Anatomy Flashcards
what type of joint is the TMJ (temporomandibular joint)
-synovial (atypical due to linings as there are 2 synovial cavities)
where does the head of mandibular condyle articulate to in TMJ
mandibular (glenoid) fossa/articular tubercle (eminence) of the temporal bone
location of TMJ (2)
- posterior to zygomatic arch
- anterior to EAM
what are articular surfaces of typical synovial joints lined with
hyaline cartilage
what are non articular surfaces of typical synovial joints lined with
synovial membrane (fluid,capsule and ligaments)
features of typical synovial joint (3)
- articular surfaces lined with hyaline cartilage
- non articular surfaces lined with synovial membrane (fluid, capsule and ligaments)
- skeletal muscles to move the joint
function of the fluid in synovial membrane lining non articular surfaces of a typical synovial joint (4)
- nourish articular surfaces
- reduce friction
- cool the joint
- remove waste products
function of the capsule in synovial membrane lining non articular surfaces of a typical synovial joint (3)
- encloses joint
- retain fluid
- prevents dislocation (articulates to eminence)
function of the ligaments in synovial membrane lining non articular surfaces of a typical synovial joint
strengthen the joint
what are the articular surfaces of the TMJ joint lined with
fibrous tissue
what is the intra-articular disc of the TMJ made of
dense fibrous tissue
what is the head of the mandibular condyle covered in
perichondrium
what is the name of the tubercle posterior to the TMJ
post-glenoid tubercle
what is the name of the tubercle anterior to the TMJ
articular tubercle (eminence)
clinical relevance of EAM and TMJ
clicking jaw appears to be very loud due to location of TMJ
attachment site for posterior fibres of buccinator
retro molar triangle
mandibular attachment site for sphenomandibular ligament
lingula
which ligament attaches to the pterygoid fovea
lateral pterygoid
which nerve passes down the mandibular foramen
inferior alveolar nerve (branch of CNV3)
bones involved in the temporal part of TMJ (3)
- post-glenoid tubercle
- glenoid fossa
- articular eminence
position of mandibular condyle in TMJ (4)
- tilted anteriorly
- flattened A-P
- elongated latero-medially
- long axis points approx 10degrees posteriorly (L-M)
role of lateral temporomandibular ligament
prevents posterior dislocation of joint
location of TMJ joint capsule
attaches around the circumferences of the articular surfaces
attachment sites of stylomandibular ligament (2)
- styloid process
- medial aspect of angle of mandible
what is the stylomandibular ligament derived from
= specialisation of the investing layer of deep cervical fascia surrounding the parotid gland
attachments of the lateral temporomandibular ligament (2)
- zygomatic arch
- posterior lateral aspect of mandible and condyle
what is the sphenomandibular ligament derived from
= remains of Meckel’s cartilage
attachments of sphenomandibular ligament (2)
- spine of sphenoid
- lingula of mandible
attachments of ptergomandibular raphe (2)
- pterygoid hamulus of medial pterygoid plate
- retromolar triangle
which muscle originates from the pterygomandibular raphe (2)
buccinator
->superior pharyngeal constrictor also joins to raphe
what is the pterygomandibular raphe derived from
fibrous material
most important clinical landmarks used in the location of the inferior alveolar nerve block (2)
- coronoid notch
- pterygomandibular raphe
- > preferred site of needle insertion lies between these 2 landmarks
location of intra-articular disc (2)
- merges with joint capsule around circumference
- separates joint into 2 spaces (upper and lower joint spaces)
role of intra-articular disc
provides stability of joint during movement by improving ‘‘fit” of joint
histology of intra-articular disc
dense fibrous connective tissue
innervation of TMJ
- mainly innervated by auriculotemporal nerve
- >very few if any nerve receptors in disc (many in capsule)
zones of intra-articular disc (5)
- anterior extension
- posterior extension
- three bands in disc proper (anterior band, intermediate zone, posterior band)
what is the anterior extension of intra-articular disc continuous with (2)
- joint capsule anteriorly
- tendon of lateral pterygoid muscle
what are the layers of bilaminar posterior extension of intra-articular disc made up of (2)
- upper layer = elastic fibres (assist returning of disc to rest position)
- upper and lower layer = vascular tissue (engorge with blood on opening and empties into pterygoid venous plexus on closing, adapting the shape of disc to space available within the joint capsule)
thickness of bands within disc proper of intra-articular disc (3)
- anterior band = thick/3mm
- intermediate zone = thin/1mm
- posterior band = thick/3mm
what are the upper and lower joint spaces of the TMJ lined with
their own synovial membrane
mandibular condyle movement during initial jaw opening (3)
- anterior rotation of head of condyle
- movement occurs in lower joint space
- disc remains in place
mandibular condyle movement during full jaw opening (to dislocation) (3)
- after initial ant. rotation of condylar head in lower joint space
- disc translates/slides anteriorly articulating with mandibular fossa and articular eminence
- movement occurs in upper joint space
location condylar movement during initial joint opening
lower joint space
location of condylar movement during full jaw opening (to dislocation)
upper joint space
what causes clicking jaw (2)
- posterior band of disc becomes ‘stuck’ during wide opening
- clicks back into place on jaw closing
clinical name of ‘clicking jaw’
‘internal derangement with reduction’
- > internal derangement describes the disc becoming stuck anteriorly
- > reduction describes the the disc returning to normal position
symptoms of clicking jaw (2)
-clicking and pain with chewing
which part of the intra-articular disc is associated with internal derangement
stretching of the posterior extension
causes of TMJ dislocation (2)
- occurs when mandibular condyle becomes fixed in the anterior superior aspect of articular eminence
- spasm of the masseter, temporalis, and internal pterygoid muscles result in trismus, preventing return of condyle to temporal fossa
how many TMJ’s are there
2 (only 1 mandible)
->movement of one TMJ will produce a movement in the other joint
movements of the TMJ (5)
- jaw opening
- jaw closing
- lateral movements
- protrusion and retrusion (translation)
- chewing (complex combination of all above movements)
movement of the TMJ’s during jaw opening
-depression (bilateral and symmetrical)
movement of the TMJ’s in jaw closing
-elevation (bilateral and symmetrical)
movement of mandibular condyles/ location during jaw opening (initial and subsequent) (2)
- initial anterior rotation (hinge within lower joint space)
- subsequent anterior translation (slide within upper joint space)
mandibular condyle movement and location during jaw closing (initial and subsequent) (2)
- initial posterior translation (upper joint space)
- subsequent posterior rotation (lower joint space)
movement of TMJ’s during lateral movements
bilateral and asymmetrical
movement of mandibular condyle at working side of lateral TMJ movement
-lateral rotation/movement
movement of mandibular condyle at non working side of lateral TMJ movement
-anterior and medial rotation
protrusion
mandible is pulled forwards relative to maxilla
retrusion
mandible is pulled backwards relative to the maxilla
what is maximal retrusion called
the ligamentous position
importance of the infratemporal fossa (2)
- local anaesthesia for restoration/extraction of mandibular teeth (inferior alveolar nerve is located within)
- extraction of upper third molar teeth (if not done properly, can potentially displace posteriorly into infra-temporal fossa)
location of infra temporal fossa (3)
- below the temporal fossa (depression on lateral aspect of skull containing temporalis muscle, which enters into infra temporal fossa beneath zygomatic arch)
- posterior to lateral aspect of lateral pterygoid plate of sphenoid bone
- medial to TMJ
boundaries of infratemporal fossa:
- posterior
- superior
- medial
- lateral
- inferior
- posterior = spine of sphenoid and articular tubercle
- superior = greater wing of sphenoid
- medial = lateral aspect of lateral pterygoid plate
- lateral = medial side of mandibular ramus
- inferior = medial pterygoid muscle, which inserts onto angle of mandible
contents of infratemporal fossa (6)
- inferior part of temporalis
- lateral pterygoid
- medial pterygoid
- pterygoid venous plexus
- maxillary artery
- nerves
where does the articular disc of TMJ drain
into pterygoid venous plexus, located within the infratemporal fossa
which nerves are located within infratemporal fossa (3)
- CNV3 and its sensory/motor branches (sensory to skin of face, motor to muscles of mastication)
- otic ganglion which hangs from nerve to medial pterygoid (CNIX/ secretomotor to parotid gland)
- chorda tympani (branch of facial nerve which joins with the lingual nerve branch of CNV3)
synapse within otic ganglion (parotid gland nerve supply)
-preganglionic parasympathetic synapse in otic ganglion -> postganglionic in auriculotemporal nerve goes to supply parotid gland
heads of lateral pterygoid (2)
- superior
- inferior
heads of medial pterygoid (2)
- superficial
- deep
attachments of medial pterygoid muscle (2)
- medial side of angle of mandible
- medial side of lateral pterygoid plate (deep head) and maxillary tuberosity (superficial head)
function of medial pterygoid muscle
-jaw closing (along with master and temporalis)
nerve innervation of medial pterygoid muscle
CNV motor root
attachments of lateral pterygoid muscle (2)
- condyle of the mandible and the intra-articular disc and capsule of the TMJ
- lateral side of the lateral pterygoid plate (inferior head) and infratemporal surface of the greater wing of sphenoid (superior head)
function of lateral pterygoid muscle
jaw opening
nerve innervation of lateral pterygoid muscle
CNV motor root
what is the pterygoid venous plexus
-plexus of veins around the lateral pterygoid muscle
connections of pterygoid venous plexus (2)
- facial vein via deep facial vein (s)
- cavernous sinus
where does the pterygoid venous plexus drain into
maxillary vein
clinical significance of pterygoid venous plexus (3)
- can cause troublesome bleeding in le fort fractures (le fort I)
- displaced upper 8’s
- infections of face can drain to brain via cavernous sinus
what two veins combine to form the retromandibular vein
- superficial temporal vein
- maxillary vein (pterygoid venous plexus drains into maxillary vein)
what does the retromandibular vein drain into
external jugular vein -> subclavian vein
arterial blood supply to infratemporal fossa
maxillary artery (branch of external carotid)
- > passes through parotid gland then between the neck of mandible and sphenomandibular ligament to enter infratemporal fossa
- can either be situated superficial to pterygoid or within
branches of maxillary artery (3)
- part 1 = before lateral pterygoid
- part 2 = in relation to lateral pterygoid
- part 3 = after lateral pterygoid
branches of part 1 of maxillary artery (4)
- 2 branches to ear
- many branches to TMJ
- middle meningeal
- inferior alveolar (to lower teeth)
branches of part 2 of maxillary artery (2)
- branches to muscles of mastication (at least 1 branch to each of the four muscles, 2x deep temporal arteries)
- buccal artery (cheek)
branches of part 3 of maxillary artery (4)
- sphenopalatine (nose/palate)
- palatine (palate)
- superior alveolar (upper teeth)
- infraorbital (upper teeth and skin of mid face)
what foramen does the middle meningeal artery (branch of 1st part of maxillary) pass through
foramen spinosum
anterior division of CNV3 nerve supply/branches (2)
- many motor branches to masticatory muscles (masseter, temporalis, medial pterygoid, lateral pterygoid)
- 1 sensory branch = long buccal nerve (supplies skin and mucosa of cheek)
where does CNV3 pass through
foramen ovale
branches of posterior division of CNV3 (3)
- auriculotemporal nerve (sensory to skin in temple region and TMJ, also carries postganglionic parasympathetic fibres to parotid gland)
- inferior alveolar nerve
- lingual nerve
route of inferior alveolar nerve (long explanation) (5)
- CNV3 and motor root of CNV join at and pass through foramen ovale in greater wing of sphenoid
- auriculotemporal and lingual nerve branch
- inferior alveolar nerve branches away from the nerve to mylohyoid and ABD in infratemporal fossa, then enters mandibular foramen
- within mandibular canal, inferior alveolar nerve branches into dental branches, incisive branch and mental nerve which exits mental foramen
branches of inferior alveolar nerve (3)
- dental branches
- incisive branch
- mental nerve
what do the dental branches of inferior alveolar nerve supply
sensory innervation to premolars and molars
what does the incisive branch of the inferior alveolar nerve supply
sensory innervation to incisors and canine
nerve supply of mental nerve (3)
- sensory to skin and mucosa of lower lip
- chin and labial mucosa
- gingiva of lower 3-3
what is chorda tympani a branch of
CNVII (facial nerve)
what connects CNVII to the lingual nerve
chorda tympani
what foramen does CNVII pass through
stylomastoid
breakdown of vertebral column (5)
- 7 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral (fused to form 1 sacrum)
- 4 coccygeal (fused to form 1 coccyx)
why do the vertebrae become larger from superior to inferior then smaller again
- become larger as they bear more weight
- become smaller again once weight has been transferred to hip bones
curvatures of vertebral column (4)
- cervical secondary curvature
- thoracic primary curvature
- lumbar secondary curvature
- sacral primary curvature
scoliosis
abnormal spinal curvature to the side
what is primary kyphosis
when thoracic primary curvature sticks out too much
what is secondary lordosis
when the lumbar secondary curvature curves in too much
functions of the spine (3)
- support weight of head and trunk in upright position
- protect spinal cord and spinal nerves
- allow movements of the head on neck and of the trunk via muscle and joint attachments
location of spinal cord
within the vertebral canal formed by the joining of vertebral foraminae
location of intervertebral foramen
form between adjacent vertebrae
what passes through the intervertebral foramen
spinal nerves
location of vertebral facet joint
between articular processes of 2 adjacent vertebrae
clinical relevance of vertebral facet joint
- affected by arthritis
- pain signals are transmitted via posterior rami
location of intervertebral discs
- strong attachment between the bodies of adjacent vertebrae
- between all vertebrae except C1-C2 and the fused sacrum/coccyx
clinical relevance of intervertebral discs
- can herniate
- pain signals transmitted via posterior rami
what type of cartilage are the intervertebral discs
secondary
length of spine made up by intervertebral discs
20-25%
breakdown of intervertebral disc structure (2)
- outer fibrous ring = annulus fibrosus (fibrocartilage which provides strong bond)
- inner soft pulp = nucleus pulposus (up to 90% water in babies, provides flexibility and protection)
herniated (slipped disc) (2)
- protrusion of nucleus pulposus through annulus fibrosis (usually posterolaterally as annulus fibrosis is thinnest here)
- this compresses the spinal nerve
spinal nerves most commonly affected by herniated (slipped) disc in the cervical region (2)
C6 and C7 (supply the upper arms)
-> important they supply the brachial plexus
ligaments of the vertebral column (5)
- ligamentum flavus
- posterior longitudinal ligament
- anterior longitudinal ligament
- supraspinous ligament
- interspinous ligament
symptoms of slipped disc in cervical region of C6 and 7
-patient complains of ‘pins and needles’ or pain in arm if you ask them to turn head during treatment
function of vertebral column ligaments
stabilise joints and discs during movement
attachments of ligament flavum (of vertebral column)
connects adjacent laminae
attachments of posterior longitudinal ligament (of vertebral column)
attaches to posterior aspects of all vertebral bodies and intervertebral discs
attachments of anterior longitudinal ligament (of vertebral column)
attaches to anterior aspects of all vertebral bodies and intervertebral discs
at which vertebrae do the posterior longitudinal ligaments begin
C2 as C1 has no body
function of posterior longitudinal ligament (of the vertebral column)
prevents over leaning
function of anterior longitudinal ligament (of the vertebral column)
prevents over extension (bending too far back)
attachments of supraspinous ligament
connects tips of spinous processes
attachments of interspinous ligament
connects superior and inferior surfaces of adjacent spinous processes
transverse foramen
within each transverse process of all cervical vertebrae
why is C1/atlas an atypical vertebrae
- does not have body/spinous process
- has posterior arch and anterior arch instead
why is C2/axis different to other vertebrae
has an odontoid process (C1s body) which projects superiorly from body
vertebrae prominens
= C7, which is the first palpable spinous process in 70% of people
what type of joint are atlanto-occipital joints
synovial
location of atlanto-occipital joints
between occipital condyles and the superior articular facets of the atlas
movements of atlanto-occipital joints
- main movements = flexion and extension of neck (nodding or saying yes)
- also permit some rotary movement (contributing to saying no)
location of atlanto-axial joints (3)
- 3 synovial joints
- > 2 between the inferior articular facets of the atlas and the superior articular facets of the axis
- > 1 between the anterior arch of the atlas and the odontoid process of the axis
craniovertebral ligaments (3)
- nuchal ligament (from external occipital protuberance attaching to all spinous processes)
- anterior-occipital membrane
- tectorial membrane
what does anterior longitudinal ligament become at the level of C2
anterior atlano-axial membrane which becomes anterior atlanto-occipitoal membrane above C1
what does the posterior longitudinal ligament become above the odontoid process of C2
tectorial membrane
what ligaments make up the ‘cruciate ligament’ (3)
- superior longitudinal band
- transverse ligament of atlas
- inferior longitudinal band
‘check’ ligaments of the neck
alar ligaments
check ligament for TMJ
sphenomandibular ligament
important landmarks when performing inferior alveolar nerve block
- pterygomandibular raphe
- coronoid notch
possible causes of difficulty moving neck during dental treatment
- arthritis of facet joints (osteoarthritis, most common type = wear and tear)
- herniated (slipped) disc in cervical region (pain may be felt locally, or referred into the upper limb)
- rheumatoid arthritis weakening the capsule and ligaments of crania-vertebral joints
what is subluxation
- partial dislocation
- result of rheumatoid arthritis weakening the capsule and ligaments of crania-vertebral joints
- spinal cord theoretically at risk
location of pharynx
space that connects the nose and mouth above to the larynx and oesophagus below
what is the pharynx involved in (7)
- breathing
- speech
- coughing
- sneezing
- vomiting
- swallowing
- gagging
protective role of pharynx
- protects agains aspiration:
- > inhalation of solids/liquids into the lungs
- > fragments of teeth, amalgam material, dental tools, orthodontic appliances etc
position of respiratory and alimentary tract in relation to each other
- respiratory tract, trachea = anteriorly
- alimentary canal, oesophagus = middle
- retropharyngeal space = posteriorly
divisions of the pharynx (3)
- nasopharynx
- oropharynx
- laryngopharynx
components of the respiratory tract (4)
- nasal cavity
- oral cavity
- larynx
- trachea
components of the alimentary tract (2)
- oral cavity
- oesophagus
location of retropharyngeal space (2)
- anterior to alar fascia
- posterior to buccopharyngeal fascia
circular muscles of the pharynx (3)
- superior constrictor
- middle constrictor
- inferior constrictor
nerve supply to pharyngeal constrictors
CNX (pharyngeal plexus)
are the pharyngeal constrictors voluntary muscles
yes but they cannot control the sequential sequence of which they contract
attachments of superior pharyngeal constrictor (3)
- pterygoid hamulus
- pterygomandibular raphe
- mylohyoid line
attachments of middle pharyngeal constrictor
greater horn of hyoid
attachments of the inferior pharyngeal constrictor (2)
- thyroid cartilage (oblique line)
- cricoid cartilage
gateway to the mouth
gap between pharyngeal constrictors
contents of gaps between pharyngeal constrictors (4)
- gateway to mouth
- CN IX
- lingual artery
- stylopharyngeus muscle
location of stylopharyngeus muscle (2)
- attaches to styloid process
- passes through ‘gateway to the mouth’/gap between superior and middle constrictors along with the glossopharyngeal nerve
longitudinal muscles of the pharynx (3)
- stylopharyngeus
- palatopharyngeus
- salpingopharyngeus
attachments of longitudinal muscles of pharynx (3)
- stylopharyngeus (styloid process)
- palatopharyngeus (palate)
- salpingopharyngeus (cartilage of pharyngotympanic tube)
- > all inser onto posterior border of thyroid cartilage
function of longitudinal muscles of the pharynx
elevate the pharynx and larynx
nerve innervation of the longitudinal muscles of the pharynx (2)
- CNX to palatopharyngeus and salpingopharyngeus
- CN IX to stylopharyngeus
vallecula
depression anterior to epiglottis
opening into larynx
laryngeal inlet
choana
pair of posterior apertures of the nasal cavity that open into the nasopharynx
pharyngeal plexus
- > nerve fibres from CNIX and CNX, sympathetic axons and parasympathetic axons
- motor mainly from CN X
- sensory mainly CN IX
nerve supply of muscles of pharynx (3)
- motor supply
- all supplied by CN X via pharyngeal plexus
- except stylopharyngess (CN IX)
nerve supply to mucosa of pharynx (3)
- mainly supplied by CNIX
- CN V2 in parts of nasopharynx
- CNX in parts of laryngopharynx
sensory nerve supply to the mucosa of the pharynx (nasopharynx, oropharynx, laryngopharynx)
- nasopharynx = CNV2 (just anterior and superior to auditory tube) and CN IX
- oropharynx = CN IX (includes tonsillar fossa and posterior tongue)
- laryngopharynx = CN IX (just superior to epiglottis) and CNX
function of gag reflex
-protective, tries to close off oropharynx
areas that stimulate the sensory nerves of CN IX, resulting in gag reflex (3)
- posterior 1/3 of tongue
- tonsils
- walls of oropharynx (also nasopharynx and auditory tube/middle ear)
muscles involved in gag reflex (3)
- pharyngeal constrictors (CN X)
- longitudinal muscles of the pharynx (CN IX and X)
- tongue and soft palate
clinical relevance of gag reflex
- patients with sensitive throats
- recurrent gag reflex can make treatment very difficult
how is gag reflex resolved in dental patients (2)
- careful technique
- relaxed patient
deglutition
swallowing
stage 1 of swallowing
- food bolus squeezed to back of mouth
- tongue against palate
stage 2 of swallowing
- nasopharynx closed off
- larynx elevated
- pharynx enlarged to receive bolus
stage 3 of swallowing
- pharyngeal constrictors contract sequentially
- epiglottis deflects bolus
stage 4 of swallowing
bolus moves into oesophagus
what type of cartilage is nasal cartilage
hyaline
why should you not use adrenaline-containing local anaesthetics near the nasal cartilages
- cartilage is avascular (relies on nutrient diffusion from skin)
- adrenaline = vasoconstrictor therefore prevents nutrient diffusion
indentation of upper lip =
filtrum
bony part of nasal septum (2)
- perpendicular plate of ethmoid bone
- vomer
roof of nasal cavity (3)
- cribriform plate
- crista galli
- anterior cranial fossa
- > cribriform plate of ethmoid bone posteriorly and nasal bones anteriorly
lateral wall of nasal cavity (4)
- superior and middle conchae
- ethmoidal air cells
- orbital plate of ethmoid
- inferior conchae
clinical relevance of ethmoid bone and le fort fractures
- le fort II and III can disrupt the cribriform plate of the ethmoid bone
- this can result in a danger of infection spreading from the nasal cavity and paranasal sinuses into the anterior cranial fossa
why is a septal haematoma incised and drained
to prevent avascular necrosis of septal hyaline cartilage which depends on diffusion of nutrients from its attached nasal mucosa
mucosa of nasal vestibule (vestibule = anterior part of nasal cavity)
keratinised stratified squamous epithelium
mucosa of middle and inferior nasal concha
respiratory epithelium (cilia for protection and moisture, mucous secreting goblet cells)
mucosa of superior nasal concha
olfactory mucosa (smells won’t be detected until they have reached this point, has to be in (aq) to be detected by cells)
location of olfactory receptor cells (2)
=1st neurones in chain
- within olfactory mucosa (in olfactory area on both the lateral and the septum)
- pass through cribriform plate of ethmoid, to meet the olfactory bulb (contains ganglion/cell bodies of 2nd neurones)
somatic sensory nerve supply to nasal cavities (2)
- CNV1 anterosuperiorly (via anterior/posterior ethmoidal branches of nasociliary nerve)
- CNV2 posteroinferiorly (via nasopalatine and greater palatine nerves)
- > dividing line = between anterior nasal spine and sphenoethmoidal recess
blood supply to nasal cavity
via:
- external carotid artery (facial and maxillary arteries)
- internal carotid artery (ophthalmic)
branches of ophthalmic artery which supply the nasal cavity (2) (ophthalmic = branch of int. carotid)
-anterior and posterior ethmoidal arteries
branches of the maxillary artery which supply the nasal cavities (2) (maxillary = branch of ext. carotid)
- sphenopalatine artery
- greater palatine artery
branches of facial artery which supply the nasal cavity (2) (facial = branch of ext. carotid)
-lateral nasal branch of facial or septal branch of superior labial artery
clinical relevance of kiesselbach’s (little’s) area
= arterial anastomosis on nasal septum (anteroinferiorly)
-common site of epistaxis (nosebleeds)
arterial branches that contribute to kiesselbach’s (little’s) area (4)
- labial (septal)
- ethmoidal
- greater palatine
- sphenopalatine
- > L.E.G.S
functions of the nasal conchae (4)
- turbinate bones
- > convey respiratory gases between the atmosphere and nasopharynx
- > warm and humidify air (due to blood supply and mucous)
- > remove particulate matter/bacteria etc (turbulent air flow, mucous, cilia)
- > special sense of smell (olfactory area)
meatuses (4)
= spaces under each nasal concha
- > sphenoethmoidal (recess)
- > superior meatus
- > middle meatus
- > inferior meatus
how do you know if a nasogastric tube has been inserted correctly
-on X ray should be in stomach via oesophagus
what separates the right and left nasal cavities (2)
- nasal septum posteriorly
- septal cartilage anteriorly
floor of nasal cavity (2)
- hard palate formed from:
- > right and left maxillae anteriorly
- > palatine bones posteriorly
which type of epithelium lines the nasal cavities
-mainly respiratory epithelium (pseudo stratified columnar with cilia and goblet/mucous secreting cells)
drainage of mucous of paranasal sinuses
-via ostia/holes in the recesses and meatuses of the lateral walls of the nasal cavities
what is contained within the paranasal sinuses
air
name the paranasal sinuses (4 types, 7/8 in total)
- 2 frontal sinuses (separated by bony septum)
- 2 maxillary sinuses (antra)
- 2 ethmoidal air cells
- 1 or 2 sphenoidal sinuses
mucosa of paranasal sinuses
mucous-secreting respiratory mucosa
where does the frontal sinus drain into
middle meatus
where do the ethmoidal air cells drain into (2)
superior and middle meatuses
where does the maxillary sinus drain into
middle meatus
what drains into middle meatus (3)
- frontal sinus
- ethmoidal cells
- maxillary sinus
where does the sphenoidal sinus drain into
sphenoethmoidal recess
lacrimal fluid drainage
inferior meatus of nasal cavity via nasolacrimal duct (continuous drainage)
what is sinusitis
inflammation of the mucosa of 1 or more of the paranasal sinuses
degree of sinusitis (3)
- acute
- subchronic
- chronic
causes of sinusitis (6)
- infection
- allergy
- autoimmune issues
- > cold weather/smoking can interfere with cilia and their ability to waft mucous toward ostia
- > viral URTI causes swelling of mucosa, reducing diameter of ostia
- > sinuses can become filled with infected mucous
symptoms of sinusitis (2)
- painful (sensation provided by CNV1 and V2)
- pain may be referred to the teeth (toothache of upper or lower tooth due to common sensory nerve supply from CNV of the maxilla/mandible,antral mucosa and all the teeth)
why is the maxillary sinus likely to become inflamed (maxillary sinusitis) (2)
- maxillary sinus ostia is located superiorly in the medial wall of the sinus compared to the floor
- maxillary sinus mucous has to drain against gravity
clinical relevance of maxillary sinus (2)
- extraction of tooth may result in pro-antral fistula (communication between the oral cavity and the antrum via the tooth socket in alveolar bone, persistent fistula is surgically closed)
- roots of upper teeth can spread infection of dental abscess into the antrum (e.g.. can cause sinusitis/sinus infection)
pterion
H shaped suture/ fibrous joint on lateral aspect of skull (thinnest part therefore easily fractured)
parts of temporal bone (2)
- squamous
- petrous (like a rock, hard, tough, featured inferior part)
clinical significance of pterion
middle meningeal artery runs directly behind, fracture to pterion can cause tear
features of petrous part of temporal bone (6)
- zygomatic process
- mandibular fossa
- styloid process
- stylomastoid foramen
- mastoid process
- extracranial opening into carotid canal
bones of anterior cranial fossa (3)
- frontal
- ethmoid
- part of sphenoid (ends at lesser wings of sphenoid)
bones of middle cranial fossa (2)
- sphenoid (greater wings)
- temporal
clinical significance of temporal bones
contain:
- special sensory organs of hearing and balance
- facial nerve (CNVII)
- vestibulocochlear nerve (CN VIII)
what nerve (s) passes through cribriform plate (anterior cranial fossa)
CN I (special sensory)
what nerve (s) pass through optic canal (middle cranial fossa)
CN II (special sensory)
what nerve (s) passes through superior orbital fissure (middle cranial fossa) (4)
- CN III (mixed)
- CN IV (motor)
- CN VI (motor)
- CN V1 (sensory)
what nerve (s) passes through foramen rotundum (middle cranial fossa)
-CN V2 (sensory)
what nerve (s) passes through foramen ovale (middle cranial fossa)
-CN V3 (mixed)
what passes through carotid canal (middle cranial fossa)
carotid arteries
what nerve (s) passes through internal acoustic meatus (posterior cranial fossa) (2)
- CN VII (mixed)
- CN VIII (special sensory)
what nerve (s) passes through jugular foramen (posterior cranial fossa) (3)
- CN IX (mixed)
- CN X (mixed)
- CN XI (motor)
what nerve (s) passes through hypoglossal canal (post. cranial fossa)
CN XII (motor)
clinical signif. of pathology in the IAM (eg. acoustic neuroma)
can damage CNs VII and VIII
function of external ear
-collects and conveys sound waves to tympanic membrane
divisions of the ear and their boundaries (3)
- external (auricle to tympanic membrane/ear drum via the external acoustic meatus)
- middle (tympanic membrane to oval window, also eustachian tube)
- internal (oval window to internal acoustic meatus)
function of middle ear
amplifies and conducts sound waves to the internal ear
function of internal ear
converts special sensory information on sound/balance into fluid waves then into APs and conducts the APs towards the brainstem
what is the skeleton of external ear made up of, and why is this important clinically (2)
- elastic cartilage
- temporal bone
- > elastic cartilage is avascular and relies on diffusion from skin, do not use adrenaline containing local anaesthetics on the external ear
production of earwax
-ear canal/EAM is lined with skin and contains ceruminous glands that produce wax (lubricates ear/tympanic membrane, protects ear, antibacterial/kills off infection)
general sensory supply to the skin of the external ear (4)
- CN2,3 supply helix and earlobe
- CN VII supply area just posterior to triages
- CN V3 supplies superior parts of EAM and most of tympanic membrane
- CN X supplies inferior parts of EAM and tympanic membrane
lymphatic drainage of auricle/ear (6)
- lateral surface of superior half (parotid lymph nodes)
- cranial surface of superior half (mastoid lymph nodes, and deep cervical)
- rest of auricle, including lobe (superficial cervical lymph nodes)
- > all eventually drain into:
- deep cervical lymph nodes (in carotid sheath)
- thoracic duct or right lymphatic duct
- venous angle
parts of the tympanic membrane (3)
- pars flaccida (thin part of tympanic membrane, superiorly)
- umbo (most inwardly depressed part of the tympanic membrane)
- pars tensa (thick part of tympanic membrane, posteroinferiorly)
otoscopic exam technique in adults and children (examination of the EAM and tympanic membrane)
- in child gently pull auricle posteroinferiorly (EAM s straight and short and speculum may damage tympanic membrane)
- in adult gently pull the auricle posterosuperiorly (the adult EAM is curved)
direction of cone of light within ear
normally anteroinferiorly
bones of posterior cranial fossa (2)
- temporal
- occipital
function of eustachian tube
-connects the tympanic cavity/middle ear cavity to the lateral wall of the nasopharynx
general sensory nerve supply to tympanic membrane (2)
- external surface = mostly CN V3 (auriculotemporal branch)
- internal surface = CNIX
what does the glossopharyngeal nerve (CNIX) provide sensory innervation to (5)
- middle ear cavity
- eustachian tube
- nasopharynx
- oropharynx
- tonsils
other names for eustachian tube (2)
- auditory tube
- pharyngotympanic tube
clinical significance of eustachian tube (2)
- bacteria/viruses can spread between middle ear cavity and nasopharynx, ie. from pharynx/tonsils causing pain and hearing loss
- common sensory nerve supply of CNIX of naso/oropharynx and laryngopharynx can cause tonsillitis/pharyngitis to mimic earache (common e.g.. of referred pain)
adenoid
pharyngeal tonsil
the ‘tonsil’
palatine tonsil
auditory ossicles (3)
- > 3 bones of the middle ear that articulate via synovial joints
- malleus (mallet) (handle of malleus creates umbo)
- incus (anvil)
- stapes (stirrup) (base of stapes fits into oval window)
epitympanic recess
superior to the tympanic membrane
umbo
-the handle of the malleus which is adherent to the internal aspect of the tympanic membrane, creates the umbo
location of tympanic cavity ‘proper’
posterior to tympanic membrane
cause of mastoiditis of mastoid process
spread of infection from middle ear cavity
aditus (within middle ear cavity)
doorway into the mastoid antrum from the epitympanic recess
what is the promontory (middle ear cavity)
bony swelling on the medial wall formed by the cochlea of the internal ear
nerve axons within facial nerve (4)
- special sensory
- sensory
- motor
- parasympathetic
course of facial nerve (3)
- connection to CNS (brainstem at junction between pons and medulla)
- intracranial part of course (directly into IAM in posterior cranial fossa -> travels through facial canal in petrous temporal bone and chorda tympani branches off)
- bass of skull foramen part of course (IAM -> stylomastoid foramen)
chorda tympani nerve supply (2)
- branch of CNVII (within middle ear cavity)
- > supplies taste buds of the anterior 2/3rds of tongue
- > parasympathetic supply to the submandibular and sublingual salivary glands for salivation
function and nerve supply of stapedius
- thinnest skeletal muscle in the body supplied by CNVII
- reduces stapes movement to protect the internal ear from excessive noise
facial canal
connects IAM to stylomastoid foramen for course of facial nerve to travel through petrous temporal bone
tensor tympani
dampens the noise produced by chewing (has the same nerve supply as the muscles of mastication)
extra cranial course of facial nerve
- exits stylomastoid foramen to supply muscles of facial expression
- chorda tympani joins with CNV3 to supply sublingual and submandibular salivary glands
clinical test of muscles of facial expression (4)
- frown
- close eyes tightly
- smile
- puff out cheeks
clinical sign of malnutrition
loss of buccal fat pat in illness giving appearance of ‘sunken’ cheeks
what part of temporal bone is the internal ear within
petrous
2 parts of vestibulocochlear nerve (2)
- cochlear nerve (for hearing)
- vestibular nerve (for balance)
location of dense otic capsule of internal ear
sits in temporal bone (otic capsule bone is denser than the surrounding temporal bone)
internal ear labyrinths
- otic capsule within temporal bone contains bony labyrinth (fluid/perilymph filled, spaces inside the otic capsule)
- within the perilymph of the bony labyrinth = membranous labyrinth made up of communicating sacs and ducts containing endolymph fluid
- > perilymph is like ECF
- > endolymph is like ICF
- > membranous labyrinth floats in perilymph within the bony labyrinth
shape of bony labyrinth (2)
- cochlea made up of 1st turn, 2nd turn and cupula (apex of spiral)
- anterior/lateral and posterior semicircular canal
what are the cochlear and semicircular ducts filled with
endolymph
location of cochlear and vestibular nerve axons (2)
- cochlear duct = cochlear nerve axons
- semicircular duct = vestibular nerve axons
steps involved in internal ear sound transmission (7)
- sound waves make tympanic membrane vibrate
- vibrations are transmitted through ossicles
- base of stapes vibrates in oval window
- vibration of stapes creates pressure waves in perilymph
- hair cells in the cochlea are moved, neurotransmitter is released, APs stimulated and conveyed to brain by cochlear nerve
- pressure waves descend and become vibrations again
- pressure waves are dampened at the round window
symptoms associated with pathology at the IAM (involving CNVII and CNVIII)
- CN VII:
- > ipsilateral loss of facial expression
- > ipsilateral loss of taste
- > dry mouth (reduced ipsilateral salivation)
- > reduced general sensation in the auricle (immediately posterior to the triages)
- CN VIII:
- > ipsilateral loss of hearing (cochlear nerve)
- > ipsilateral loss of balance (vestibular nerve)
what is the lymphatic system made up of (4)
- organs (bone marrow, spleen and thymus)
- lymphatic vessels (e.g. thoracic duct)
- lymph nodes
- mucosa-associated lymphoid tissue (MALT e.g. tonsils)
function of lymphatic system (3)
- removes excess fluid (interstitial/tissue) from the tissues of the body and returns it as lymph to the venous system
- carries fat from the GI tract
- produces immune cells (lymphocyte, plasma cells and monocytes) in the defence against infection and cancer
thoracic duct
- major lymphatic vessel in the body
- returns lymph to large veins in the neck
lymph
excess tissue fluid once it has been taken up by the lymphatic vessels
daily volume of cardiac output
approx 8000L
daily volume of plasma ultra-filtered
approx 20L
daily volume of tissue fluid reabsorbed
approx 16-18L
daily volume of lymph produced and returned to blood at venous angles
approx 2-4L
daily volume of lymph produced in the head and neck
approx 400ml
elephantiasis
- accumulation of lymphatic tissue and fluid causing significant swelling, particularly in lower limb
- due to insignificant drainage of lymphatic fluid from tissue fluid
location of lymph nodes
along the pathways of the lymphatic vessels travelling from the anatomical structures of the head and neck back to the thoracic duct/right lymphatic duct
function of lymph nodes
- filter lymph
- lymphocytes and macrophages within the lymph nodes screen lymph for infectious agents/cancer cells
state of lymph node if fighting an infection in the lymph
- germinal centres produces
- lymph node enlarges and becomes painful due to stretching of capsule
metastasis
growing of secondary tumour in lymph node following cancel cells becoming stuck and escaping the notice of the immune surveillance system
regional lymph nodes
group of lymph nodes that first receive lymph from any given structure/area
2 groups of lymph nodes found in the head and neck (2)
- superficial ring
- deep cervical nodes
superficial ring of regional lymph nodes (drain scalp, face and superficial neck region) (8)
- parotid nodes
- buccal nodes
- submental nodes
- submandibular nodes
- occipital nodes
- mastoid nodes
- superficial cervical nodes
- external jugular vein
deep cervical lymph nodes (5)
- > drain deep structures of head and neck/ final common pathway from head and neck
- retropharyngeal nodes
- submental nodes
- submandibular nodes
- deep cervical nodes
- internal jugular vein
location of left venous angle
between IJV and SCV
tonsils of the head and neck (4)
- palatine tonsil/’tonsil’ (in oropharynx)
- ‘palate associated lymphoid tissue’
- pharyngeal tonsil/’adenoid’ (superior aspect of nasopharynx,superior to auditory tube)
- tubal tonsils (in nasopharynx, posterior to auditory tube)
waldeyer’s (defensive) ring of lymphoid tissue
- > first line of defence against exogenous aggressors
- made up of:
- > pharyngeal tonsil (adenoid)
- > tubal tonsils
- > ‘palate associated lymphoid tissue’
- > palatine tonsil (‘tonsil’)
- > lingual tonsil
which cells do the germinal centres of the tonsil generate
B cells
where does the lymph from the palatine tonsil drain to
-specific deep cervical lymph node = jugulodigastric node
jugulo-digastric node
- regional lymph node for the palatine tonsil
- commonly enlarged with tonsillitis
lymphatic drainage of teeth/gingivae (3)
- lower anterior teeth, alveolar bone, gingiva, middle of lower lip and chin, tip of tongue drain to submental nodes first before submandibular nodes
- all other teeth, alveolar bone, and gingiva reminder of lips and anterior palate drain to the submandibular lymph nodes first
- > submandibular lymph nodes then drain to the deep cervical nodes
effect of dental abscesses on lymph nodes
may cause enlarged & painful submental and submandibular lymph nodes
lymphatic drainage of tongue
- posterior 1/3rd:
- > drains bilaterally to superior deep cervical nodes
- anterior 2/3rds:
- > middle drains bilaterally to inferior deep cervical nodes
- > sides drain unilaterally to submandibular nodes
- > tip drains bilaterally to submental nodes
state of lymph nodes due to infection, e.g.. dental abscess
- swollen
- painful
- soft
- smooth
- not fixed (stuck to) adjacent structures
- improve rapidly with antibiotics etc
state of lymph nodes due to cancer e.g.. of tongue or gingiva
- swollen
- not painful
- hard
- irregular
- fixed
- do not improve with antibiotics
clinical examination of lymph nodes during full examination of dental patient
-should include assessment of the submental, submandibular and deep cervical lymph nodes
symptoms of hayfever (3)
- sneezing and stuffy runny nose (due to activation of hay fever ganglion causing nasal glands to secrete mucous
- watery eyes (activation of hay fever ganglion causes lacrimal gland to produce tears)
- acute inflammation of nasal mucosa (dilated blood vessels)
what causes hayfever
pollen allergy
what is ‘allergic rhinitis’
hayfever
location of the pterygopalatine fossa (6)
- anterosuperiorly to foramen ovale within the infratemporal fossa
- beneath the apex of the orbital cone (beneath posterior orbit)
- anterior to the pterygoid process of the sphenoid bone
- posterior to the maxilla
- medial to the infratemporal fossa
- lateral to the posterosuperior part of the lateral wall of the nasal cavity (conchae)
communications of the pterygopalatine fossa (4)
- the orbit (via inferior orbital fissure anteriorly, along with Vb-infraorbital, zygomatic)
- middle cranial fossa (via foramen rotundum,Vb before branch and pterygoid canal nerve of pterygoid canal posteriorly)
- infratemporal fossa (via pterygomaxillary fissure laterally)
- nasal cavity (via sphenopalatine foramen,sphenopalatine artery from maxillary, which supplies lateral and medial walls of the nasal cavity medially)
location of sphenopalatine foramen
- from pterygopalatine fossa to the nasal cavity
- in lateral wall of nasal cavity, between body of sphenoid and perp. plate of palatine bone
contents of pterygopalatine fossa (3)
- terminal 1/3rd of maxillary artery
- CN Vb (FR, pterygopalatine fossa)
- pterygopalatine ganglion (‘ganglion of hay fever’) = parasympathetic ganglia of head and neck
parasympathetic ganglia of head and neck (4)
- pterygopalatine ganglia (ganglia of hay fever)
- otic (secretomotor to parotid)
- ciliary (oculomotor nerve associated with orbit)
- submandibular ganglion (secretomotor supply to the submandibular and sublingual glands)
branches of first part of maxillary artery (5)
- superficial temporal
- deep auricular
- anterior tympanic
- middle meningeal (+accessory) meningeal
- inferior alveolar
branches of 2nd part of maxillary artery (4)
- masseteric
- pterygoid
- deep temporal
- buccal
branches of 3rd part of maxillary artery (5)
- mental (branch of inferior alveolar = branch of 1st part)
- sphenopalatine
- descending palatine
- posterior/middle/anterior superior alveolar
- infraorbital
location of 3rd part of maxillary artery
anterior to lateral pterygoid
arterial blood supply to the maxillary teeth (3)
- > third part of maxillary artery:
- posterior superior alveolar artery supplies molars
- middle superior alveolar artery supplies premolars
- anterior superior alveolar artery supplies anteriors
areas supplied by third part of maxillary artery
- arterial blood supply to the maxillary teeth (posterior/middle/anterior superior alveolar artery)
- arterial blood supply to the skin of the face (infraorbital artery)
- arterial blood supply to the palate and nasal cavity (sphenopalatine artery and greater and lesser palatine arteries)
arterial blood supply to the palate
greater and lesser palatine nerves (branches of 3rd part of maxillary artery)
blood supply to the nasal cavities (3)
- opthalmic artery via anterior and posterior ethmoidal arteries
- maxillary artery via sphenopalatine and greater palatine arteries (maxillary becomes sphenopalatine @ sphenopalatine foramen)
- facial artery (via lateral nasal branch of facial or septal branch of superior labial artery)
nerve that accompanies the sphenopalatine artery
nasopalatine nerve
(somatic) sensory innervation of nasal cavity (2)
- CN V1 anterosuperiorly (anterior ethmoidal branch of nasociliary)
- CN V2 posteroinferiorly (nasopalatine nerve supplies midline septum, lateral wall supplied by lateral nasal branches of greater palatine nerve)
branches of maxillary division of trigeminal nerve (CNV2) ????
- pterygopalatine ganglion after CNV2 enters foramen rotundum (ganglionic branches = nasopalatine supplying nasal septum and greater and lesser palatine supplying lateral wall of nasal cavity)
- zygomatic branch passes through infraorbital fissure onto prominence of cheek and branches into zygomatigotemporal and zygomaticofacial
- posterior superior alveolar nerve branches
- as maxillary branches into infraorbital groove/canal, middle and anterior superior alveolar nerve passes off
- > passes through infraorbital foramen
branches of CNV3 (9)
- From the pterygopalatine fossa:
- > Infraorbital nerve through Infraorbital canal
- > Zygomatic nerve (zygomaticotemporal nerve, zygomaticofacial nerve) through Inferior orbital fissure
- > Nasal Branches (nasopalatine) through Sphenopalatine foramen
- > Posterior superior alveolar nerve
- > Palatine nerves (Greater palatine nerve, Lesser palatine nerve), including the Nasopalatine nerve
- > Pharyngeal nerve
- In the infraorbital canal[edit]
- > Middle superior alveolar nerve
- > Anterior superior alveolar nerve
- > Infraorbital nerve
where does V2 enter pterygopalatine fossa to reach the ganglion
foramen rotundum
division of palate into hard and soft
- anteriorly in line with maxillary 3rd molars = hard palate (extends to maxillary tuberosity)
- posterior to this = soft palate
bones of hard palate (2)
- palatine processes of maxilla
- horizontal plates of palatine bone
what passes through incisive canal
nerve and vessels from nasal cavity to oral cavity
epithelial lining hard palate
keratinised stratified squamous
epithelial lining soft palate
non keratinised stratified squamous
incisive papilla
little bump over incisive foramen
palatine raphe
midline joining of palatine shelves, almost looks like zip on mucosa
why are palatal injections painful
mucosa is REALLY tightly bound to bone
cause of cleft palate
-due to failure of lateral palatine processes to meet and fuse (to each other/septum/maxilla)
complications of cleft palate (4)
- speech
- dental health (overcrowding, therefore tooth decay more likely)
- feeding
- hearing
nerves and vessels of palate (3)
- greater and lesser palatine arteries and nerves (CNV2)
- nasopalatine nerve
do greater/lesser palatine nerves synapse in pterygopalatine ganglion
- no
- only parasympathetics synapse here
somatic sensory nerve supply to palate (3)
- greater palatine nerves (most of anterior hard palate)
- lesser palatine nerves (posterior hard palate)
- a branch of nasopalatine nerve (passes through incisive foramen and supplies palatal gingiva of anterior teeth and mucosa of anterior palate)
clinical importance of lymph nodes in retropharyngeal space
can travel all the way down to mediastinum and diaphragm therefore infection/cancer of palate can spread to these areas
dorsum surface of tongue
posterior surface, lift tongue up to see anterior surface which touches floor of mouth
uvula
- (one of) skeletal muscles of soft palate
- 2 muscles coming together to form one
arches of the soft palate
=skeletal muscles covered in mucosa
- > palatoglossal arch (anterior)
- > palatopharyngeal arch (posterior) from palate-pharynx
5 pairs of muscles of the soft palate (5)
- levator veli palatini (elevates palate)
- tensor veli palatini (tenses palate)
- palatoglossus (palate towards tongue)
- palatopharyngeus (longitudinal muscle of pharynx,pulls pharynx up towards palate)
- musculus uvulae
nerve supply to muscles of soft palate
- all supplied by CNsX/CNXI
- except tensor veil palatini which is supplied by CNV3
- > cranial part of accessory nerve comes up through foramen magnum and comes through jugular foramen with vagus, passes INTO vagus and comes down to the soft palate VIA vagus nerve
- > CNX except tensor veil palatine = acceptable answer
palatine aponeurosis
- tensor veli palatini attaches superiorly to sphenoid bone
- turns medially and enters soft palate
- > loops under pterygoid hamulus
- its tendon then flattens out within the soft palate and and joins with tendon of opposite muscle to form palatine aponeurosis (tendon that connects soft palate-hard palate)
attachments of levator veil palatini
petrous temporal bone - soft palate
attachments of tensor veil palatini
from sphenoid bone - soft palate
attachments of salpingopharyngeus
auditory tube - pharynx
attachments of palatopharyngeus
soft palate to pharynx posterior to palatoglossus
clinical testing of muscles of soft palate (cranial nerves X and V3 and technically CNXI too)
- ask patient to say ‘aaah’
- > if nerves function normal the uvula should lift straight up in midline
- > if there is unilateral nerve pathology, uvula will be pulled away from the non functioning side by the working side
functions of soft palate (3)
- stops food entering nose during swallowing (musculus uvula lifts up in middle and helps thicken/close off)
- directs air into nose or mouth during speech, sneezing, coughing and vomiting
- helps to close off entrance to oropharynx during gag reflex
tonsillar crypt
palatine tonsil
boundaries of the oral cavity:
- > anterior
- > posterior
- > roof
- > floor
- > anterior (alveolar/dental arches of mandible/maxilla)
- > posterior (oropharyngeal isthmus-space bounded laterally by palatoglossal folds)
- > roof (hard palate/soft palate)
- > floor (tongue, muscles of floor of mouth)
palatoglossal folds
boundary between oral cavity anteriorly and oropharynx
what travels within mandibular canal
inferior alveolar nerve (V3/c)
lingual sulcus
deepest part of area between tongue and teeth
buccal sulcus
deepest part of the cheek part of vestibule
what is the buccinator lined with internally
buccal mucosa
buccinator papilla
opening of parotid duct opposite the maxillary second molar tooth
mucosa of hard palate
palatal mucoperiosteum (tightly bound directly to bone)
alveolar mucosa (4)
- upper labial alveolar mucosa (continuous with upper labial mucosa)
- lower labial alveolar mucosa (continuous with lower labial mucosa)
- buccal alveolar mucosa (continuous with buccal mucosa)
- lingual alveolar mucosa (continuous with mucosa of floor of mouth)
why is alveolar mucosa red in comparison to the pink gingiva
- red = non keratinised stratified squamous (upper and lower labial alveolar mucosa)
- keritinisation of gingiva and hard palate reduces transparency of mucosa so less redness from oxygenated blood shines through
junction between gingiva and mucosa
mucogingival junction
free gingivae groove
between free and attached gingivae
labial frenula (frenulum = singular)
folds of mucosa connecting alveolar bone onto lips
attached gingivae
directly associated/stuck to alveolar bone
free gingivae
associated with superior extend of tooth
gingival sulcus/ free gingival groove
->passing probe into free gingivae = passing into gingival sulcus, roof of sulcus = free gingival groove
lingual sulcus
deepest part of floor of mouth, between tongue and mandibular teeth
sublingual fold
openings for ducts of sublingual gland
sublingual papillae
openings for submandibular gland duct
fimbriated folds
- embryological remnants of developing tongue, remains as soft tissue mucosal folds with no function
- on inferior (anterior) surface of tongue
location of deep lingual vein
- on inferior (anterior) surface of tongue
- bilateral or maybe unilateral structure, can cause problems for tongue piercing
frenulum of tongue
-fold of mucosa running from under surface of tongue to floor of the mouth
gingiva/mucosa of internal aspect of mandibular teeth
- lingual gingiva
- lingual alveolar mucosa, continuous with mucosa of floor of mouth
location of sublingual papillae
lateral to frenulum
anterior belly of digastric muscle origin
- associated with floor of mouth (inferior view)
- extends from anterior aspect (digastric fossa)/depression in bone
nerve supply to anterior belly of digastric
nerve to mylohyoid (branch of CNV3)
muscle which forms diaphragm of floor of mouth
- mylohyoid muscle
- >right and left meet in middle at midline raphe, extend from the body of mandible to midline
nerve supply to mylohyoid muscle
CNV3 (nerve to mylohyoid)
does the submandibular duct arise from the superficial or deep part of the gland
deep
attachments of geniohyoid muscles
attach to genial mental spines/genial tubercles of mandible
location of deep part of submandibular gland
deep to mylohyoid muscle
location of sublingual gland (2)
- deep to mylohyoid
- lateral to geniohyoid
lingual nerve (CNV3)
relays general sensation of anterior 2/3rds of tongue back to brain, along with special sense of taste
where does submandibular duct enter floor of mouth
sublingual papillae
->arises from deep part of submandibular gland and passes over lingual nerve
location of lingual nerve
passes internal to rams of mandible
submandibular ganglion
-associated with parasympathetic supply to sublingual and submandibular gland, secretomotor supply synapse here
route of facial nerve CNVII (5)
- leaves skull via IAM
- travels through petrous part of temporal bone
- greater petrosal nerve branches off (carries presynaptic parasympathetic fibres to ganglion of hay fever)
- > before facial nerve passes through stylomastoid foramen, chorda tympani leaves petrous part of temporal bone and hitches a ride with lingual nerve)
- facial passes through stylomastoid foramen to supply muscles of facial expression
nerve supply of chorda tympani branch of CNVII (2)
- parasympathetic secretomotor to submandibular and sublingual glands (preganglionic parasympathetic to ganglion)
- special sense of taste to anterior 2/3rds of tongue
function of tongue (5)
- formation of food bolus
- pushing food bolus to posterior part of oral cavity ready to be swallowed
- keeping mouth clean
- speech
- tasting/sensing the food
location of posterior 1/3rd of tongue
- vertical part
- lies in oropharynx (cannot see when stick tongue out)
groove dividing anterior and posterior tongue
terminal sulcus
location of lingual tonsil
under mucosa on posterior part of tongue
foramen caecum
at point of terminal sulcus on tongue
nerve supply to tongue for general sensation and taste of anterior/posterior (3)
- general sensation and taste both of posterior tongue supplied by CN IX
- general sensation of anterior supplied by CNV3 (lingual nerve)
- taste sensation of anterior supplied by CN VII (via lingual nerve and chorda tympani)
papillae of tongue, function and nerve supply (4)
- vallate papillae (taste buds, CN IX)
- foliate papillae (taste buds CNVII)
- filiform papillae (touch etc, CNV3)
- fungiform papillae (taste buds, CNVII)
motor supply to muscles of tongue
-CNXII, hypoglossal nerve (except palatoglossus muscle of the palate, supplied by vagus nerve, CN X)
intrinsic muscles of the tongue
- originate and insert within the tongue
- act to alter the shape of the tongue
extrinsic muscles of the tongue
originate outwith the tongue from bone and insert into it
4 pairs of extrinsic tongue muscles
- palatoglossus
- styloglossus
- hypoglossus
- genioglossus
types of intrinsic muscles of tongue and functions (2)
- > longitudinal muscles make the tongue short and thick
- >transverse and vertical muscles make tongue long and narrow
attachments of palatoglossus muscle
-palatine aponeurosis down onto side of the tongue
attachments of styloglossus muscle
from styloid process to side of tongue
attachment of hyoglossus
from hyoid bone onto lateral aspect of tongue
clinical testing of CNXII (hypoglossal nerve)
- stick tongue straight out
- > if both CN XIIs are normal the tongue should stick out remaining in midline
- > if one CNXII is damaged, tongue points towards side of injured nerve
function of genioglossus muscle
both genioglossus muscles contract in pushing the tongue tip forwards (sticking tongue out)
functions of oral cavity (3)
- preparation of food bolus for swallowing (involves: mastication/teeth and muscles of mastication, saliva, tongue)
- defence against ingestion of toxins/infection (involves tonsils/lymphoid tissue, special sense of taste)
- speech (oral/nasal sounds involving soft palate and articulation/making sounds of speech involving tongue/lips)
location of larynx (4)
- enclosed in the VISCERAL layer of the pretracheal fascia of neck
- > anterior to laryngopharynx
- > between carotid sheath structures
- > between vertebral levels C4-C6 @cricoid cartilage
- > just posterior to strap muscles
layers of pretracheal fascia (2)
- visceral
- muscular (very thin)
contents of pretracheal fascia (5)
- strap muscles
- thyroid gland
- trachea and larynx
- oesophagus and pharynx
- recurrant laryngeal nerves
laryngopharynx
region of pharynx from epiglottis to oesophagus
carotid sheath structures
- internal jugular vein
- common carotid artery
- CN X
- deep cervical lymph nodes
communications of larynx (2)
- communicates with oropharynx above (oral/nasal cavity)
- communicates with trachea below (at C6)
role of larynx (3)
- rigid skeleton helps keep URT open/maintains patency of URT due to cartilages
- help prevent entry of foreign bodies into LRT (vocal cords and cough reflex)
- produces sound (vocal cords)
boundaries of nasal cavities (right and left)
- > medial wall
- > lateral wall
- > floor
- > roof
- > medial wall = septum (ethmoid, vomer, cartilage, most people have deviated septum, relatively featureless)
- > lateral wall = featured conchae
- > floor = palate
- > roof = anterior cranial fossa
structure of larynx
composed of cartilages suspended from hyoid bone
structure of trachea
- > C shaped anterior rings of hyaline cartilage
- >tracheal smooth muscle completes the posterior wall of the trachea
cricothyroid membrane
- connects cricoid cartilage and thyroid cartilage
- >access point for cricothyroid puncture
what type of cartilage is the laryngeal cartilages
- > all = hyalin
- >EXCEPT for the epiglottis which is elastic cartilage
which laryngeal cartilage is a full ring structure
- cricoid cartilage
- >all other laryngeal cartilages = C shaped filled in with muscles
why is cricothyroid membrane used for emergency breathing access rather than thyrohyoid membrane
below level of vocal cords therefore prevents damaging of vocal cords and there will be nothing blocking the access into trachea
adams apple
=laryngeal prominence of thyroid cartilage
->more prominent in males, however also present in females
what type of joint is the cricothyroid joint and what movement does this jaw allow
- synovial
- nodding movement (A-P) between the thyroid and cricoid cartilages helping to change pitch of voice
laryngeal inlet
entrance into larynx
role of arytenoid cartilages
- move vocal cords
- point at fromt = vocal process (attaching to vocal cords), point at back = muscular process (attaching to muscles)
what is corniculate cartilage
little fold at top of arytenoid cartilages, diff.cartilage itself
attachments of vocal cords (2)
- anteriorly to internal aspect of thyroid cartilage
- posteriorly to vocal processes of arytenoid cartilages
space between vocal cords through which air passes between
rima glottides of larynx
mucosa lining internal aspect of epiglottis
laryngeal mucosa
difference between ‘vocal cords’ and ‘vocal cartilages’
nothing, mean the same thing (vocal cords are thicker cartilages)
muscles that support laryngeal inlet (2)
- cuneiform cartilages
- corniculate cartilages
- > located deep to laryngeal mucosa at arytenoid cartilages
- > have no role in moving vocal cords
laryngeal cartilages (3 pairs, 3 single cartilages)
- pairs:
- > cuneiform
- > corniculate
- > vocal cords
- single:
- > epiglottis
- > cricoid
- > thyroid
laryngoscopy insertion point (for viewing of interior larynx)
-laryngoscope blade inserted into posterior aspect of vallecula (space between the tongue and epiglottis)
space between tongue and epiglottis
vallecula
endotracheal intubation
- > placing breathing tube inside teachea
- endotracheal/ET tube inserted through mouth/pr wider nasal cavity -> oropharynx (or nasopharynx first) -> laryngeal inlet -> rima glottidis of the larynx -> trachea
mucosa lining inside of larynx (2)
- mainly respiratory epithelium
- >except for vocal cords = stratified squamous epithelium
mucociliary escalator
- most of mucosal lining of larynx = respiratory
- > mucous glands secrete mucous onto epithelial surface
- > cilia beat mucous and foreign bodies superiorly towards pharynx to be swallowed
- > prevents build up of mucous in respiratory tract
2 diff. sets of vocal cords (2)
- superior = false vocal cords (vestibular folds)
- inferior = true vocal cords (vocal folds)
why are the superior vocal cords (vestibular folds) called false vocal cords
- they have nothing to do with producing sound, all they are is thickened folds of membrane
- function = protecting airway from foreign bodies passing down
diff between vocal cord and vocal ford
- thickened ligament = vocal cord/vocal ligament
- when covered in mucosa = vocal fold
space between vocal folds
ventricle
nerve supply of laryngeal mucosa
- all sensory innervation supplied by CNX (vagus nerves)
- > everything superior to vocal fold supplied by internal laryngeal branches of superior laryngeal branch of CNX
- > vocal fold and inferior supplied by recurrent laryngeal branches of CN X
laryngeal branches of vagus nerve (4)
- vagus nerve passes through jugular foramen
- superior laryngeal nerve branches off (and splits into internal and external laryngeal branches)
- vagus nerve descends through the neck within carotid sheath
- recurrent laryngeal nerve (branches off CNX in mediastinum)
- inferior laryngeal nerve = continuation of recurrent laryngeal
loop of recurrent laryngeal nerves on left and right
- left loops under arch of aorta
- right loops under subclavian
motor and sensory innervation to larynx
both via vagus nerves and branches (CNX)
intrinsic muscles of larynx (4)
- > skeletal muscles (voluntary control)
- tensors of vocal cords (cricothyroid muscles)
- relaxers of vocal cords (thyro-arytenoid muscles)
- adductors of vocal cords (lateral circo-arytenoids & arytenoid muscles)
- abductors of vocal cords (posterior circo-arytenoid muscles)
somatic motor supply to intrinsic muscles of larynx
via somatic motor branches of vagus nerve
attachments of intrinsic muscles of larynx
attach between cartilages, act to move cartilages which move the vocal cords
tensors of vocal cords
=cricothyroid muscles of larynx
- ‘nodding’ the thyroid cartilage anteriorly at the cricothyroid joints, stretching the vocal cords
- > produce high pitched sound
relaxers of vocal cords
- thyro-arytenoid muscles
- relax vocal cords when they contract
- pull arytenoid cartilages towards the thyroid cartilage
- > produce low pitch voice (more relaxed vocal cords)
vocalis muscles
tiny muscles between thyroarytenoid and vocal cord
adductors of vocal cords (2)
- > lateral crico-arytenoid muscles (rotate the arytenoid cartilages so that the vocal processes of the cartilages come together at the midline)
- > arytenoid muscles (transverse and oblique arytenoids, assist the lateral cricoarytenoids to gently close the rima glottidis,sphincter function)
what happens if lateral circo-arytenoid muscles, arytenoid muscles AND cricothyroid muscles contract at the same time
tight closure of airway sphincter can occur
abductors of vocal cords
=posterior crico-arytenoid muscles
- > rotate arytenoid cartilages so that the vocal processes of the cartilages move laterally
- > widens the rima glottidis
only muscle of larynx that can abduct vocal cords and help rima glottidis open
posterior crico-arytenoid muscles
state of laryngeal muscles during normal resting respiration
laryngeal muscles are relaxed
state of laryngeal muscles during forced respiration
posterior crico-arytenoids contract
state of laryngeal muscles during phonation (talking/sound production)
- arytenoids contract
- assist lateral crico-arytenoids
state of laryngeal muscles during whispering
- lateral crico-arytenoids contract
- >tiny posterior opening to allow air to pass over vocal cords and allow whispering
anatomical steps involved in sound production (6)
- inspiration
- controlled expiration
- phonation
- articulation
- > oral sounds
- > nasal sounds
what is involved in inspiration during sound production
- diaphragm and/or intercostal muscles
- >phrenic and intercostal nerves
phonation
- producing a sound in the larynx
- stream of air expired over vocal cords
what dictates the pitch of sound produced by vibration of vocal cords
the length/tension of vocal cords (controlled by intrinsic muscles)
- > thyro-arytenoids produce low pitch by relaxing vocal cords
- > cricothyroids produce high pitch by tensing/stretching vocal cords
what happens in the articulation step of sound production
production of recognisable sound within oral/nasal cavities
how are oral sounds produced during articulation of sounds (3)
- soft palate tenses (CNV3) and elevates (CN X) to close off entrance into nasopharynx
- directs steam of air through oral cavity
- sound interrupted by tongue (CN XII) and the teeth/lips (CNVII) to produce most vowels/consonants in english
how are nasal sounds produced during articulation of sounds (3)
- soft palate tenses (CNV3) and descends (CNX) to close off entrance into oropharynx
- directs steam of air through nasal cavities
- produces one of three sounds (‘m’, ‘n’, ‘ing’) depending on position of tongue (CNXII) teeth and lips (CNVII)
clinical testing of vagus nerves (CNX) (3)
- > sensory and motor supply to the palate,pharynx and larynx
- ASK PATIENT TO SWALLOW SMALL SIP OF WATER (watch larynx move up and down, do they splutter)
- LISTEN TO PATIENT SPEAK (is voice hoarse? are the intrinsic muscles of larynx functioning normally to move vocal cords)
- ASK PATIENT TO COUGH (is cough normal and powerful? also requires functioning diaphragm,phrenic nerves abdominal wall etc)
stage 1 of swallowing (3)
- close lips
- food bolus squeezed to back of mouth
- tongue against palate
stage 2 of swallowing (4)
- nasopharynx closed off
- > soft palate tenses
- larynx elevated
- pharynx enlarged to receive bolus
stage 3 of swallowing (2)
- pharyngeal constrictors contract sequentially
- longitudinal muscles of pharynx raise larynx to close off laryngeal inlet
stage 4 of swallowing (2)
- epiglottis deflects bolus
- bolus moves into oesophagus
what is deglutition
swallowing
anatomy of coughing (5)
- breath in using diaphragm (phrenic nerves)
- close vocal ligaments (CNX)
- contract abdominal wall to build up pressure beneath the closed vocal ligaments
- suddenly open vocal ligaments (CN X)
- tense (CNV3) and raise (CNXI) the soft palate to direct the steam of air through mouth
the most important protective reflex in humans
coughing
what triggers coughing reflex
-foreign bodies that hit the larynx (inside of larynx is acutely sensitive to touch, CNX)
what is aspiration and what are the causes (2)
- > inhalation of liquid or solid into lungs
- caused by either:
- > abnormal swallowing (accidental or pathological eg.following stroke)
- > breathing in (abnormal coughing, pathological e.g. following stroke, cough reflex inhibited by general anaesthetic)
- > especially stroke affecting CNX
how does brainstem stroke affect cranial nerves
bleeding from, or blockage of, branches from the vertebral arteries or basilar artery which also supply the cranial nerves attaching to the brainstem
symptoms of patient with damage to CNX (3)
- hoarse voice
- abnormal swallow
- weak cough
emergency airway management techniques (2)
- heimlich manoeuvre
- cricothyroid puncture
divisions of upper arm (2) and bones that make up both divisions
- arm (humerus)
- forearm (radius + ulna)
pectoral girdle
associated with clavicle and scapula
location of ulna
medial in anatomical position (next to pinky finger)
location of radius
lateral in anatomical position (thumb side)
location of cubital fossa (2)
- depression on anterior aspect of elbow
- anterior to distal humerus and elbow joint (which sit deep)
most superficial structures of cubital fossa
veins
boundaries of cubital fossa triangle (5)
- > superior
- > medial
- > lateral
- > floor
- > roof
- superior = imaginary line connecting medial and lateral epicondyles (bumps extending from distal end of humerus)
- medially = flexor muscles arising from medial epicondyle
- laterally = extensor muscles from lateral epicondyle
- floor = brachial and supinator muscles of arm and forearm
- roof = deep fascia, bicipital aponeurosis, superficial fascia, skin
location of supinator muscle
deep to arteries and veins of cubital fossa on medial aspect of brachialis muscle
bicipital aponeurosis
extension of tendon of bicep that then blends with deep fascia covering the muscles of the forearm
contents of cubital fossa (4)
- terminal brachial artery and commencement of radial and ulnar arteries
- biceps brachii tendon
- median nerve
- radial nerve
bifurcation of brachial artery
-into ulnar and radial artery within median cubital fossa
biceps brachii tendon insertions
extends from muscle belly of biceps to its insertion site - tuberosity of radius
where does median nerve arise
brachial plexus (median nerve = 1 of 5 named branches)
superficial contents of fascia overlaying cubital fossa (3)
- median cubital vein (anterior to brachial artery)
- basilic (medial) and cephalic (lateral) veins
- medial and lateral cutaneous nerves of forearm
median cubital vein
- connects cephalic vein to basilic
- blood sample usually taken from here
- not within cubital fossa (sits superficial to it)
drainage of dorsal venous plexus (2)
- > drains into basilica vein medially (side of pinky)
- >drains laterally into cephalic vein (side of thumb)
drainage of cephalic and basilic vein (3)
- basilic vein dives deep to become the brachial vein which then becomes the axillary vein upon entering the axilla (armpit)
- cephalic vein drains into axillary vein after running through the delto-pectoral groove
- > axillary vein then becomes subclavian vein at the lateral border of first rib
- > subclavian vein + IJV = brachiocephalic vein, brachiocephalic veins -> SVC -> RA
cycle of venous blood to lungs then back to arterial system including valves (6)
- SVC and IVC -> RA
- RA -> RV (via tricuspid valve)
- RV->pulmonary trunk and arteries going to lungs (via pulmonary valve)
- lungs ->LA via pulmonary veins
- LA->LV (via mitral valve)
- LV->arch of aorta (via aortic valve)
clinical significance of structures deep to median cubital vein
- common vein for taking blood
- potentially could miss target and hit important deep structures
deep contents of cubital fossa (from lateral to medial) (5)
- brachioradialis muscle (lateral border)
- biceps brachii tendon/aponeurosis
- brachial artery
- median nerve
- pronator teres muscle (medial border)
origin of radial/ulnar arteries
-arch of aorta -> brachiocephalic trunk -> subclavian artery -> axillary artery -> brachial artery -> splits into radial artery (lateral on thumb side) and ulnar artery (medial on pinky side)
which artery gives peripheral pulse
radial artery
CNS
brain + spinal cord
nerve plexuses (and 2 eg.’s of named branches)
=adjacent spinal nerves mix their fibres
- > great auricular nerve (C2,3)
- > phrenic nerve (C3,4,5)
origin of brachial plexus
spinal nerves C5-T1
->terminal branches break off in armpit region
nerve axons of median nerve
- sensory (to skin of forearm, arm and palm)
- motor (muscles of arm and forearm)
- sympathetic
- > supplies structures in distal upper arm (forearm, wrist and hand)
nerve important in dental local anaesthesia injection
- trigeminal nerve
- > Vb maxillary division
- > Vc mandibular division
areas anaesthetised by dental local anaesthesia (8)
- teeth
- gingivae (labial/buccal/lingual/palatal)
- alveolar mucosa
- labial mucosa
- buccal mucosa
- lingual mucosa
- floor of mouth
- hard palate
dental local anaesthesia techniques (4)
- topical (surface anaesthetic via cream)
- injection:
- > infiltration (infiltrates target tissue)
- > block (blocks particular nerve trunk)
- > supplemental techniques (as not all techniques work)
e.g. of dental LA infiltration injection
- apex of tooth
- > depends on density of surroundings
- > maxilla is thinner/more porous than mandible
eg. of block injection (dental LA) (4)
- inferior alveolar nerve
- lingual nerve
- long buccal nerve
- mental/incisive nerve blocks
how do LA drugs work
- REVERSIBLY block sodium channels (pass through axon membrane and bind to sodium channel from inside of nerve)
- > sodium channels usually open, sodium enters, threshold is reached and action potential is fired (therefore to block action potentials, sodium channels are reversibly blocked)
do LA drugs work well if infection is present
no
eg’s of LA drugs (4)
=amide drugs
- > lidocaine (gold standard)
- > prilocaine, mepivacaine
- > bupivacaine
- > articaine (newish)
dental procedures requiring use of LA drugs (3)
- > restorations (pulp anaesthesia)
- > extractions (pulpal anaesthesia and adjacent soft tissue anaesthesia)
- > biopsies (gingivae or mucosa in the lesion site)
buccal tissues (and innervation) (3)
- buccal sulcus
- buccal mucosa
- buccal gingivae
- > all innervated by long buccal nerve except upper buccal gingivae
lingual tissues (and innervation) (4)
- lingual sulcus
- lingual mucosa
- lingual gingivae
- floor of mouth mucosa
- > all innervated by lingual nerve
location of lingual alveolar mucosa
between lingual sulcus and lingual gingivae
nerves involved in maxillary anaesthesia of incisors and canines (3)
- dental branches of anterior superior alveolar nerves supply teeth and gingival branches supply labial gingivae
- incisive branch of nasopalatine nerve supplies palatal gingivae
nerves involved in maxillary anaesthesia of premolars (3)
- dental branches of middle superior alveolar nerves supply teeth and gingival branches supply buccal gingivae
- branches of greater palatine nerve supply palatal gingivae
nerves involved in maxillary anaesthesia of molars (3)
- dental branches of posterior superior alveolar nerves supply teeth and gingival branches supply buccal gingivae
- branches of greater palatine nerve supply palatal gingivae
maxillary infiltration LA:
->labial/buccal infiltration
->palatal infiltration
(aim and results)
- > labial/buccal infiltration:
- into labial/buccal sulcus (alveolar mucosa)
- aim for apex of tooth
- result = pulpal anaesthesia (dental branches) and labial/buccal anaesthesia (gingival branches)
- > palatal infiltration
- into palatal mucoperiosteum
- result = palatal soft tissue anaesthesia
mandibular infiltrative anaesthesia
-only effective for anterior region (bone too dense for LA to reach posterior tooth apices)
mandibular nerves blocked by LA (4)
- inferior alveolar nerve
- lingual nerve
- long buccal nerve
- mental and incisive nerve
where does the inferior alveolar nerve enter mandibular canal
via mandibular foramen, in level with mandibular occlusal plane
application of inferior alveolar nerve block (inc. landmarks)
- aim to deposit LA close to IAN before it enters the mandible (within pterygomandibular space therefore complex anatomy)
- > landmarks = retromolar triangle, pterygomandibular raphe, coronoid notch of ramus and opposing premolars
- > thumb in coronoid notch, look into retromolar region, needle inserted between the two
- > insert needle until bone is touched (2.5cm)
borders of pterygomandibular space (lateral, medial, posterior, anterior, superior)
- lateral = ramus
- medial = medial pterygoid muscle
- posterior = parotid (+VII nerve)
- anterior = buccinator
- superior = lateral pterygoid muscle
lingual nerve block
- same location as inferior alveolar nerve block
- insert needle until bone is touched (2.5cm) then withdraw needle by 1cm
key sign of success of inferior alveolar nerve block
numb lip (mental nerve)
dangers of injecting inferior alveolar nerve block too deep
- inject into parotid
- block facial nerve (CNVII) -> motor supply to muscles of facial expression, causing facial palsy (smiling on one side)
- > risk of intravascular injection
how common is it for inferior alveolar nerve blocks to fail
1/5
mental and incisive nerve block
- aim to deposit LA beside mental foramen (normally below lower premolars)
- anaesthetise:
- > mental nerve (soft tissues incl. lip, labial mucosa and gingivae)
- > incisive nerve (anterior teeth)
dental nerve innervation (maxillary and mandibular) (5)
- maxillary 3-3 = anterior superior alveolar nerve
- maxillary premolars and mesio buccal root of 1st molar = middle superior alveolar nerve
- remainder of maxillary molars = posterior superior alveolar nerve
- mandibular 3-3 = incisive nerve
- mandibular premolars and molars = inferior alveolar nerve
dental mucosal innervation (9)
- upper labial mucosa = infraorbital nerve
- hard palate = incisive branch of nasopalatine nerve and greater palatine nerve
- soft palate = lesser palatine nerve
- buccal mucosa = long buccal nerve
- lingual mucosa = lingual nerve
- inferior labial mucosa = mental nerve
- gingivae of maxillary incisors = anterior superior alveolar nerve
- gingivae of maxillary premolars and mesiobuccal root of molar = middle superior alveolar nerve
- gingivae of remaining maxillary molars = posterior superior alveolar nerve
application of maxillary infiltration LA injection
- use mirror to retract lip
- inject solution into alveolar mucosa, very slowly (over about a min)
- > eventually anaesthetic diffuses through the bone and reaches apex of tooth
why are upper 6’s difficult to anaesthetise
-divergent roots
bone around 6 is a lot thicker as zygomatic process of maxilla is above
->inject infront of 6, behind 6 and into palate to innervate all roots
pterygomandibular space
space between pterygoid muscle and mandible
pterygomandibular raphe
attachment of buccinator to superior constrictor
