CONGENITAL MALFORMATIONS OF EAR Flashcards
Name the congenital malformations of external ear?
Preauricular sinus or cyst
Atresia of external auditory meatus
Complete or partial absence of auricle
Accessory auricle
Anomalies in size or shape of pinna
How is preauricular sinus formed?
Preauricular sinus forms due to failure of complete fusion between the first and second branchial arch elements in the auricle
Where is preauricular sinus situated?
External opening of preauricular sinus is situated between the tragus & crus helix
Symptoms of preauricular sinus or cyst?
Usually no symptoms but if it gets infected it produce symptoms like pain,swelling,redness and discharge
After treatment surgical excision is needed
What is atresia?
Atresia is characterised by non canalisation of external auditory canal
Often associated with microtia
There is conductive deafness
Absence of external auditory meatus
Treated by reconstructive surgery
How does anomalies of the pinna occurs?
Anomalies of the pinna occurs due to failure of development of the six auricular tubercles
What is anotia?
Anotia is the complete absence of pinna
How is pinna developed?
Pinna is developed from six tubercles from first and second arch,which fuse together
Accessory auricle?
Sometimes the arch doesn’t fuse and forms the accessory auricle
What is microtia?
Microtia is a small pinna
What is bat ear or Lop ear ?
Usually big ear ,outwardly projecting pinna
Congenital abnormalities of middle ear?
Treacher Collin’s syndrome
Abnormal ossicles
Congenital fixation of stapes
What do you know about treacher collins syndrome
Hereditary malformation of the lower face which is hypoplastic together with varying degree of developmental failure of the external and middle ear
What is the other name of treacher collins syndrome
First arch syndrome
What are the ossicles that are most commonly deformed?
Incus and malleus
Abnormal ossicles are fused to?
May be fused together or sometimes to the bony wall of middle ear cavity
Treated by removal of deformed ossicles followed by tympanoplasty
What is congenital fixation of stapes?
In this footplate of stapes is congenitally fixed to the oval window or footplate may fuse into the window
Treated by performing stapes mobilization operation
Congenital malformations of inner ear
Scheibe dysplasia
Mondini dysplasia
Bing siebenmann dysplasia
Michael dysplasia
What is scheibe dysplasia?
Involves saccule and cochlea
70 % of cases of hereditary deafness
Mondini dysplasia?
Cochlear duct is reduced to one and a half turns and organ of corti may be absent
Bing siebenmann dysplasia?
Membranous labyrinth is underdeveloped
Michael dysplasia?
There is total absence of both labyrinth
