VMD 513: Pet animal Breeding, Management, Nutrition and Health Care (1+1)

TOOTH EXTRACTION

Simple Extraction

• A simple extraction refers to the extraction of a small single-rooted tooth, such as an incisor. An appropriate-sized dental elevator is placed in the gingival sulcus to sever the attachments of the gingiva around the tooth. The elevator should be advanced apically between the alveolar bone and the root. The periodontal ligament can be torn by rotating and holding the elevator 90 degrees for 15-second intervals. A dental extraction forceps can then be placed on the crown to rotate the tooth and remove it from the alveolus.

Multi-Rooted Extraction

• Multi-rooted teeth include the premolars and molars which may be difficult to extract when only one root is affected with the other roots firmly attached to the alveolar bone. Most roots are embedded in the alveolar bone at divergent angles which further anchors the tooth into the surrounding bone. Sectioning of a multi rooted tooth into two or three segments converts the procedure into multiple simple extractions. A tapered fissure bur on a high-speed hand piece is an efficient technique for sectioning teeth. The furcation is located prior to sectioning the tooth. This can be done by elevating the gingiva with a periosteal elevator. The bur is placed at the furcation and directed through the crown. The segments of the tooth are then independently extracted.

Complicated or Surgical Extraction

• A complicated or surgical extraction technique is generally reserved for dog’s teeth that are difficult to extract because of their large root structure including the canine teeth, mandibular 1^st molars and the maxillary 4^th premolars.
• Numerous steps are involved in the performance of a surgical extraction. The initial step is creation of a mucoperiosteal flap. Careful and adequate elevation of the mucoperiosteal flap is important for gaining access to the underlying buccal alveolar bone so that during the procedure the gingiva is not perforated. The next step involves location of the furcation and sectioning of a multi-rooted tooth. The buccal alveolar bone is then removed as needed to provide an efficient controlled technique for delivering large rooted teeth. Excessive removal of buccal bone should be avoided particularly when extracting mandibular teeth because this causes unnecessary weakening of the mandible. Elevation and extraction of each segment is accomplished by gently placing the dental elevator into the periodontal space advancing the elevator apically and gently rotating and holding the elevator for 10-15 seconds around the entire gingival sulcus until the segment can be easily extracted with an extraction forceps. An alveoloplasty is performed prior to closure to give the extraction site a smooth boney contour decreasing postoperative pain that may be associated with sharp edges of bone beneath the mucoperiosteal flap. A small dental curette is placed in the alveolus to remove any necrotic debrie, calculus or bone fragments and the alveolus and flap are flushed prior to closure. The mucoperiosteal flap is repositioned and sutured in place. If there is tension on the mucoperiosteal flap when attempting to close a surgical extraction site the tension can be released by incising the inner most layer of the flap, the inelastic periosteum, at the apical portion of the flap. Incision of the periosteum will permit tensionless apposition of the flap and prevent postoperative dehiscence.
• When performing a mucoperiosteal flap for the surgical extraction of the maxillary 4^th premolar several structures should be carefully avoided. When making the mesial (rostral) portion of the incision the infraorbital artery, vein and nerve should be avoided as they exit the infraorbital canal immediately rostral to the periapical bone of the mesiobuccal root of the maxillary 4^th premolar. These structures can be avoided by digitally retracting them dorsally and not extending this incision too far apically. When making the distal (caudal) part of the incision the parotid and zygomatic salivary duct papillae should be visualized and avoided.
• There are two approaches for the surgical extraction of the mandibular canine teeth including the labial and lingual approach.² The labial approach utilizes a mucoperiosteal flap located on the labial aspect of the tooth while a lingual approach utilizes a lingually located flap. Equal amounts of alveolar bone are present buccally and labially so there is no advantage of one technique over the other with regard to bone removal. The mental artery, vein and nerve exit through the mental foramen located near the labial aspect of the apex of this tooth. A lingual approach would avoid potential damage to these structures.