Oral Surgery – Extractions

Oral Surgery – Extractions

Cynthia Charlier

VDENT Veterinary Dental Education, Networking and Training, Elgin, IL, USA

The most commonly performed oral surgery is exodontia or extraction of teeth. While the primary goal of dentistry is to preserve tooth structure, situations may exist where removing the tooth results in a better outcome for the patient. The objective of oral surgery is to remove the entire tooth and root without damaging the surrounding soft tissue and bone.

A maxillofacial and intraoral examination should be completed as part of every physical examination. A tentative treatment plan can be formulated based on grossly visible pathology and should be reviewed with the client during the initial exam. The discussion with the client should include information about general anesthesia, pain management, the oral surgery procedure, potential complications, and postoperative care. Ultimately, the decision to extract a tooth or teeth is dependent on the patient’s health status, physical examination, laboratory evaluation, intraoral examination under general anesthesia, and intraoral radiograph findings in combination with the wishes of the client. Whether tooth extraction is the best treatment option for a particular patient is also dependent upon the ability of the owner to provide home care for their pet. Client consent is required before any tooth extraction. An examination under general anesthesia, including dental charting and full mouth intraoral radiographs, allows the practitioner to identify all oral pathology and formulate a definitive treatment plan. A complete evaluation of the status of the tooth and periodontal tissues includes a visual exam, utilization of a probe and explorer, and radiographic evaluation of the tooth and surrounding structures.

The skill and knowledge of the veterinarian should always be considered. If you are not comfortable with a particular procedure based on your equipment, knowledge, skill, and/or the pathology that is present, it is best to refer the patient to a board certified veterinary dentist.

11.1 Indications

Periodontal disease is the most common reason for tooth extraction in veterinary practice. Other indications for tooth extraction include: malocclusions, crowded teeth, impacted or unerupted teeth, supernumerary teeth that predispose adjacent teeth to periodontal disease, teeth with advanced caries, tooth resorption, and inflammatory conditions (stomatitis). Additionally, all teeth affected by pulp necrosis or irreversible pulpitis that are not amenable to endodontic treatment or for which the owner does not wish to complete endodontic treatment should be extracted. Teeth that are potentially non‐vital include: complicated or uncomplicated crown or crown root fractures; discolored teeth; teeth with severe periodontitis that results in endodontic disease; and teeth that have radiographic findings consistent with endodontic disease. Advanced periodontal surgery and endodontic treatment may be considered for diseased teeth and should be offered to clients as an alternative to extraction if indicated. Indications for exodontia in immature patients include: persistent deciduous teeth; fractured deciduous teeth; and interceptive orthodontics for treatment of deciduous malocclusions.

Contraindications for extraction may include: poor general health of the patient (general anesthesia is not possible or when the benefits of the procedure do not outweigh the risk to the patient), patients with coagulation disorders or those on medications that might affect coagulation, and teeth in an area previously treated with radiation therapy [1].

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.
Image described by caption.

Figure 11.1 Oral surgery/extraction pack: (a) Minnesota lip retractor; (b) feline lip retractor; (c) Miller bone curette; (d) periosteal elevator; (e) straight and winged elevators; (f) small breed extraction forceps; (g) needle holders; (h) iris scissors; (i) thumb forceps; (j) scalpel blade handle.

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.

11.7 Steps to Surgical Extractions

As with any surgical procedure, it is important to follow the same steps for all patients to ensure consistency in care and outcome.

11.7.1 Chlorhexidine Rinse

When surgery in the oral cavity is performed the oral cavity should be rinsed with chlorhexidine gluconate (0.12%). This procedure reduces the amount of skin and oral mucosal contamination of the surgical site, decreases the microbial load of any aerosols created while using highspeed drills during the surgical procedure, and decreases the number of microorganisms entering the patient’s bloodstream [7].

11.7.2 Supragingival and Subgingival Scaling and Polishing

Basic oral care should be completed prior to beginning the oral surgery procedure to minimize contamination of the surgical site with calculus and bacteria.

11.7.3 Radiographs of the Affected Tooth or Teeth

Imaging is necessary to evaluate the tooth and root structure and the alveolar bone, and determine if there is pathology present in the surrounding alveolar bone that may predispose to extraction complications.

11.7.4 Preoperative Analgesia

Preemptive multimodal pain management including intraoral regional nerve blocks is recommended prior to any extractions [8] (see Chapter 9 – Anesthesia and Pain Management).

11.7.5 Intrasulcular Incision

Make an intrasulcular incision in the gingiva circumferentially around the tooth or teeth to be extracted utilizing a number 15 or 15C scalpel blade. This is the first step in all surgical extractions.

11.7.6 Create a Flap

Several principles of flap design must be considered when planning the mucoperiosteal flap. The base (apical portion) of the flap must be broader than the free margin (coronal portion). The flap must be large enough to allow for adequate visualization of the area. Soft tissue heals across the incision not along the length of the incision and sharp incisions heal more rapidly than torn tissue. Therefore, a long straight incision heals more rapidly than a short, torn incision [9]. The flap should be designed to avoid injury to local vital structures, which include neurovascular bundles and salivary ducts. For oral surgery procedures in dogs and cats, an envelope flap, a triangular flap, or a broad‐based pedicle flap may be utilized depending on the location of the tooth to be extracted, the patient, and surgeon preferences. Envelope Flap

An envelope flap (Figure 11.2) is a full thickness flap created by a making a horizontal incision in the gingival sulcus at the crestal bone, followed by elevation of the attached gingival tissue with a periosteal elevator. The horizontal incision may extend to just the mesial and distal aspect of the tooth involved or it may be extended beyond the tooth to be extracted to incorporate adjacent teeth, which allows for greater flap reflection and exposure [10]. If the envelope flap is not elevated apical to the mucogingival line then it is considered a mucogingival flap not a mucoperiosteal flap.

Photo displaying the envelope flap (dashed line) near the mesial and distal aspects of the teeth of an animal.

Figure 11.2 Envelope flap. Mucoperiosteal Flap

A mucoperiosteal flap is a full thickness flap, elevated beyond the mucogingival line to include the periosteum. A mucoperiosteal flap is utilized to improve visualization and facilitate exposure of the furcation and periodontal ligament space around the tooth roots. A triangular mucoperiosteal flap includes only one vertical releasing incision that extends apical to the mucogingival line. A pedicle or broad‐based flap is a four‐cornered flap created with two vertical releasing incisions. Triangular and broad‐based flaps are often utilized when the removal of buccal alveolar bone (alveolectomy) is necessary. To prevent flap failure, adhere to the following principles: the apical portion of the flap should be wider than the coronal portion, the edges of the flap should be approximated over healthy bone, the flap should be gently handled, and the flap should be sutured without any tension [11]. Triangular Flap

A triangular (three‐cornered) flap (Figure 11.3

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Aug 15, 2020 | Posted by in GENERAL | Comments Off on Oral Surgery – Extractions

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