Unit 304 oral anatomy Flashcards
The whole mouth is lined with what tissue?
epithelial mucosal tissue
What is epithelial mucosal tissue a type of?
mucous membrane
What are the 3 ypes of mucous membrane throughout the oral cavity?
- Lining membrane
-masticatory membrane
-specialised membrane
Where is the buccal sulcus located + what is it?
space between the posterior teeth and the mucous membrane lining the cheeks.
Where is the labial suclus located?
between the anterior teeth and lips
What makes the frenum?
band of fibrous tissues
When the band of fibrous tissues that makes the frenum is thicker what can it cause with the upper central incisors?
median diastema
What is the purpose of the lining membrane?
physical barrier between anything entering the mouth and the deep structures of the oral cavity.
Acts as a cushion lubrication + cleansing
Where is the lining membrane located and what does it look like?
inner surface of the cheeks and lips, floor of the mouth, underside of the tongue, soft palate
red + smooth and moist membrane
contains minor salivary glands
Where is the masticatory membrane located and what does it look like?
Covers gingivae, topside and edges of the tongue, hard palate
red, moist membrane often ridged or stippled
Forms the MUCOPERIOSTEUM
What is the purpose of the masticatory membrane?
hard wearing surface that prevents traumatic damage from food etc.
Where is the specialised membrane located and what does it look like?
interspersed throughout the masticatory membrane covering of the topside and edges of the tongue
discrete, papillary structures of the taste buds, visible pattern over the tongue.
What is the purpose of the specialised membrane?
provides taste sensation
What is the soft palate?
a flap of soft tissue attached to the back of the hard palate.
What is the soft palates function?
seal off the oral cavity from the nasal cavity during swallowing
What is the uvula?
central prolongation
part of the soft palate
What is the oropharynx?
back of the mouth - contains your tonsils
What is the tongue?
a muscular organ situated in the oral cavity and extending behind into the throat
What is the base of the tongue?
posterior 1/3 section
lies in the throat and attaches to the floor of the mouth
swallowing movements
The correct word for swallowing:
deglutition
What is the body of the tongue?
anterior 2/3
lie within the oral cavity and is relatively moveable
taste, chewing, speech
What enables the tongue to attach to the floor of the mouth?
lingual frenum
When there are access fibrous tissues of the lingual frenum, what may the patient face?
tongue tied - lisp is created
What cranial nerve supplies the tongue?
12th cranial nerve
hypoglossal nerve
What is the bolus?
food that has been chewed and mixed in the mouth with saliva
What is the function of swallowing?
Aims to direct the food bolus into the oesophagus while preventing it from entering the nasal cavity or larynx
What is glossitis?
Disorder of the tongue
Soreness/inflammation of the tongue and can occur in conditions such as anaemia, vitamin b deficiency and hormal disturbances.
Thin, smooth, glazed appearance
What is dysphagia?
Disorder of the tongue
difficulty in swallowing, that occurs frequently and has several causes.
Psychological, xerostomia, oesophagitis, cancers, central nervous system.
What does oesophagitis mean?
inflammation of the oesophagus, due to acid reflux
What are teeth?
anatomical structures within the oral cavity
How many sets of teeth do humans have?
2
deciduous
permanent
What does tooth morphology mean?
The shape of each tooth and its function
What tooth is not present in the primary dentition?
pre-molars
What is the crown of the tooth?
section of tooth visible in the oral cavity
What is the neck of the tooth?
where the tooth and gingival tissues are in contact with each other, when tooth emerges through the gum.
What is the root of the tooth?
the non-visible section that holds the tooth in its bony socket.
What is enamel?
Highly calcified protective outer covering of the crown, hardest substance in the body.
96% mineral crystals that are arranged as prisms in the organic matrix called interprismatic substance.
What are the mineral crystals called that make up enamel?
calcium hydroxyapatite
The junction that lies between the enamel and dentine is called?
the amelodentinal junction ADJ
How is enamel formed prior eruption?
ameloblast cells
What is dentine?
tissue forms the main bulk of a tooth and occupies the interior of the crown and root.
80% mineral crystals
Composed of hollow tubes
Where do odontoblast cells lie after tooth eruption?
inner edge of the pulp chamber
The hollow tubes in dentine contain sensory nerve endings called..
fibrils - run from the nerve tissue within the pulp chamber
What is cementum?
calcified protective outer covering of the root and is similar in structure to bone.
65% mineralised with calcium hydroxypatite crystals
formed by cells called cementoblasts
What is the point called where the cementum and the root dentine are in contact with each other?
dentinocemental junction
does the cementum contain any nerves or blood vessels?
NO
Does the pulp contain any mineral cystals?
No
What is the pulp composed of?
soft tissue
Where is the coronal pulp located?
crown
where is the radicular pulp located?
each root
What is the radicular pulp usually called?
root canal of the tooth
The sensory nerves in the pulp are part of what cranial nerve?
5th
trigeminal nerve
Where do the pulp tissues pass through to enter the tooth?
apical foramen
The pulp chamber is lined by what?
odontoblast cells
What can the pulp chamber become blocked by?
Pulp stones - formed by lumps of calcium containing crystals
How can we tell which tooth a tooth is?
shape, size, number of cusps, number of roots.
What does curvature of the root help to identify?
whether a tooth is from the left or right side of the dental arch
What is the correct name for the natural loss of deciduous teeth?
exfoliation
How many teeth are in a set of deciduous teeth?
20
Deciduous roots are described as…
divergent
Do deciduous teeth have a larger pulp chamber than permanent?
yes
What makes deciduous teeth more prone to developing dental caries?
thinner enamel
When do deciduous teeth begin erupting and finish?
6 months
29 months
How many roots do deciduous upper molars have?
3
How many roots do deciduous lower molars have
2
How many teeth are in a set of permanent teeth?
32
what is the difference between permanent and deciduous teeth?
permanent teeth are larger in size and darker - smaller pulp chamber
When the deciduous molar teeth fall out what are they replaced with?
pre-molar teeth
When do permanent teeth begin erupting and when do they usually finish?
6 years old - 13 years old except for 3rd molars
When do the third molars begin to erupt?
18-25 years old
Upper molar- 3 roots arranged as a tripod and the canals are called:
palatal, mesiobuccal, distobuccal
Lower molar- 2 roots and the canals are called:
mesial and distal
Upper first pre-molar - 2 roots, and the canals are called:
buccal and palatal
After a permanent tooth has erupted how long does it take for root growth to be complete and the apex to close?
3 years
Labial surface:
adjacent to lips, relates to incisor and canine teeth both arches
Buccal surface:
adjacent to the buccinator muscle of the cheeks, both arches pre-molars and molars
Palatal surface:
adjacent to the palate, applies to upper teeth
Lingual surface:
adjacent to the tongue, applies to lower teeth
mesial surface:
mesial = forward (midline)
distal surface:
distal = backwards (furthest from the midline)
contact point:
mesial and distal surfaces are in contact with each other
incisal surface:
biting edge of anterior tooth - incisors (not canines have a cusp not an edge) both arches
occlusal surface:
biting surface of posterior teeth, both arches pre-molars, molars
Cervical surface:
the neck region of any tooth, buccal, labial, palatal, lingual surface
in the primary dentition there are how many teeth in each quadrant of the mouth?
5
in the secondary dentition there are how many teeth in each quadrant of the mouth?
8
Central incisors
chisel shaped
1 root
U1 is the largest of all incisors
palatal or lingual surface has a raised area called the cingulum
what tooth is the smallest?
lower central incisor
What are the functions of central incisors?
- cut food
-assist tongue and lips
Lateral incisors
narrow chisel shaped
1 root
- peg laterals
What tooth can sometimes have a second (lingual) root canal if the root has split into two?
Lower lateral incisor
Canine
corner of each dental quadrant
1 root
root apex sometimes curved
what tooth is the longest?
canine
what are the functions of a canine?
pierce food/tear, support oral soft tissues, provide guidance for normal occlusion
First pre-molar
permanent successors to the deciduous first molars
occlusal surface 2 cusps buccally n palataly or buccally n lingually
mesial and distal edges are raised into “marginal ridges”
Upper 2 roots
Lower 1 root
Which teeth are usually extracted for orthodontic reasons?
Pre-molars
What is the canine fossa?
concarvity between the roots mesially
Functions of a first pre-molar:
assist canine to pierce and tear food - cusps
assist molars to grind food - occlusal surface
maintain shape of mouth
Second pre-molar
Occlusal surface 2 cusps buccally n palataly (upper) or buccally n lingually(lower)
Upper slightly SMALLER than first premolar, lower slightly LARGER
1 ROOT - apex sometimes curves distally
With a upper second pre-molar what area can they lie close to?
floor of the maxillary antrum
First molar
upper cusps = 4 (2 buccally n 2 palatally)
Lower cusps = 5 (3 buccal n 2 lingual)
CUSP OF CARABELLI Upper first molar
Upper 3 roots
Lower 2 roots
Where is the cusp of carabelli?
Upper first molar
What is the furcation area?
Junction of the roots beneath the crown
Function of the first molar:
grind and masticate food chunks so that they can be swallowed.
In regards to upper first molars where can there root apices lie close to or penetrate?
floor of the maxillary antrum
Second molar
Crown of upper and lower is smaller than first molar
upper and lower = 4 cusps 2 buccal 2 palatal/lingual
Upper 3 roots
Lower 2 roots
Same function as first molar
Third molar
Referred to as wisdom teeth - not always present
3-4 cusps with marginal ridges present
Upper 3 roots
Lower 2 roots
Where is the midline?
mesial edges of upper and lower central incisors form one straight vertical line.
Supporting structures of the teeth are called…
periodontium
Alveolar bone
specialised bone found only in the JAWS
support the teeth
individual socket for each tooth
What is the inner layer of bone called within the alveolar bone?
compact bone
What is the outer layer of bone called within the alveolar bone?
compound bone
What is the outer surface of bone called within the alveolar bone?
lamina dura
What colour does the lamina dura show up on an xray?
white lining
What is alveolar mucosa?
covers the outer surface of alevolar bone that forms the gingivae around the necks of teeth.
Gingiva is the anatomical term for what?
gums
What is gingiva?
continuous layer of specialised epithelium found only in the oral cavity, is firmly attached to the underlying alveolar bone as a mucoperiosteal layer.
Attached gingiva:
covering the majority of the alveolar process, firmly attached to the underlying bone as the mucoperiosteum
Marginal gingiva:
forming the gingival margin of the teeth
free from the underlying bone and follows the shape of each toop and extends between teeth in contact areas = free gingival groove
Junctional tissues:
specialised gingival tissue lying within the gingival crevice and forms the anatomical junction between teeth and the oral epithelium the point is called= junctional attachment and the tissues are called = junctional epithelium
The junctional attachment within the gingiva is the area where what diseases develop?
periodontal disease and tooth loss
what part of the gingiva provides a mechanical barrier between the oral cavity and the deeper periodontal tissues, preventing micro-organisms from gaining entry and causing disease?
Junctional attachment
What does the gingival crevice exist as?
shallow space of less than 3mm between the tooth surface and the gingival margin
What is the interdental papilla?
gingival tissue that occurs between each tooth
What is the correct term when gingiva overgrows due to medication etc?
Hyperplastic
What is the periodontal ligament?
specialised fibrous tissues which attach the teeth to the alveolar bone and surrounding gingivae.
- acts as a shock absorber to teeth during chewing
Fibres in the periodontal ligament are made up of what?
protein - collagen
Alveolar crest fibres:
run from the alveolar bone crest to the cementum
prevent tooth movements in and out of the socket
tilting and rotation
Horizontal fibres:
horizontally from the alveolar bone to the cementum, below the crest fibres
tilting and rotation
oblique fibres:
an angle from the alveolar bone down to the cementum
intrusion and rotation of the tooth
Apical fibres:
at the root apex and run between the bone and cementum
extrusion and rotation of tooth
transseptal fibres:
between cementum of adjacent teeth through the interdental region
maintain gingival attachments between the teeth and their positions
free gingival fibres:
cervical cementum into the gingival papillae
maintain gingival cuff around each tooth
What is proprioception?
the ability of the tooth to detect and transmit sensations (pressure, pain, touch, temperature etc)
What is the main function of the salivary glands?
to produce saliva
what are exocrine glands?
salivary glands in the oral cavity
what are endocrine glands?
structures elsewhere in the body
secretions pass directly into the adjacent blood vessels
What are ducts?
transport saliva to the oral cavity
tube-like structures
Parotid gland:
located between the ramus of the mandible and the area and deep to the muscles in that area.
Which gland is affected by the viral infection Mumps (paramyxovirus)?
parotid gland
Which duct is connected to the parotid gland?
stenson duct
which cranial nerve is the parotid gland associated with?
glossopharyngeal 9TH
which salivary gland is most commonly associated with benign and malignant tumours?
parotid gland
submandibular gland:
located in the posterior area of the floor of the mouth beneath the mylohyoid muscle
Which duct is connected to the submandibular gland?
wharton duct
which salivary duct is the longest and most likely to become blocked by salivary stones?
wharton duct - submandibular gland
which cranial nerve is linked with the submandibular gland?
facial nerve - 7th
What is the correct word for salivary stones?
calculi
sublingual gland:
located in the anterior area of the floor of the mouth above the mylohyoid muscle
which cranial nerve is linked with the sublingual gland?
facial nerve - 7th
What is the sublingual duct?
the duct of bartholine
several sublingual ducts
Mucous secretory cells:
produce a thick, mucus like secretion which aids lubrication in the oral cavity, contains minterals and enzymes
serous secretory cells:
produce a thin, serum like secretion containing antibodies and electrolytes
What are leucocytes?
white blood cells - fight against infection/disease
what is salivary amylase?
digestive enzyme that begins starch digestion before food is swallowed.
What are antibodies?
immunoglobulins (IgA)- fight infections
What kind of saliva will patients produce if they are high risk of caries?
water saliva with a low mineral content
What kind of saliva will patients produce if they are high risk of calculus development?
high mineral thick saliva
How is saliva slightly alkaline?
because of its electrolyte components
saliva keeps the PH at a neutral level of?
7
What is the reason behind xerostomia (dry mouth)?
decreased production of saliva
what are the 3 common causes of xerostomia?
irradiation - cancer treatment
medications - affect nerve supply to the salivary glands
sjogrens syndrome - rheumatoid arthritis, bodys defence system attacks itself and destroys its own glandular tissues
Reducation in saliva could have what consequences on the patient within dentistry?
caries, oral infections, oral soft tissue trauma, problems with speech, swallowing, chewing, poor taste sensation
What can help increase the salivary flow for patients with xerostomia other than changing medication?
salivary stimulants and artifical salivary sprays
plain water constantly
high fluoride toothpaste perscribed
What is ptyalism?
excessive salivation
system associated with an underlying disease rather than its own disorder.
What disorders can cause ptyalism?
periodontal disease
oral soft tissue injury/trauma
oesphagitis (acid reflux)
disorders that affect the nervous system such as parkinsons
What drug can be used during oral/maxillofacial surgery to reduce saliva flow and provide a clear dry operating field?
Atropine
