The ABCs of veterinary dentistry: X is for intraoral x-rays

When a patient presents with chronic non-weight bearing lameness, you inform the owner that x-rays are needed to see what is going on. The same is true for patients that have been vomiting or coughing for a while, as well as a host of other reasons. It’s a given that your full-body radiograph unit is an integral diagnostic tool. But how many of your patients present with halitosis? How important are intraoral x-rays to your practice? How can you incorporate them into your workflow in every case? How should you communicate the safety, importance, and expense of dental x-rays to your clients? Read on.

The importance of dental x-rays

Covered by gingiva encased in the alveolus and located subgingivally, about 60% of the oral anatomy in dogs and cats is not visible to the naked eye.¹ Because skull radiographs result in superimposition of teeth, they are nondiagnostic in most cases (Figure 1). After the learning curve, it is easy to incorporate intraoral radiography in any dental workflow, and it’s the key to unlocking a dental treatment plan.

Figure 1. (left) Referral skull image of the mandibular canines. (center) A radiologist’s interpretation based on the skull image: probable tooth root abscess. (right) Intraoral radiograph shows no evidence of periapical disease, reinforcing the indication for intraoral radiographs.

Incorporating intraoral radiography into your workflow

Incorporating intraoral radiography into your practice elevates dentistry from a one-size-fits-all quote over the phone and a drop-off for “a dental” to practicing diagnostic dentistry. Each dental appointment should include at least 3 client conversations: before they leave their dog or cat with you, during the procedure once pathology is found, and at patient discharge.

The initial phone call

During the initial client conversation, discuss what will happen when the pet comes to the clinic, when results of the exam under anesthesia with intraoral films will be available, and what your client is able and willing to do at home with regard to daily plaque control. Here’s how it should play out.

When a client calls to schedule a professional teeth cleaning appointment for a pet with halitosis, the receptionist advises the client that the pet must see the doctor for a general examination and preanesthesia testing either days before or on the day of the visit. The receptionist also explains that the veterinarian will find the cause of the pet’s halitosis via a tooth-by-tooth examination that includes full mouth dental x-rays and, while the pet is anesthetized, contact them to share the findings and recommend treatment options. Treatment can be performed during that visit or at a later time, depending on the day’s schedule and the client’s preferences. Finally, the receptionist shares the initial examination fees, preoperative laboratory testing, dental scaling, tooth-by-tooth examination, polishing, and intraoral radiographs. (In some practices, the veterinarian discusses fees with the owner.)

The money conversation

It’s a shame animals do not walk into our offices holding credit cards with unlimited maximums to pay for their care. Fortunately, many payment options are available to allay clients’ money fears while allowing you to provide needed veterinary care.

If the client expresses cost concerns, discuss payment plan options and let the client know the entire team is dedicated to providing what their pet needs. A number of options are available today that enable clients to delay or divide payments over time, including CareCredit, Scratchpay, and Vetbilling, among others.

In addition, many wellness plans now include annual full mouth dental radiographs as well as anesthetized dental scaling and polishing. These plans go a long way when you ask whether your client “wants” x-rays during an elective dental procedure.

The dental care visit

The following is a general timeline for an oral assessment, treatment, and prevention visit with a pet that has halitosis:

• 9:00 am: When the client brings their pet into the exam room, review the patient history and previous laboratory results, and examine the pet, focusing on the oral cavity. Discuss the client’s willingness and ability to provide daily plaque control. If the client has not been given a fee schedule, the doctor or assistant shares the fees for the initial diagnostics and dental scaling before the client leaves the exam room. The client agrees in writing that they understand that you will place their pet under anesthesia as well as the associated risks, and that there are likely to be additional fees for needed care. Discuss payment options openly. Inform the client what to expect over the course of the day and arrange a time to speak to the owner while the dog or cat is still anesthetized after determining the cause of the pet’s halitosis
• 9:30 am-11:00 am: The staff acquires preanesthetic test results to share with you, and then prepares the patient for anesthesia.
• 11:30 am-12:45 pm: Staff members anesthetize the patient, scale and polish the pet’s teeth, and obtain intraoral radiographs for the veterinarian to examine chairside. A team member then hands the veterinarian a dental probe to conduct the tooth-by-tooth examination and create a treatment plan, dictating the results to an assistant who creates the dental chart. The assistant tabulates additional fees, and creates and sends an email or text report to the client.
• 1:00 pm: Review with the client your findings and the optimal treatment plan, explaining all associated fees and discussing payment options if needed.
• 3:00 pm: Perform the necessary treatment.
• 5:30 pm: Meet with the client to review the diagnosis and therapy. Have the client set a follow-up appointment to evaluate healing and create a tailored daily plaque prevention program. To leave clients with a lasting positive impression, send them home with a simple digital report that includes clinical before and after images and radiographs of their pet.

Optimal vs functional care

Our patients do not need their teeth to live a full life, but they do need comfort. Root planing, local antimicrobial administration, and laser periodontal surgery are often recommended for optimal care but are not in the comfort range of some clients who cannot provide or afford needed follow-up care. In these cases, a treatment plan aimed at creating a pain-free functional mouth is the goal. You can make the pet comfortable by extracting teeth with complicated fractures and teeth affected by established periodontal disease.

One of the challenges in veterinary dentistry is getting the client to agree to your recommendations and having sufficient time to provide care during the same visit as the exam. When there is only 1 treatment table or extra time is not available, treatment staging becomes more imperative. In these cases, prepare your client that the diagnostics and teeth cleaning, polishing, and irrigation are performed during the initial visit, followed by a review of pathology with therapeutic recommendations, with the treatment itself performed 1 to 2 weeks later after the client agrees to the recommendation and has financial arrangements in place.

Interpreting oral x-rays and determining treatment

Periodontal disease Radiographs, which provide a 2-dimensional view of a 3-dimensional object, are used to determine indirectly the degree of bone (tooth support) loss. The bone level in periodontal disease often decreases as inflammation extends and bone is resorbed. In order to visualize bone loss radiographically, 40% of the bone has to be affected. Distribution of bone loss is classified as either localized or generalized, depending on the number of areas affected. Localized bone loss occurs in isolated areas, whereas generalized bone loss involves the majority of the marginal bone. You can classify specific areas of bone loss as horizontal (perpendicular to the tooth) or vertical (angular along the side of the root).

Periodontal disease is classified into 4 stages based on radiographic and clinical signs. In the normal cat or dog without periodontal disease, the alveolar margin resides within millimeters apical to the cementoenamel junction. Stage 1, gingivitis, occurs when the gingiva appears inflamed. There is no periodontal support loss or radiographic change.

Stage 2, early periodontitis, occurs when attachment loss is less than 25%, as measured from the cementoenamel junction to the apex. Clinically, early periodontitis is typified by pocket formation or gingival recession. Radiographically, stage 2 periodontitis appears as blunting (rounding) of the alveolar margin in addition to bone loss. There may also appear to be a loss of continuity of the lamina dura at the alveolar margin level.

Stage 3, moderate periodontitis, is diagnosed when 25% to 50% of attachment loss occurs (Figure 2). The direction of bone loss is either horizontal or vertical (angular). Horizontal bone loss appears radiographically as decreased alveolar bone along adjacent teeth. Normally, the alveolar margin bone is located 1 mm apical to the cementoenamel junction. With horizontal bone loss, both the buccal and/or lingual bone plates, as well as interdental bone, are resorbed. Clinically, horizontal bone loss is typified by a suprabony pocket, which occurs when the epithelial attachment is above the bony defect.

Figure 2. (left) Measurement of bone loss. (right) Stages 2, 3, and 4 periodontal disease.

Vertical bone loss, resulting from infrabony defects, occurs when the pocket walls are within a bony housing. Periodontal disease may cause a vertical defect to extend apically from the alveolar margin. Alveolar bone expansion appears clinically as bulging alveoli around 1 or both maxillary and/or mandibular canines. Radiographically, this lesion appears as bone loss around the root and expansile alveolar bone growth.

Stage 4, advanced periodontal disease, is typified by deep pockets and/ or marked gingival recession, tooth mobility, gingival bleeding, and purulent discharge. Attachment loss is greater than 50% of the root length.

Furcation exposure results from bone loss at the root junction of multirooted teeth due to advanced periodontal disease. Unless there is a radiolucent area in the region of the furcation, it is sometimes difficult to determine radiographically whether the interradicular space is involved. Lack of radiographically detectable furcation involvement is not confirmation of the absence of periodontal destruction. Advanced furcation exposures, where both cortical plates are resorbed, are easily recognized on radiographs.

Stage 1 furcation involvement exists when the tip of a probe can just enter the furcation area. Bone partially fills the area where the roots meet. Radiographically, there may be decreased opacity of the bone at the furcation.

Stage 2 furcation involvement exists when the probe tip extends horizontally into the area where the roots converge but does not exit on the other side. Radiographically, there will be bone loss at the furcation.

Stage 3 furcation exposure lesions exist secondary to advanced periodontal disease. Alveolar bone has resorbed to a point that an explorer probe passes through the defect unobstructed. Radiographically, there will be an area of complete bone loss.

Tooth resorption

Because tooth resorption is not observed clinically in most cases, intraoral x-rays are important in the diagnosis and treatment planning for canine and feline tooth resorption. Radiographically, when the external resorption lesion is located apically, the apex will appear shortened, blunted, or square, and the lesion will be ragged or irregular. If the lesion is internal resorption, then the root canal system has an enlarged area and the margins of the lesion are sharp, smooth, and clearly defined. The canal is not present in the lesion, and the size is variable.

Classification of tooth resorption takes into account the extent of lesion progression, anatomic location, and etiology. The clinician should know whether the resorption is internal or external and, if external, whether it has extended to the oral cavity. Some investigators believe that 3 radiographic appearances of tooth resorption exist and have clinical significance related to therapy.

Type 1 usually involves loss of alveolar bone adjacent to an often well-defined area of tooth resorption; normal periodontal ligament space is maintained at other areas of the tooth. If the lesion extends to the oral cavity, the entire tooth should be extracted (Figure 3).

Figure 3. Type 1 tooth resorption of the right mandibular canine root.

Type 2 involves loss of the periodontal ligament space and lamina dura due to fusion of the tooth root and alveolar bone (dentoalveolar ankylosis); the resorbing tooth structure may appear less radiopaque than the unaffected tooth (replacement resorption) (Figure 4). If the lesion extends to the oral cavity, the crown can be reduced in height below the gingiva followed by gingival closure.

Figure 4. Type 2 tooth resorption of both mandibular canines.

Type 3 includes features present in types 1 and 2. If the lesion extends to the oral cavity, the tooth should be extracted.

Jan Bellows, DVM, DAVDC, DABVP, FAVD, owns All Pets Dental in Weston, Florida. He is a diplomate of the American Veterinary Dental College and the American Board of Veterinary Practitioners. He can be reached at dentalvet@aol.com.

Reference

1. Bellows J. Small Animal Dental Equipment, Material and techniques, ed 2. Wiley; 2020.