Oral surgery

Lecture 7

Done by: Bayan Mrayan

Impacted wisdoms

Today we are going to talk about impacted wisdoms, now what’s

the difference between impacted teeth and unerupted teeth?

,,every impacted tooth is unerupted tooth but not every

unerupted tooth is an impacted one, if we have a10 years old

child who doesn’t have the 6es and they are still in the jaw do we

call this case an impaction ? No, of course we call it unerupted

which might erupt or may not erupt, now an impacted teeth is

simply a tooth that has passed the time of eruption and it can’t

erupt any more .

Now what are the indications to take wisdoms out…..

In the past American dentists used to take the wisdoms out

whether the case indicates extraction or not, for personal gains

to take money from their patients, on the other hand British were

honest in dealing with their patients so they put specific

guidelines (medical indications to take wisdoms out).

There is a group of people called NICE Stands for National

institute for clinical excellence they are Belonging to the

Ministry of Health they are responsible for putting these

guidelines

The indications are ….

1. If there is evidence of pathology like a cyst or tumor

surrounding the wisdoms or any sort of

Pathology.

2. A tooth that is involved in osteomylitis (sclerosing

osteomylitis” Chronic focal sclerosing osteomyelitis is a

periapical lesion that involves reactive osteogenesis evoked

by chronic inflammation of the dental pulp. In most cases, this

lesion develops in the mandibular molar region in response to

a low-grade infection of the pulp that results from a deep

carious lesion. A case is presented in which incomplete tooth

fracture was the apparent cause of this type of periapical

pathosis.”

3. teeth are impeding surgery the patient has problems in

opening the mouth and the surgeon wants to move the

mandible, some time the presence of wisdoms prohibits the

movement of the jaw anteriorly or posteriorly in this case we

need to take the wisdoms out

4. Gum Infection (Pericoronitis) it’s an infection in the soft tissues

that surround partially erupted wisdom tooth When a wisdom

tooth is partially erupted, food and bacteria collect under the

gum causing a local infection. This may result in bad breath,

pain, swelling and trismus (inability to open the mouth fully).

The infection can spread to involve the cheek and neck. Once

the initial episode occurs, each subsequent attack becomes

more frequent and more severe. The patient come to you

complaining from swelling in his mouth this is what we called

MILD PERICORONITIS. After that the swelling gets bigger and

a limitation in mouth opening starts to appear this is what we

called MODERAT PERICORONITIS ,when there is severe

trismus and signs and symptoms of infection redness ,malaise

,pain that gradually increase till it reaches to its severe stage

This is called SEVERE PERICORONITIS ,now here the infection

starts to convert itself to an abscess which is problem because

this abscess can go through the spaces, like submassetric

space because this space is closed by both massetric and

buccinators muscles, it diffuse to the sulcus near 6or 7 which

we called migratory abscess of pericoronitis .Now how do we

manage this case ,if its mild we can just irrigate under the

operculum “it’s the soft tissue that covers partially erupted

tooth by using( hydrogen peroxide(extra information)),and

OHI, there is no need to give antibiotic because there is no

signs of systemic involvement ,in moderate and sever we

need to give antibiotic the eventual solution is extraction of

the tooth but according to NICE guideline pericoronitis is

considered as indication for extraction if it comes twice or

more than twice a year, but after the episode of pericoronitis

is resolved not immediately.

5. Caries, here we don’t treat wisdoms conservatively like other

teeth , extraction takes the priority here .

6. As a cause of periodontal disease to the adjacent tooth, when

the tooth is Lying on the adjacent tooth it can cause resorption

to the inter septal bone distally to the second molar

7. resorbtion to the 2nd molar due to horizontal positioning of 3rd

molar and eruption capacity when the root are still small .

8. Cyst and tumor like dentigerous cyst and odontogenic tumer

like Ameloblastoma this is dentigerous cyst ….

9. Prosthetic reasons, for example a patient needs a complete

denture but he has impacted teeth here there is two different

decision you can make either to extract it ,because with time

the ridge will resorbe and the tooth will reveal or you can

leave it and remove it later on.

10. orthodontic reasons :some orthodontist claim that third

molars can cause later lower anterior teeth crowding ,other

orthodontic reasons, is making space to push molars

posteriorly to make space for other teeth to move .

11. Socio economic reasons just to avoid any expected

complications that may impede their work or the patient social

life and business, the doctor Showed a picture of

ameloblastoma surrounding an impacted molar and pushing it

downward here is one picture ….

12.unexplained facial pain they found that some patient when

you examine their wisdoms you don’t find any indications for

extraction but they have pain ,when you take their wisdom out

they feel better this for small percent1-2% of people not always

right they may have TMG dysfunction syndrome that explain that

pain .

13. prevention of fracture usually wisdoms are found at the angle

of the mandible imagine that they are deeply impacted and

horizontal they will occupy most of the angle, if the patient was

beaten on his mandible the area occupied by the molar will

fracture because its weak those people advised to take wisdoms

out to lay down bone at the area of extraction

Now moving to the contra indication for extraction …

1. Extreme age, he may have medical problems ,his mandible

will be so thin so in those patient we have to weigh things

carefully in our mind before taking wisdom out .

2. medically compromised patient like systemic diseases or

bleeding problems ,local factor like radiotherapy, or a

patient who has a tumor, now if the operator is intending to

take the tumor out we remove the tooth that is involved in

that tumor , but in a case that the patient has a tumor in the

neck and the tumor is expanding to the mandible there is

no definitive management to this patient we Shouldn’t mess

with them as we may cause transferring of the tumor from

side to side .

3. potential damage to adjacent structure like if the tooth is

very close to vital structure like ID canal we may cause

parasthesia to the nerve ,if we extract it in the usual ways so

we do what’s we called decavitation to the tooth by

removing the crown and leaving the roots as not to cause

injury. or in the case of the upper were its closed to the

sinus or infratemporal space behind the maxilla, so we

don’t extract it ,we give antibiotic if its inflamed and we

treat it conservatively not to get benefit of it but rather not

to extract it .

Now moving to operative assessment related to patient it self

…..

First of all as we know we take history and what’s we called

general assessment, like the patient age and personality in

many cases of extraction the pain is not the main problem,

rather the stress is the main problem so if the patient from the

beginning is frightened his pain threshold will be very low, so

you as a surgeon has to decide whether to do it under

sedation with local anesthesia or under GA .so take into

account (personality and difficulty of the procedure).

Local assessment related to the tooth itself…..

1. Access to the tooth and make sure the width of mouth

opening is appropriate for such a procedure (rima oris

in Latin)…

Now PELL and GREGORY put a classification for wisdom

teeth it applies for upper and lower they made 2 types of

classes ,class1,2,3and class A,B,C, class A,B,C it applies

for upper and lower, class 1,2,3 it applies only for lower

wisdoms .Now lets explain each type of these classes…

CLASS1: the tooth is found completely anterior to the

anterior border of ramus of the mandible.

CLASS2: the tooth is found in the middle, part of it is found

anterior to the anterior border of the ramus and the other

part is posterior to the anterior border of the ramus .

CLASS3: The entire tooth is found posterior to the anterior

border of the ramus .And here is a picture for these

classes ….

.

1.

We will talk about class ABC later on….but you need to know that

class 1,2,3 is part of access assessment…

Lets talk about classification according to Winter based on the

inclination of the impacted wisdom tooth to the long axis of second

molar…..he created 3 lines (white line ,amber line, red line) they

are not that specific but you should know about them ….

White Line

The white line is drawn along the occlusal surfaces of the

erupted mandibular molars & extended over the 3rd molar

posteriorly. It indicates the difference in occlusal level of

the 1st & 2nd molars & the 3rd molar.

Amber Line

The amber line represents the (height of the) bone level.

The amber line is drawn from the surface of the bone on

the distal aspect of the 3rd molar (or from the ascending

ramus) to the crest of the inter-dental septum twixt the 1st

& 2nd molars. This line denotes the margin of the alveolar

bone covering the 3rd molar and gives some indication to

the amount of bone that will need to be removed for the

tooth to come out.

Red Line

The red line is an imaginary line drawn perpendicular from

the amber line to an imaginary point of application of an

elevator. Usually, this is the cemento-enamel junction on

the mesial aspect of the impacted tooth (unless, it is the

disto-angular impacted tooth where the application point

is the distal cemento-enamel junction). The red line

indicates the amount of bone that will have to be removed

before elevation of the tooth i.e. the depth of the tooth in

the jaw & the difficulty encountered in removing the tooth as

the red line become longer extraction become harder its not

that much applicable.

Now the classification for Winters are (mesio-angular,disto-

angular, horizontal, vertical) ,to differentiate between them..

we draw a line on the long axis of the next-door tooth the 7

and a line on the long axis of the 8 and we check the angle

between them.

If the lines are parallel its vertical look at the picture…..

If the long axis of third molar is horizontal the angle will

be 90 so it’s Horizontal…..

Disto-Angular. The long axis of the 3rd molar is angled

distally / posteriorly

awayfrom the 2nd molar.

Mesio-Angular. The impacted tooth is tilted toward the

2nd molar in a mesial direction….

2. Now the second assessment is according to the depth of the

tooth inside the bone……Now we apply Pell and Greogory

classA,B,C…

Class A. The occlusal plane of the impacted tooth is at the same level as

the

occlusal plane of the 2nd molar. (The highest portion of impacted 3rd

molar is on a level with or above the occlusal plane).

Class B. The occlusal plane of the impacted tooth is between the occlusal

plane

& the cervical margin of the 2nd molar. (The highest portion of impacted

3rd

molar is below the occlusal plane but above the cervical line of the 2nd

molar).

Class C. The impacted tooth is below the cervical margin of the 2nd

molar. (The

highest portion of impacted 3rd molar is below the cervical line of the of

2nd

molar). Note that it’s only the depth that is changing not the distance from

the anterior border of the ramus as in Class1,2,3

Now what’s about obliquity…in general in.most of the

cases third molar positioned lingual to the rest of the

teeth….

Buccal / Lingual Obliquity. In combination with the above,

the tooth can be

buccally (tilted towards the cheek) or lingually (tilted

towards the tongue)

impacted.we call it bucco or linguo-version tooth, look at

the pictures below…

3. You have also to asses number and shape of the roots

….

If we have a tooth with one root and its conical in shape

we expect that the extraction is easy..

If we have a tooth with 3 roots and they are erratic we

expect the extraction to be difficult…here we think of

surgical extraction, we open a flap ….

Another thing to consider is the point of application when

the tooth is mesioangular the POA is mesial and when its

distoangular the POA is distal….. All of these we could

specify them by the proper assessment of the tooth and X-

rays…

Some time the problem is not the third molar it self but the

problem is with the next-door tooth, so we afraid that there

will be some sort of trauma to the next -door tooth so if you

have amesioangular third molar adjacent to an overfilled 7

you may cause fracture to the filling or even the tooth it

self so its better to do surgical extraction in this case so

always check third molar and next door tooth .if you have

a third molar with a big crown and small root you may

think its easy to remove it ,you are wrong its so difficult to

extract it in non –surgical procedure. And it will be more

difficult to have a ball in socket when the tooth is not fully

formed a follicle surrounds the crown so the tooth starts to

rotate in its place when you try to remove it …

4. Assess shape of the root…

If we have a second molar with a conical shape root and

we put the elevator between 7and 8 to extract the 8 we will

definitely extract the 7 because it will be easy to remove it

due to the shape of it’s’ root

5. Assess bone texture for older people bone is much harder

than younger age groups who have resilient bone

texture…in sclerotic bone its more difficult to take teeth

out. .

6. Assess the tram line (skeet al7adeed) when you look at the

x-ray you will find 2 lines for ID canal if they are away from

the tooth we are in the safe side ,extraction will not affect

the nerve .

There is a study done in 1990 by Roods an Shehap in which

they brought patients with wisdom teeth and they took X-rays

for them, they started looking at the teeth in relation to the ID

they found different situations….

if there is radiolucecy on the root of the wisdom (at the

apical third)

if the ID canal is derooted as it change its direction .

if one of the tram line at the region of the root of third

molar disappeared either at the upper or the lower .

if the root are straight and suddenly you notice

deflection at the ID canal region .

if the roots of the molar start as normal in shape when

they arrive to the ID canal region they either appear

constricted or flared .

If any of these cases is noted the possibility of having

numbness after extraction is higher..

One of the students asked about the diameter of ID canal

I think?

The doctor answered that he doesn’t have a specific

number but its not less than 4mm.

Now lets talk about some definitions related to this study

….perforation, grooving,notching,

Notching: the tooth has one root but it has a notch or a

small opening at the end (apical third) this is where the

ID canal enters and passes the tooth.

Perforation: during the growth of teeth, part of it will

grow above the canal and the other part under the canal

it seems perforated …. Its unlikely to see such cases, its

used for academic reasons mainly, what I want you to

know that if we have such these appearances or cases we

think of surgical extraction, because when you do simple

extraction you may do sectioning for the tooth in small

pieces, always think before doing any thing … I really

tried hard looking for more obvious definitions of these

terms, this is what I found according to radiographic

appearance …

1- Notching: Radiolucent band at the apex of the roots, a break in the

continuity of the upper radio dense border, and narrowing at the expense

of the top of the canal.

2- Grooving: Radiolucent band across the root above the apex, interruption

of both superior and inferior borders of the canal and narrowing of the

canal space.

3-. Perforation: Radiolucent band crossing the root above the apex with

loss of both superior and inferior borders of the canal at the area where

they cross the roots and constriction of the canal maximal in the middle of

the root. This is perforation …..

.

( Notching, grooving and perforation were regrouped as

true relation)

Let’s talk about different terms of sensation …..

Parasthesia of the lip and tongue

Anesthesia full loss of sensation

Hypoesthesia reduction in sensation still feel

sensation

Paresthesia is abnormal sensation there is

something going wrong in sensation It is more generally

known as the feeling of "pins and needles

Dysesthesia : unpleasant sensation they feel like electric shock after surgical procedure abnormal

sense of touch

Hyperalgesia increase response to stimulus which

may be caused by damage

to nociceptors or peripheral nerves

There is a third sensation I couldn’t here it but it

means that the patient feel pain spontaneously in

the lips even without touching them,

The doctor showed a picture about Roods

classification this is what I found….

. A, darkening of apex;

B, reflexion of apex; C, narrowing of apices; D, bifid apices on

canal; E, deviation of canal; F

narrowing of canal; G island-shaped apex.

We can take wisdoms in three ways or under three

sources of anesthesia

Local anesthesia

Local with sedation (nitrous oxide for children not as

useful for the adult , midazolam,or we can ask the

patient to take diazepame orally 5 mg the day before

the surgery ,midazolam is more effective and have

immediate action .the way we use, is determined by

the patient personality and cooperation .

But the question is why do we use local anesthesia for

a patient to be treated under GA?

For vasoconstriction and for Pre-emptive analgesia to

anesthetize C-fibers which are responsible for pain

transduction, so the patient will feel lesser pain after he

wakes up …

The end of part 1

العالمين ا لحمدهلل رب

Done by: Bayan Mrayan

Sorry for any mistake

سل المعالَي عنا إننا َعَرٌب *********شعاُرنا: المجُد يهوانا ونهواه هي العروبة لفظ إن نطقت به *********فالشرق، والضاد، واإلسالم معناه