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

[kavan]

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.

I don't think you are going to predict your own outcome (or have anyone else here predict it for you) by the responses here in the absence of a surgical plan and in the absence of ANY visual (like a ceph or profile shot) of what you're starting out with.

If you wanted to get into predicting potential outcomes, you would need to look at many many maxfax cases where you're shown the start point and end point of the patient and also the displacements the patient had and could relate that back to a solid grounding in geometrical relationships.

[Post bimax]

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.

I agree LF1 can improve lip contour depending on the starting position.  I remember that case Plosko shared from another thread (it may have been one of mine actually).  Catastrophic decision.

When I said even the 'correct' LF1 advancement can result in chimp lip, I meant 'correct' advancement with regard to other orthognathic relationships.  As you noted, sometimes the tradeoff of chimp-lip is still worth it if bigger issues are solved.  My point was that the surgeon could do everything right and still have the patient end up with a convex philtrum, which is the detail Gadwins was curious about.

I think the two examples of over-advancement you provided describe Plosko's case and my case, respectively (Plosko can correct if I'm wrong).  It's good that CCW-r is becoming more widely practiced.  Older surgeons who continue to apply linear MMA in every case out of pride are stubbornness are a threat to prospective patients.

[PloskoPlus]

Surgeons who refuse to do CCW-r claim it's unstable.

[kavan]

I agree LF1 can improve lip contour depending on the starting position.  I remember that case Plosko shared from another thread (it may have been one of mine actually).  Catastrophic decision.

When I said even the 'correct' LF1 advancement can result in chimp lip, I meant 'correct' advancement with regard to other orthognathic relationships. As you noted, sometimes the tradeoff of chimp-lip is still worth it if bigger issues are solved.  My point was that the surgeon could do everything right and still have the patient end up with a convex philtrum, which is the detail Gadwins was curious about.

I think the two examples of over-advancement you provided describe Plosko's case and my case, respectively (Plosko can correct if I'm wrong).  It's good that CCW-r is becoming more widely practiced.  Older surgeons who continue to apply linear MMA in every case out of pride are stubbornness are a threat to prospective patients.

OK, I was just responding to what I quoted:

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

But, ya even a correct advancement could kick it up. We are both making same/similar point.

I get my examples by looking at a lot of cases and/or reading what revision doctors tell the patient with 'this or that' thing they want fixed. But I 'de-identify' the info (just in case).

[ODog]

Chimp lip is certainly caused by overadvancement, but nobody should take comfort if their advancement is moderate or even mild since the positioning or tilt of the maxilla has equal impact. I had a flat nasiolabial angle preop and was advanced only 6 mm and have a bit of a chimp lip. CCW-r would have mitigated this by providing support to the vermillion as opposed to the mid-philtrhum getting all the “push.”

I can’t really imagine one getting chimp lip if the tilt of the maxilla is such that the teeth lend an upward curl to the vermillion - even in cases of moderate to large advancement. Models have prognathic maxillas but good support at the ‘correct’ place. 

Connor mcgregor for example has a chimp lip in profile because in addition to a prognathic maxilla he has a vertically long downward rotated maxilla, bulging out the mid philtrhum like this (, where the bottom of the line is the vermillion, getting less support or “push out.”

Others, e.g. models, can also have prognathic maxillas but with different lip support which looks more like this ), which offsets this appearance.

So what causes this: Steep occlusal plane/ vertically long maxilla getting a linear advancement, or a flat occlusal plane getting CW rotational advancement (Which happened to me). That said, my occlusal plane was flat to ‘tipped up’ pre-op and my vermillion still didn’t have any support... that’s where soft tissue can play a role and exacerbate things even more, so having thin unsupported lips pre-op is also a risk factor.