11.2 Equipment and Instrumentation

Intraoral radiographs are essential to formulate a treatment plan and must be completed prior to extraction of any tooth. Radiographs allow the veterinarian to visualize the root structure and the condition of the surrounding alveolar bone. The typical number of tooth roots for a given tooth is known, but radiographs may reveal supernumerary roots, abnormally shaped roots, convergent roots, fused roots, dilacerated roots, fractured roots, or root resorption, all of which may change the surgical approach to extraction of that tooth. Radiographs are also important to evaluate the alveolar bone surrounding the tooth root for pathology. In the mandibles, periapical pathology and horizontal or vertical bone loss may cause weakening of the surrounding bone and make the area more prone to fracture during the extraction procedure. This information is critical to avoid potential complications when formulating a treatment plan.

Availability of proper equipment and the use of sharp hand instruments assist in the successful extraction of teeth. A water‐cooled highspeed handpiece is required to facilitate the removal of buccal alveolar bone (alveolectomy) and to section multirooted teeth. Fiberoptics incorporated into the high‐speed handpiece provide an additional light source at the surgical site. Adequate surgical lighting and magnification with a light source will facilitate exodontic procedures and are very helpful for retrieval of fractured root tips.

Gloves, eye protection, masks, and surgical caps should be worn by veterinarians performing oral surgery and by the technician assisting with the procedure. Although the oral cavity cannot be considered a sterile site for oral surgery, surgical instruments that are used to penetrate soft tissue or bone should always be sterilized after each use [2]. An autoclaved, sterile oral surgery pack should be available for each patient.

The following instruments are commonly utilized for tooth extractions and should be contained within the oral surgery/extraction pack (Figure 11.1):

• A highspeed handpiece should be held between the thumb and first two fingers at the working end of the handpiece in a modified pen grasp while resting a finger on the patient. This allows the operator to have more control and better tactile sense while using the highspeed drill.
  
• Carbide burs in a water‐cooled highspeed handpiece are used to remove buccal bone (alveolectomy) and to section multirooted teeth into single roots prior to extraction. Commonly utilized burs include round burs (number 1/2, 1, 2, 4, 6), taper fissure crosscut burs (699L, 701, 701L, 702), and diamond burs.
  
• A number 15 or 15C scalpel blade with a standard scalpel blade handle or a round scalpel blade handle is utilized to incise gingival and mucosal tissues.
  
• A periosteal elevator (Freer or Molt) is utilized to elevate the periosteum away from the underlying bone. It is placed in the palm of the operator’s hand with the index finger placed close to the working end of the instrument. This short finger stop prevents inadvertent damage to surrounding soft tissue should the instrument slip. The periosteal elevator is used in a pushing or prying motion to elevate the attached gingival tissue and periosteum of the alveolar mucosal tissues from the underlying alveolar bone.
  
• Dental elevators vary in size and shape. The elevator is placed into the periodontal ligament space utilizing a short finger stop and is rotated to stretch and fatigue the periodontal ligament and facilitate extraction. The size of the elevator should conform to the size of the root being extracted. Wing‐tipped elevators are very useful as they have curved sides that easily conform to the root. The size of the elevator corresponds with the width of the elevator in millimeters. The sizes most commonly used in veterinary dentistry are sizes 2 through 5 mm. A 2 mm elevator may be utilized to assist in the elevation of a cat premolar tooth and a 5 mm elevator may be utilized to assist in elevation of a canine tooth in a large dog.
  
• Dental luxators vary in size and shape. The luxator is placed in the periodontal ligament space and utilized as a wedge to cut and break down the periodontal ligament. The tip of the luxator is very thin, which allows it to be easily introduced into the periodontal ligament space in an apical direction. Luxators are not to be used with rotational pressure as rotational pressure will damage the luxator tip.
  
• Root tip picks come in various shapes and sizes and are utilized to assist in the removal of fractured root tips from within the alveolus.
  
• Extraction forceps are available in a variety of shapes and sizes. Small breed extraction forceps are most commonly used in veterinary dentistry. The size of the forceps should conform to the operator’s hand and the tooth size. The forceps are utilized only after the tooth is mobile following successful elevation or luxation. They are placed on the tooth at the cementoenamel junction, and the tooth is then rotated along its long axis to displace it from the alveolus.
  
• Root tip extraction forceps have small tips and are utilized to remove root tips from within the alveolus.
  
• A Miller bone curette is used to debride granulation tissue, bone fragments, and debris from within the alveolus following tooth extraction.
  
• Thumb forceps are used to hold gingival tissue. Commonly utilized thumb forceps include Adson tissue forceps (with or without teeth) and Bishop Harmon (1 × 2) forceps. The tissue forceps should be used to gently hold the tissue while avoiding crushing the gingival tissue.
  
• Scissors are utilized to debride tissue and may be used to release the periosteum of the mucoperiosteal flap. Curved iris scissors work well for this purpose but some veterinary dentists prefer LaGrange scissors or Metzenbaum scissors.
  
• Small needle holders should be used for oral surgery. 4½–5 inch Mayo Hegar (without scissors) or Olsen Hegar (with scissors) needle holders may be utilized depending on the preference of the surgeon.
  
• Retractors are utilized by an assistant to retract the cheek, tongue, and/or mucoperiosteal flap to increase exposure for the operator. A Minnesota retractor or small feline retractor may be utilized for this purpose.
  
• Suture material for extraction sites is based on the size of the patient, condition of the tissue, and surgeon preference. A 4‐0 and 5‐0 absorbable suture with a reverse cutting or tapered needle is most commonly utilized.

11.3 Pain Management in Exodontia

Use of preemptive multimodal pain management provides oral surgery patients with a more comfortable intraoperative and postoperative period. Tooth extraction and the manipulation of oral tissues stimulate local pain receptors and initiate local inflammation. It is best to interrupt these afferent impulses before a painful stimulus occurs. Opioids, alpha‐2 agonists, non‐steroidal anti‐inflammatory drugs, and intraoral regional nerve blocks may be utilized in pain management protocols for oral surgery cases (see Chapter 9 – Anesthesia and Pain Management).

11.4 Anatomy

Knowledge of basic anatomy of the maxilla and mandible is critical to avoid key structures during extraction (see Chapter 1 – Oral Anatomy and Physiology). Knowing the number of roots in each tooth and the location of the furcation facilitates multirooted tooth extractions, allowing the practitioner to section the teeth into single root segments. Although individual variations exist, three rooted teeth are located only in the maxilla. In the dog, they include the maxillary fourth premolars and first and second molars, and in the cat include only the maxillary fourth premolar tooth. Two rooted teeth in the dog include the maxillary second and third premolars and the mandibular second, third, and fourth premolars, and first and second molars. In the cat two rooted teeth include the maxillary third premolar and mandibular third and fourth premolars and molar. The maxillary second premolar and the maxillary molar in a cat have either two roots, fused roots, or a single root. All the remaining teeth in the dog and cat are single rooted [3]. Gingival connective tissue attaches directly to the root cementum between the base of the gingival sulcus and the alveolar crestal bone. A surgical blade or periosteal elevator can be used to sever this epithelial attachment circumferentially around the tooth as the first step in tooth extraction. The periodontal ligament has fibers that attach to the cementum of the tooth root and to the alveolus. Stretching and breaking down the periodontal ligament is the key to successful tooth extraction.

Neurovascular anatomy is an important consideration in oral surgery. In the dog, the infraorbital neurovascular bundle exits the infraorbital foramen apical to the distal root of the maxillary third premolar tooth. In the cat, the infraorbital neurovascular bundle exits the infraorbital foramen where the zygomatic arch meets the maxilla apical to the maxillary third premolar tooth. The caudal, middle, and rostral mental foramina are located in the rostral mandible in the dog and the cat. The middle mental foramen in the dog is in the ventral third of the mandible apical to the mesial root of the mandibular second premolar. In the cat, the middle mental foramen is in the ventral half of the mandible beneath the lip frenulum in the interdental space between the mandibular canine tooth and third premolar tooth. The mandibular canal, containing the inferior alveolar neurovascular bundle, is located in the ventral third of the mandible. The parotid and zygomatic salivary ducts are present in the mucosal ridge distal to the maxillary fourth premolar in dogs and should be identified prior to extraction of the caudal cheek teeth.

11.5 Simple versus Surgical Extraction

A simple tooth extraction is completed without elevation of a mucoperiosteal flap or removal of alveolar bone. Simple extractions are indicated for small single‐rooted teeth or teeth that have attachment loss from severe periodontal disease. The gingival attachment to the tooth is severed with a number 15 or 15C scalpel blade. The dental elevator is inserted into the periodontal ligament space to elevate and extract the tooth. Non‐surgical extractions of multirooted premolars or molars are indicated when they are very mobile secondary to severe periodontal disease or periapical pathology. The procedure for non‐surgical extraction of multirooted teeth is the same as for simple extraction except that after the gingival attachment is severed, the tooth is sectioned into single‐rooted segments and then extracted.

A surgical extraction involves creation of a mucoperiosteal flap to remove the tooth. Elevation of a mucoperiosteal flap improves visibility and expedites access to the extraction site [4].

For all but the simplest extractions, consider a surgical extraction. Surgical extractions involve raising a mucoperiosteal flap, removing buccal or lingual alveolar bone, sectioning multirooted teeth into single root segments, and apposition of the mucoperiosteal flap to the palatal or lingual gingival tissues following extraction of the tooth. Surgical extractions are often necessary in dogs due to the large root‐to‐crown ratio and diverging root structure. Indications for surgical extractions include large single‐rooted teeth (canine teeth), multirooted teeth with minimal mobility or disease present, and multirooted teeth that have periodontal or endodontic disease affecting only one root.

The alveolus of all extraction sites, regardless of whether the extraction was simple or surgical, should be debrided to remove debris, the surgical site should be lavaged, and the gingival tissue should be sutured. Closure of oral surgery sites allows for primary intention healing, which occurs more rapidly with a lower risk of infection than if the wound is left to heal by secondary intention. The soft tissue edges are opposed and sutured in essentially the same anatomic position they were in before the extraction. This method of wound repair lessens the amount of re‐epithelialization, collagen deposition, contraction, and remodeling needed for healing [5].

11.6 Biomechanical Principles for Oral Surgery to Extract Teeth

Elevators are used primarily as levers. Levers transmit a modest force (with the mechanical advantage of a long lever arm and short effector arm) into a small movement against great resistance [6]. Elevators, when they are placed in the periodontal space and rotated, utilize the surrounding alveolar bone as a fulcrum.

A wedge is used when a luxator or small straight elevator is wedged into the periodontal ligament space and pressure is directed apically in a longitudinal direction along the long axis of the tooth to displace the tooth. Luxators are made of softer metal and are unsuitable for use as a lever.

A wheel and axle movement is utilized when an elevator is placed between two roots or between the root and the alveolus and rotated. The handle serves as the axle and the elevator as the wheel when it engages and elevates the tooth from the socket [6]. Teeth that are to remain in the mouth should never be used as a fulcrum as they could be fractured during the process of extraction of adjacent teeth.