When is an absent tooth not absent - the clinical importance

Incomplete dentition is a common problem in veterinary patients. The first possible cause of visibly absent teeth is that the teeth was lost because of periodontal attachment loss, traumatic avulsion, fracture or extraction.   Roots retained after tooth fracture can cause localized inflammation and extraction might be indicated.

Another potential cause is that such teeth might have never developed. A third and clinically a very significant cause, is that such teeth might have developed, but never erupted.

An unerupted (better described as a retained) tooth can have a normal anatomy but  are often malformed.

Retained teeth could be either

• Embedded teeth have a lack of eruptive force that prevent the eruption .(SHAFER 1983) or
• impacted teeth.  In the latter the path of eruption is obstructed by a physical barrier. (SHAFER 1983, PETERSON 1993, LEGENDRE 2019)

This cause occurs in pet animals and usually affects the canines and the premolar teeth. The first premolars in brachycephalic dogs are often involved, but potentially any tooth can be affected. (HARVEY 1993, NIEMIC 2018) A lack of knowledge and understanding implies a significant under diagnosis of this condition. Reports in the veterinary literature are less common and even rare in  zoo animals with only a single case reported in 1976 by Boever et al. (BOEVER, 1976).

This case reports discusses clinically absent canine teeth in three different species. It will attempt to demonstrate that visibly absent teeth should be considered a significant finding by zoo veterinarians. Radiographic investigation is always indicated in all cases of clinically absent teeth and surgical intervention is indicated for retained or traumatised teeth.