Class II Aesthetics

There are three things an orthodontist can do to a patients upper lip. They can preserve lip fullness. They can enhance lip fullness. They can retract the upper lip and reduce lip fullness. The most popular type of treatment for a Class II malocclusion is non-surgical orthodontic compensation, where the upper incisors are retracted to correct the overjet. The greater the overjet, the more the upper incisors and upper lip are retracted. The trick is to share the correction between the upper and lower to reduce the amount of upper retraction.

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Xbow two phase non-extraction treatment to preserve the upper lip

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Initial (I was the second opinion. Initial opinion was the extraction of four bicuspids and braces.Instead, I treated non-extraction with Xbow two phase treatment)

1. Xbow___ 2. RME___ 3. FEA

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The Xbow system for Class II compensation is "bottom up orthodontics". It is based on building the maxillary foundation for

ideal treatment as if we were proceeding with jaw surgery. After maxillary expansion and upper anterior alignment, instead of

proceeding with full braces and jaw surgery we use the Xbow appliance to share the correction between both arches to minimize

retracting the upper incisors and upper lip, compared to headgear or upper extractions.

initial

1. 2X6 RME 2. Xbow (springs for 2 months)

14 months full braces

Upper lip preservation with a convex profile and obtuse naso-labial angle, non-extraction in a crowded Class II deep overbite patient

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Initial

1. Xbow 2 months left spring, 3 months right spring 2. Compensatory maxillary expansion 3. 18 months full braces

Sharing the correction between the upper and lower arches preserves upper lip fullness

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Non-extraction treatment to preserve the upper lip

Initial

16 months

Years ago this case would have been treated by four bicuspid extraction. That would have resulted in upper incisor and upper lip

retraction. Instead we maintained the upper lip. This is a case where I used the "Daughter Test". If I would not treat my own daughter

with a particular appliance or treatment plan, then why would I use it on a patient. We know that most orthodontic treatment needs

life long retention. Esthetics should trump the endless pursuit of stability without retainers.

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Surgical correction to preserve the upper lip

 

Initial ____________________________15 months total treatment time including

lower bicuspid extraction site space closure and lower jaw surgery by Dr. Bill McDonald

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Initial

After lower bicuspid extraction site space closure and lower jaw surgery by Dr. Bill McDonald. The upper

second molars are unopposed and can be removed if they ever cause a problem which is very rare.

There are only two upper molars in occlusion and the molar relationship is Class III. In these cases we look

for a Class I bicuspid relationship. When a patient chooses surgery we concentrate on ideal facial esthetics.

The upper incisors are slightly proclined which prevents the upper lip from hanging straight down.

This creates complementary curves between the nose and upper lip, and the lower lip and chin.

Upper lip projection should be slightly ahead of the lower lip. Lower lip projection should line up with chin.

The nose blends in beautifully with the face.

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Preference vs evidence based treatment decisions

If the best option for a Class II patient is mandibular advancement surgery, but they decline, then treatment will be some sort of orthodontic compensation.  By

definition, dental compensation for a jaw problem will be a compromise.  The choices are either upper incisor retraction only, or sharing the correction between

the upper and lower.  That is really all we are doing with functional appliances, other than a small skeletal effect.


The Catch 22 is that both choices have drawbacks.  Too much upper incisor retraction will result in noticeable upper lip retraction.  If we’re not retracting the

upper incisor and lip we are proclining the lower incisor and increasing lower lip protrusion.  If we extract four bicuspids to keep the lower incisors upright, in an

attempt to improve stability, then we retract the upper incisors and upper lip even more. The fact that we can't predict individual facial growth complicates matters

more.

The lower lip flattens 3.5 mm on average with growth and if first bicuspids are extracted it flattens another 2 mm on average for a total of 5.5 mm. Another way

of saying this is that a slight protrusion appears more youthful. I prefer a slight protrusion to a flattened profile in most cases.

As far as stability goes, practically all orthodontic movement is unstable and requires long term (life long) retention. Proclined lower incisors will relapse if not

retained. I retain every full treatment case, anyways.

As much as we want to make evidence based decisions, orthodontist and patient preference plays a major role in the decisions we make. In the 1980's my Class

II patients fell into four groups. 1. Orthodontic decompensation and jaw surgery. 2. Two phase non-extraction beginning with a functional appliance (which

evolved into Herbst followed by Xbow). 3. One phase four bicuspid extraction and headgear (I still have a few of these). and 4. One phase upper bicuspid

extraction (I still have a few of these, as well). For a very short time I tried one phase headgear, followed by Forsus to the archwire (if they didn't wear the

headgear). I have always waited for second molars to erupt before indirect bonding, so with these cases I was leaving the Class II correction to later in treatment

compared to two phase. I preferred two phase where I corrected the Class II buccal segments early on, and opened space for the erupting upper canines. It

wasn't evidence based. It just made sense to me to connect the Class II springs to the RME when I was expanding the maxilla on so many of my Class II

patients. It gave me something to do while I was waiting for second molars to erupt and the patient was growing. Welding tubes to the upper first

bicuspid bands made early incisor alignment and canine management more comfortable and efficient, compared to connecting the archwire to the first molars.

 

One thing became clear. If I extracted four bicuspids in a deep overbite case, I ended up chasing the lower incisors in what I call the "never ending overjet". It

was in these cases where I saw the most lip retraction, or profile flattening. I began treating more and more of these cases non-extraction and in two phases. By

this time I was expanding the maxilla in just about every two phase Xbow case and I used a lot of RME X 6's to align and open space for upper canines. My

treatment time for phase two decreased to about a year. I sent all my Xbow patient cephs to the U of A for analysis. I wanted to be evidence based but really it

came down to my preference. Non-extraction without headgear turned out to be my patient's preference, as well.


No matter which interarch Class II appliance I used, I proclined lower incisors.  Whether it was Xbow or Herbst or Twin Block or Class II elastics or Forsus, it

didn't  matter. Expand buccally? Interproximal reduction?  Fill the slot and tie back? Minus six degree lower incisor brackets? They still proclined.

 
I didn’t worry about proclining lower incisors with functional appliances until I began using Herbst. (So this is what happens with full time wear.) Even then, I

didn’t see any gingival recession which agrees with the article by Hans Pancherz and a systematic review on proclination.  I am more comfortable with  lower

incisor tipping followed by partial uprighting with Xbow and non-edgewise Herbst,  than I am with bodily mesialization with a rectangular archwire and minus six

degree lower incisor brackets, which I find results in root prominence. Again, it's a preference. There isn't good evidence, one way or another.

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Below are pretreatment cephs with Class I skeletal patterns with good lip fullness, but different soft tissue convexity angles and midface development.

Patient #1 pretreatment ceph________________Patient #2 pretreatment ceph

Patient #1: Class I skeletal, upper and lower incisors are naturally more proclined than established "norms"

Lips are slightly protrusive and balanced perfectly to Rickett's E plane due to short nasal projection

Is a slight protrusion the new ideal?

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Patient #2: Class I skeletal, high soft tissue convexity angle due to strong nasal growth , upper lip retrusive to Rickett's E plane

The goal should be to maintain the upper incisor position. If this is not possible it is better to end up with a slight protrusion and long term retention

instead of a retrusion based on wishful thinking of better stability. We cannot predict how much more nasal growth will occur, only that it will.