unilateral Loss of a mandibular primary canine

Cause: resorption (ectopic eruption of lateral incisors)

When a primary canine is lost in the mandible due to root resorption caused by ectopic eruption of a permanent lateral incisor, it is a strong indicator of an underlying tooth size-arch length discrepancy (TSALD). First, check the contralateral side for canine mobility. If mobile, go back and classify this as a bilateral canine loss case. Management options are as follows:

    • Pros: may prevent midline shift, maintain arch symmetry, and allow for spontaneous resolution of crowding.

    • Cons: may enhance deleterious dimensional changes (collapse) of the arch.

    • Pros: prevent midline shift, maintain arch symmetry, maintain overall arch dimensions.

    • Cons: incisors may not be in favourable position for space maintenance, may be of limited value if extraction of permanent teeth will be needed in future to treat the TSALD.

    • Pros: as for (2), but balancing extraction may allow for spontaneous improvement of arch symmetry before LLA is placed to maintain arch dimensions.

    • Cons: as for (2).

    • Pros: minimize current costs and burden of care, may need extraction of permanent teeth in the future anyway.

    • Cons: May miss opportunity to space maintain, complicating future orthodontic treatment.

The decision will be heavily influenced by how you expect the case to be managed orthodontically in the future. 

  • Cases that will be treated non-extraction are more likely to benefit from intervention.

  • Cases that will require extraction of permanent teeth anyway may be best left alone for now (or treated as a serial extraction case).

Since management of this situation can be challenging and very patient specific, Dr. Jeff likes to air on the side of caution and refer to a specialist to create a comprehensive long-term plan when uncertain.