Head And Neck Session 9 Flashcards
What is the oral vestibule?
Slit-like space between the teeth, gingiviae, lips and cheeks
What peri-oral muscles control the oral fissure?
Orbicularis oris, buccinator, risoris, depressors and elevators of the lips
What is gingiva?
Fibrous tissue covered with mucous membrane that reflects in the alveolar sockets with the periosteum
How does gingiva proper appear?
Pink, stippled and keratinized
How does the alveolar mucosa appear?
Shiny, red and non-keratinised
What do the lips contain?
Orbicularis oris, superior and inferior labial muscles, vessels and nerves
What is the labial frenulum?
Free-edged fold of mucous membrane in the midline from the vestibular gingiva to mucosa of upper and lower lips
Which labial frenulum is longer?
Superior
What provides blood supply to the upper lip?
Facial and infra-orbital arteries
What gives arterial supply to the lower lip?
Facial and mental arteries
Where are buccal glands found?
Between buccinator and mucous membrane
Where are the buccal fat pads?
Superficial to buccinator
Why are the buccal fat pads larger in infants?
To prevent cheeks from collapsing during suckling
What is the vermillion border?
Change in epithelium from highly to less keratinised to continue with labial mucosa
How many generations of dentition do humans have?
2
What are the primary/deciduous teeth?
20 small teeth that erupt from 6 months to 3 years
At what age do the deciduous teeth exfoliate?
6 y.o.
What replaces the deciduous teeth after exfoliation?
Secondary/permanent
Describe the secondary/permanent teeth.
32, do not regenerate
Where do permanent teeth remain dormant if the overlying primary tooth is not lost?
Alveolar bone
What is the term used for the internal surface of maxillary teeth?
Palatal surface
What is the term used for the internal surface of mandibular teeth?
Lingual surface
What are the teeth anchored in?
Alveolar processes of maxilla and mandible
How are the secondary/permanent teeth named?
Central incisor, lateral incisor, canine (cuspid), 1st and 2nd premolars (bicuspid), 1st, 2nd and 3rd molars
What is the colloquial name for the 3rd molars?
Wisdom teeth
What is the major structural difference between gingiva proper and alveolar mucosa?
Gingiva proper is firmly attached to the underlying structure, alveolar mucosa is free
What gives arterial supply to the teeth?
Superior and inferior alveolar arteries from maxillary
What gives venous drainage to the teeth?
Alveolar veins that follow arteries
Where does lymph from the teeth and gingiviae drain?
Submandibular lymph nodes
What is the oral cavity proper?
Space between upper and lower dental arcades, palate and oropharynx
What is the oral cavity occupied by when the mouth is closed and at rest?
Tongue
What anatomical feature marks the start of the oropharynx?
Junction of hard and soft palate
What are the components of the hard palate?
Palatine process of maxilla, lateral and medial pterygoid plates, pterygoid hamulus, vomer and choanae
What becomes the maxilla after ossification?
Lateral palatine process
What fuses in the foetus to form the palatine raphe?
Median and lateral palatine processes with nasal septum
What is found at the anterior end of the palatine raphe?
Incisive fossa
What muscles make up the soft palate?
M. levator palatini, m. uvulae, m. tensor veil palatini, m. palato glossus, m. palato pharyngeus
Which muscles forms the anterior/palatoglossal arch?
M. palato glossus
What muscles forms the posterior/palatopharyngeal arch?
M. palato pharyngeus
Where does the soft palate attach to the hard palate?
At the anterior border of the choanae, just posterior to the great and lesser palatine foramina
Where does m. tensor veli palatini attach?
Pterygoid hamulus
Why does the uvula deviate away from the side of lesion?
All except m. tensor veli palatini are innervated by the vagus nerve so a lesion causes unopposed muscle action away from affected side
What gives blood supply to the hard and soft palates?
Greater, lesser and ascending palatine arteries
What gives venous drainage to the hard and soft palates?
Pterygoid venous plexus
What gives sensory innervation to the gingiviae, mucous membranes and glands of the hard palate?
Greater palatine artery
What gives sensory innervation to the mucous membranes of the anterior hard palate?
Nasopalatine nerve
What gives sensory innervation to the soft palate?
Lesser palatine nerve
Where does the duct of the parotid gland open?
Buccal mucosa opposite 2nd molar
Where do the submandibular glands empty?
Papilla each side of the frenulum
How are the sublingual glands drained?
Via several ducts through lots of papillae
What vein is visible on the sublingual surface of the tongue?
Deep lingual
What divides the tongue into its root and body?
Terminal sulcus
What are the 4 types of lingual papillae?
Valate, foliate, filiform, fungiform
Which lingual papillae are sensitive to touch?
Filiform
What is the foramen cecum?
Non-functional embryological remnant of the thyroglossal duct marking the middle of the terminal sulcus
Is the pharyngeal part of the tongue visible on inspection?
Not without a mirror or tongue depressor
What lymphoid tissue is found in the root of the tongue?
Lymphoid nodules of lingual tonsil
What does the midline groove of the tongue overlie?
The lingual septum
What forms the anterior wall of the oropharynx?
Pharyngeal part of tongue
What gives motor innervation to the tongue?
CNXII
What gives general and special sensory innervation to the posterior 1/3 of the tongue?
CNIX
What gives general sensory innervation to the anterior 2/3 of tongue?
CNV
What gives special sensory innervation to the anterior 2/3 of the tongue?
CNVII
What are the extrinsic muscles of the tongue?
Styloglossus, hyoglossus and genioglossus
What are the intrinsic muscles of the tongue?
Superior longitudinal, vertical, transverse, inferior and longitudinal (named according to muscle fibre direction)
What action do the superior longitudinal fibres of the tongue have?
Pull the sides of the tongue up
What is the action of the longitudinal muscles fibres of the tongue?
Pull the sides of the tongue down
Why does the tongue deviate towards the side of lesion?
Unopposed push
Where should you look for uvula deviation?
At the base
What forms Waldeyer’s ring?
Adenoid, tubal, palatine and lingual tonsils
Where does exudate accumulate in tonsilitis?
Crypts of palatine tonsils
Where are the tubal tonsils found?
End of the Eustachian tube
Where are the palatine tonsils located?
Between anterior and posterior arches
What can cause uvula deviation other than nerve lesion?
Peritonsillar abscess
What type of joint is the TMJ?
Modified hinge-type synovial
What forms the TMJ?
Mandibular fossa, articular tubercle and head of mandible all covered in fibro cartilage
What splits the TMJ joint into two cavities?
Articular disc
What lines the 2 cavities of the TMJ?
Superior and inferior synovial membranes
What forms the superior cavity of the TMJ?
Temporal bone and upper part of articular disc
What forms the inferior cavity of the TMJ?
Mandibular condyle and inferior aspect of articular disc
What shapes does the articular disc have?
Upper surface is concavo-convex and lower surface is concave. Thinner centrally than at edge
Why is the capsule surrounding the TMJ relatively thin and loose?
Allow for movement
What ligaments are found at the TMJ?
Lateral, 2 medial, sphenomandibular and stylomandibular
Which ligament of the TMJ is the strongest?
Lateral
Describe the structure of the lateral ligament of the TMJ.
Zygoma –> neck and ramus of mandible with deep fibres blending with the joint capsule
Describe the structure of the sphenomandibular ligament.
Spine of sphenoid –> lingula
How does the sphenomandibular ligament prevent inferior dislocation of the TMJ?
Keeps a constant length and tension at all mandibular positions
Describe the structure of the stylomandibular ligament.
Styloid process –> posterior ramus of mandible as an extension of the deep parotid fascia
Which two structures does the stylomandibular ligament separate?
Parotid and submandibular glands
Does the stylomandibular ligament contribute significantly to the strength of the TMJ?
No
What does movement of the TMJ require?
Displacement of the mandible
What movements can the TMJ carry out?
Translation (gliding), rotation (pivoting), elevation, depression, retraction and protrusion
Which cavity of the TMJ is responsible for translational movement?
Superior cavity
Which cavity of the TMJ facilitates rotation of the joint?
Inferior
What stabilises the jaw when closed?
Mandibular condyle into mandibular fossa and action of teeth
Where does the majority of force pass through during chewing?
Teeth
What prevents posterior dislocation of the jaw?
Posterior glenoid tubercle
What prevents anterior dislocation of the jaw?
Articular tubercle
What prevents inferior dislocation of the jaw?
Spheno- and stylomandibular ligaments
What muscles are involved in closing the mouth?
Temporalis acting at the superior cavity and temporalis, masseter and medial pterygoid acting at the inferior cavity
What allows protrusion of the mandible?
Lateral pterygoid acting the superior cavity
What allows depression of the mandible?
Digastric acting at the inferior cavity
Is digastric a prime mover of the mandible?
No
What is the infratemporal fossa?
Irregularly shaped space deep and inferior to the zygomatic arch, below middle cranial fossa, deep to the ramus of the mandible and posterior to the maxilla
How does the infratemporal fossa communicate with the temporal fossa?
Through interval between zygomatic arch and cranial bones
What forms the roof of the infratemporal fossa?
Greater wing of sphenoid
What forms the medial border of the infratemporal fossa?
Lateral pterygoid and plate of sphenoid
What forms the posterior border of the infratemporal fossa?
Carotid sheath
What forms the lateral border of the infratemporal fossa?
Ramus of mandible
What forms the floor of the infratemporal fossa?
Medial pterygoid muscle
What forms the anterior border of the infratemporal fossa?
Psterior surface of maxilla
What are the muscular contents of the infratemporal fossa?
Inferior temporalis, inferior parts of medial and lateral pterygoid
What is the venous contents of the infratemporal fossa?
Pterygoid venous plexus, maxillary vein and MMV
What are the arterial contents of the infratemporal fossa?
Maxillary artery becoming MMA
How does the MMA exit the infratemporal fossa?
Foramen spinosum
Which artery runs next to the infratemporal fossa to supply the scalp?
Superficial temporal
What are the nerve contents of the infratemporal fossa?
Mandibular nerve and its branches, chorda tympani and parasympathetic fibres from Otic ganglion
How does the mandibular nerve exit the infratemporal fossa?
Through foramen ovale
What are the branches of the mandibular nerve found in the infratemporal fossa?
Auriculotemporal, buccal, lingual and inferior alveolar
Which two fissures are found in the infratemporal fossa?
Inferior orbital and pterygomaxillary
What canal is found in the infratemporal fossa?
Alveolar
How does a mandibular nerve block give a wide area of regional anaesthesia in the oral region?
Anaesthetic infiltrates mandibular nerve upon entry to the infratemporal fossa causing anaesthesia of its branches
How can either side of the mandibular teeth and lower lip be anaesthetised?
Inferior alveolar nerve block where anaesthetic is injected into the mandibular foramen
Which branch of the mandibular nerve does the chorda tympani travel with?
Lingual
Which branch of the mandibular nerve do the parasympathetic fibres supplying the parotid gland travel in association with?
Auriculotemporal
