Ass. Prof. of Oral and Maxillofacial Surgery Surgical Exodontia By Dr: Waleed A Abdullah Bds, Msc, Phd Ass. Prof. of Oral and Maxillofacial Surgery King Saud University

Trans-alveolar Extraction It is essentially a technique that includes dissection of a tooth or root from it’s bony attachments. It is often referred to as “Open” method.

Trans-alveolar Extraction - Indications Any tooth which resists attempts at intra-alveolar extraction when moderate force is applied. Retained roots which cannot be either grasped or delivered with an elevator. A history of difficult or attempted extractions. Hypercementosed and ankylosed teeth.

Trans-alveolar Extraction - Indications Any heavily restored tooth, especially when root filled or pulpless. Impacted and dilacerated teeth. Teeth shown radiographically to have a complicated root patterns. During immediate denture treatment, where there is a need to trim some alveolar bone.

OPERATIVE PROCEDURES Determination of the type of anesthesia to be used. Formulation of overall treatment plan. Important components of such a plan are: 1. Incision to gain access to the area 2. Removal of adequate amount of bone 3. Sectioning of the tooth (tooth division) 4. Elevating the tooth or root from its socket 5. Preparing the wound before closure 6. Closure of the wound or incision 7. Postoperative care

Instruments used in trans-alveolar surgery

Incision to gain access to the area: Mucoperiosteal flap

Principles of flap design : Incisions should avoid anatomical structures, such as major nerves or blood vessels. Anatomical structures to be avoided in the mandibular arch include Lingual nerve, Mental nerve, Long buccal nerve, Facial artery, and Buccinator artery. The anatomical structures to be avoided in the maxillary arch include Greater palatine nerve, artery, and vein, Incisive papilla, Nasopalatine nerve.

2. incisions far enough away from the surgical area: The wound margins should rests on sound bone, so that it won't collapse into the bony defect, and at the same time rapid revascularization is preserved. Radiographically, the lesion may look smaller than its true size, and so, the incision should be placed in an area far enough from the expected periphery of the lesion.

Incisions should be made parallel to major blood vessels, The base of the flap should be wider than the apex to ensure adequate blood supply. A firm pressure upon a sharp scalpel should be used so that both the mucosa and periosteal layers of the gingiva are incised down to bone Incisions are made in one operation, as extensions and "second cuts" often leave ragged flap margins and delay healing. The scalpel should be used as a pen not as a plough, and the soft tissues cut at right angles to the surface of underlying bone.

6. The MPF should be made large enough to provide for visibility, accessibility and adequate room for instrumentation. It should be known that a large flap heals as rapidly as a small flap and that post surgical pain does not appear to be related to the size of the flap as much as the amount of bone removed. Incisions should not be made in an area of thinned mucosa e.g. over an exostosis or bony protuberances because the blood supply is reduced, suturing is difficult, and the rate of dehiscence is high.

The vertical releasing (relaxing) incision should be avoided if the horizontal incision will provide adequate access. This is because the vertical releasing cut reduces the blood supply to the flap and cause added discomfort The vertical releasing incision, if needed, should be made at a line angle to maintain the integrity of the interdental papilla, which is not included with the flap because of the difficulty in precisely re-approximating them.

Types;

However, the following terminology is commonly used to describe the various types of MPFs. Envelope Flap : It is a full-thickness flap. Incision is made horizontally along the crest of the ridge or in the buccal gingival crevice. When incision is made around teeth, it extends at least one tooth distal and two teeth mesial to the site of the operation. Has no vertical incision.

Advantages 1. It is the flap of choice for most surgical procedures. 2. Provides the broadest base and fully covers the resultant bony cavity. 3. With the envelope flap, there is little danger of violating any major anatomical landmarks. 4. During the procedure, the envelop flap can be extended as needed; if still greater access is required, a vertical relaxing incision can be placed.

Triangular (three-cornered) Flap It is an envelop flap with one vertical relaxing incision. The horizontal incision extends from one tooth distal to the surgical site to one tooth mesial. Advantages It is the next most useful flap for exodontia. It provides greater access; therefore, it is used primarily for surgery in the vicinity of the apex of the tooth or in a deeply impacted tooth.

Rectangular (four-cornered) Flap : It is an envelope flap with two vertical relaxing incisions. It provides substantial access. However, it have limited anteroposterior dimension.

Semilunar Flap Most useful for retrieval of small root tips and periapical endodontic surgery of a limited extent. The horizontal component of this incision should not cross major prominences, such as the canine eminence. The incision should be placed at least 2 mm apical to the base of the gingival sulcus (4-5mm from gingival margin).

Advantage and disadvantage No involvement of the gingival sulcus, thus, avoids trauma to the papilla and gingival margin. Provides limited access because the entire root of the tooth is not visible.

Making the incision The No. 15 scalpel blade on a No . 3 scalpel handle is used and held in the pen grasp. In the edentulous areas, a crestal incision is made. Incisions placed around teeth are made by placing the scalpel blade at a slight angle to the teeth and into the periodontal sulcus. Incision is made to the height of the crestal bone moving from posterior to anterior by drawing the knife toward the operator. If making a vertical relaxing incision, tissues are apically reflected, with the opposite hand tensing the alveolar mucosa so that the incision is made cleanly through it. Because scalpel blades dull rapidly after being pressed against bone they should be changed between incisions if more than one flap is to be reflected.

Instruments used in trans-alveolar surgery – Blade Handle Handles for the blades

Instruments used in trans-alveolar surgery – Surgical Blade #15 is the most commonly used scalpel blade. #15 is a smaller version of #10 #11 is pointed (stab incisions for Incision and Drainage). #12 is hooked

Instruments used in trans-alveolar surgery – Disposable Blade

Reflection of the Flap: 2 Flaps are reflected with the mucoperiosteal elevators. Using the sharp pointed end of the elevator → interdental papilla are freed from the underlying bone (using the tooth as a fulcrum). Using the broad end of the elevator in a push stroke, the attached gingiva and alveolar mucosa are reflected to the desired extent. Using the mucoperiosteal elevator in a pull stroke can sometimes shred the periosteum.

Handling The Instruments The scalpel is held with thumb, middle and ring finger while the index finger is placed on the upper edge to help guide the scalpel. The scalpel should never be used in a "stabbing" motion especially while raising a flap.

Retraction of the Flap: 3 A periosteal elevator is used as a retractor for small flaps and the Minnesota or Austin retractors for large flaps. Minnesota periosteal elevator Austin

The retractor should be placed beneath the flap and held firmly perpendicular on sound bone with no soft tissue trapped between. In order not to focus on the retractor rather than the surgical field, do not force the retractor against the MPF in an attempt to pull the soft tissue out of the field but rather the retractor is held in contact with the bone so that the flap rests on it passively.

Bone Removal : 3 Bone is remove some to expose the underlying tooth/root. Bone, must not be sacrificed unnecessarily and removal must be limited to what is required to achieve certain objectives. Removal of bone is intended to: Expose either the tooth or roots before their delivery. Provide a point of application for an elevator or forceps. Create a space into which the tooth or root may be displaced.

Instruments Used for removing bone : Chisel and mallet The chisel is a fine instrument for removing bone. Monobeveled or bibeveled. Driven by hand, mallet or engine. Bone Gauge Unibeveld Chisel Bibeveld Chisel Mallet

Hand driven chisel (bone gouge):  Used for removing thin or weakened bone. The mallet driven chisel  Used for removing less porous and porous bone in the mandible or maxilla, respectively. bibeveled chisel (osteotome) :  Used for sectioning teeth. Using mallet is alarming to the conscious patient, and so, it is preferred to used under GA. The engine driven chisel (impactor) is mounted on a handpiece and cuts bone when pressure is applied to bone and stops cutting when pressure is released.

Bone burs The most frequently used method for bone removal. Available in many forms: crosscut fissure burs, tapered, or round. Bone can be reduced or removed in 3 ways: Using the round bur, holes in a necklace or postage-stamp pattern are created above the area of surgery. The holes are then connected and the disc or postage-stamp piece of bone is removed permitting entry into the surgical area.

Using the fissure bur, bone is removed alongside the periodontal membrane in a "guttering" action. Using a large round bur, bone is grounded down to the desired amount (sometimes a tooth root may be ground down with the bur "atomization"). N..B: Round burs are also used to create a purchase point or point of application by directing the bur at an angle of 45° to the vertical axis of the root

Rongeur forceps It is a forceps-like instrument used to remove bone by shearing on a planning action. It has sharp blades that are squeezed together by the handles, cutting or pinching through the bone. Rongeur forceps have a leaf spring between the handle so that the instrument will open when the hand pressure is released. This allows the surgeon to make repeated cuts without manually reopening the instrument.

The side-cutting rongeur (Cleveland or Blumenthal rongeur): - ideal for alveolectomy procedures. - used in a horizontal position with one of the biting edges of the forceps locked high on the alveolus while the other blade is brought to it in a planning action. End-cutting Cleveland bone rongeur: - used for removal of interradicular bone

3. The side- and end-cutting rongeur (Cleveland or Blumenthal rongeur): - more practical for most dentoalveolar surgical procedures that require bone removal. - As it is end cutting, it can be inserted into sockets for removal of interradicular bone, but can also be used to remove sharp edges of bone.

Bone file or rasp It is a double-ended instrument with a small and large end. used only for final smoothing of the bony ridge after gross removal with the rongeur. Filing before suturing the MPF back into position should always follow use of the rongeur.

Bone File

Tooth Sectioning : 4 Indication: Bone is insufficiently elastic. Multi-rooted teeth in which the lines of withdrawal of different roots prevents removal with either the forceps or buccal application of elevator. The roots are separated to be removed along their individual paths of withdrawal. Tooth division may be effected using a bur, an osteotome or tooth-splitting forceps (tooth shear forceps).

Guidelines During sectioning using a surgical bur, irrigation is a must. Considerable heat may be generated, and the tooth structure clogs the bur blades quickly. When dividing the root-mass of a lower molar, expose the bifurcation and separate the roots from below upwards with the bur. This method allows you to know when the roots are completely divided; whereas it is difficult to be certain if you cut down towards the bifurcation from above.

5 Elevating the tooth or root from the socket: If a firm grip of the root or root-mass can be obtained, forceps is used, if not, the use of elevators is necessary. When applying buccal force it is necessary to engage the elevator in a notch on the side of the root-mass. Bifurcation of lower molars. Created with a round bur. When using elevators, excessive force is never necessary if the principles outlined for their use are followed. If a tooth or root resists elevation, the elevator should be discarded and the cause discovered and overcame

Removal of the tooth segment with a forceps Removal of the root with an elevator applicated in a prepared purchase point Removal of the tooth segment with a forceps

6 Preparing the Wound Before Closure: Gently irrigate the wound with sterile warm saline and then inspect the wound. Any tooth or bone residual fragments should be removed. All pathological tissue should be removed. Any sharp edges should be Smoothed, especially the interdental septum in molar sockets which is frequently mistaken for a piece of tooth by the patient. If greater irregularities are present, a regular alveoloplasty may be done. Compress the alveolar process between the thumb and forefinger. Finally irrigate the wound before closure.

7 - Closure of the Wound: