Minimally Invasive Buccotomy

Take Home Message—Minimally invasive buccotomy (MIB) techniques are indicated if fractures of the clinical crowns of cheek teeth render oral extraction with forceps impossible or for the removal of intra-alveolar dental remnants. MIB can be performed in standing sedated and locally anesthetized animals or under general anesthesia. All maxillary cheek teeth and all but the mandibular -10s and -11s can be removed using this technique.

I. Aim of the presentation

To describe how to create a MIB portal and to explain how to remove a cheek tooth or dental fragments using this trans-buccal approach Introduction.

II. Introduction

Although oral extraction is the preferred technique of cheek teeth exodontia, this method has its limitations.^1,2 Fractures of the clinical crown and fractures of root fragments are complications observed during oral extraction attempts with forceps.¹ Occasionally the procedure cannot be completed successfully necessitating an alternative way of tooth removal such as dental repulsion with punches or Steinman pins,^1-3 buccotomy as described by Lane^1,4 or MIB techniques as described by Stoll^5-7 and Nowak.⁷ The latter techniques will be focused upon in this abstract.

III. Materials and methods

Indications

MIB techniques are indicated if fractures of the clinical crowns of cheek teeth render oral extraction with forceps impossible or fractured root fragments cannot be removed from the alveolus with root elevators. All maxillary cheek teeth and all but the mandibular -10s and -11s can be removed using this technique.^5-8

Equipment

Cheek tooth removal through a trans-buccal approach is greatly facilitated if oral endoscopic assistance is available^5-8 (see in Proceedings: Endoscopy-Aided Extraction of Cheek Teeth).

Although transbuccal exodontia can be performed with a basic set of surgical instruments and some additional items available in hardware stores, a specially designed instrument set for transbuccal tooth removal has been designed and is commercially available.^a,5-8

Preparation of the Patient

• The horse is sedated and a local nerve block (see in Proceedings: Local Anesthesia for Dental Procedures) is performed. The required waiting time until the local anesthesia is fully effective should be observed. Non steroidal anti-inflammatory therapy (e.g. flunixin meglumine 1.1 mg/kg BW i.v.) and perioperative antibiotic therapy is initiated prior to surgery.
• The surgical site (15 x 15 cm area centered over the tooth to be removed) is prepared for surgery with antiseptic scrub.
• It is recommended to open the mouth using a full mouth speculum which enables free access to the buccal region and has no cheek pieces (Gunther or Stubbs specula).
• The 2 main branches of the facial nerve, the branches of the facial artery and vein and the parotid duct are palpated and their positions are marked with indelible ink.

Creation of the Buccotomy Port

• The placement of the buccal approach is dependent on which tooth is to be extracted. The tooth should be approached along its eruption pathway. Digital palpation and using a pair of long handled root elevators facilitate to center the portal at mid-level of the tooth and as far ventral (for maxillary cheek tooth extraction) or dorsal (for mandibular cheek tooth extraction) as possible to enable ideal access with straight instruments.
• Infiltration anesthesia of the superficial and deep tissue layers of the cheek is performed.
• A dorso-ventrally orientated skin incision (7-10 mm) is created. Depending on the available instruments, the perforation of the deep tissue layers (buccinator or masseter muscles) and oral mucous membrane into the oral cavity is accomplished using specially designed (blunt and sharp) trocars. Alternatively blunt preparation with Metzenbaum scissors might be used. The use of a trocar significantly reduces instrument- induced soft tissue trauma in close proximity of the portal and might help to reduce post-operative wound healing complications. A longer trocar and cannula are needed for more caudal approaches through the masseter muscle.

Trans-Buccal Exodontia

Screw Extraction (Stoll-technique)^5-8

This approach was developed using tools purchased at a hardware store.^5-8 Subsequently a set of instruments has been manufactured to make this a safe and effective way to remove broken teeth and dental fragments.^6,8

• To facilitate extraction, the tooth or dental fragment has to be loosened sufficiently prior to any extraction attempt. This can be accomplished by widening the adjacent interdental spaces using chisels or modified (sharpened) screw drivers as elevators under endoscopic control. If possible, the periodontal attachment on the buccal aspect should also be broken in order to further loosen the tooth. Accessing the periodontal space on the palatal/lingual side of the tooth is impossible in most cases because of difficulties aligning the instruments.
• Following sufficient disruption of the periodontal attachment a drill guide and a 5-6 mm surgical drill (length: 20 cm) are advanced through the buccotomy port and positioned securely at the buccal aspect of the masticatory surface or fractured crown. Endoscopic control facilitates the correct positioning of the drill. A serrated dill guide facilitates secure positioning on the dental surface. A hole is drilled obliquely through the loosened tooth. Radiography is used for depth control. Excessive drilling inflicts damage to the surrounding alveolar bone or results in the penetration of a paranasal sinus compartment and should consequently be avoided.
• The drill hole is cleaned of debris and tapped. The commercially available instrument set contains a 5 mm surgical drill and a 6 mm tap.
• A long, threaded bolt with a washer disc attached to its end (supplied with the instrument set) is carefully screwed into the drill hole.
• Further loosening of the tooth can now be accomplished by manipulating the bolt.
• The tooth or dental fragment is finally extracted using a slotted hammer. Repeated gentle taps with the hammer on the washer disc are used to dislodge the tooth from the alveolus.
• Once extracted the tooth is manually detached from the bolt and removed from the oral cavity.
• The alveolus is carefully inspected and palpated for remaining fragments or defects. Post-extraction radiographs should be obtained.
• Alveolar packing is performed with identical materials as described for oral extraction.
• The skin incisions is closed with sutures or skin staples⁵ or left open^5,7 to heal by second intention.

Alternative Techniques for Transbuccal Cheek Tooth Removal^7,8

If transbuccal screw extraction is not feasible or has failed for other reasons (see in Proceedings: Cheek Tooth Exodontia Complications), the loosened, split or fractured cheek tooth can be further fragmented under endoscopic control with sharpened chisels inserted through the trocar. The dental fragments are then removed orally. Alternatively rotating instruments with small diameter burrs can be inserted through the buccotomy port to cut indentations into unwieldy and large dental remnants to facilitate their fractioning into smaller pieces under endoscopic control. Root elevators or straight instruments inserted through the buccal trocar are subsequently used to split, loosen and dislodge the fragments.

Discussion

This technique is not exceedingly difficult to perform but does require special instruments, training, and attention to detail to avoid complications.⁸ It allows direct access to the dental area with straight instruments. This approach is usually utilized for the removal of fractured teeth or retained root fragments. Other indications are to evaluate and treat oral fistulas or perform restorative procedures on diseased cheek teeth.^5-8 The possibilities of damage to a branch of the facial nerve, facial artery, or parotid duct are the major risks of this technique. Hence anatomical orientation is a mandatory prerequisite for performing a minimal invasive trans-buccal surgical approach.⁸

References and footnote

1. Dixon PM, Dacre I, Dacre K et al: Standing oral extraction of cheek teeth in 100 horses. Equine Vet J 2005;37:105-112.
2. Dixon PM, Hawkes C, Townsend N: Complications of equine oral surgery. Vet Clin North Am Equine Pract 2008;24:499-514.
3. McDonald MH, et al: Removal of maxillary tooth fragments and root remnants in standing horses, in Proceedings. AAEP Focus on Dentistry, Indianapolis, 2006;148-155.
4. O’Neill HD, Boussauw B, Blandon BM, et al: Extraction of cheek teeth using a lateral buccotomy approach in 114 horses (1999-2009). Equine Vet J 2011;43:348-353.
5. Stoll M. How to perform a buccal approach for different dental procedures. In Proceedings. Am Assoc Equine Pract 2007;53:507-511.  [...]