Modified Labial Button Technique for Maintaining Occlusion After Caudal Mandibular Fracture/Temporomandibular Joint Luxation in the Cat

Transcription

1 Step-By-Step Modified Labial Button Technique for Maintaining Occlusion After Caudal Mandibular Fracture/Temporomandibular Joint Luxation in the Cat Journal of Veterinary Dentistry 2016, Vol. 33(1) ª The Author(s) 2016 Reprints and permission: sagepub.com/journalspermissions.nav DOI: / jov.sagepub.com Alice E. Goodman, DVM 1, and Daniel T. Carmichael, DVM, DAVDC 1 Maxillofacial trauma in cats often results in mandibular symphyseal separation in addition to injuries of the caudal mandible and/or temporomandibular joint (TMJ). Caudal mandibular and TMJ injuries are difficult to access and stabilize using direct fixation techniques, thus indirect fixation is commonly employed. The immediate goals of fixation include stabilization for return to normal occlusion and function with the long-term objective of bony union. Indirect fixation techniques commonly used for stabilization of caudal mandibular and temporomandibular joint fracture/luxation include maxillomandibular fixation (MMF) with acrylic composite, interarcade wiring, tape muzzles, and the bignathic encircling and retaining device (BEARD) technique. This article introduces a modification of the previously described labial reverse suture through buttons technique used by Koestlin et al and the labial locking with buttons technique by Rocha et al. In cases with minimally displaced subcondylar and pericondylar fractures without joint involvement, the labial button technique can provide sufficient stabilization for healing. Advantages of the modified labial button technique include ease of application, noninvasive nature, and use of readily available materials. The construct can remain in place for a variable of amount of time, depending on its intended purpose. It serves as an alternative to the tape muzzle, which is rarely tolerated by cats. This technique can be easily used in conjunction with other maxillomandibular repairs, such as cerclage wire fixation of mandibular symphyseal separation. The purpose of this article is to demonstrate a modified labial button technique for maintaining occlusion of feline caudal mandibular fractures/tmj luxations in a step-by-step fashion. Keywords button, mandibular fracture, temporomandibular joint luxation, cat, maxillofacial trauma Maxillofacial fractures in cats commonly result in mandibular symphyseal separation as well as injuries involving the caudal mandible and/or temporomandibular joint (TMJ). 1 Due to the unique anatomy and very thin bone, caudal injuries present inherent challenges for stabilization. Fractures in this region can be difficult to stabilize with direct fixation methods, so indirect fixation is often employed. The goals of fracture fixation, whether direct or indirect, include stabilization that results in a bony union and reestablishes normal occlusion to allow return to normal function. 2 Commonly utilized indirect fixation techniques for stabilization of caudal mandibular and temporomandibular joint fracture/luxation include maxillomandibular fixation with acrylic composite (MMF), interarcade wiring, tape muzzles, and the bignathic encircling and retaining device (BEARD) technique. 1,3,4 The choice of technique depends on a number of factors including, but not limited to, the extent of injuries, available equipment, clinician s skill level, financial resources of the owner, and patient factors such as the presence of canine teeth, age, conformation, and anesthetic risk. Alternative indirect stabilization techniques have been described. 5,6 In the study by Koestlin et al, follow-up was obtained in 72 cats with caudal mandibular fractures and TMJ luxations treated using the labial reverse suture through buttons technique. Upon reevaluation, 94% of the treated patients were free of discomfort, and 68% of the fractures and luxations 1 Dentistry Department, Veterinary Medical Center of Long Island, West Islip, NY, USA Corresponding Author: Alice E. Goodman, Dentistry Department, Veterinary Medical Center of Long Island, 75 Sunrise Highway, West Islip, NY 11795, USA. aegoodman@vmcli.com

2 48 Journal of Veterinary Dentistry 33(1) Figure 1. Photograph showing supplies needed to perform the modified labial button technique. Supplies include sterile surgical gloves, 0 nonabsorbable polypropylene suture (Prolene [Polypropylene suture]; Ethicon, Inc, Somerville, New Jersey], needle holder, hemostatic forceps, Mayo-Hegar scissors, tissue forceps, and three 2-hole buttons (Favorite Findings [buttons]; Blumenthal Lansing Co, Lansing, Iowa), ideally with smooth edges. Buttons can be autoclaved or sanitized. Esophagostomy feeding tube placement or any other procedures that require anesthesia (eg, repair of a fractured limb) should be ideally done immediately prior to labial button procedure. Figure 2. The patient is placed in dorsal recumbency to allow exposure and aseptic preparation of the surgical sites. Both upper lips and the ventral chin should be clipped and aseptically scrubbed. The cadaver used for this demonstration is a juvenile; therefore, the proportions are slightly different than those of an adult cat. showed radiographic healing. 5,7 Rocha et al found the labial locking with buttons method to be successful in achieving proper occlusion, with clinical healing occurring between 17 and 33 days. 6 Accordingly, in cases with minimally displaced subcondylar and pericondylar fractures without joint involvement, the labial button technique can provide sufficient stabilization for healing. 8 In the traditional version of this technique described by Koestlin and Rocha, 2 lines of suture are used, each connecting a ventral button to the left or right lip with knots tied over each labial button. 5,6 The method described here is a modification, using a single line of suture for all three buttons with only one knot secured on the ventral chin. In the authors opinion, this modification allows for improved accuracy in achieving appropriate occlusion via simultaneous application of tension to both sides of the construct when securing the ventral knot (see Figures 1-11). Advantages of the modified labial button technique include ease of application, noninvasive nature, and use of readily available materials. It is an alternative to the tape muzzle which can be difficult to fit and is poorly tolerated by cats. The labial button technique is preferred over MMF in immature patients, as it avoids rigid fixation that can interfere with normal development and growth. 1 The construct can remain in place for a variable of amount of time, depending on its intended purpose. It can serve as a short-term, first-aid measure to prevent further trauma prior to planned surgery, remain in place for 7 to 14 days after TMJ luxation reduction, or be maintained for 5 weeks for stabilization of more complicated fractures. 1,6,8 This technique can also be easily used in conjunction with other maxillomandibular repairs, such as cerclage wire fixation of mandibular symphyseal separation. 7 Postoperative management includes multimodal analgesia, nutritional support, and possibly antibiotic therapy in cases of open fractures and significant soft tissue trauma. Placement of an esophagostomy feeding tube is recommended to ensure proper nutrition during the immediate postoperative period. An Elizabethan collar will be necessary to prevent selftrauma to the fixation device and/or esophagostomy site. The objective of this article is to demonstrate a modified labial button technique for maintaining occlusion of feline caudal mandibular fractures/tmj luxations in a step-by-step pictorial. Figure 3. A 2-hole button is placed on the ventral midline of the chin with each hole oriented laterally (A). The needle and suture are inserted through the left hole and into the skin (B). The needle is directed dorsally toward the oral cavity, between the soft tissue and the periosteum of the lateral mandible, exiting caudal to the gingiva of the left mandibular canine and rostral to the left mandibular labial frenulum (C). The needle is pulled through and a hemostat is clamped to the free end of the suture until the end of the procedure.

3 Goodman and Carmichael 49 Figure 4. Photograph showing suture passing through the ipsilateral upper lip from within the oral cavity starting just apical to the mucogingival line and caudal to the left maxillary canine tooth (A). The needle is directed dorsally through the soft tissue and exits the skin 5 mm lateral to the left alar fold (B). A second button is held to the skin as the needle threads the medial button hole (C). Figure 5. The needle is redirected through the unused button hole, penetrating the skin and soft tissue of the lip (A) while directing the needle ventrally. The suture enters the oral cavity just 2 mm from the initial suture entry point, just apical to the mucogingival line (B). Figure 6. The needle is inserted through the lower lip on the ipsilateral side starting in the oral cavity rostral to the mandibular labial frenulum, 2 mm away from the initial suture site (A). The needle is directed in a ventromedial direction through the soft tissue and exits the skin on the ventral chin through the ipsilateral button hole (B). Half the length of suture is pulled through the button hole in order to have enough working length for the other half of the procedure (C).

4 50 Journal of Veterinary Dentistry 33(1) Figure 7. The needle is guided through the unused/contralateral button hole on the chin (A), and the same procedure is repeated on the contralateral side of the mandible and maxilla, first entering the oral cavity just rostral to the right mandibular frenulum (B). The suture is passed through the right upper lip (C), exiting the skin 5 mm lateral to the left alar fold (D), threading the needle through the third button while securing it to the skin (E). The suture is redirected through the unused button hole (F), through the skin and into the oral cavity (G), then through the mucosa rostral to the right mandibular frenulum (H), and out the button hole on the right side of the chin (I).

5 Goodman and Carmichael 51 Figure 8. After passing the needle through the skin of the ventral chin, any necessary adjustments can be made to ensure proper occlusion (A). The authors use the endotracheal tube diameter as a guide for how much of a mouth opening to maintain, as it will provide approximately 5 mm of space between the maxillary and the mandibular arcades. This amount of space allows tongue movement for drinking and lapping up a slurry of liquefied food. However, endotracheal intubation using a pharnygotomy or transmylohyoid technique9 will allow more accurate occlusion evaluation without extubation. It is important that the suture is not overly tightened, compressing the buttons too tightly to the skin. After the degree of opening has been established, the end of suture clamped by the hemostat is tied to the leading end of suture over the ventral button using an initial surgeon s knot, then excess suture is cut away (B). Figure 9. Occlusion prior to extubation of a cadaver (A) and of a patient (B). Figure 10. Photograph of a cadaver after extubation showing the mouth in proper occlusion with a small space between the upper and the lower incisor teeth.

6 52 Journal of Veterinary Dentistry 33(1) Figure 11. If buttons are not available, they can be created using a syringe plunger top from a 1 cm 3 syringe (A). The plunger top is cut off using a dental bur or nail trimmers. Rough edges of the plunger top are removed with a nail file or dental bur until smooth (B). The cut surface should be directed away from the skin to minimize skin irritation. Two holes are created in each plunger top using a #2 surgical length round bur. This size will freely allow the passage of size 0 nonabsorbable monofilament suture (C). Buttons can be safely autoclaved or sanitized with alcohol and dilute chlorhexidine gluconate solution. Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Funding The author(s) received no financial support for the research, authorship, and/or publication of this article. References 1. Wiggs RB, Lobprise HB. Oral Fracture Repair. Veterinary Dentistry Principles and Practice. Philadelphia: Lippincott-Raven; 1997; Rudy RL, Boudrieau RJ. Maxillofacial and mandibular fractures. Semin Vet Med Surg (Small Anim) 1992;7(1): Nicholson I, Wyatt J, Radke H, Langley-Hobbs SJ. Treatment of caudal mandibular fracture and temporomandibular joint fractureluxation using a bi-gnathic encircling and retaining device. Vet Comp Orthop Traumatol. 2010;23(2): Smith MM, Legendre LFJ. Maxillofacial repair using noninvasive techniques. In: Verstraete FJM, Lommer MJ, Bezuidenhout AJ, eds. Oral and Maxillofacial Surgery in Dogs and Cats. Edinburgh: Elsevier Ltd; 2012: Koestlin R, Matis U, Teske U. Lip Closure with Buttons- a simple method for immobilization of temporomandibular joint injuries in the cat [in German]. Tierartzl Prax. 1996;24(2): Rocha AG, Rosa-Ballaben NM, Moraes PC, Padilha Filho JG, Minto BW. Labial locking with buttons for managing mandibular fractures in cats. Ars Veterinaria. 2013;29(2): Matis U, Koestlin R. Symphyseal separation and fractures involving the incisive region. In: Verstraete FJM, Lommer MJ, Bezuidenhout AJ, eds. Oral and Maxillofacial Surgery in Dogs and Cats. Edinburgh: Elsevier Ltd.; 2012: Lantz GC, Verstraete FJM. Fractures and luxations involving the temporomandibular joint. In: Verstraete FJM, Lommer MJ, Bezuidenhout AJ, eds. Oral and Maxillofacial Surgery in Dogs and Cats. Edinburgh: Elsevier Ltd.; 2012: Soukup JW, Snyder CJ. Transmylohyoid orotracheal intubation in surgical management of canine maxillofacial fractures: an alternative to pharnygotomy endotracheal intubation. Vet Surg. 2015; 44(4):