Temporal bone

Temporal bone, by the way, is the most complex bone in our body. It is embryologically formed by the fusion of 11 ossification centers* that incorporate the peripheral part of the audio-vestibular system and provide all necessary channels and openings for multiple cranial nerves & blood vessels passing through it.


  • *Navjot Singh. Prenatal growth of cranium, facial and oral structures. Chapter 3 from the Textbook of Orthodontics, ed. Gurkeerat Singh, third ed. JAYPEE, 2015, p21—27.

  • Icon of crossfade image Download JPG image
    Temporal bone ex situ Temporal bone in situ
    Os temporale dxt. ex situ & in situ.

    Icon of crossfade image Postero-medial aspect of temporal bone with the terminology markup
    Postero-medial aspect of temporal bone
    Dorsomedial aspect of right temporal bone.
    The list of terms: Pars squamosa (facies cerebralis) – Squamous part (cerebral surface)
    Pars petrosa (pyramis) – Petrous part (pyramid) of temporal bone
    Pars petrosa (processus mastoideus) – Petrous part (mastoid process)
    Incisura parietalis – Parietal notch
    Fissura petrosquamosa – Petrosquamous fissure

    Icon of crossfade image Lateral view of right temporal bone with the terminology markup
    Lateral view of right temporal bone
    Lateral aspect of the right temporal bone.
    The list of terms: Pars squamosa (facies temporalis) – Squamous part (temporal surface)
    Processus mastoideus (pars petrosa) – Mastoid process (petrous part)
    Pars tympanica – Tympanic part
    Incisura parietalis – Parietal notch
    Crista supramastoidea – Supramastoid crest
    Processus zygomaticus – Zygomatic process
    Fissura tympanomastoidea – Tympanomastoid fissure
    Fissura tympanosquamosa – Tympanosquamous fissure
    Fissura petrosquamosa – Petrosquamous fissure
    Fissura petrotympanica (Glasseri) – Petrotympanic fissure (glasserian fissure)
    Porus acusticus externus – Opening of external acoustic meatus
    Sulcus tympanicus – Tympanic groove
    Incisura tympanica – Tympanic notch
    Meatus acusticus externus – External acoustic (auditory) meatus

    Icon of crossfade image Medial view of right temporal bone with the terminology markup
    Medial view of right temporal bone
    Medial aspect of the right temporal bone.
    The list of terms: Margo sphenoidalis – Sphenoidal border
    Margo parietalis – Parietal border
    Incisura parietalis – Parietal notch
    Margo occipitalis – Occipital border
    Margo posterior partis petrosae – Posterior border of petrous part of the temporal bone
    Margo superior partis petrosae – Superior border of petrous part of the temporal bone
    Apex partis petrosae – Apex of petrous temporal bone
    Porus acusticus internus
    Meatus acusticus internus – Internal acoustic (auditory) meatus
    Apertura externa aqueductus vestibuli – External opening of vestibular aqueduct
    Sulcus sinus sigmoidei – Groove for sigmoid sinus
    Foramen mastoideum – Mastoid foramen
    Impressiones digitatae – Digitate impressions
    Juga cerebralia – Cerebral ridges of cranium

    Icon of crossfade image Anterior view of right temporal bone with the terminology markup
    Anterior view of right temporal bone
    Anterior aspect of right temporal bone.
    The list of terms: Fissura petrosquamosa – Petrosquamous fissure
    Canalis musculotubarius – Musculotubal canal
    Semicanalis m. tensoris tympani – Semicanal for tensor tympani muscle
    Semicanalis tubae auditoriae (auditivae) – Semicanal for the auditory tube
    Canalis caroticus – Carotid canal
    Hiatus n. petrosi minoris – Hiatus of canal for lesser petrosal nerve
    Hiatus n. petrosi majoris – Hiatus of canal for greater petrosal nerve

    Icon of crossfade image Top view of right temporal bone with the terminology markup
    Top view of right temporal bone
    Top aspect of right temporal bone.
    The list of terms: Fissura petrosquamosa – Petrosquamous fissure
    Tegmen tympani – Roog of tympanic cavity
    Eminentia arcuata – Arcuate eminence
    Impressio trigeminalis – Trigeminal impression
    Apex partis petrosae – Apex of petrous temporal bone
    Hiatus nervi petrosi minoris – Hiatus of canal for lesser petrosal nerve
    Sulcus n. petrosi minoris – Groove for lesser petrosal nerve
    Hiatus nervi petrosi majoris – Hiatus of canal for greater petrosal nerve
    Sulcus n. petrosi majoris – Groove for lesser petrosal nerve
    Sulcus sinus petrosi superioris – Groove for superior petrosal sinus

    Icon of crossfade image Posterior view of right temporal bone with the terminology markup
    Posterior view of right temporal bone
    Posterior aspect of right temporal bone.
    The list of terms: Porus acusticus internus
    Meatus acusticus internus – Internal acoustic (auditory) meauts
    Apertura externa aqueductus vestibuli – External opening of vestibular aqueduct
    Fossa subarcuata – Subarcuate fossa
    Sulcus sinus petrosi superioris – Groove for superior petrous sinus
    Sulcus sinus sigmoidei – Groove for sigmoid sinus
    Sulcus sinus petrosi inferioris – Groove for inferior petrous sinus
    Incisura jugularis – Jugular notch
    Processus intrajugularis – Intrajugular process
    Processus styloideus – Styloid process
    Vagina processus styloidei – Sheath of styloid process
    Incisura mastoidea – Mastoid notch
    Sulcus a. occipitalis – Groove for occipital artery
    Foramen mastoideum – Mastoid foramen

    Icon of crossfade image Bottom view of right temporal bone with the terminology markup
    Bottom view of right temporal bone
    Bottom aspect of right temporal bone.
    The list of terms: Tuberculum articulare – Articular tubercle
    Fossa mandibularis – Mandibular fossa
    Fissura tympanosquamosa – Tympanosquamous fissure
    Fissura petrotympanica – Petrotympanic fissure
    Processus mastoideus – Mastoid process
    Incisura mastoidea – Mastoid notch
    Sulcus a. occipitalis – Groove for occipital artery
    Foramen mastoideum – Mastoid foramen
    Processus styloideus – Styloid process
    Foramen stylomastoideum – Stylomastoid foramen
    Canalis facialis – Facial canal
    Canalis caroticus – Carotid canal
    Fossa jugularis – Jugular fossa
    Canaliculus mastoideus – Mastoid canaliculus
    Fossula petrosa – Petrosal fossula
    Canaliculus tympanicus – Tympanic canaliculus
    Apertura externa canaliculi cochleae – External opening of cochlear canaliculus
    .

    Icon of crossfade image Markup for the canalis facialis within semi-transparent bone
    Canalis facialis within semi-transparent bone
    Canalis facialis within the semi-transparent right temporal bone.
    The list of terms: Meatus acusticus internus – Internal acoustic (auditory) meatus
    Canalis facialis – Facial canal
    Foramen stylomastoideum – Stylomastoid foramen
    Genu canalis facialis – Genu of facial canal
    Hiatus nervi petrosi majoris – Hiatus of canal for greater petrosal nerve
    .

    Icon of crossfade image Markup for the osseous labyrinth within the semi-transparent temporal bone
    Osseous labyrinth within the semi-transparent temporal bone
    Internal acousttic meatus and the osseous labyrinth within the temporal bone.
    The red structure you see in the image above is the osseous labyrinth – the channel system surrounded by a thick cortical bone layer within the petrous part of the temporal bone. This cortical bone is one of the densest structure in our skeleton (petrous in Latin means stone-like), so the vestibular and hearing apparatus arranged in these channels is particularly well protected.
    The list of terms: Meatus acusticus internus – Internal acoustic (auditory) meatus
    Cochlea
    Vestibulum
    Canales semicirculares – Osseous semicircular canals

    Download JPG image Cellulae mastoideae within the semi-transparent bone
    Cellulae mastoideae within the semi-transparent temporal bone. The lateral projection.

    Download JPG image Interal structures of temporal bone
    The complex view of some major internal structures of the temporal bone, including mastoid cells (yellow), the facial canal (green), labyrinth (red), tympanic cavity with canalis musculotubarius (magenta), and meatus acusticus internus (blue).

    Temporal bones ex situ & in situ. 360° rotation.

    First published: May/2019
    Last update: 14/Nov/2020