Middle ear ossicles
Citation, DOI, disclosures and article data
At the time the article was created Frank Gaillard had no recorded disclosures.
View Frank Gaillard's current disclosuresAt the time the article was last revised Craig Hacking had the following disclosures:
- Philips Australia, Paid speaker at Philips Spectral CT events (ongoing)
These were assessed during peer review and were determined to not be relevant to the changes that were made.
View Craig Hacking's current disclosures- Ossicular chain
There are three tiny articulating bones in the middle ear known as ossicles (from lateral to medial):
Their role is to mechanically amplify the vibrations of the tympanic membrane and transmit them to the cochlea where they can be interpreted as sound. They are located in the middle ear cavity and articulate with each other via two tiny synovial joints. The stapes also articulates with the oval window via the stapediovestibular joint, which is a syndesmosis 3; this joint transmits the ossicular vibrations to the endolymph in the vestibule.
Interestingly, they are the only bones in the body that do not grow after birth and are also the smallest bones in the body (variant tiny sesamoids aside).
Radiographic features
CT
On axial images (in the plane of the lateral semicircular canal), the normal landmarks of the ossicles can be remembered with the following mnemonic, from superior to inferior 4,5:
- ice cream cone (level of horizontal tympanic segment of facial nerve): incudomallear joint involving head of malleus (ice cream) and body of incus (top of cone), and short process of incus (tip of cone)
- two dots (level of oval window): neck of malleus (lateral dot) and long process of incus (medial dot)
- two dashes: handle/manubrium of malleus (lateral line), incudostapedial joint involving lenticular process of incus and head of stapes (medial line)
References
- 1. FRCS CSS. Last's Anatomy. Churchill Livingstone. (2011) ISBN:0702033952. Read it at Google Books - Find it at Amazon
- 2. Clemente CD. Anatomy. Lippincott Williams & Wilkins. (2011) ISBN:1582558892. Read it at Google Books - Find it at Amazon
- 3. Tavernier L, Linthicum FH. Sesamoid bone in the stapediovestibular articulation with conductive hearing loss. (2006) Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 27 (5): 741-2. doi:10.1097/01.mao.0000224077.32108.0d - Pubmed
- 4. Kelly HR. Temporal Bone Anatomy. American Society for Head and Neck Radiology. 2017. Slides
- 5. De Brucker Y, Allemeersch GJ, Buisseret T, de Mey J. Basic and advanced temporal bone anatomy using different figures as landmarks. European Congress of Radiology. 2017. doi: 10.1594/ecr2017/C-2478
Incoming Links
- Animal and animal produce inspired signs
- Cochlear aplasia
- Treacher Collins syndrome
- External auditory canal atresia
- Tympanic membrane retraction
- Branchio-oto-renal dysplasia
- Congenital ossicular anomalies
- Ossicular chain fixation
- Stapes
- Incudomalleolar joint
- Ossicles
- Axial skeleton
- Tympanic paraganglioma
- Incus
- Malleus
- Middle ear
- Mesotympanum
- Paget disease (bone)
- Tympanic membrane
- Ice cream cone sign (vestibular schwannoma)
- Ossicles (Gray's illustrations)
- Middle ear ossicles
- Incudomalleolar dislocation
- Odontoid fracture and incudomalleolar disruption
- Cochlear incomplete partition - type II
- Incudomalleolar dislocation
- Automastoidectomy with labyrinthine fistula
- Epidural hematoma, temporal bone fracture and incudomalleolar joint disruption
- Cholesteatoma - external auditory canal
- Keratosis obturans
- Middle ear anatomy (illustration)
- Deossification of ossicles in chronic suppurative otitis media
- Normal temporal bone CT
- Malleus: annotated CT
- Stapes: annotated CT
- Incus: annotated CT
- Incus: anatomy illustration
- Ossicles (illustration)
- Comminuted mixed temporal bone fracture
- Chronic otomastoiditis
Related articles: Anatomy: Head and neck
- skeleton of the head and neck
-
cranial vault
- scalp (mnemonic)
- fontanelle
-
sutures
- calvarial
- facial
- frontozygomatic suture
- frontomaxillary suture
- frontolacrimal suture
- frontonasal suture
- temporozygomatic suture
- zygomaticomaxillary suture
- parietotemporal suture (parietomastoid suture)
- occipitotemporal suture (occipitomastoid suture)
- sphenofrontal suture
- sphenozygomatic suture
- spheno-occipital suture (not a true suture)
- lacrimomaxillary suture
- nasomaxillary suture
- internasal suture
- basal/internal
- skull landmarks
- frontal bone
- temporal bone
- parietal bone
- occipital bone
- skull base (foramina)
-
facial bones
- midline single bones
- paired bilateral bones
- cervical spine
- hyoid bone
- laryngeal cartilages
-
cranial vault
- muscles of the head and neck
- muscles of the tongue (mnemonic)
- muscles of mastication
-
facial muscles
- epicranius muscle
- circumorbital and palpebral muscles
- nasal muscles
-
buccolabial muscles
- elevators, retractors and evertors of the upper lip
- levator labii superioris alaeque nasalis muscle
- levator labii superioris muscle
- zygomaticus major muscle
- zygomaticus minor muscle
- levator anguli oris muscle
- malaris muscle
- risorius muscle
- depressors, retractors and evertors of the lower lip
- depressor labii inferioris muscle
- depressor anguli oris muscle
- mentalis muscle
- compound sphincter
-
orbicularis oris muscle
- incisivus labii superioris muscle
- incisivus labii inferioris muscle
-
orbicularis oris muscle
- muscle of mastication
- modiolus
- elevators, retractors and evertors of the upper lip
- muscles of the middle ear
- orbital muscles
- muscles of the soft palate
- pharyngeal muscles
- suprahyoid muscles
- infrahyoid muscles
- intrinsic muscles of the larynx
- muscles of the neck
- platysma muscle
- longus colli muscle
- longus capitis muscle
- scalenus anterior muscle
- scalenus medius muscle
- scalenus posterior muscle
- scalenus pleuralis muscle
- sternocleidomastoid muscle
-
suboccipital muscles
- rectus capitis posterior major muscle
- rectus capitis posterior minor muscle
- obliquus capitis superior muscle
- obliquus capitis inferior muscle
- accessory muscles of the neck
- deep cervical fascia
-
deep spaces of the neck
- anterior cervical space
- buccal space
- carotid space
- danger space
- deep cervical fascia
- infratemporal fossa
- masticator space
- parapharyngeal space
- stylomandibular tunnel
- parotid space
- pharyngeal (superficial) mucosal space
- perivertebral space
- posterior cervical space
- pterygopalatine fossa
- retropharyngeal space
- suprasternal space (of Burns)
- visceral space
- surgical triangles of the neck
- orbit
- ear
- paranasal sinuses
- upper respiratory tract
- viscera of the neck
- blood supply of the head and neck
-
arterial supply
-
common carotid artery
- carotid body
- carotid bifurcation
- subclavian artery
- variants
-
common carotid artery
- venous drainage
-
arterial supply
- innervation of the head and neck
-
cranial nerves
- olfactory nerve (CN I)
- optic nerve (CN II)
- oculomotor nerve (CN III)
- trochlear nerve (CN IV)
-
trigeminal nerve (CN V) (mnemonic)
- trigeminal ganglion
- ophthalmic division
- maxillary division
- mandibular division
- abducens nerve (CN VI)
- facial nerve (CN VII)
-
vestibulocochlear nerve (CN VIII)
- vestibular ganglion (Scarpa's ganglion)
- glossopharyngeal nerve (CN IX)
- vagus nerve (CN X)
- (spinal) accessory nerve (CN XI)
- hypoglossal nerve (CN XII)
- parasympathetic ganglia of the head and neck
- cervical sympathetic ganglia
- greater occipital nerve
- third occipital nerve
-
cervical plexus
- muscular branches
- longus capitis
- longus colli
- scalenes
- geniohyoid
- thyrohyoid
-
ansa cervicalis
- omohyoid (superior and inferior bellies separately)
- sternothyroid
- sternohyoid
- phrenic nerve
- contribution to the accessory nerve (CN XI)
- cutaneous branches
- muscular branches
- brachial plexus
- pharyngeal plexus
-
cranial nerves
- lymphatic drainage of the head and neck
- embryological development of the head and neck