Missing tooth! Why do we need to recommend dental radiographs?

In dogs, we may find that permanent teeth are missing on the oral examination and most often this is an incidental finding. However, this is an important finding, as it may cause problems to the animal. Therefore, complete oral examination and dental radiographs under general anaesthesia are recommended to determine the nature of the problem.

Congenitally missing teeth cause no clinical problem to the animal and the reason for a missing tooth is mostly unknown, but may be hereditary. Dental radiographs are needed to confirm the true absence of the teeth (Fig. 1).

The tooth can also be missing if it has exfoliated due to severe periodontitis, or as a result of periodontal trauma (avulsion). Another reason for a missing tooth is previous dental extraction. Healing of the alveolus is rapid and active bone remodeling with radiographic evidence of new bone formation is visible in 6-8 weeks, and (radiographic) healing of the extraction site is completed after 6-8 months. Once the vacated alveolus has (radiographically) healed, it is usually impossible to determine the reason for a clinically missing tooth.

The tooth will also be missing clinically, if it has failed to erupt (e.g., unerupted tooth, impacted tooth), which can also be diagnosed by dental radiographs (Fig. 2). Extraction of an unerupted tooth is usually indicated. Extraction is not necessary easy and it depends on the position of the tooth (impacted or abnormally positioned unerupted teeth). If an unerupted permanent tooth is left in place, chances are this will lead to a formation of a dentigerous cyst (Fig. 2b, c). If untreated, dentigerous cysts expand, which may lead to an extensive bone loss (Fig. 3), possibly resulting in jaw fracture.

A tooth may also be clinically missing after it has fractured, with root remnants persisting in the bone, which can be seen on dental radiographs (Fig. 4). Retained roots are the source of infection and pain and should be removed. Complete removal of the roots should be confirmed radiographically.

Selected references:

  1. Babbitt SG, Krakowski Volker M, Luskin IR (2016). Incidence of radiographic cystic lesions associated with unerupted teeth in dogs. J Vet Dent 33(4):226-233.
  2. Boy S, Crossley D, Steenkamp G (2016). Developmental structural tooth defects in dogs – experience from veterinary dental referral practice and review of the literature. Front Vet Sci 8;3:9.
  3. Kirby S, Miller B (2018). Dental and oral examination and recording. In: Reiter AM, Gracis M, eds. BSAVA manual of canine and feline dentistry and oral surgery, 4th ed. BSAVA, Gloucester: 33-48.
  4. Kuntsi H, Schwarz T, Mai W, Reiter AM (2018). Dental and oral diagnostic imaging and interpretation. In: BSAVA manual of canine and feline dentistry and oral surgery, 4th ed. BSAVA, Gloucester: 49-88.
  5. Moore JI, Niemiec B (2014). Evaluation of extraction sites for evidence of retained tooth roots and periapical pathology. J Am Anim Hosp Assoc 50(2):77-82.
  6. Reiter M (2018). Commonly encountered dental and oral pathologies. BSAVA manual of canine and feline dentistry and oral surgery, 4th ed. BSAVA, Gloucester: 89-118.
  7. Shetty V, Le AD (2012). Oral soft tissue wound healing. In: Verstraete FJM, Lommer M, eds. Oral and maxillofacial surgery in dogs and cats. Saunders Elsevier, Edinburgh: 1-5.
  8. Verstraete FJ, Zin BP, Kass PH, Cox DP, Jordan RC (2011). Clinical signs and histologic findings in dogs with odontogenic cysts: 41 cases (1995-2010). J Am Vet Med Assoc 239(11):1470-1476.
Fig. 1a
Fig. 1b
Fig. 2a
Fig. 2b
Fig. 2c
Fig. 3
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DVM Ana Nemec
DVM Ana Nemec
DVM, PhD, Dipl. AVDC, Dipl. EVDC, veterinary dentist, Slovenia. Dr. Nemec is a dentistry expert: She teaches students at the Veterinary Faculty, University of Ljubljana; she is a guest lecturer at the postgraduate study programme in surgery, anaesthesiology, ophthalmology, and veterinary dentistry at the Veterinary Faculty, University of Zagreb, Croatia. Since 2015, she has contributed to over 60 veterinary conferences in the USA, Malaysia, South Africa, Russia and several European countries, as well as in Slovenia. Dr. Ana Nemec works at the Small Animal Clinic of the Veterinary Faculty in Ljubljana. Follow Dr. Ana Nemec and her amazing work on Instagram @ananemecvetdentist and on Facebook or website.

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