what are the 3 main branches of the trigeminal nerve
ophthalmic branch
maxillary branch
mandibular branch
what are the lower molars innervated by
the mandibular branch of trigeminal nerve
what is cranial nerve 1
olfactory
what is cranial nerve 2
optic
what is cranial nerve 3
oculomotor
what is cranial nerve 4
trochlear
what is cranial nerve 5
trigeminal
what is cranial nerve 6
abducens
what is cranial nerve 7
facial nerve
what is cranial nerve 8
vestibulocochlear
what is cranial nerve 9
glossopharyngeal
what is cranial nerve 10
vagus
what is cranial nerve 11
spinal accessory
what is cranial nerve 12
hypoglossal
what division does the inferior alveolar nerve come from
mandibular branch of CN V
what does the inferior alveolar nerve give off anteriorly
the mental nerve
what does the mental nerve exit the mandible from
metal foramen
what does the mental nerve supply
chin and lower lip
what can often be accidentally anesthetized as well as the inferior alveolar nerve
lingual nerve
where does the inferior alveolar nerve supply to
lower central
does not cross the middle
where do we want to inject
not hitting the nerve
want to deposit next to the nerve on the bone
if patients feels that their lip has been hit what is most likely done
you have hit the nerve
what does hitting the inferior alveolar nerve do
the numbness may remain due to a temporary damage of the ID nerve
what is paraesthesia
an abnormal sensation typically tingling or picking (pins and needles)
why is paraesthesia a good sign if the ID nerve has been hit
the nerve has not been completely anesthetized
what is dysaesthesia
an abnormal unpleasant sensation felt when touched, caused by damage to the peripheral nerves
why should parents be warned when it comes to LA
lip cannot be felt
child may bite lip
can cause ulceration
why is the damage done to the ID nerve temporary
you have traumatized the nerve
so there is swelling pressing on the nerve
there is no complete dissection of the nerve so no permanent damage
what nerve is involved in the afferent (sensorial response) of the gag reflex
glossopharyngeal nerve
what nerves are involved in the motor response of the gag reflex
trigeminal glossopharyngeal vagus accessory hypoglossal
what is stimulated in the gag reflex as well as the cranial nerves in the motor response
the motor (secretory) visceral nerves of the salivary glands are also stimulated
what are afferent (sensory neurons)
carry a message to the CNS
they are going towards the brain or spinal cord
what are efferent (motor neurons)
they carry a message to a muscle, gland or other effect. they carry the message away from the CNS
what are interneurons (connecting neurons)
these neurons connect one neuron with another
in many reflexes interneurons connect the sensory neurons with the motor neurons
how do we manage patients who gag
make sure mixture is not too runny
keep patients chin down and come from the back of the patient for upper
ask patients to breathe from their nose
if patient gags - distraction techniques
what is the posterior part of an RPD constructed with
a retaining mesh to facilitate the attachment of acrylic extension
in addition, this approach will reduce the weight of a large metal connector
when is the retaining mesh design indicated
when the post dam cannot be tolerated by the patient (gagging reflex) allowing it to be adjusted more easily
what do magnets on RPD do
stop it from going further back
what is bells palsy
motor disorder
what are symptoms of bells palsy
inability to wrinkle brow
drooping eyelid; inability to close eye
inability to puff cheeks; no muscle tone
drooping mouth; food stuck in cheek
what nerve is affected in bells palsy
facial
what does facial muscle supply
orbicularis oris
buccinator
what do the orbicularis oris and the buccinator do
help to control food bolus and prevent spillage
what is bells palsy defined as
any type of facial paralysis that does not have any other associated causes such as tumors, trauma and salivary gland inflammation
what are causes of bells palsy
infections (HSV/Cold sores)
otitis media (inflammation of the middle ear)
diabetes
trauma
toxins
temporary by infiltration of LA to the facial nerve branches during dental treatment
how can you infiltrate LA to facial nerve
occurs when the infection is given too far distally and the parotid gland is penetrated allowing the diffusion of the LA through loose glandular tissue, which then affects all 5 terminal branches of the facial nerve
what is the effect of facial nerve paralysis (ID block)
effect is seen in inability to close the eye or blink, and inability to raise the corner of mouth or puff the cheeks
patients may feel that something is wrong but be unable to identify exactly what the problem is, and it is usually the operator who notices these specific changes
what should be advised to patients who have had facial nerve paralysis
patients should be informed, reassured as to the transitory nature of the palsy, and the eye should be protected with a loose pad such that the cornea is protected until the protective blink reflex returns
recovery often occurs in a relatively short time (within an hour)
what is trismus
irritation of muscle fibres
what is kept if the roots and their PDL remain
periodontal mechanoreceptors allow finer discrimination of food texture, tooth contacts, and levels of functional loading
what does decrowning and retaining the root allow
a better appreciation of food and a more precise control of mandibular movement than is provided by full dentures
what is the psychological benefit of decrowning the tooth and retaining the PDL
preventing the feeling of total loss of natural teeth
makes eventual transition to conventional complete dentures more acceptable
what are these dentures called (that sit on PDL)
over dentures
what are used to help in the support of the denture which sits on the PDL
precision attachments
what does the loss of periodontal mechanorecpetion influence
control of jaw function
precision of magnitude
direction
rate of occlusal load application
what is the threshold of mechanorecpetors
low - 0.5mN
what do mechanoreceptors do if there is constant stimulus
adapt
what is the definition of a mechanoreceptor
sensory receptor that responds to mechanical pressure or distortion
are periodontal mechanoreceptors sensitive
very
what do periodontal mechanoreceptors allow
enable us to assess the direction of the forces applied to teeth
what do periodontal mechanoreceptors contribute to
mastication (food consistency)
salivation
interdental discrimination
what does interdental discrimination allow
ability to gauge extent of mouth opening coordination of masticatory movements monitoring size of food particles detection of high spots foil threshold 8-60 micrometers
what are the receptors that contribute to the interdental size discrimination
TM joint receptors
muscle receptors
PDL receptors
what is shim stock
a metal foil for occlusal testing
what is proprioception
self sense
awareness of position and orientation of body part
what is proprioception serve by
joint recpetors muscle receptors (muscle spindles and golgi tendon organs) periodontal receptors
what may joint receptors signal
joint position
joint movement
information useful in controlling jaw movements
what does the loss of periodontal mechanorception result in in complete dentures
they do not carry enough information to restore the necessary natural feedback pathways for motor function
what are causes of dysphagia
stroke brain injury MS GORD tumors
how do we assess for stroke
comparing sensorial and motor responses from both sides of face and oropharynx can easily detect stroke
stroke is unilateral
what are nociceptors
respond to intense noxious stimuli
usually associated with pain
nociceptors in the dental pulp are the most important ones for dentists
where else do we find nociceptors
muscle
joints
mucosa
Which tissues are sensitive
oro-facial tissues are very sensitive
receptors have low thresholds for activation
not all regions are equally sensitive
how can we tell the shape and taste of food
smell and taste
using memory
using two point discrimination between tongue and hard palate we can compress it to identify two different surfaces
what does the sense of smell stimulate
salivary glands
as a result, smelling disorders often affect the sense of taste
in cases of infection of nasopharynx, a loss of olfactory sense (anosmia) might be associated
patients have difficulty to discern between taste and olfaction, thus interchanging the terms
