Skill Group: Clinical Skills

Reading Dental Radiographs – An Order of Operations

Dr. Stephen Horvath and Krystal Bowers

Evaluating dental radiographs is similar to a physical exam and a full mouth oral exam as you’ve learned in your previous clinical skills labs. By that I mean it is important to perform your evaluation in the same order every time. Having an organized, methodical, approach will help ensure that you don’t miss anything.  Additionally, keep in mind that there are often grey areas in dental X-rays. Remember, imaging should always be combined with an anesthetized full mouth oral exam to help develop your treatment plan.  


  1. Reading Dental X-rays: An Order of Operations
    • Below we offer an order of operations to help you begin reading dental X-rays. Included, is a corresponding flow chart for you to make notes and treatment decisions with.   Initially, it will take you some time (~1 hour) to go through a full mouth imaging study on your own, and your speed will improve quickly with repetition. Eventually you will not need to complete the full chart and you will be able to just make notes on any significant findings. This will reduce you time to around 15 minutes or less depending on the case.

Dental Rads Interpretation Chart 12-2020 Horvath

Blank Dental Rads Interpretation Chart for lab

    • Recommended order of operations (refer to chart)
      • Review each tooth in sequential order beginning with 101 and ending with 411 (409 for cats).
      • Is the tooth Normal, Abnormal, or Missing? Mark appropriately
      • If the crown is missing are there any Retained Roots visible on the image? If so evaluate the root like any other tooth as described below.
      • Is there a stage of Periodontal Disease present? Document the stage, 2-4, and its location. Ex: PD2 mesial root 206.
        • Refer to PD staging definitions in the Periodontal Disease chapter as defined on the AVDC nomenclature website.
        • Remember that only one root needs to be affected to diagnose the entire tooth.  For example if  307’s mesial root has ~10% attachment loss and the distal root has 40% attachment loss the diagnosis would be PD3 for the entire tooth.
      • Is there Tooth Resorption occurring? If so, is this in the crown, the root(s), or both?
        • This can be further classified using the resorption scheme presented on the AVDC nomenclature website as described in the resorption module. This dictates what type of extraction to perform.
      • How does the Pulp cavity look?
        • Non-vital tooth – As an animal ages, the inside of the pulp cavity is filled in with dentin thus the cavity narrows with age. If it is wider and larger compared to the teeth around it, or its mirror tooth on the other side of the mouth, this indicates the tooth is dead or non-vital.
        • Pulpitis – This is indicated when the pulp cavity is irregular, enlarged, and has irregular margination.  This is the tell tail sign of inflammation and infection which if left untreated will progress to a tooth root abscess.
        • Pulp Exposure – This is caused by a complicated crown fracture. In some teeth it is hard to tell from visual exam or with the use of the dental explorer. A good example of this is a crown tip fracture of a feline 04 tooth. An X-ray at the right angel can help determine this. Depending on chronicity pulpitis may also be present.
      • Is the Apical portion of the root abnormal?
        • Sometimes the tips of the root are curved. This is termed a dilacerated root.
        • A normal finding is a smooth space at the root tip called the chevron sign which is common in canine teeth, but can also commonly be seen in incisors, and even 309 and 409.
        • Tooth Root Abscess – This is seen by a lucent sphere of expansion and bone loss around the root tip. It can also look like a more lucent area of the alveolar bone indicating necrosis.
      • Are there any Deciduous teeth present?
      • Other – Are there any Other abnormal findings?
        • Supernumerary teeth – An extra permanent tooth not normally present
        • Furcation exposure 3. Sometimes a more lucent area of bone at the furcation can indicate possible furcation exposure 2, which you can confirm on oral exam.
        • Fractured root
        • Unerupted tooth
        • Odontogenic cyst
        • Masses / tumors
        • Etc.
      • Treatment Options
        • No treatment needed – don’t mark anything
        • Root Plane – closed or open and apply perioceutical antibiotic gel
        • Surgical Extraction – full extraction vs crown amputation vs combination of the two.
      • Referral procedures – root canals, hemi-mandibulectomy, etc.

Here is a link to the second part of the Today’s Veterinary Practice dental X-ray interpretation series entitled Interpretation of Dental Radiographs in Dogs and Cats, Part 2: Normal Variations and Abnormal Findings, by Santiago Peralta, DVM, DAVDC, and Nadine Fiani, BVSc, DAVD, Cornell University

*Note-Reading this article for the lab is not mandatory, but it is encouraged and recommended. It is an excellent resource to refer back to as you begin your practice of veterinary dentistry and intra-oral dental radiographs.




OSU CVM Veterinary Clinical and Professional Skills Center Handbook Copyright © 2018 by Dr. Stephen Horvath and Krystal Bowers. All Rights Reserved.

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