What are the causes for a chimp lip and possiblity of correction

[Gadwins]

So I think the subject says everything. I want to anticipiate my aesthetic resultat and I really want to have concave philtrum. I am not sad, if I get a chimp lip, solong there are possiblities to correct it.
I know that an over advancement could produce a chimp lip. But how much is too much? Does the angle of my upper teeth play a role?

Thank you for your answers.

[Post bimax]

So I think the subject says everything. I want to anticipiate my aesthetic resultat and I really want to have concave philtrum. I am not sad, if I get a chimp lip, solong there are possiblities to correct it.
I know that an over advancement could produce a chimp lip. But how much is too much? Does the angle of my upper teeth play a role?

Thank you for your answers.

Even the 'correct' amount of maxilla advancement can cause chimp-lip because the LF1 is not a perfect osteotomy.  In my opinion, all we can really talk about is tendencies rather than absolute measures:

Factors that will tend toward chimp-lip:
- Larger advancement
- Retroclined incisors
- Flat pre-op philtrum
- Steep occlusal plane

Factors that will tend toward philtral concavity:
- Smaller advancement
- Proclined incisors
- Concave pre-op philtrum
- Flat occlusal plane

I don't think there's a sure-fire way to predict the outcome other than making an educated guess based on the above criteria.  Everybody's bone and soft-tissue structure is different, and soft-tissue response to bone movement is different.  You need the right amount of bone support at the right angle with the right tissue thickness and elasticity for an ideal philtrum.  That's too many factors to identify and predict with any certainty.

[kavan]

The most common culprit for chimp lip is linear advancement of the maxilla in cases where the maxillary plane (Maxillary Plane (MxPl) The plane demonstrated by a line through the anterior and posterior nasal spines) or the Occlusal plane is inclined 'too far away' from a horizontal plane. Basically, a situation where to get the horizontal displacement vector for the maxilla, an UNWANTED vertical vector comes with it because one is advancing over somewhat of a steep diagonal line.

[Gadwins]

So that means, if my maxillary plane is already in ccw direction and it will be advanced along this line, then I shouldn't get a chimp lip?

[Post bimax]

So that means, if my maxillary plane is already in ccw direction and it will be advanced along this line, then I shouldn't get a chimp lip?

That is the tendency but no guarantee.  One user on this forum who shared their result with me got a convex philtrum despite having a pretty flat occlusal plane.  Their advancement was in the mid-range.

[GJ]

Post-Bimax's list is pretty complete.

I'm interested how much the teeth effect it. Proclined incisors cause gum recession. Yet, in theory, it seems they should help with this. I just don't know if they do to any meaningful degree.

[kavan]

So that means, if my maxillary plane is already in ccw direction and it will be advanced along this line, then I shouldn't get a chimp lip?

if you get 'a lot' of linear advancement when ANS-PNS is in a 'steep' CCW direction, you can get an overly rotated nose tip; 'pig snout'.

[Gadwins]

ok, but as far I understood, that correcting a nose seems to be no problem. But to correct a bad philtrum seems to be not easy, right? There seems to be something like a spina nasalis osteotomy, but how well could it make a convex philtrum to a concave one?

[kavan]

ok, but as far I understood, that correcting a nose seems to be no problem. But to correct a bad philtrum seems to be not easy, right? There seems to be something like a spina nasalis osteotomy, but how well could it make a convex philtrum to a concave one?

Changes to the philtral area are a function of many factors, including but not limited to your start point orientation, displacement vectors associated with the maxillary advancement. The function has a CURVE and that curve can be seen on a ceph displacement proposal as the contour diagram. My suggestion would be to find a surgeon who gives you a ceph displacement diagram where you can see the estimated contour of the changes to the profile because the changes to the the philtral area are somewhat predictable by the person KNOWING the factors of the multi-factorial function.

[PloskoPlus]

ANS reduction is often done to minimize the effect on the lip.  Sometimes the ANS is removed entirely. It can be overdone.

[Post bimax]

ok, but as far I understood, that correcting a nose seems to be no problem. But to correct a bad philtrum seems to be not easy, right? There seems to be something like a spina nasalis osteotomy, but how well could it make a convex philtrum to a concave one?

I wouldn't go this far.  There are potential solutions, but rhinoplasties have one of the highest revision rates of all plastic surgeries.  A rhino + revision could easily sink you another $20k.

[Gadwins]

ok, I assume you are talking about the US. But from another topic I understood so far, that your prices are behind the moon.

Just one thing what I didn't get: If I have already a straight philtrum and it is over average long, am I also in risk to get a chimp lip independently from all the other factors, which you told me?

edit: @kavan: thank you for your answer, I will keep it in my mind.

[Post bimax]

ok, I assume you are talking about the US. But from another topic I understood so far, that your prices are behind the moon.

Just one thing what I didn't get: If I have already a straight philtrum and it is over average long, am I also in risk to get a chimp lip independently from all the other factors, which you told me?

edit: @kavan: thank you for your answer, I will keep it in my mind.

Any time you get LF1 advancement you are 'at risk' to get chimp lip.  The above are potential mitigating or exacerbating factors

[kavan]

ANS reduction is often done to minimize the effect on the lip.  Sometimes the ANS is removed entirely. It can be overdone.

That patient actually did NOT need any ANS removal because she started with an overly acute base of nose to philtrum angle + maxillary recession. Advancement of the maxilla to take it out of it's recessive position would have actually normalized her overly acute nose to lip angle and SUPPORTED her downwardly rotated tip. That is to say, her nose AND lip would have IMPROVED with the maxillary advancement (in her case). I'm AGHAST as 'what was he thinking' when he removed her ANS because that's something to do, for example, when a person starts with an overly OBTUSE nose to lip angle where there is 'tethering' of the lip to the base of the nose. He just ended up making her overly ACUTE base of nose to philtrum angle MORE overly acute and caused her to SACRIFICE the the colum support and counter rotation of the downward rotated tip that she could have had with the maxillary advancement. What a dumb dumb doctor.

[kavan]

Any time you get LF1 advancement you are 'at risk' to get chimp lip.  The above are potential mitigating or exacerbating factors

Operative concept is OVER advancement of the maxilla; advancement in excess of what could actually be avoided if the surgeon had all the right 'tools' in his box. Although sometimes, some unwanted advancement can't be avoided and can be considered a 'trade-off' of getting a LOT of OTHER aesthetic problems improved. So, here I'm defining 'over advancement' as type that could be avoided rather than that of a trade-off that could come from a surgeon needing to correct a 'boat load' of aesthetic problems where a 'trade-off' of convex lip can't be avoided.

The risk is lower if one starts with a short philtrum, overly acute nose to lip angle and maxillary recession. Have a look at the photo Plosko entered and my response to follow my drift.

One exception I can think of to that is if someone, in addition to having a recessed maxilla (class 3 type), the ALSO have EXCESS lower jaw advancement. Like class 3 with recessive maxilla AND pro-gnathic mandible and they get ONLY maxilla advanced to match the pro-gnathic mandible and not a BSSO to set the mandible back. In which case, one would get an OVERLY advanced maxilla where the over advancement would be proportional to the the BSSO set back that was NOT also done.

Risks are higher, and IMO, the highest when the doctor wants to do LINEAR ADVANCEMENT of both jaws by an equal amount when both jaws DON'T 'need' to be advanced equally along their 'native plane'. Classic example of OVER advancement of the maxilla is in a sleep apnea case where one wants to expand the airway where instead of the doctor doing a CCW rotation of the maxilla to minimize unwanted maxillary advancement and maximize wanted mandibular advancement, maximization of the mandibular advancement comes with the aesthetic 'cost' of maximizing UNWANTED maxillary advancement AND along a NATIVE PLANE (diagonal) that's unfavorable to aesthetic optimization.

So, those are 2 examples of OVER advancement of the maxilla. There are some maxillary advancements that can be quite favorable to the nose to lip angle and contour.