Exodontia & Surgical Extractions
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There are many indications for the removal of teeth. Most teeth are removed because they are unrestorable, but they can also be removed if there is associated pathology or the tooth is in the way of optimal treatment. It is possible for the tooth to be restorable but the patient is unable or unwilling to go through the cost and effort of restoring a tooth. You may see patients that need to have teeth removed for medical reasons. Before radiation therapy or serious surgery to the head and neck it is preferential to remove any teeth that pose an infectious risk. Before commencing bisphosphonate therapy (especially IV bisphosphonates) it is important to avoid future extractions to minimize the risk of bisphosphonate related osteonecrosis of the jaw (BRONJ).
Any systemic condition that impairs healing, clotting or immune function can see elective extractions contraindicated. These can include uncontrolled diabetes, end-stage renal disease, leukemia/lymphoma, poorly managed ischaemic cardiac disease (uncontrolled hypertension, unstable angina, recent infarct), bleeding disorders (hemophilia, thrombocytopenia), and certain medications (long term IV bisphosphonates, chemotherapy, anticoagulants, long term high dose steroids). You should be careful removing teeth if a patient has received head and neck radiation therapy. Previous treatment with IV bisphosphonates increases the risk of osteonecrosis of the jaw. It is not recommended to remove teeth in a patient with acute ANUG, or an acute infection with uncontrolled cellulitis.
PREGNANCY
Pregnancy is not a contraindication for extractions but dental management of pregnant or lactating patients requires special attention. In the first trimester, during organogenesis, the fetus is most susceptible to teratogens. If possible, elective treatment can be postponed or diverted to the second trimester. Care should be taken when selecting medications, making sure none pose a risk. During pregnancy, most women may experience respiratory alterations, heartburn, nausea and vomiting. Patients may feel more ill in the morning so afternoon appointments could suit better. Decubitus hypotension syndrome/vena cava syndrome is seen in the final stage of some pregnancies, causing difficulty in the venous return to the heart. A mum may not be able to lie flat in the dental chair. There may be an increased risk of caries (vomiting, dietary changes) and periodontal disease. Estrogen levels can increase by 10 fold and progesterone by 30 fold, leading to increased incidence of pregnancy gingivitis and pyogenic granulomas. Recommendations for pregnant patients are:
- First and third trimester – Patient education (oral hygiene instruction), periodontal prophylaxis and emergency treatments only, avoiding routine radiographs (can be taken safely if needed).
- Second trimester – Patient education (oral hygiene instruction), periodontal prophylaxis and emergency treatments, the control of active oral diseases. Elective dental care is safe, avoiding routine radiographs (can be taken safely if needed).
IMPACTED TEETH
Any tooth can become impacted, but the third molars are the most common. The impaction can be described according to the position (Pell and Gregory) and angulation of the tooth.
- Angulation – mesioangular, vertical, distoangular, horizontal. Mesioangular impactions are often the easiest to remove in the mandible and most difficult in the maxilla, distoangular the most challenging in the mandible and the easiest in the maxilla.
- Class (number) – relationship to the anterior border of the mandible. Class 1 is normal (least challenging), Class 2 sees half the crown buried into the ramus, Class 3 sees the entire crown embedded within the ramus (most challenging).
- Class (letter) – relationship to the alveolar ridge/occlusal plane. A Class A tooth is at the same occlusal plane as the neighboring molars, Class B between the occlusal plane and CEJ of the second molar, Class C below the CEJ of the second molar.
Incomplete roots or fused roots, a large follicle or wide periodontal ligament space, young elastic bone, and increased distance from the inferior alveolar nerve makes surgery less difficult. More difficult extractions can often be predicted from the examination and preoperative radiographs. An elective surgical approach is recommended if you think the tooth will require excessive force to remove. A surgical approach is considered when:
- Routine extraction has failed.
- Dense bone is encountered.
- Older patients with more inelastic bone.
- Bruxer patients (dens bone).
- Hypercementosis or divergent/long root anatomy.
- Extensive coronal loss (caries, crown fracture, cracked tooth etc.).
- Impacted tooth that does not permit adequate movement.
Impacted third molars may require extraction if they cause periodontal disease (deep pocketing), several bouts of acute pericoronitis (which can lead to fascial space infections), caries, root resorption, or are associated with pathology (cysts or tumors). If a tooth presents with acute pericoronitis it is advisable to clear the infection before extracting the tooth.
Pericoronitis describes inflammation of the soft tissues (operculum) associated with a partially erupted crown, most commonly the mandibular third molars. Overerupted or malpositioned maxillary third molar can lead to trauma and inflammation of the operculum. Signs and symptoms include pain, bad taste, inflammation, and occasional purulent discharge due to acute pericoronal abscess which could lead to systemic signs (fever, malaise etc.) Treatment includes empirical antibiotics and irrigation. As soon as the acute symptoms subside, extraction is often implemented to prevent recurrence. An operculectomy (removal of operculum) can sometimes be curative.
Third molars should only be extracted if there are legitimate problems/pathology associated, which could include:
- Multiple bouts of pericoronitis.
- Advanced periodontal disease.
- Poor oral hygiene due to impaction leading to problems.
- Pathology such as cyst or neoplasm.
- Chronic pain.
- Resorption or damage to neighboring teeth.
ORAL SURGERY ARMAMENTARIUM
Scalpel blades – commonly used are the #10, #11, #12 and #15 which is the most common.
Periosteal elevator – The periosteal elevator is used to lift a muco-periosteal flap off the bone when performing surgical extractions.
Luxator – a sharp instrument with a less concave blade than an elevator, used to sever Sharpey’s fibers within the periodontal ligament space and loosen the tooth prior to forceps application.
Elevators – Elevators provide leverage to dislodge a tooth or root from its socket. The fulcrum is usually the crest of the alveolar bone. Adjacent teeth can be used as a fulcrum if they are also to be extracted. The contact point on the tooth or root surface where force is delivered is the purchase point. Can be straight or angular/curved.
Root pick – “small elevator” to loosen small root fragments from bony socket with thin, pointed, angled working ends. They can be single or double ended, curved or straight.
Curette – used to remove tissue or debri from the surgical socket.
Hemostat – securely holds small items, clamps blood vessels, and removes small pieces of tooth/bone.
Needle holder – to hold and manipulate suturing needles. Similar to hemostat but contain a small concavity on the area inside of the beak to accommodate the suture needle.
Sutures – used to close wounds and approximate tissues for optimal healing. Varying materials attached to a stainless steel needle. Sutures may be resorbable (plain gut, chromic gut, and polyglycolic acid (PGA) like Dexon and Vicryl) or non-resorbable (silk, polyester, nylon, polypropylene (Prolene), mersilene (Dacron)), braided or mono-filament. Absorbable and braided (silk, catgut) materials cause more tissue irritation. They are sized according to the material diameter. 3-0, 4-0, and 5-0 are the most commonly used in dentistry. The larger the number, the smaller the diameter and finer the suture material. Very fine sutures (6-0 and up) are used for cosmetic skin sutures. Needles can be tapered point, cutting or reverse cutting. Non-resorbable sutures are removed after 5-7 days.
Surgical handpiece/units – surgical handpieces can appear similar to operatory handpieces, but are set up to exhaust away from the patient to avoid surgical emphysema (trapped subcutaneous air). Though they can have built in saline delivery, external irrigation may be needed to avoid temperature increase. Slower speeds are commonly used to reduce friction. A variety of burs can be used, but often are longer for adequate reach.
Rongeurs – to cut and contour bone, removing any sharp edges or exostoses (alveolectomy and alveoplasty). Can be side cutting or end cutting.
Bone chisel – can also be used to cleanly remove bone from the alveolar ridge, and exostoses (i.e. tori), alveoplasty. Best done under general anesthesia (not pleasant for the patient).
Bone file – to adjust and smooth sharp contours on the alveolar ridge, often following rongeurs. They can be straight or curved, single or double ended, with either straight cutting sides or crosscut ridges.
Austin tissue retractor – deflects and retracts the periosteum from the bone.
Senn tissue retractor – deflects and retracts the periosteum from the bone.
Seldin tissue retractor – deflects and retracts the tissue flap from the bone. Blunt, round, double ended. Can be used to aid periosteal elevation.
Minnesota retractor – holds the tongue and cheek away from the surgical site, soft tissue protection.
Shuman tongue and cheek retractor – holds the tongue and cheek away from the surgical site, soft tissue protection.
Weider tongue and cheek retractor – holds the tongue and cheek away from the surgical site, soft tissue protection.
Mouth prop/Bite block – keeps the mouth open during sedation, general anesthesia or long procedures under local anesthesia. Comes in adult and pediatric sizes.
Adson tissue pliers – grasping and stabilizing soft tissue flaps during suturing and reconstructive procedures like tissue grafting. They are similar in shape and appearance to cotton pliers with serrated tips for securely grasping tissue flaps.
Allis tissue forceps – grasping and stabilizing soft tissue flaps during suturing and reconstructive procedures like tissue grafting. Comes with hemostat type handles and serrated tips.
EXTRACTION FORCEPS
Extraction forceps are handheld, hinged instrument used to hold, manipulate, and remove teeth and tooth fragments. Three components are handle, hinge, and beaks. The shape of the beak determines the tooth targeted. Some are designed to be Universal, others quadrant specific.
#99 Maxillary anterior and premolar forceps – straight handles and beaks, with beaks designed to conform to the facial and lingual root contour just apical to the CEJ. They are universal.
#150 (Cryer) Maxillary anterior and premolar forceps – straight handles and curved beaks, with beaks designed to conform to the facial and lingual root contour just apical to the CEJ. They are universal. #150 is the maxillary counterpart to the #151.
#151 (Cyer) Mandibular anterior and premolar – curved beaks and handle, beaks designed to conform to the buccal and lingual contour of the root surfaces just apical to the CEJ. Universal.
#18R Maxillary right molar (first and second) – curved beaks and right quadrant specific. Molars have differing buccal and palatal root surface anatomy just below the CEJ. The rounded beak contours to the palatal root, the pointed beak contours to the bifurcation of the mesio-buccal and disto-buccal roots (beak to cheek). The 53R has the same beak but straight handles. The #18L and #53L would be used for the upper left quadrant.
#88R Maxillary right molar (first and second) – curved beak and right quadrant specific. Bayonet design to engage between the furcation on the buccal side, and bilaterally adjacent to the palatal root. Like an upper cowhorn. #88L would be used for the upper left quadrant.
#210 Maxillary third molar – Bayonet design, curved beak designed to conform to the buccal and palatal contour below the CEJ. Universal.
#65 Maxillary anterior and root tip – slender beaks designed for difficult access, overlapping teeth or thin retained root tips. Curved beak, universal.
#69 Maxillary and mandibular anterior and root tip – more continues curve but similar form and function to the #65. Can be used for lower teeth.
#74 Mandibular root tip – universal bird beak design.
#15 Mandibular molar (first and second) – Curved, pointed beaks designed to engage the buccal and lingual bifurcations apical to the CEJ. The beak design allows for universal lower quadrant use. #15 and #17 forceps have identical beak designs, however #15 has one curved handle whereas in #17 both are straight.
#23 Cowhorn/Mandibular molar (first and second) – pointed beaks designed to conform to the bifurcation between the mesial and distal roots on both the buccal and lingual side. Universal design. #23 has two straight handles, #16 a similar design but one handle is curved.
#222 Mandibular third molar – bayonet design, universal.
EXTRACTION TECHNIQUES
A recommended extraction protocol is maxillary teeth before mandibular, posterior teeth before anterior. The initial force applied with forceps is apical. Bucco-lingual forces on mandibular posterior teeth are less effective due to dense mandibular bone.
The force exerted on a tooth is largely dictated by the root morphology. Round roots lend themselves to rotational forces. Incisors, canines, lower premolars and the upper second premolar generally have round roots (in cross section). All teeth are delivered with a primary buccal force (except deciduous maxillary molars) to expand the buccal plate and avoid alveolar fracture on the lingual side. Luxation forces are perpendicular to the long axis of the tooth.
Compressing the alveolar ridge after extraction used to be advocated, but may also damage the cortical plates and is likely unnecessary. A curette is used to remove periapical cysts and granulomas. Most extraction sockets do not need to be sutured. Direct pressure applied with a gauze pad for 20 minutes should provide adequate haemostasis.
Indications for surgical extractions include failed routine extraction, dense bone, older patients with less elastic bone, hypercementosis or widely divergent roots, or extensive decay/destruction of the tooth. The first step in surgery is exposure that allows for adequate visibility and removal. An envelope flap is the most commonly used, with or without relieving/releasing incisions. Though there are many flap designs the fundamentals principles of flap design are:
- Know your anatomy, avoid important anatomical structures.
- Incisions are over sound bone, avoid over bony prominence.
- Flaps should have a broad base ensuring good blood supply.
- Flaps should provide adequate visualization of the surgical area.
- The relieving incision is started in the buccal vestibule (but never beyond the depth of the sulcus/mucobuccal fold), extended to gingival margin.
- Releasing incisions line up with tooth line angles, not through papillae or mid-crown.
- A full thickness flap includes the periosteum.
- The flap should be handled with care.
Care should be taken making an incision distal to the third molar area due to the supracrestal route of the lingual nerve. Next, bone removal is often needed for atraumatic extractions, the extent determined by the procedure and level of impaction. Usually the clinician starts with a buccal trough to the CEJ, then additional bone removal or tooth sectioning as required. Bone is almost never removed on the lingual aspect of mandibular teeth because of the lingual nerve. The tooth is delivered after sectioning, and the surgical site irrigated with copious (isotonic) saline to remove fractured tooth or bone spicules which would cause postoperative problems. Any sharp bony margins are adjusted (alveoplasty, using a bone file, rongeurs or surgical handpiece). Packing may be introduced, and the soft tissue flap sutured back into place.
