Palatally impacted canines are easily my least favorite things to encounter in orthodontics. The first question we should ask is "why do they occur?" The best study on this: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3467862/#:\~:text=Prevalence%20and%20Etiology&text=%5B9%5D%20Baccetti%5B10%5D,and%20small%20maxillary%20lateral%20incisors.

There is an important difference between canines that are facially/bucally directed and ones that go palatal. Facially directed canine tend to be strongly related to crowding and a lack of eruptive space. Thus, things like traditional palatal expansion, primary canine extractions, and fixed appliances tend to be exceedingly helpful

Palatal canines, on the other hand, have different etiologies. In some studies, it was noted that 85% of palatally impacted canines actually have physical room to erupt. So why do they become impacted? Two main reasons: genetics and small or missing lateral incisors.

The rates of palatal impacted canines correlate very highly with either pegged or even missing lateral. The "guided eruption" theory posits that in order to erupt, the canine "guides" down the root of the lateral incisors. When the laterals are either missing or inappropriately sized, they get "lost" on their way. Palatally impacted canines are also much more likely to cause resorption of the upper laterals and/or central and thus, we need to identify them early.

So how can we approach these in a conservative way that 1) allows for canine eruption and 2) prevents damage to the laterals?

As with most things, Vince Kokich was on to this years ago: Open Exposure of palatal canines. The canines are "exposed" and left "open" by the oral surgeon. No active chains, no appliances, no nothing - simply a path created on the palate for its eruption. Then, with enough time, the canines erupt on the palate and can be addressed much more simply with basic orthodontic techniques.

Here are 2 examples:

First patient is 10y/o. Both mom and brother have had a history of canine impactions in the past. I didn't see the laterals as undersized - this one is likely a genetic predilection.

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We referred for open exposure to the oral surgeon's office. No additional treatment was provided orthodontically other than making a lower lingual arch for space maintenance. Fast forward 2 years:

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