Beneficial ancillary treatments in veterinary dentistry (Proceedings)

May 1, 2011

Article

As one can see, dentistry can cover a myriad of disciplines and procedures. There are three types of procedures that can be a beneficial addition to the treatment options that are currently available. These additions in some cases may require some training for the veterinarian and equipment investment, but some use supplies readily available in the practice.

Tape muzzles

As members of the veterinary team, there have been instances where you have had to fix things using materials out of the hospital. In this day and age, that would be seen as eco-friendly. What this lecture will be focusing on is the application and construction of the tape muzzle. The tape muzzle has many uses in jaw fracture repair. They are used to keep the jaw stabilized and keep the teeth in occlusion while the jaw is healing.

Conditions that merit the use of tape muzzles

Emergency triage – tape muzzles can be placed on the patient once admitted to the hospital to prevent displacement of the fracture until the fixation procedure can be performed. This would be contraindicated in patients that were vomiting, have pulmonary injuries, or are in respiratory distress.

Mandibular fractures – if the fracture is unilateral, with minimum displacement, a tape muzzle can be used for stabilization. Due to the rich blood supply in the oral cavity, this area does not need a rigid fixation in order to achieve adequate healing. During the healing process, a larger callous may be seen in areas that are not totally immobilized. In mandibular ramus fractures or minimally displaced condyloid process fractures, due to the muscular support in this area of the mandible, the tape muzzle can provide additional support.

Pathologic fractures due to periodontal disease – in these cases, other methods of fixation are not possible due to the disease present. Complete union of the sections is not likely even with regeneration therapy. The stability that the tape muzzle provides can allow fibrous union to form.

Tape muzzle general information

Tape muzzles are contraindicated in brachycephalic breeds because they rely on open mouth breathing for efficient respiration. Tape muzzles are also contraindicated in patients that are vomiting or are in respiratory distress.

The loop that is around the muzzle of the patient should be loose enough to allow the patient to lap up soft food, water, and be able to pant. The interdigitation of the canine teeth keeps the mouth from having lateral movement

Fabric muzzles, with careful fitting that support the mandible can be used. Since multiple muzzles need to be dispensed, this could prove cost prohibitive to the client. The clinic would also need to keep a stock of all sizes at all times. Depending on the design of the fabric muzzle, a portion of the maxillary support may need to be cut away to prevent rubbing which could lead to skin maceration.

Construction of the tape muzzle

Equipment needed – stock bottles from around the hospital, 1"and 2" adhesive tape

1. Step 1 – using stock bottles from the practice, place a stock bottle nose to bottle end. Choose a bottle whose diameter would allow the patient to open their mouth 0.5 -1.0 cm. Then choose a bottle whose length would be from midpoint of the nose to just behind the ears.

2. Step 2 - using the bottle that measured the nose diameter, choose either the 1" or 2" adhesive tape based on what would fit the patient comfortably just behind the canine teeth to the 4th premolar. Wrap the tape sticky side out around the bottle. Remove the tape ring from the bottle and place on the patient. Size the ring to allow the patient to open their mouth 0.5 to 1.0 cm.1,3 Once sized complete the ring by laying another piece of tape sticky side down around the ring.

3. Step 3 – place the ring on the table as it would be on the patient's nose and place the bottle that was used to measure the length of the head end to end. Take a piece of 1" tape and wrap the tape from the cranial edge of the tape ring around the back of the bottle to the cranial edge of the tape ring on the other side. Leave a little extra tape to make adjustments. Trial-fit the muzzle and make adjustments to the length. The muzzle length should fit just behind the ears to keep the ring from sliding off the nose. Once the adjustment has been made, take a second piece of tape and place it along the inside surface of the tape you just measured incorporating the muzzle ring.

4. Step 4 - trial-fit the muzzle again and make adjustments. If the ring is cutting into the skin near the eyes, you can make small curved cuts on the ring to bring the tape away from that area. Make sure the muzzle allows the patient to open the mouth enough to lap up water and soft food and to pant. This tape muzzle becomes your template. Repeat the process and make 2-3 more muzzles. Make sure each muzzle fits the same way.

5. Step 5 – put on the muzzle making sure the canine teeth are correctly occluding.

Management of the tape muzzle

• After each meal, the muzzle must be removed and cleaned wiping it down with a soapy sponge and following up with a wet towel. Once the patient's face has been cleaned and dried, replace with a clean dry muzzle. Rotate the spare muzzles.

• Make sure to check the skin around the tape muzzle for signs of swelling, dermatitis or skin maceration.

• Rechecks of the fracture site should occur every 3-4 weeks with radiographs to monitor progress.

Conclusion

The tape muzzle can be used in some cases as the sole method of jaw fracture fixation or provides extra support if wiring and/or splinting procedures are performed. Having the skills to make and manage tape muzzles is an important asset to any practice where jaw fracture repair is performed. Once the template muzzle is made for the patient, multiple people can sit in and make the extra muzzles. This will speed up the process.

Esophagostomy tubes and the dental patient

General information

Esophagostomy tubes are an option when long term nutritional support is necessary. Patients requiring the placement of an esophagostomy tube are those that are not able to take in food orally. In veterinary dentistry, this works out well for patients with full or caudal mouth extractions, maxillary or mandibular fractures, oral or nasal neoplasia. Placement of the esophagostomy tube is contraindicated in vomiting patients and in patients with esophageal disorders such as esophagitis, esophageal strictures, megaesophagus, or those patients that have undergone esophageal surgery.

Choosing the tube

The best tube for this procedure is the red rubber catheter. In the cat 12-16 fr. works best and in the dog 12-24 fr.

Placing the esophagostomy tube

Patients must be under general anesthesia for this procedure. It is best done right after the dental procedure is completed. Place the patient in lateral recumbency.

Supplies needed are a large Kelly or Carmalt forcep, appropriate size red rubber catheter, Luer slip catheter plug, 1" tape, non-absorbable suture material, scalpel blade, permanent marker, cast padding, needle holders, thumb forceps, clippers and scrub.

Clip the entire lateral cervical region from the ventral midline to near dorsal midline. Surgically prep the area.

Cut the distal rounded tip of the tube or widen the lumens of the side vents to facilitate the food administration and remove the possibility of any food impaction in the tube. Measure the feeding tube by placing the tip at the 7th or 8th intercostal space. The other end should be marked with a permanent marker at the midcervical area where the tube will exit the skin.

Insert the Kelly or Carmalt forcep into the mouth and into the proximal cervical esophagus. Turn the tip of the forcep toward the lateral aspect of the patient so that the instrument can be seen and palpated through the side of the neck.

Place 2 fingers on either side of the protruding forcep tip. Using a scalpel blade, make an incision just large enough for the tip of the forcep to pass through and be opened large enough for the catheter to be grabbed by the forcep.

Once the catheter has been grabbed by the forcep, pull the catheter into the esophagus and out through the mouth. Then turn the tip back into the esophagus and push it in as far as possible. With your finger on the catheter in the mouth, pull gently on the same time at the other end of the catheter coming out of the incision. Once the catheter inside the esophagus unfolds down along the esophagus, the external part of the catheter will flip to point towards the head. Pull the catheter until the marked part of the tube is visible above the skin. Place the catheter plug in the end of the catheter.

Just above the marked area of the tube, swipe the catheter with clean gauze, and then wrap a piece of tape leaving wings on either side. Suture each wing to the skin using a simple interrupted stitch. Apply a dab of triple antibiotic ointment at the incision site.

Apply a light bandage placing the catheter along the dorsal neck area with the tip of the catheter pointing caudally. Use cast padding as the first layer followed by vet wrap. Secure the catheter to the neck bandage using tape.

Feeding through the esophagostomy tube

The large bore of these catheters allows the feeding of a gruel recovery diet. If you need to dilute with water, dilute the food to the consistency of a soft pudding. Make sure the mixture has no lumps that can clog in the tube.

Calculate the amount of food needed using the standard enteral feeding calculation:

• RER (resting energy requirement) = 30 x (body weight in kg) + 70

• For patients <2kg or >45kg use this calculation

• RER = 70 x body weight in kg

• RER÷kcal/ml = ml of formula/day

Feeding schedule

Warm the food to body temperature and administer through a catheter tip syringe over 10-15 minutes. Medications can be mixed into the food and given through the tube. Medications in tablet form should be ground up before adding to the food. Medications in capsule form are opened and the powder is mixed with the food.

On day 1, divide the formula into feedings every 3-4 hours. Follow each meal with 10mls of warm water. Then, increase the volume of food administered and decrease the number of feedings until 3 meals are administered per day.

Change the bandage every 1-2 days and clean around the incision site with an antiseptic. Complications are generally uncommon but can include premature removal, vomiting, and infection at the exit site.

Transition to oral feeding

Watch for signs of interest in food. Always allow the patient to try to lap up the blended diet before tube feeding. When the patient is eating voluntarily, then start subtracting food from the tube feeding and giving it orally and continue to increase the amount. Once the patient has eaten voluntarily for several days, the tube can be removed.

Removing the tube

Remove the wrap. Snip the skin sutures and withdraw the tube slowly. Wipe around the incision site with an antiseptic. Place a light wrap around the neck for 24 hours. The incision will heal by second intention.

Conclusion

Placing an esophagostomy tube in a dental patient allows for quicker and more comfortable healing by bypassing the oral cavity. Feeding through the tube and tube care can be easily taught to clients allowing the patient to recover at home. Rechecks at the clinic should be performed weekly where the bandage can be changed and the tube checked.

Restorative dental materials

Purpose of restorative dentistry

• Return the tooth to optimum form and function

• Prevent the breakdown of any remaining tooth structure

• Protect the pulp tissue from infiltration by bacteria and debris, which could lead to infection and in some cases pulpal necrosis

• Return the tooth to a more normal appearance

Common uses for dental materials in general practice

• Enamel only defects of the crown surface

• Grade 1 odontoclastic resorptive lesions – this does carry an 80% failure rate due to the progressive nature of the disease.

• Surface irregularities on the occlusal surface of molar teeth

Types and function of common restorative materials

• Bonding Agent – used to attach restorative material to a tooth. It is applied to an etched enamel or dentin surface forming a strong micromechanical bond. A single step bonding agent is the easiest one to use.

• Composite Resins – a tooth colored plastic silicon dioxide mixture. A compactable or condensable composite has a thick malleable consistency to restore large and deep defects in the tooth surface. A flowable composite is a more liquid material used in areas of low stress.

• Dental Adhesive – an intermediate substance, usually a bonding agent, to allow two materials to stick together

• Dental Etchant – a liquid or gel made of maleic or phosphoric acid. It is applied to the enamel or dentin surface to remove the smear layer. This allows the bonding agent to penetrate the dentinal tubules to allow the micromechanical bond between the tooth and the restoration.

• Glass Ionomer Cement – a dental material with low strength and toughness which is generally used in small restorations in low stress areas such as in class 1 resorptive lesions or as an intermediate layer where there is pulp exposure and you need extra protection against leakage between the pulp and the restoration.

• Dental Sealants or Pit and Fissure Sealants – this is usually applied to occlusal surfaces to cover any surface irregularities. These usually have a fluoride component to help prevent cavities. They can be applied to maxillary molars where early staining is noticed.

• Curing or polymerization – this can occur either chemically when a base and catalyst are mixed, or by exposing the restorative material to a high intensity blue plasma or halogen light. Some restorative materials will be cured in 2 stages – chemically – when the materials are initially mixed followed by light curing.

Basic steps of a dental restoration

• Prepare the filling site – remove any unsupported enamel using a bur, dental chisel or a sharp curette. The margins of the site should be beveled to provide the most bonding surface area. This does not apply to the occlusal surfaces.

• Clean the surface – polish the surface using flour pumice. Pumice does not contain any additives such as fluoride and glycerin which may not allow the restorative materials to work properly. Rinse and air dry the surface.

• Acid etch the surface – this step removes any smear layer on the surface and allows the restoration material to enter into the dentinal tubules which allows the bonding mechanism to occur. Place gauze sponges around the tooth to protect the soft tissue. Apply enough etchant to fill the defect and the margin edges and allow it to sit on the surface per the manufacturer's instructions. Using a cotton swab, remove as much of the etchant material as possible. Place a gauze sponge behind the tooth and thoroughly rinse away any remaining etchant into the sponge. Dry the surface using oil free air. The surface should appear chalky.

• Apply the bonding agent – place a drop of the bonding agent into a dappen dish. Apply the bonding agent using a microbrush in a thin layer. Blow a gentle stream of air over the bonding material to thin out the layer and avoid pooling. Using a light bonding gun, cure the bonding agent per the manufacturer's instructions.

• Apply the restorative material – Flowable – squeeze a small amount of flowable composite material onto the surface. Use a brush to spread the material out evenly including the edges of the surface. Using a light bonding gun, cure the composite per the manufacturer's instructions.

• Apply the restorative material – Compactable – remove a small amount of composite material using a working instrument and pack it into the defect. In general, compactable composite is placed in 2.0mm layers. Using a light bonding gun, cure each composite layer per the manufacturer's instructions.

• Shaping the hardened composite – using sanding disks on a contra angle on a low speed handpiece or finishing burs, the restoration is smoothed to match the level of the normal enamel. This step requires training given by a dental specialist.

Conclusion

As veterinary technicians we will usually be assisting the doctor with restorative procedures. It is important for the technician to know which restoratives will be used for which procedures. In some cases, the technician will need to prepare the ingredients prior to placement. It is also important to know the steps of each restorative procedure so that materials can be laid out ahead of time in the proper order.

References

Gorrel, C. (2004). Emergencies. In Veterinary Dentistry for the General Practitioner (pp. 131-155). Edinburgh: Saunders.

Tutt, C. (2006). Jaw fracture repair. In Small Animal Dentistry - A Manual of Techniques (pp. 173-184). Ames: Blackwell.

Wiggs, R., & Lobprise, H. (1997). Oral fracture repair. In Veterinary Dentistry Principles and Practice (pp. 259-279). Philadelphia: Lippincott-Raven.

Tefend, M., & Berryhill, S. (2006). Companion animal clinical nutrition. In D. McCurnin, & J. Bassert, Clinical Textbook for Veterinary Technicians, sixth edition (pp. 438-492). St. Louis: Elsevier Saunders.

Vannatta, M., & Bartges, J. (2004, July). Esophagostomy feeding tubes. Vet Med, 596-600.

Wortinger, A. (2007). Assisted feeding in dogs and cats. In A. Wortinger, Nutrition for Veterinary Technicians and Nurses (pp. 221-230). Ames: Blackwell.