwata J. (2016). Molecular mechanisms of midfacial developmental defects. Dev. Dyn. , 245, 276-93. PMID: 26562615 DOI.
  5. Vipawee Panamonta, Suteera Pradubwong, Manat Panamonta, Bowornsilp Chowchuen Global Birth Prevalence of Orofacial Clefts: A Systematic Review. J Med Assoc Thai: 2015, 98 Suppl 7;S11-21 PubMed 26742364

Terms

Head Terms (expand to view) 
  • branchial arch - see pharyngeal arch.
  • clefting - the way in which the upper jaw forms from fusion of the smaller upper prominence of the first pharyngeal arch leads to a common congenital defect in this region called "clefting", which may involve either the upper lip, the palate or both structures, see palate and head abnormalities.
  • coronal suture - skull term for the fibrous connective tissue joint that connects the frontal bone with the parietal bones.
  • cranial fossae - skull term for the base bones of the cranial vault that form a container and support for the brain.
  • cranial vault - skull term for the space formed by bones of the skull that enclose the brain.
  • cysts - refers to a cervical sinus abnormality, remants of the cervical sinus remains as a fluid-filled cyst lined by an epithelium, see pharyngeal arch and head abnormalities.
  • dolichocephaly - see scaphocephaly.
  • fistula - refers to a pharyngeal membrane abnormality, a tract extends from pharynx (tonsillar fossa) beween the carotid arteries (internal and external) to open on side of neck, see pharyngeal arch and head abnormalities.
  • lambdoid suture (lambdoidal suture) skull term for the fibrous connective tissue joint that connects the parietal bones with the occipital bone, and is continuous with the occipitomastoid suture.
  • metopic suture - skull term for the fibrous connective tissue joint that connects the two fontal bones. In the adult skull this suture is not always present.
  • oxycephaly - (turricephaly) term meaning premature fusion of coronal suture + others, see skull and head abnormalities.
  • pharyngeal arch - (branchial arch) a structure that forms in the cranial region of the embryo having contributions from all germ layers. In humans, the arches appear in week 4 (GA week 6) in a rostra-caudal sequence and are numbered (1, 2, 3, 4, and 6). Each arch contributes a different part of the head and neck and the associated components.
  • pharyngeal cleft - (groove) surface ectoderm that externally separates each pharyngeal arch. In humans, only first pair persist as the outer ear external auditory meatus.
  • pharyngeal groove - see pharyngeal cleft.
  • pharyngeal membrane - surface ectoderm and pharynx endoderm contact region lying between each pharyngeal arch. In humans, only the first membrane pair persist as the tympanic membrane.
  • pharyngeal pouch - pharynx endoderm internal out-pocketing that separates each pharyngeal arch.
  • plagiocephaly - term meaning premature unilateral fusion of coronal or lambdoid sutures, see skull and head abnormalities.
  • Reichardt's cartilage - (pharyngeal arch 2 cartilage) The superior portion of the hyoid forms the ventral portion of this cartilage and the middle ear stapes is thought to form from the ends of this cartilage.
  • sagittal suture - skull term for the fibrous connective tissue joint that connects the two parietal bones in the midline.
  • scaphocephaly - (dolichocephaly) term meaning premature fusion of sagittal suture, see skull and head abnormalities.
  • sinuses - refers to a pharyngeal groove (cleft) abnormality, when a portion of the pharyngeal groove persists and opens to the skin surface, located laterally on the neck, see pharyngeal arch and head abnormalities.
  • squamosal suture - skull term for the fibrous connective tissue joint that connects the squamous portion of the temporal bone with the parietal bones.
  • suture - skull term for a fibrous connective tissue joint. In humans, the main sutures are coronal, sagittal, lambdoid and squamosal sutures, with the metopic suture (frontal suture) occurring as an anatomical variant in the adult skull.
  • turricephaly - see oxycephaly.
Other Terms Lists  
Terms Lists: ART | Birth | Bone | Cardiovascular | Cell Division | Endocrine | Gastrointestinal | Genetic | Head | Hearing | Heart | Immune | Integumentary | NeonatalNeural | Oocyte | Palate | Placenta | Radiation | Renal | Respiratory | Spermatozoa | Statistics | Ultrasound | Vision | Historic | Drugs | Glossary
Palate Development (expand to see terms)  
  • cleft - An anatomical gap or space occuring in abnormal development in or between structures. Most commonly associated with cleft lip and cleft palate. Term is also used to describe the external groove that forms between each pharyngeal arch during their formation.
  • cleft lip - An abnormality of face development leading to an opening in the upper lip. Clefting of the lip and or palate occurs with 300+ different abnormalities. Depending on many factors, this cleft may extend further into the oral cavity leading to a cleft palate. In most cases clefting of the lip and palate can be repaired by surgery.
  • cleft palate - An abnormality of face development leading to an opening in the palate, the roof of the oral cavity between the mouth and the nose. Clefting of the lip and or palate occurs with 300+ different abnormalities. In most cases clefting of the lip and palate can be repaired by surgery. Palate formation in the embryo occurs at two distinct times and developmental processes called primary and secondary palate formation. This leads to different forms (classifications) and degrees of clefting.
  • hard palate - anterior part of the palate that becomes ossified. The posterior palate part is the soft palate.
  • epithelial mesenchymal transition - (EMT, epitheliomesenchymal transformation) conversion of an epithelium into a mesenchymal (connective tissue) cellular organization. Process required during lip and palate developmental fusion.
  • epitheliomesenchymal transformation - (epithelial mesenchymal transition) conversion of an epithelium into a mesenchymal (connective tissue) cellular organization.
  • incisive papilla - anterior midline palate near the incisors lying at the end of the palatine raphe.
  • levator veli palatini - Muscle forming part of the soft palate, elevates the soft palate for swallowing.
  • mastication - (chewing) Process of crushing and grinding food within the mouth.
  • maxilla - (pl. maxillae) upper jaw bone forming from the maxillary process of the first pharyngeal arch.
  • medial edge epithelial - (MEE) opposing palatal shelves adhere to each other to form this epithelial seam.
  • musculus uvulae Small muscle forming part of the soft palate lying within the uvula, shortens and broadens the uvula.
  • palatine raphe (median raphe) palate midline ridge (seam) of the mucosa, from the incisive papilla to the uvula.
  • palatal rugae - (palatine rugae, rugae) Transverse series of ridges forming on the secondary hard palate that are sequentially added during development as the palate grows. Involved in the process of mastication.
  • palatal vault - (palatine vault) Term describing the curved "arch" shape of the palate that mainly develops postnatally.
  • palate - The roof of the mouth (oral cavity) a structure which separates the oral from the nasal cavity. Develops as two lateral palatal shelves which grow and fuse in the midline. Initally a primary palate forms with fusion of the maxillary processes with the nasal processes in early face formation. Later the secondary palate forms the anterior hard palate which will ossify and separate the oral and nasal cavities. The posterior part of the palate is called the soft palate (velum, muscular palate) and contains no bone. Abnormalities of palatal shelf fusion can lead to cleft palate.
  • palatine bones - Two bones that with the maxillae form the hard palate.
  • palatogenesis - The process of palate formation, divided into primary and secondary palate development.
  • palatoglossus - (glossopalatinus, palatoglossal muscle) Small muscle forming part of the soft palate required for swallowing.
  • palatopharyngeus - (palatopharyngeal or pharyngopalatinus) Small muscle forming part of the soft palate required for breathing.
  • pharyngeal arch - (branchial arch, Greek, branchial = gill) These are a series of externally visible anterior tissue bands lying under the early brain that give rise to the structures of the head and neck. In humans, five arches form (1,2,3,4 and 6) but only four are externally visible on the embryo. Each arch has initially identical structures: an internal endodermal pouch, a mesenchymal (mesoderm and neural crest) core, a membrane (endoderm and ectoderm) and external cleft (ectoderm). Each arch mesenchymal core also contains similar components: blood vessel, nerve, muscular, cartilage. Each arch though initially formed from similar components will differentiate to form different head and neck structures.
  • philtrum - (infranasal depression, Greek, philtron = "to love" or "to kiss") Anatomically the surface midline vertical groove in the upper lip. Embryonically formed by the fusion of the frontonasal prominence (FNP) with the two maxillary processes of the first pharyngeal arch. Cleft palate (primary palate) occurs if these three regions fail to fuse during development. Fetal alcohol syndrome is also indicated by flatness and extension of this upper lip region.
  • soft palate - (velum, muscular palate) posterior part of the palate that becomes muscular. Forms 5 muscles: tensor veli palatini, palatoglossus, palatopharyngeus, levator veli palatini, musculus uvulae. The anterior palate part is the hard palate.
  • T-box 22 - (TBX22) a transcription factor that cause X-linked cleft palate and ankyloglossia in humans. Tbx22 is induced by fibroblast growth factor 8 (FGF8) in the early face while bone morphogenic protein 4 (BMP4) represses and therefore restricts its expression. (More? OMIM - TBX22)
  • tensor veli palatini - (tensor palati, tensor muscle of the velum palatinum) Small muscle forming part of the soft palate required for swallowing.
  • Transforming Growth Factor-beta - (TGFβ) factors induces both epithelial mesenchymal transition and/or apoptosis during palatal medial edge seam disintegration.
  • uvula - (Latin = a little grape) a pendulous posterior end of soft palate used to produce guttural consonants. First named in 1695.
  • Van der Woude syndrome - common syndromic cause of clefting (2% of cleft lip and palates). Van der Woude syndrome 1 1q32.2 Van der Woude syndrome 2 1p36.11
  • velopharyngeal insufficiency - (VPI) associated with cleft palate repair, describes the velum and lateral and posterior pharyngeal walls failing to separate the oral cavity from the nasal cavity during speech.
Other Terms Lists  
Terms Lists: ART | Birth | Bone | Cardiovascular | Cell Division | Endocrine | Gastrointestinal | Genetic | Head | Hearing | Heart | Immune | Integumentary | NeonatalNeural | Oocyte | Palate | Placenta | Radiation | Renal | Respiratory | Spermatozoa | Statistics | Ultrasound | Vision | Historic | Drugs | Glossary
Hearing Terms  
Hearing and Balance Development
  • altricial animal - Term used to describe an animal born in a helpless state, with incomplete development of sensory systems at birth. For example rats and mice are born with incomplete development of visual and auditory systems. (More? Animal Development)
  • ampulla - Term used to describe an anatomical dilation of a tube or canal lumen. Anatomical description of the opening end of the uterine tube lying above the ovary and the enlarged initial segmeny of the semicircular canals of the inner ear vestibular system. (More? inner ear)
  • aneurism - (Greek, aneurysma = a widening, aneurysm) A term used to describe an abnormal widening of a vessel or anatomical tubal structure.
  • aquaeductus vestibuli - see vestibular aqueduct (More? inner ear)
  • auditory neuropathy - (AN) abnormality of transmission of sound information to the brain.
  • auditory tube - (eustachian tube) between the middle ear and oral cavity, has a bony (tympanic 1/3) and cartilaginous (pharyngeal 2/3) portion. The main role is equalization of pressure and fluid drainage in the middle ear. (More? middle ear)
  • auricular hillock - see hillock (More? middle ear)
  • atresia - narrowing, usually of an anatomical tube or cavity.
  • autophagocytosis - (Greek, auto = self, phagy = eating, also called autophagy) a cell death mechanism that uses the cell's own lysosomes to self digest.
  • border cells - columnar cells within the organ of Corti on the medial portion of the basilar membrane. (More? inner ear)
  • canalis reuniens - (ductus reuniens, canaliculus reuniens, canalis reuniens, Hensen's canal, Hensen's duct, uniting canal, canalis reuniens of Hensen) short narrow canal connecting the cochlea duct to the saccule. (Victor Hensen, 1835-1924) (More? inner ear)
  • cerumen - (ear wax) produced by glands in the skin of the outer portion of the ear canal. (More? Outer Ear)
  • chondrified - the developmental differentiation of cartilage from mesenchye, an embryonic connective tissue.
  • cristae ampullaris - located in the ampulla of the membranous semicircular canals a region with both supporting and hair cells. The hair cell cilia are embedded in the gelatinous cupula. (More? inner ear)
  • claudius cells - (cells of Claudius) columnar cells with microvilli overlying the basilar membrane and extend from Hensen's cells to the spiral prominence. Barrier cells that lie external to the organ of corti in endolymph. (More? inner ear)
  • cochlear sac - embryonic structure, which will form the coiled cochlear duct and contribute to the saccule. (More? inner ear)
  • cochlear aqueduct - a bony channel containing the fibrous periotic duct. It connects the basal turn of the cochlea perilymphatic space with the subarachnoid space of the posterior cranial cavity. (More? inner ear)
  • cochlin - major constituent of the inner ear extracellular matrix. (More? inner ear)
  • collagen type II - major constituent of the inner ear extracellular matrix. (More? inner ear)
  • conductive loss - term used to describe one of the two major classes of hearing loss involving external and middle ear abnormalities (other form is Sensorineural loss).
  • connexins - channel proteins of the gap junctions that allow rapid communication between adjacent cells. The two connexins Cx26 and Cx30 are the major proteins of cochlear gap junctions.
  • connexin 26 - A strikingly high proportion (50%) of congenital bilateral nonsyndromic sensorineural deafness cases have been linked to mutations in the GJB2 coding for the connexin26
  • cupular deposits - basophilic material on the cupulae of the semicircular ducts, an postnatal ageing phenomenon seen in some vestibular labyrinth. (More? inner ear)
  • clinical weeks - taken from last menstrual period (LMP) and therefore approximately two weeks before fertilization occurs.
  • Deiters' cells - (outer phalangeal cells)
  • discoidin domain receptor 1 - (DDR1) a tyrosine kinase receptor activated by native collagen, expressed in the basement membrane and with fibrillar collagens. Found in basal cells of the stria vascularis, type III fibrocytes, and cells lining the basilar membrane of the organ of Corti. {Meyer zum Gottesberge, 2008 #1877}
  • ductus utriculosaccularis - (More? inner ear)
  • endochondral ossification - the process of bone formation from a pre-existing cartilage template. (More? middle ear)
  • endoderm - One of the initial 3 germ cell layers (ectoderm, mesoderm and endoderm) formed by the process of gastrulation. The endoderm forms as a cuboidal epithelium and contributes not only to the trilaminar embryo, but also lines the yolk sac. It will form the entire epithelial lining of the gastrointestinal tract (GIT), contribute to the accessory organs of GIT and also forms the epithelial lining of the respiratory tract.
  • endolymphatic fluid - (endolymph, Scarpa's fluid) fluid that fills all the membranous labyrinth of the inner ear, except for the cochlea scala tympani and scala vestibuli which are filled with perilymph.
  • endolymphatic sac - inner ear structure that has anatomically both an intraosseous and extraosseous component. Th e sac has functions regulating endolymph that are both secretory and absorptive. Also the site of endolymphatic sac tumors either sporadical occurring or associated with the autosomal-dominant von Hippel-Lindau (VHL) disease, due to a germ line mutation. (More? inner ear)
  • embryological weeks - taken from the time of fertilization which typically occurs around the middle (day 14), or just after, of the typical 28 day menstrual cycle. (More? Embryonic Development)
  • Emx2 - homeobox gene affecting middle ear and inner ear development.
  • eustachian tube - (auditory tube) A cavity linking the pharynx to the middle ear, which develops from the first pharyngeal pouch. Named after Bartolomeo Eustachi (1500 - 1574) an Italian anatomist. (More? middle ear)
  • external auditory meatus - (ear canal) develops from the first pharyngeal cleft. (More? Outer Ear)
  • espins - calcium-resistant actin-bundling proteins enriched in hair cell stereocilia and sensory cell microvilli and spiral ganglion neurons (SGNs)
  • eustachian tube - (auditory tube) between the middle ear and oral cavity, equalization of pressure in the middle ear. (More? middle ear)
  • external auditory meatus - (EAM, ear canal) cavity connecting the external ear to the tympanic membrane. The adult human ear canal is about 2.5 cm long and 0.7 cm in diameter. (More? Outer Ear)
  • fenestra ovalis - (oval window) separates the tympanic cavity from the vestibule of the osseous labyrinth. (More? inner ear)
  • fenestra rotunda - (round window) separates the tympanic cavity from the scala tympani of the cochlea. (More? inner ear)
  • fetus - (foetus) term used to describe human development after the 8th week (10th clinical week, LPM) and covers the developmental periods of second and third trimester.
  • fibroblast growth factor 1 - (Fgf-1) a growth factor released from cochlea sensory epithelium which stimulates spiral ganglion neurite branching.
  • fibroblast growth factor 8 - (Fgf-8) a growth factor released by inner hair cells which regulates pillar cell number, position and rate of development.
  • fibroblast growth factor receptor 3 - (Fgfr-3) a tyrosine kinase receptor with a role in the commitment, differentiation and position of pillar cells in the organ of corti
  • fundamental frequency - (natural frequency) the lowest frequency in a harmonic series, for the female voice this is about 225 Hz.
  • helicotrema - term used to describe the cochlear apex. (More? inner ear)
  • Hes - (hairy and enhancer of split) family of factors, which has been shown to be a general negative regulator of neurogenesis (Zheng, 2000).
  • hillock - a small hill, used to describe the six surface elevations on pharyngeal arch one and two. (More? Outer Ear)
  • Incus - (anvil) auditory ossicle (More? middle ear)
  • inner phalangeal cells - in the cochlea a single row of cells, that along with and three rows of outer phalangeal cells (Deiter's cells), are the hair cell supporting cells. (More? inner ear)
  • inner pillar cells - organ of Corti cells arranged in rows and form a boundary between the single row of inner hair cells and three rows of outer hair cells. These cells have surface-associated microtubule bundles. (More? inner ear)
  • inner sulcus - area of the cochlear duct. (More? inner ear)
  • internal auditory meatus - (internal acoustic meatus, IAM) Anatomical canal in which CN VII and CN VIII ganglia reside and pass through to the brainstem. This bony canal lies between the posterior surface of the petrous pyramid and the bony labyrinth within the dense petrous bone. Also associated clinically with the site where acoustic neuromas may occur. (More? inner ear)
  • kinocilium - inner ear hair cell specialised type of cilium on the cell apex.
  • Kolliker's organ - (Kollicker's organ, greater epithelial ridge) Developing cochlear structure consisting of columnar-shaped supporting cells filling the inner sulcus and lying directly under the tectorial membrane. This transient organ regresses and generates the space of the inner sulcus. Rudolph Albert von Kolliker (1817-1905)?? (More? inner ear


  • lateral semicircular duct


  • limbus -


  • LMP - acronym for last menstrual period, used to clinically measure gestation.


  • malleus - (hammer) auditory ossicle (More? middle ear)
  • mastoid process - of temporal bone (More? middle ear)
  • Math1 - homolog of the Drosophila proneural gene atonal, necessary and sufficient for the production of hair cells in the mouse inner ear. Negatively regulated by Hes1 and Hes5
  • meatal plug - temporary blockage of the external auditory meatus which forms at the end of the embryonic period and remains present until the seventh month.
  • meatus - anatomical opening, cavity or space (external acoustic meatus, internal auditory meatus)
  • mechano-electrical transduction - (MET) occurs within the cochlear hair cells hair bundle. A mechanical stimulus of the hair bundle causes the tip-links to be tensioned, opening ion channels, resulting in the generation of the cell receptor potential. (More? inner ear)
  • Meckel's cartilage - first pharyngeal ach cartilage, located within the mandibular prominence. This cartilage first appears at stage 16, stage 20 the beginning of membranous ossification. Named after Johann Friedrich Meckel, (1781 - 1833) a German anatomist. (http://www.whonamedit.com/doctor.cfm/1840.html) (More? middle ear)
  • mucopolysaccharidosis - (MPS IIIB, Sanfilippo Syndrome type B) abnormality caused by a deficiency in the lysosomal enzyme N-acetyl-glucosaminidase (Naglu). Children with MPS IIIB develop abnormal hearing, and mental functioning culminating in early death.
  • netrin-1 - secreted growth factor, expressed in the organ of Corti and spiral ganglion cells, role in process outgrowth. (More? inner ear)
  • otoacoustic emissions testing - (OET) hearing test measures sounds generated by the outer hair cells of the cochlea in response to clicks or tone bursts emitted and recorded by a tiny microphone placed in the infant’s external ear canal. (More? Hearing test)
  • olivocochlear - brainstem cholinergic and GABAergic efferent system that innervates sensory cells and sensory neurons of the inner ear.
  • organ of Corti protein II - (OCP-II) cytosolic protein or transcription factor? (More? inner ear)
  • otolithic membrane - extracellular matrix that cover the sensory epithelia of the inner ear. (More? inner ear)
  • ossicle - (small bone) the individual bone of the three middle ear bones (auditory ossicles), which reduce vibrational amplitude but increase force to drive fluid-filled inner ear. (More? middle ear)
  • otic capsule -
  • otic cup -
  • otic placode - Embryonic ectodermal epithelium giving rise to inner ear structures. (More? inner ear | Placodes)
  • otoconin - inner ear biominerals required for vestibular apparatus function. (More? inner ear)
  • otogelin - (Otog) an inner ear specific glycoprotein expressed in cochlea cells at different developmental times. (More? inner ear)
  • otolithic membrane - a membrane within the utricle and saccule containing embedded hair cell cilia and small crystalline bodies of calcium carbonate (otoliths). Functions to detect head motion.
  • otoliths - small crystalline bodies of calcium carbonate found within the otolitic membrane of the utricle and saccule. (More? inner ear)
  • ototoxic - compound or drug causing temporary or permanent hearing loss.
  • outer hair cells - (OHCs) three rows of hair cells that function to increase basilar membrane motion through a local mechanical feedback process within the cochlea, the " cochlear amplifier".
  • outer pillar cells - arranged in rows and form a boundary between the single row of inner hair cells and three rows of outer hair cells. (More? inner ear)
  • paratubal musculature - muscles lying beside the auditory (Eustachian) tube. The tensor veli, palatini (TVP) and tensor tympani muscles. (More? middle ear)
  • perilymph - perilymphatic space - Periotic Capsule - petrous portion - of temporal bone
  • pejvakin gene - in humans, two missense mutations in this gene cause nonsyndromic recessive deafness (DFNB59) by affecting the function of auditory neurons.
  • pharyngeal arch - (More? Outer Ear) pharyngeal pouch pharyngeal membrane Pharynx
  • pillar cells - (PC) form an inner and outer row of support cells that form a boundary between inner and outer hair cells. (More? inner ear)
  • preyer reflex - ear flick in mouse in response to sound.
  • presbyacusis
  • prestin - a motor protein structurally similar to the anion transporter family expressed in cochlear outer hair cells. (More? inner ear)
  • preauricular tag - skin tags located in front of the external ear opening, are common in neonates and in most cases are normal, though in some cases are indicative of other associated abnormalities.
  • protocadherin 15 - (Pcdh15) required for initial formation of stereocilia bundles and changes in the actin meshwork within hair cells. The Ames waltzer (av) mouse mutant has both auditory and vestibular abnormalities from a mutation in this gene.
  • Reichert's cartilage - pharyngeal arch 2 cartilage, named after Karl Bogislaus Reichert (1811 - 1883) a German anatomist. (More? middle ear | pharyngeal arch)
  • Reissner's membrane - (vestibular membrane, vestibular wall) is a membrane located inside the cochlea separating the scala media from scala vestibuli. Named after Ernst Reissner (1824-1878) a German anatomist. It primarily functions as a diffusion barrier, allowing nutrients to travel from the perilymph to the endolymph of the membranous labyrinth.
  • rhombomere - hindbrain rostrocaudal segmentation established by expression of Hox homeodomain transcription factors. Histologically rhombomeres are visible as undulating folds (scalloping) of the neural tube in the hindbrain region and have associated cranial nerves.
  • saccular macula - (macula of saccule) thickened anterior part of the saccule containing the saccular filaments of the acoustic nerve. (More? balance)
  • Saccule - (Latin, sacculus = a small pouch) (More? balance)
  • sacculocollic reflex -
  • scala tympani - one of the three cochlea cavities, it is filled with perilymph.
  • Scarpa's ganglion - (vestibular ganglion) primary afferent vestibular neuron ganglion of the vestibular nerve. Located within the internal auditory meatus. (More? inner ear)
  • semicircular canals - series of fluid-filled loops of the inner ear required for balance and sensing acceleration. (More? inner ear)
  • sensorineural - term used to describe one of the two major classes of hearing loss involving the central pathway from the cochlear (other form is conductive loss).
  • space of Nuel - within the cochlea, an organ of Corti space between the outer pillar cells and the phalangeal and hair cells. Named after Jean-Pierre Nuel (1847-1920) a Belgian ophthalmologist. (More? inner ear)
  • spiral ganglion neurons - (SGN) innervate the inner (Type I) and outer (Type II) hair cells of the cochlea. (More? inner ear)
  • stapedius muscle - (innervated by CN VII tympanic branch) one of the two muscles in the middle ear, contraction of this muscle pulls the stapes and dampens auditory ossicle movement. (More? middle ear)
  • stapes - (stirrup) a middle ear auditory ossicle (bone) (More? middle ear)
  • startle response - {Moro reflex)
  • stereocilia -finger-like projections from the apical surface of sensory hair cells forming the hair bundle in the cochlea. Formed by tightly cross-linked parallel actin filaments in a paracrystalline array with cell surface specializations (tip links, horizontal top connectors, and tectorial membrane attachment crowns).
  • stratified squamous epithelia - classification of epithelium which transiently forms a plug in external ear canal to the outer eardrum.
  • stria vascularis - forms the outer wall of the cochlear duct of the mammalian cochlea is composed primarily of three types of cells. Marginal cells line the lumen of the cochlear duct and are of epithelial origin. Basal cells also form a continuous layer and they may be mesodermal or derived from the neural crest. Intermediate cells are melanocyte-like cells, presumably derived from the neural crest, and are scattered between the marginal and basal cell layers. The stria forms endolymph and also contains a rich supply of blood vessels. (More? inner ear)
  • sulcus -
  • synostotically - anatomically normally separate skeletal bones fused together. (More? middle ear)
  • tectorial membrane - within the cochlea an extracellular matrix produced by interdental cells, that covers the sensory epithelial hair cells of the organ of corti. (More? inner ear)
  • alpha-tectorin and beta- (TECTA, TECTB) major non-collagenous protein component of the tectorial membrane forming a striated-sheet matrix. Synthesized as glycosylphosphatidylinositol-linked, membrane bound precursors.
  • tensor tympani - (innervated by CN V mandibular nerve) one of the two muscles in the middle ear, contraction of this muscle pulls the malleus and tenses the tympanic membrane, dampening auditory ossicle movement. The muscle arises from auditory tube (cartilaginous portion) and is inserted into the malleus (manubrium near the root).
  • teratogens -
  • tonotopy - term describing the mapping along the tectorial membrane within the cochlea of the different sound frequencies. (More? inner ear)
  • tympanic membrane - (ear drum)
  • utricle -
  • vacuolization -
  • vesicle -
  • vestibular apparatus -
  • vestibular evoked myogenic potential - (VEMP) a test for vestibular disorders (utricle and superior nerve) response elicited by loud clicks or tone bursts recorded from the tonically contracted sternocleidomastoid muscle.
  • vestibular ganglion - (Scarpa's ganglion) primary afferent vestibular neuron ganglion of the vestibular nerve. Located within the internal auditory meatus. (More? inner ear)
  • vestibular membrane - (Reissner's) extends from the spiral lamina to the outer wall and divides the cochlea into an upper scala vestibuli, a lower scala tympani. (More? inner ear)
  • Vestibulocochlear Nerve - Cranial Nerve VIII CN VIII
  • Whirlin - A PDZ scaffold protein expressed in hair cells at the stereocilia tips, essential for the stereocilia elongation process. The DFNB31 gene mutations cause hearing loss in human and mouse. This protein can interact with membrane-associated guanylate kinase (MAGUK) protein, erythrocyte protein p55 (p55). (More? inner ear)
  • Wnt7a - signaling through the Wnt pathway regulates the development of hair cell unidirectional stereociliary bundle orientation. (More? inner ear)
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Cite this page: Hill, M.A. (2018, June 19) Embryology BGDB Face and Ear - Abnormalities. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/BGDB_Face_and_Ear_-_Abnormalities

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© Dr Mark Hill 2018, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G