Deepbite Correction in Adult
Question
Just looking for some info for this case. When the pt has a deep anterior bite, will extrusion occur naturally (as a result of the aligners) in the posterior or should I be putting some in to help reduce how much intrusion needs to happen anteriorly?
Answer
In cases with a deep bite, we don’t need to focus much on the posterior. Most of the correction will occur through anterior intrusion.
Typically, we assess the smile first. The only time we'd intrude the upper anterior teeth is when the patient has a very gummy smile. Otherwise, we avoid upper intrusion because we know the upper lip will drop as the patient ages—approximately 0.1 millimeters per year. Over a decade, that’s a 1-millimeter drop in the lip line. The concern with upper intrusion is that it may prematurely age the patient.
In most cases, I prefer to focus on the lower teeth for deep bite correction.
If there is minimal crowding, intrusion becomes more challenging. I discuss this more in my lecture on deep bite correction, but generally, less crowding leads to less relative intrusion, requiring more direct intrusion into the bone. For these challenging cases, it's essential to have 3-4 millimeter horizontal attachments on the lower premolars and first molars.
Once the intrusion is complete, we don't want the bite to end flat. Instead, we aim for a bit of extra intrusion on the lower incisors, so that, from a frontal view, the patient finishes edge to edge, ideally with zero overbite or even a slight open bite.
If I could add something else to the Clearly Select template, it would be extrusion of the premolars and first molars, avoiding the second molar. A little extrusion in these teeth creates a reverse-curve of Spee effect, similar to a reverse-curve arch-wire in braces.
When it comes to occlusion, there should be heavy red contact on the premolars and first molars. We don’t need heavy contact on the second molars, so that can be undone. The heavy contact on the premolars and molars is fine because it's more about the forces applied than the exact contacts.
In terms of staging, you could request the technician to use "caterpillar" or "frog" staging. This means the incisors would intrude first, followed by the canines, in stages. However, in this case, I wouldn’t worry about intrusion using those techniques. Traditional staging should be sufficient.
For attachments, I don’t think you need any on the current teeth. I would remove them. On the lower canine, I’d consider switching to a 3-millimeter horizontal attachment.
Lastly, in deep bite correction, it can be beneficial to use lingual attachments. These allow the patient to bite down on the attachments, aiding in the intrusion. I typically avoid using bite ramps, as they can alter the torque of the teeth, and I like to add a little extra palatal root torque. Bite ramps tend to counteract that correction.