OS Lec#5 By Sarah Waia

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OS Lec#5 By Sarah Waia

Post by Sura on 31/10/2011, 2:31 am

http://www.mediafire.com/?8vci7ig0h344gl1
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Re: OS Lec#5 By Sarah Waia

Post by Shadi Jarrar on 31/10/2011, 4:46 am

Oral surgery sheet #
Surgical exodontia

The aim of surgical extraction is to gain direct access to the bone /root, meaning you want to elevate the mucoperiosteom.

When do I need surgical exodontia?

You may start with what you think is a simple extraction and you end up with a surgical one or you can know from the panoramic image: dense bone around the roots, ankylosed teeth , diverged multirooted teeth ,dilacerations.

All posterior teeth require periapical xrays or panorama prior to extraction.

Not all remaining roots require surgical extraction unless they were subgingival or subcrestal .

In a posterior periapical xray : if you take a transverse line at the widest area from the mesial root to the distal root and it was larger than the largest width of the crown then this tooth probably won’t come out with simple extraction. Because the socket itself is smaller than the crown.In cases like this do it surgically from the beginning.







Principles of flap design :

-The flap should be outlined by an incision using a blade.Otherwise,the mucosa can tear and won’t heal nicely leaving a scar ,increasing the pain ,inflammation and patient’s discomfort.

-The flap should carry its own blood supply.

-It should allow surgical access to the underlying structures.

-It should be able to be placed in its original position and get sutured.

Types of flaps:

1- Gingival ( one-sided)

The least traumatic but has limited use due to its limited exposure .

It offers restricted access to hard tissues at the crest of the alveolus.

Eg .remaining roots without sufficient tooth structure to be held using a forceps.

The flap should start at least one tooth behind and one in front the one to be extracted in order not to tear the flap.



2- Two-sided flaps >>the most commonly used

We start by a gingival flap then do a release (usually an anterior one)

The incision should always be cut to the mucogingival fold because it can be easily elevated ( unlike the attached gingival)



** read from the book what structures to avoid while doing an anterior release, and where to start the incision in relation to papillae.

The biggest mistake is to take your incision right through the papilla,it will remain unaesthetic forever. Especially if the patient has a high smile line. So you either include all of it or exclude it.





3- Three-sided flaps

We hardly use it , it is the most traumatic.

It allows extra mobilization of the tissues ( advancement flaps)

Apicoectomy,oro-antral fistulas



Design parameters



You have to remember that you’re dealing with a vital structure with a blood supply, if it was lost especially to the flap’s margins >> healing by secoundary intention occurs and a scar results.



Flaps blood supply : main artery and veins or capillaries

In order to increase the blood supply , the flap’s base should be wide and therefore insicion lines are oblique .



The flap should be done at the correct position with the right width .



In the mandible: if the flap is anterior to the mental foramen we should be careful that the releasing incision should be behind the mental nerve.

So we try to do the gingival flap in that area as much as possible.

You don’t want to end up with a patient with a numb lip after simple oral surgery.



I have to design a flap that I will be able to suture at the end of surgery.



Why do we suture?

In order to heal by primary intention >> minimal scarring



Armamentarium



-A scalpel & a number 15 blade.

Hold it with firm pressure until you reach the bone in order to incise the mucosa + the periosteom

**The best incision is done once because no matter how accurate you are ,you can’t put the blade at the same place twice which will result in 2 incisions.

Two incisions result in increased pain and inflammation + more scarring .

*The best incision is when the blade is at right angle to the mucosa as this results in better healing.



-Now I need to raise the flap I’ve incised using a mucoperiosteal elevator .

It has a concave surface which should be facing the bone while the convex surface facing the tissues .

You raise the mucosa slowly in order not to tear it.



-Special armamentarium for bone removal :



1- Surgical bur on a straight handpiece

This handpiece has higher torque to provide more stability and weight.

It is slower than the cons. high speed bur.

It’s better if it’s electric-driven not air-driven in order to prevent bone emphysema.

2- Bone rongeurs ( bone nibbler)

3- Osteotome , chisel + a mallet ( hammer)

The fastest and the most common is the bur but there should be a coolant (normal saline) because heat can cause more inflammation.

The burs can be tungsten carbide or sharp stainless steel burs.

-the rest of methods are less traumatic but require patient’s compliancy and the dentist should be experienced enough.

*The osteotome and chisels generate less heat but require experience and therefore are not commonly used.





After raising the flap , if there’s enough tooth structure you laxate the tooth and take it out with a forceps without taking bone out.

Bone is precious and one shouldn’t take it out unless indicated ,because some patients require bone grafts.



*Blood supply to the alveolar bone in the mandible :

Alveolar artery and the periosteom.

With age the role of the alveolar artery diminishes so the periosteom becomes the main blood supply to the bone.



Raising a mucoperiosteal flap deprives the bone from its blood supply temporarily causing resorption necrosis even if you are cautious.



In dental surgery you always raise a mucoperiosteal flap and not just a mucosal one.



For example ,I have a remaining root , I have raised the mucoperiosteom, and decided that bone should be removed, I have to make an application point for my straight elevator so should remove a minimum amount of bone for this point and then start laxating the tooth .



*Single rooted teeth

Most of the time a gingival flap is sufficient,always work by layers and expose 2-3 mm from the root for the application point. Always pull out the tooth using forceps and not an elevator ,because the patient may swallow the tooth.



*Multi rooted teeth

You need to divide the roots.

In lower molars we avoid a releasing incision because we have the metal nerve so a gingival flap is ideal.



The best thing is to remove enough bone to expose the furcation.

You should try start drilling using a fissure bur from the furcation outwards, because if you start from the occlusal surface going downwards you may not reach the furcation area.



When you remove the first root ,the cryer can be inserted into the socket to take out the other root.



If we had remaining roots in an upper molar, you should do the Mercedes sign .



We should be careful when extracting a posterior maxillary tooth , the maxillary sinus is right up there.



If a root’s tip got fractured , you can just leave it if the tooth was vital,but if the tooth was infected we have to take it out.



So in the end we have taken all of the tooth out , debride the socket using normal saline , because the bur can leave some debris . If sharp bony edges existed take them out using a bone rongeurs because they can cause irritation to the patient. A curette can be used as well. Suture and close up .



Goodluck

Done by Sarah Waia



















































































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Shadi Jarrar
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