Surgical removal of wisdom teeth

Transcription

1 Oral surgery/dr.hazem Lecture #8 Rand Herzallah Surgical removal of wisdom teeth Wisdom teeth extraction is harder than the extraction of any other teeth; because of: 1) The anatomical location of the third molar at the angel of the mandible where the boarder is thick, strong and calcified. 2) The roots are mostly curved or Convergent or divergent or fused. 3) The roots are close to the lingual nerve. We need to do an adequate flap (envelope or three-cornered/triangular flap): a) Envelope flap: for example if we look at the mandible we do the flap from the mesial aspect of the lower six going posteriorly to the retromolar pad area. Some surgeons don't prefer it because if there was gingivitis or infection around the lower seven this might cause gingival recession after healing. And sometimes although the incision is long the access could be a bit hard a three cornered flap is preferred from the mesial aspect of the second molar going down to the sulcus but not very deep to avoid catching the buccal branch of the facial artery if we catch it excessive bleeding would occur and it takes time to be controlled. After reaching the sulcus we go distally to reach the bone (try to feel the ramus of the mandible with your finger as a guide) then we do a sub-periosteal elevation (a full thickness flap). The incision must be made with a smooth stroke of the scalpel, which is kept in contact with bone throughout the entire incision so that the mucosa and periosteum are completely incised; this allows a full-thickness mucoperiosteal flap to be reflected. If we took a partial thickness flap this will tear the mucosa or the periosteum and things will be really messy.

2 For Maxillary third molar: it's easier to do a three-cornered flap. A good trick is to avoid making a small flap. Making a reasonably large flap that allows you to have a good access to the tooth. Large flaps heal as good as small flaps. On slide 30: a clinical photo shows a partially erupted lower third molar; to manage this case we first take a full examination, panoramic radiograph and depending on the result of the panorama we can take a CBCT scan if needed then if everything is safe we can proceed to do a surgical extraction. We do a triangular (three-cornered) flap -as we can see on slide 31- distal to the third molar, subperiosteally, down and around the crown of the third molar and then doing the other arm of the flap exposing the buccal bone covering the third molar. Remove the bone if it covers the tooth; by using: 1. A surgical hand piece (drill) with a surgical bur. 2. Chisel and hummer; used under general anesthesia and it's very annoying to the patient. Also it needs an experienced clinician if not done properly can fracture the mandible. We remove the bone from the buccal aspect avoiding the lingual aspect because of the lingual nerve that is found on the lingual plate and if the bur just went a little bit downward it may catch it causing damage. So we start making small holes around the crown all the way buccally and distally. It's very important to remove the bone distally because the tooth is usually inclined distally. Doing a good irrigation and suction is a must. Always remember that if bone is drilled it means that we are provoking inflammatory reactions in the body (edema, swelling and pain) from the inflammatory mediators that are present in the cells so as good surgeons we should try to minimize the amount of bone removed by using the sectioning technique; with a surgical bur sectioning the crown and the tooth from the middle then elevating the tooth without/with minimal bone removal the patient will be a

3 lot happier. We can also use the Chisel to section the crown but again we should be careful not to fracture the tooth and mandible. This all depends on the angulation of impaction: A. Mesioangular: It's the least difficult, by sectioning the distal half of the crown to make the path of elevation easier. First buccodistal bone is removed to expose the crown then the distal cusp is sectioned and deliverd out then a small straight elevator can be inserted into the surgically exposed mesial aspect of the crown to deliver the remainder of the tooth. B. Horizontal impaction: Bone overlying the tooth is removed with a bur exposing the superior aspect of the distal root and the majority of the buccal surface of the crown (removing as minimal bone as possible to not fracture the mandible or reach the nerve or causing any complications), the crown is then sectioned from the roots and is removed separately. Roots are then delivered separately by the cryer elevator used with rotational movement.

4 C. Vertical impaction: The tooth is deep so we need to remove more bone. We do sectioning of the crown from the middle then elevate each root separately especially if there was a curvature in the root and each root has a different path of elevation. D. Distoangular: Is the most difficult. Bone is removed with a bur, the crown is then sectioned and delivered with a straight elevator and then the roots are delivered with a cryer elevator. Impacted maxillary teeth: We don t use Chisel; because we might reach the sinus. And we don't section the tooth because the overlying maxillary bone is usually thin, soft and relatively elastic so the tooth is removed easily

5 with a straight elevator with no resistance from the bone unlike the mandible which is very resistant and calcified. and usually we avoid the forceps we use it only if we have obvious mobility of the tooth but mainly the elevator is really efficient to do the job alone. We also avoid excessive force. Once soft tissue has been reflected, a small amount of buccal bone is removed mainly from the mesial aspect with a bur or the pointed end of a periosteal elevator then the tooth is delivered by a straight elevator from the mesial aspect. Note that in most circumstances bone removal using a bur is not required when removing impacted maxillary third molars. A rule in general: there are no definite guide lines on where the straight elevator should be placed, this depends on each case independently that s why we need to assess each case by clinical examination and panoramic radiographs. Debridement of the wound: Remove bone chips and debris Irrigate with saline Smooth sharp edges Primary closure; by sutures. We don't do a really tight closure of the wound: 1. To try to avoid tension in the bone adjacent, to not cause necrosis and failure of healing.

6 2. Try to close the superior part of the flap going distally, leaving the mesial arm of the flap unsutured for drainage of blood; because after the surgery there will still be a lot of bleeding so if we closed the wound tightly blood will accumulate inside the tissue going to the neck causing a huge swelling. 3. And the flap tissues are usually in tight contact with bone so there's no need to tight suture it. Post-operative care: 1. Post-operative Analgesic agents: paracetamol or panadol extra especially for patients with gastric irritation (2 tablets for 3-4 times daily) these are mild analgesics. The best dental analgesic that we can use is NSAIDs such as Voltaren but they're contraindicated for patients with gastric irritation and peptic ulcers so we go for a selective NSAID such as Celebrex. Question: Can we give an IM Voltaren to get rid of the gastric irritation effect? Answer: No, because the effect is systematic. Usually we don't go for Opioid unless there's severe pain, it needs a special prescription from the hospitals. 2. we also give a pre-operative analgesia (they have found that this minimize the amount of post-operative analgesia needed) and we give them a prophylactic antibiotics for healthy patients to reduce the incidence of infection, it's preferable to give the antibiotic before the procedure because bleeding will occur causing hematoma (dead blood) so this hematoma should be loaded with antibiotic before it occurs preventing infection. Note: prophylaxis against infective endocarditis is given for: patients with Prosthetic heart valve or history of infective endocarditis or congenital heart disease or cyanosis.

7 3. Swelling is reduced by: a) The technique: sectioning the tooth is much better than bone removal. And if it's possible to do the extraction without a flap this reduces the swelling and hematoma after the surgery. b) Ice packs: at the first 2 hours after the surgery might help reducing the edema. c) Medication: -The most potent drugs in reducing the swelling are steroids that provide sufficient anti-inflammatory activity to greatly limit edema. Dextamethasone is a long-acting steroid, the most one used in dentistry. 4-8mg is given pre-operatively, can then be continued for 2 to 3 days post-operatively to control edema. -NSAIDs can also be given. -Danzen (Serratiopeptidase); is a proteolytic enzyme that cuts the peptides and causes break down to the proteins to lower the osmotic pressure therefore don't allow excessive fluid to come out. It's not used that much in dentistry, mainly used for chronic edema in the legs. Sometimes an immediate swelling can happen during the procedure due to surgical emphysema; trapping of air within the facial tissues. This condition is very simple you don't have to do anything about it. Complications: Intraoperative: Soft tissue injuries to the gingiva or lip or the tongue and cause ulceration. Injuries to oseous structures, like fractures in the maxilla or the mandible and the alveolar bone. Oroantral communications, especially in the extraction of the upper third molar where it's close to the sinus. How can you tell if you have perforated the antrum or the axillary sinus? After the procedure the patient will notice blood coming out of his nose while rinsing his mouth. So to test if there's perforation let

8 the patient fill his mouth with water and let him try to blow the water through his nose, if air bubbles is formed this means there's a sinus perforation. We can put a gutta percha and take a radiograph. Fractures of the mandible Injuries to adjacent teeth Complications with the tooth being extracted it could fracture during extraction. If the apical part of the root is fractured don't force to remove it (this could cause injury to the adjacent nerve) if it's vital just leave it, by time it can come up to the surface. Injuries to adjacent structures As you can see on slide 52 that the lingual nerve is just touching the lingual plate close to the third molar so you might catch it easily with the bur. On slide 53: the third molar is within the canal of the lingual nerve, it's symptomatic and needs removal what can we do? -full examination. -we take CBCT to see the exact location of the tooth. -consent form is a must. -we can do coronectomy to cut the crown and leave the roots, but this may cause infection and during coronectomy we might move the roots causing injury to the nerve. -the best solution is doing an Extrusion to the third molar to let it move away from the nerve canal (depending on the physiology of bone remodeling) then we do the extraction. Postoperative complications: Bleeding, is reduced by applying good pressure. Delayed healing and infection THANK YOU I've added some information from the book to make things more understandable.