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8/3/2019 Oral Physio ,, First Script
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( Introduction to Oral Physiology)
Oral physiology is different from general physiology. Oral physiology is the science that deals to
the different function in science of mouth.
The some topic of oral physiology is (overview)
i) when the teeth work together they can chew food, this process is called
mastication of food.
ii) You also can sense some pain in your teeth, so the transmission of pain also
the topic of oral physiology.
iii) You can also use your teeth and the oral structure in speech and the way that
different sound produce in the mouth also include in oral physiology in the
mouth..
iv) Swallowing food into GIT also deal with the function of the mouth.
v) When you taste something also include in oral physiology of the mouth.
So,This is oral physiology and text book that we can recommend for oral physiology is Oral
Bioscience by fredson , no need to bring this text book if you dont want. Because its too detail.
But, You can have it as refference and photocopy if you want. If you want to bring the book,
PLEASE BRING histology book.
Then the doctor talk about the syllibus.
Introduction to Oral Physiology
This topic is really interesting because its talk about function. Oral physiology is A branch of
biology that deals with the study of functions of living matter. Oral physiology in contrast also
the study of the functions of the mouth and associated structures.
Now, what is the function of human mouth?
1) Mouth is the portal to the GIT. It is the root that leads to GIT. Thats why it is
important for guiding food intake. And also preparing food for swallowing and
digestion
2) Mouth important for speech production. This is the human traits because
usually most mammals or most other animals are not able to use their mouth and
speech. They just can produce sounds. And usually this sound are produce by
vocal cord without any effect added from the mouth. But in human and in some
upper primates like chipanze and gorillas this people can use the mouth sometimes
for the production of different speech but this speech not very develop like in the
human.thats why speech production is human traits and requires complicated
control of many oral, pharyngeal and laryngeal structures. Why laryngeal?
Because sounds are produce from the larynx and they passes through the pharynx
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and then into the mouth and nose. Where it gets modify until the speech produce
will be understood by the others. It is very important for communication.
3) Mouth also Prehensile (holding objects). Prehensile means tool used for holdingobjects. This function not really big in humans. Because human have developing
hand and no need mouth to carrying object. But in many other animal used their
mouth to carry object such example cat can carry their kids by using mouth.Prehensile is more evidence in animal.
Lets talk about guiding foor intake. When you start eating, you have so many things moving
at the same time. So the mouth is open and you put the food between your teeth and you
start to move your teeth against each other to chew your food. In this case you are also
moving the muscle of the lips,muscles of cheek and the muscle of mastication. All these
muscle are in movement. Also the temperomandibular joint is also used. So thats why this
process is very complicated and finally when you put the food in your mouth, you can taste
the food. You can feel the consistency of that food either it is a solid, a liquid, hard, soft and
etc. So, you can feel the general sensation of the food youre eating. Then, you prepare thatfood to be swallowed to be pass to the gastrointestinal tract. Sometimes, if you are eating
something that you didnt want to be swallowed, you will expel the food. Function of the
oral cavity are very organised.
Food analyzed by sensory systems involved in perception of taste, smell, touch, temperature
and pain. When you put food in your mouth, you can taste it, you can touch it, you can smell
it by your tongue, so you can have some information about the consistency or the hardness,
the softness and different characteristic of that food. Also, you can have information about
the temperature of that food. Sometime, the food can be painful. Also we can collect
information about painfulness.
Sensory information is integrated in the brain, as a result. After you put the food in your
mouth, then the information will be sent to the brain. What does the brain do? The brain
then asked the salivary gland to secreted saliva. We need saliva as it is use for lubrication.
And also as a result, saliva secretes calcium and these will result the formation of calculus
which is not very good. Then, chewing movement begin, mastication begin. Mastication is
the movement of lower jaw and upper jaw. This movement is very organized and occlusion is
very important. You need to occlude both teeth together in order to allow for masticate.
Also you will have muscular control of muscle movement occur. The muscles of mastication
are in harmony because the brain sent information in harmony way so that to be able for
chew. This is important for protection from tissue damage. This is why sometime we can eat
unconsciously. Thats why it should be very organized. Finally, swallowing eventually takes
place.
Why do we need to study oral physiology? It is because the knowledge of normal function of
the mouth leads to explanation of orofacial dysfunction. When you know the normal
function of the mouth, then you will know when it occurs abnormally. Also this leads to
explanation of orofacial dysfunction. And this is important for suggesting better methods for
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diagnosis and treatment. Practically, knowledge of oral physiology has an impact on industry
and marketing. Dont worry about the last point.
Now, we talk about the first topic in oral physiology which is pain .
We start by this, let say it is experience like sentence. Dentistry owes it history beginning to
request of pain relief. And why do people seek dentist? Because they have pain in general. Alldental problem occur in mouth without pain. Then, you will not know what happen inside the
mooth. Basically, people seek dentist when they have pain. This is not proper. We need to seek
dentist regularly although without pain. Okay, classical foundations of dental profession. First,
you need to identify the pain, then diagnose that pain and finally eliminate that pain. So, this is
the way we deal with the pain.
This slide is very important (slide 7). Pain has different characteristics. Pain is a subjective
symptom. This means it differ from one to another. Some person may feel a pain with the same
severe but some people will just feel it mild. Usually female feel more severe pain than male.
Thats why we say pain is subjective. It varies from one person to another. Pain is an action
elicited by stimulus. Pain occurs because we have factors that cause that pain. For example youcan feel pain when you eat something cold or sweet if you have decay in your tooth. So, we say
coldness and sweetness is the stimulus of that pain. Pain may involve tissue damage. In order for
you to feel pain, there should be a process of tissue damage. Lets say for example inflammation.
The tissue damage may be minor (controllable) or non-controllable. For example when you bite
your friend, he feels pain but when you bite gently, we say this tissue damage reversible but
when you bite him severely, we say it is irreversible. It will end up with inflammation and it
needs time to heal.
Pain provides warning to seek for treatment.
In contrast, some females, may feel pain just when the decay is very small because they feelpain, they seek treatment. Thats why pain or dental pain is a blessing. Tooth problems usually
painful. General ?? problems usually painless. So thats why pain is a blessing.
Pain can be acute or chronic.
What does acute means? Acute: it is a sharp pain and lasts for a short period of time. Like for an
example, palpitis. Palpitis is medical symptom in which the dental pulp becomes inflamed. But
some people have pain for a long period of time but usually chronic pains are low pain.
Pain can be spontaneous or provoked.
Spontaneous means it appears by itself. Provoked, there is affective that causes it to appear. Forexample you are okay but suddenly you have toothache. We called this pain spontaneous. For
example you are exercising and suddenly drop off. We say it a trauma or youre dropping off is
the fact that causes your pain. Thats why we said that the pain is provoked. Some people have
pain when they eat something sweet or drink something cold. Thats why we called it provoked
pain not spontaneous. Sometimes, the way the pain is described by your patient is important
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and telling you some ideas about the diagnosis and the best way to treat or to deal with that
pain.
Pain can be continuous or intermittent.
For example the pain started 3 days ago, and now I am still in pain. It is called continuous pain.
Example for continuous pain is the pain caused by eruption of 3rd
molar. From time to time,
maybe once every 2 or 3 months, you have severe pain around the gum related to the eruption
of 3rd
molar. For intermittent, when the pain started and lasted for 5 minutes and it disappeared.
Then after a few hours, it reappeared again. Lasting for 5 minutes and disappeared. We called it
intermittent.
Pain can be recurrent.
What does recurrent means? Pain can appear again which means the pain appear and remain for
some period of time then, disappear. After a while it appears again. Usually such kind of pain, we
described it as periodic pain. Meaning, the periods of pain stopping are equal. The intervals
between the different episodes of pain are equal. Pain can be localized which means specific to a
certain location.
Pain can be spreading.
The pain started in the 1st
location and from that location it spreads to another location. That is
spreading pain.
Pain can be called migrating pain.
Pain started in your ?? then it moves until you had headache. But at the 1st
location you dont
have pain anymore. Pain also can be referred.
Referred pain is when the pain starts in certain location which is not the area of damage or the
area of problem. It is very important to understand and differentiate the characteristics of each
types of pain.
Pain
If you want to define the pain, we can define it as complex series phenomena or unpleasant
experiences associated with actual or potential tissue damage or abnormal affective state arouse
by pathological activity of a specific sensory system.
Pain is not simply an excessive stimulation of some other sense such as touch and
temperature. If you put your hand in warm water, you start feel the temperature of warm
water. When the water boil, in this case, you will feel pain but not excessive temperature. You
will continued feeling temperature until the limit and temperature stop and it replace by relief
pain. That why the pain is not an excessive stimulation of some other sense such as touch and
temperature.
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But instead is related to tissue damage at cellular level. Because pain related to tissue damage,
its difference because temperature or touch is not related to tissue damage. It will continued
feel temperature until tissue damage take place. Once tissue damage took place, we dont have
any feeling of temperature or touch but we start to have feeling of pain. So thats why
temperature or touch not associated with tissue damage. Only pain is associated with tissue
damage.
This is why physiologist replace pain with noxious and pain receptors with nociceptor.
Noxious is stimulus related to tissue damage and Nociceptors means the receptors in your
body respond to tissue damage. Thats why feeling of pain receptor is difference with other
sensation. Other sensation are not related to tissue damage. The only sensation thats related to
tissue damage is pain receptor.
Pain stimulant products of tissue damage are Hydrogen ion, potassium ion, prostaglandins,
polypeptides, Histamine, and serotonin. When you start has tissue damage, your body will
release many difference material and induce pain.
Aspirin blocks the chemicals receptors. When you take paracetamol or aspirin to relief pain,
does this will stop tissue damage? No. But you will still pain. What happen? You are blocking the
receptor, so the tissue damage will continued. Then what are you doing? You will taking a drug
for example aspirin to block the receptors that respond. Thats why tissue damages are still
present but you dont treatment.
Nociceptors
Touch and temperature are well define.
Pain receptors or nociceptors respond to painfull stimuli.
Nociceptors is a term used to describe a nerve ending that respond to stimuli that actually or
potentially produce tissue damage.
Nocicepors may respond to very gross mechanical stimuli. Sometimes, if you have mechanical
stimulus, you can activated the nociceptor.
Other stimuli may result in painful sensation when level of stimulus is increased. When you
increased the temperature or touch in certain limit you will start feeling pain.
A single noxious heat stimulus it sense as painful only when the heating exceed the normal limit
that can be sense by your temperature receptors.
Repetitive stimulation of temperature receptors with less powerful stimuli may inhibit
the passage of pain
If you have temperature receptors, if you keep stimulating this temperature receptors,
repetitively, then it will less powerful stimuli, this may lead to the inhibition of the
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passage of painful. And this is actually the theme of acupuncture ( ).
Which work by putting needles in certain places that will relief pain.
*the doctor said something about gate control theory in Arabic which I couldnt
understand but we will discuss this point separately InshaAllah.
Acupuncture treatment is based on the stimulation of, for example, touch receptors. As
the touch receptors stimulate repetitively, at the same time of the feeling of pain, this
prevents or block the passage of pain. Does this block the tissue damage? No.
Tissue damage is still occurring but information from the tissue damage area to the brain
is blocked. Thats why we dont feel it.
If the impulses in the nociceptive nerves could proceed up to the cortex, pain would be
perceived the pain gate would be opened.
This explains why pressing on a painful area or clenching on a painful tooth relieves the
pain.
{Sometimes if you have painful tooth ; if you bite or press on this painful tooth; pain is
relieved, this is explained by the gate control theory, because when you press on this
pain : you are stimulating other mechanical receptor which function is in
blocking/preventing the perception of the pain from original site of effect from reaching
the cortex. }
A or C fibers.
There are two different types of fibers that carry pain sensation, these can be A or Cfibers. Information originating in nociceptors travels over small diameter afferent nerves.
What is afferent means? Afferent means taking the informatin from the periphery of the
body to the central nervous system.
Because we have two different fibers rensponsible for the passage of pain,we have what
we call the Double nature of pain.
The function of these fibers is carrying pain impulses from the type of effect to the brain.
A fibers are faster and producing stinging pain (sharp of high intensity initial pain).
C fibers are slower, so they conduct the pain stimulus in a slower rate, and this produce
the agonizing intolerable - diffuse second pain. For example: you are walking and
suddenly you hit your big toe with something (like the table), what you'll feel? First of all
you will feel a sharp pain, that is a very sharp and not very painful, and after two seconds
you know that something is coming, which is the very intolerable pain which last for 10
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seconds, this is the one induced by C fibers. (The first pain is by A fibers and the second
one is by C fibers).
Characteristic of A or C fibers.
1st type: A fibers
y These are myelinated nerves (myelinated nerve make things travel faster )2.5min diameter
y They conduct at high speed 12-30 m/s
y They have high threshold {high threshold: the stimulation has to be high to create
an impulse in these nerves}
y Transmit information from nociceptors or mechanoreceptors (they can also carryimpulses from mechanoreceptors that work.)
y Activated by intense mechanical stimulation
y Involved with 1st pain; which is sharp localized sensation from obvious
mechanical damage
2nd
type: C fibers
y Non myelinated {the diameter is thinner than the myelinated; because it's0.4-1.2 m compared with 2.5 m in myelinated}
y They conduct at (0.5-0.2 m) {much slower than A fibers}
y Polymodal (not unimodal): they could be affected by more than one type ofstimuli.
-Transmit a number of different stimuli; so different stimuli can cause the impulses
to run with their nerves.
-They are thought to be purely nociceptive in human: they can't carry any other
stimulus that causes any other nerve impulse other than pain.
y Excited by intense mechanical, thermal and chemical stimuli.
y Involved with 2nd pain-Diffuse & dull that follows 1
stpain
-May arise independently
Done by : malasian student
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