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Special Cases of Note

Special cases that are instructional and illustrative of typical zoo dentistry cases

Siberian tiger mandibular canine endodontic procedure

October 16, 2014
Milwaukee County Zoo.
Dr. John Scheels - Exotic Animal Dentistry
Transporting Tula
photo by Mike Nepper

"Tula" is a 2 1/2 year old Siberian tiger, weighing 242 pounds. She fractured her mandibular canine when playing with her littermate, sister, on an elevated structure. An observant zookeeper spotted the canine tip piece, approximately 1 1/2 cm. long, shortly after the incident and confirmed by observing the tigress, that the canine was short, fractured.

Tula did not seem to be in pain or distress and her behavior was normal according zookeepers. However, I am aware of fresh fractures of this type, exposing the pulp and nerve caused some captive carnivores to be in so much pain and distress that they attacked and killed a cage mate. ("Bubba", Brookfield zoo, year?)

Approximately ten days later, on October 16, 2014 the zoo veterinarians, primarily Drs. Jennifer Haussmann and Vickie Clyde, sedated Tula, and transported her to the Milwaukee County Zoo Animal Health Center. Following the vets and techs establishing an intravenous line, attaching a pulse-oximeter and intubation establishing general anesthesia, we were given permission to start the dental procedure.

Dr. John Scheels - Exotic Animal Dentistry
Figure 1
photo by Mike Nepper

A brief oral exam revealed no other oral or dental pathology warranting treatment other than the mandibular right canine. The pulp was exposed with pulp tissue at the surface of the opening. The fractured canine segment and observation of the tooth had already established the pulp exposure (Figure 1).

The pulp was vital. The preoperative radiograph (Figure 2) revealed the pulp on this young animal widened a short distance beyond the fracture.

After explaining to the veterinarians, I used the high speed dental hand piece to cut another approximate cm off of the tooth to permit optimal pulp access for the endodontic procedure (Figures 3 and 4).

Dr. John Scheels - Exotic Animal Dentistry
Figure 2
photo by Mike Nepper
Dr. John Scheels - Exotic Animal Dentistry
Figure 3
photo by Mike Nepper
Dr. John Scheels - Exotic Animal Dentistry
Figure 4
photo by Mike Nepper

I extirpated the pulp and nervous tissue with a 100 mm endo file. Working length was established at 72 mm. This correlated with my measurement and estimation from the preoperative radiograph. Using successively larger diameter files, and copious irrigation with NaOCl and RC prep the canal was shaped and dissenfected (Figures 5, 6 and 7).

Dr. John Scheels - Exotic Animal Dentistry
Figure 5
photo by Mike Nepper
Dr. John Scheels - Exotic Animal Dentistry
Figure 6
photo by Mike Nepper
Dr. John Scheels - Exotic Animal Dentistry
Figure 7
photo by Mike Nepper

Hemostasis was established and the pulp was dried with sterile pipe cleaners. They must be actual pipe cleaners comprised of absorbent cotton. Not colorful craft items. Bag and sterilize (Figure 8).

Dr. John Scheels - Exotic Animal Dentistry
Figure 8
photo by Mike Nepper

After fitting the master gutta percha cone at the established working length, the canal was then obturated with PCA endo filler paste (a ZOE based paste) by placing the Large Volume Veterinary Endodontic Syringe needle at the apex and backfilling as it is withdrawn. The paste was deposited with a 20 gauge, 2 1/2 inch spinal needle (Figure 9). Additional gutta percha points were then placed and condensed in the canal.

A zinc phosphate cement base was placed over the endo fill. The access opening was briefly prepared and a composite resin restoration placed. I rounded and smoothed off the fractured canine edges when polishing the composite resin (Figure 10).

Dr. John Scheels - Exotic Animal Dentistry
Figure 9
photo by Mike Nepper
Dr. John Scheels - Exotic Animal Dentistry
Figure 10
photo by Mike Nepper

The entire dental procedure was completed in 53 minutes. Tula recovered from her anesthesia uneventfully. A successful procedure facillitared by excellent general anesthesia by the veterinarians. See the fill radiograph (Figure 11).

Dr. John Scheels - Exotic Animal Dentistry
Figure 11
photo by Mike Nepper

This conventional endo approach also called coronal or orthograde is certainly the technique of choice for a fresh, vital pulp, endodontic procedure. Considering the delta apex on mature carnivore teeth, if this tooth was abscessed and or a significant amount of lysis of the apex or a large lytic area in the adjacent alveolar bone was observed, a surgical retrograde approach would have been necessary to treat properly. Also, again considering the delta apex of the tooth, periodic examination including radiography of the tooth root is necessary to monitor the success of the conventional endodontic procedure. The necessity of such follow up should be indicated in the patient's chart so that if she must be sedated for some other reason, the dental exam and radiographs will be done also.

Zookeepers are reminded to be particularly observant of behavior or signs that may indicate pain or abscessation of the tooth.


Bonobo Makanza

February, 2015
Milwaukee County Zoo.

Photos by Mark Scheuber, Zoo Keeper/Photographer

Dr. John Scheels - Exotic Animal Dentistry
Bonobo Makanza, sedated, being prepared for dental treatment. L to R, zookeeper Stacy Whitaker, hospital keeper Celi Jeske and Veterinarian Dr. Jennifer Hausmann.
Dr. John Scheels - Exotic Animal Dentistry
Maxillary left central incisor and lateral incisor residual roots. Region was inflamed, edematous prior to two weeks of antibiotic therapy.
Dr. John Scheels - Exotic Animal Dentistry
Conventional dental film in position. Digital Phos Phor plates were also exposed.
Dr. John Scheels - Exotic Animal Dentistry
Dr. Hausmann and Dr. Scheels positioning Nomad radiography unit.
Dr. John Scheels - Exotic Animal Dentistry
Digital image reveals periapical lesion on central incisor residual root.
Dr. John Scheels - Exotic Animal Dentistry
Incision on crest of ridge.
Dr. John Scheels - Exotic Animal Dentistry
556 surgical bur used to remove approximately 2mm. of alveolar bone surrounding each root ("ditching".)
Dr. John Scheels - Exotic Animal Dentistry
Luxator technique utilized to remove residual roots.
Dr. John Scheels - Exotic Animal Dentistry
Extracted roots.
Dr. John Scheels - Exotic Animal Dentistry
Roots
Dr. John Scheels - Exotic Animal Dentistry
Simple interrupted sutures placed with knots inside the wound so that Makanza will find it difficult to disturb them with his fingers and tongue.

Rachel - Mongolian (Bactrian) Camel

Milwaukee County Zoo.
Dr. John Scheels - Exotic Animal Dentistry
Mongolian (Bactrian) camels
Dr. John Scheels - Exotic Animal Dentistry
Rachel with keeper Danielle
Dr. John Scheels - Exotic Animal Dentistry
Initial exam, Rachel sedated, flushing out food debris. Note foamy saliva, indicative of oral discomfort, constant tongue action, excessive salivation. Edema over right mandible, premolar area. Promptly identified mobile mandibular right first premolar. Removed easily. Purulent drainage flowed out of the alveolus. At that point, we realized that we had a more serious problem than just one relatively small painful tooth.
Dr. John Scheels - Exotic Animal Dentistry
Intraoral view. Note papilla on cheek. Food packed in area of pain by patient. Common sign in herbivores, attempt to relieve discomfort.
Dr. John Scheels - Exotic Animal Dentistry
Initial radiograph, taken after I had removed the small first premolar. Purulent exudate flowed out of alveolus. Fracture line along mesial border of second premolar. Antibiotics administered, animal allowed to recover while we discussed further treatment.
Dr. John Scheels - Exotic Animal Dentistry
Bactrian Camel Skull.
Dr. John Scheels - Exotic Animal Dentistry
Abscess pointed, it was explored and drain placed.
Dr. John Scheels - Exotic Animal Dentistry
Dr. Travis Henry, a board certified veterinary equine dentist, placing an equine mouth “gag” to keep mouth open for visualization and treatment.
Dr. John Scheels - Exotic Animal Dentistry
Radiograph prior to extraction of premolar.
Dr. John Scheels - Exotic Animal Dentistry
Hallway of zoo Animal Health Center ICU/quarantine area, with equipment set up prior to procedure.
Dr. John Scheels - Exotic Animal Dentistry
Equine instruments, note Baseplate Wax. Camel skull.
Dr. John Scheels - Exotic Animal Dentistry
Extraction forceps.
Dr. John Scheels - Exotic Animal Dentistry
Dr. Henry examining area, Scheels assisting, retracting.
Dr. John Scheels - Exotic Animal Dentistry
Forceps in use.
Dr. John Scheels - Exotic Animal Dentistry
Extracted premolar, crown segment, fractured during removal.
Dr. John Scheels - Exotic Animal Dentistry
Rachel in Animal Health Center Intensive Care/Quarantine stall.
Dr. John Scheels - Exotic Animal Dentistry
Keepers assisting in sedation procedure. Two times I removed bone shards that were shed from jaw ventral border.
Dr. John Scheels - Exotic Animal Dentistry
Keepers returning Rachel to the camel area following ? months intensive care. A few days later she kicked Robert (second from left) fracturing his tibia.

Bird and Reptile Beaks

Bird beaks and bills, and reptile beaks are not teeth, however, often dentistry techniques have been attempted to repair them. Beaks and bills are made of keratin, not enamel and dentin. There grow in numerous configurations throughout the life of the animal, with a wide range of vascularity.

I attempted to repair various configurations with a range of success. Early on, I like many others was “learning on the job”.

Some basic facts to know are that you cannot bond composite resin restorations to keratin. The nature of the surface and its’ continuous growth will not accept bonding adhesion. Placing retentive pins does not solve that challenge. Slower growing beaks or bills may seem to accept prosthetic additions, but they will eventually fail with even seemingly solid fixation.

If vascular support remains, a damaged beak or bill can grow, so sometimes prosthetic support will allow repair or even regrowth. In these cases, again due to the constant growth, this almost always requires close monitoring and additional repair measures. One should always use the simplest, least intrusive measures, to allow the patient optimum function, with minimum interference to function.

These days there are numerous references to be found on the internet on beak and bill repairs.

Dr. John Scheels - Exotic Animal Dentistry
First attempt to reattach, using bonding only to remnants of beak at germinal layer. This failed within a couple days.
Dr. John Scheels - Exotic Animal Dentistry
Green conure maxillary beak reattachment. Following technique published by Dr. Thomas Clark (Louisville Zoo) used on a salmon crested cockatoo. Beak sloughed off due to an infection at the germinal base. I did attempt to bond with composite resin to the remaining beak base. However, it failed in just a few days. Procedure done with veterinarian Dr. Steven P Raabe.
Dr. John Scheels - Exotic Animal Dentistry
Orthodontic wires placed through the skull.
Dr. John Scheels - Exotic Animal Dentistry
Beak rebuilt with composite resin, bulk done prior to procedure anesthesia, in place. Wires bent to engage slots cut into the beak. Sheet plastic was bonded inside to create a horizontal barrier, separating oral cavity and nasal openings.
Dr. John Scheels - Exotic Animal Dentistry
Finished beak. Proved totally functional for years. Owners moved and we learned that they had a dentist reinforce it with resin when it was becoming loose.
Dr. John Scheels - Exotic Animal Dentistry
South American Jay. Lower beak split due to trauma. Composite bonding was attempted to splint them together. However, after it failed, a combination of orthodontic elastics and a pliable band that is commonly used to color code the handles of dental instruments was used. They proved to be effective and allowed the beak to grow and eventually repair it self.
Dr. John Scheels - Exotic Animal Dentistry
African spoonbill. Upper beak was bent up due to trauma while being transported to our zoo. Bird unable to grasp food with the beak bent up, flexing at the fracture joint. A six inch plastic ruler was used as a rigid splint. I rounded off the corners. I wrapped flexible metal mesh, used to splint loosened teeth, around the bill, fastening the ends with composite resin. Note the red vascular supply around the circumference of the bill. This clearly provided a regeneration of the bill in the broken area. When we removed the splint in approximately six weeks, the broken area was rigid, repaired.

Haley, Polar Bear

Brookfield Zoo
Abscessed mandibular canine extraction, following failed endodontic treatment

Haley arrived at Brookfield Zoo with a draining abscess of right mandibular canine, at the root apex. At previous zoo she had coronal root canal treatment. She was less than two years old. The canal was very large, the canine immature. The apex had not matured, closed when the endodontic fill was completed. The fill material, consisting primarily of paste extruded through the open open apex. If it had been supposed to be an apexification treatment, it had failed completely, leaving her with an external fistula through the ventral border of the mandible. White paste crumbles were coming through the fistula. Dr. Meehan said the the previous zoo had not provided any dental treatment records. She was on antibiotics. We considered the treatment options. We agreed that removal of the canine would allow the bone to fill in. We agreed that bone would be stronger than trying to keep the canine, reinforcing it with a post. She was being kept apart from her future mate. We agreed to keep her apart until we did a follow up in three months. We did this to protect her from any trauma to the weakened mandible. At three months a radiograph revealed that complete bone repair had been achieved and she was then allowed to be with her mate.

Dr. John Scheels - Exotic Animal Dentistry
Radiograph of canine endo fill Note tiny vestigal premolar distal to canine crown
Dr. John Scheels - Exotic Animal Dentistry
Canine with amalgam restoration An incision was made on crest of ridge and the vestigial premolar removed
Dr. John Scheels - Exotic Animal Dentistry
Amalgam removed with high speed hand piece
Dr. John Scheels - Exotic Animal Dentistry
Gutta percha fill being removed
Dr. John Scheels - Exotic Animal Dentistry
Halls’ OS straight handpiece with round bur used to cut three longitudinal slots in the tooth
Dr. John Scheels - Exotic Animal Dentistry
Cutting slots in the tooth as far as the handpiece bur could reach
Dr. John Scheels - Exotic Animal Dentistry
Exudate flushing from the apex area
Dr. John Scheels - Exotic Animal Dentistry
Elevator use
Dr. John Scheels - Exotic Animal Dentistry
Third slot being cut
Dr. John Scheels - Exotic Animal Dentistry
The fragments, still connected near apex being loosened
Dr. John Scheels - Exotic Animal Dentistry
The two inch plus root removed in one piece with luxators “A pink dental wax plug was formed, about half of the length of the tooth root and forced into the alveolus. Dissolving sutures were used to close as possible and hold the wax in place.”
Dr. John Scheels - Exotic Animal Dentistry
Alveolus packed half depth with pink dental wax. Dissolving sutures over to close as possible and keep wax in place. It eventually dissolved and alveolus filled with bone.
Dr. John Scheels - Exotic Animal Dentistry
Haley
THE WEDGE®
Dr. John Scheels - Exotic Animal Dentistry
PATENTED

Radiolucent Mouth Prop for Dogs and Cats

  • Anatomically designed to provide secure, open mouth
  • Use for anesthesia, radiography, oral surgery, and dentistry
  • No moving parts, use if canines are absent
  • Ultrasound, heat, or cold sterilize
  • SMALL size for cats and smaller dogs, LARGE size for medium to large dogs
Dr. John Scheels - Exotic Animal Dentistry 

The WEDGE® is a one-piece, radiolucent mouth prop. The patented, anatomic design holds the carnivore mouth open during anesthesia by securely engaging the premolars and molars.

NOTICE: Veterinarians have used spring-loaded mouth "gags" in cats and dogs for many years. However, the spring-loaded devices are no longer recommended. A study published in THE VETERINARY JOURNAL (2014) showed that the spring-loaded "gags" generating constant force contributes to bulging of the soft tissues between the mandible and the tympanic bulla in cats. This force leads to the compression of the maxillary arteries as they course through the osseous structures. In cats the maxillary arteries are the main source of blood supply to the retinae and brain.

Reduction of the blood flow can result in temporary or permanent blindness and neurologic abnormalities. Spring-loaded "gags" constant force can also cause jaw muscle strain and injury to the temporomandibular joints.

It is recommended to use "static" mouth props such as the WEDGE. Be sure to not open the jaw to its maximum to avoid muscle strain and temporomandibular joint injury.

 

The WEDGE®:

Dr. John Scheels - Exotic Animal Dentistry 
 

Developed and patented by Dr. John L. Scheels, dental consultant to the Milwaukee County Zoo, Adjunct Assistant Professor, University of Wisconsin-Madison School of Veterinary Medicine.

"The (Scheels) Veterinary mouth prop's biggest asset is its simplicity - open the mouth and stick it in!...it does not interfere with radiographic detail, can be ultrasounded, and autoclaved...can be used for dental and oral surgery procedures...is positioned within the mouth, unlike the spring loaded (extra-oral) devices which can be in the way of the operator and interfere with positioning the patient..."

~ Paul E. Howard, D.V.M.,

Vermont Veterinary Surgical Center, Burlington, Vermont.

Order The WEDGE® from any of these veterinary equipment suppliers:


L.V.V.E.S

Large Volume Veterinary Endodontic Syringe™

Click here for more details

Dr. John Scheels - Exotic Animal Dentistry 
Dr. John Scheels - Exotic Animal Dentistry 

An endodontic syringe developed by Dr. John Scheels specifically for veterinary use in all species for complete and consistent obturation of root canals over 30mm long or with large pulp chambers. It permits the positive deposition of endodontic sealer and filler pastes at the apex of these long teeth. NO SPECIAL NEEDLES are required as it may be used with any standard size hub. Plastic, metal, threaded or non-threaded needle hubs will seal well on the tapered syringe nipple.

Purchase from Shipp's