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Case Study: How “Walking the Midline” Shifted this Patient’s Teeth and Confidence

Written by POS Course Adviser | 3/12/18 10:39 PM

This is a guest post by POS graduate (and now POS instructor) Dr. Jacques Cilliers. Learn how he successfully helped his patient Yolin go from a 12 year old who hated her smile, to a confident teenager who loves taking selfies.

My name is Dr. Jacques Cilliers. I have been offering comprehensive orthodontic care since 2012 and treat about 10 new orthodontic patients a month. I find orthodontics enjoyable and love seeing how happy it makes my patients.  

I had always wanted to do orthodontics because it looked really fun (I’m a bit of a nerd and geek out on appliances and computer planning). Previously, my patients kept asking me to put braces on them. They preferred staying in house since they didn’t know the orthodontist or like her 1 day per week schedule. Since there weren’t any comprehensive orthodontic programs for dentists in Africa (and I couldn’t afford to close my practice to get a specialty), I asked POS to teach dentists in Africa. They agreed, and that was the beginning of my orthodontic career.

Yolin is one of my patients whom I helped with orthodontics. Here is her story:

My patient, Yolin

Summary:

  • 12 years old
  • Open bite, tongue thrust, crowding, and midline shift
  • 2mm Class II on the right and 6mm Class III on the left
  • Treated by using a TPA, extracting all the 4s and walking the midline with moderate anchorage
  • 2 year treatment

When I spoke to Yolin, she mentioned that she was unhappy about her teeth sticking out. She told me “my smile is ugly”. Her mum was worried that she didn’t smile in pictures or around other people.

My Orthodontic Analysis

After doing a thorough orthodontic analysis, I saw that her arches were not well formed. There was 7mm and 3mm of lower and upper crowding and an upper midline shift to the left. Although she had a perfect Class I molar relationship, she had 2mm Class II on the right and 6mm Class III on the left. Her panorex showed that she had short upper incisor roots, a high sinus, and most importantly that her 24 was missing, which caused her asymmetry.

My cephalometric analysis revealed that she was skeletally open, meaning that extraction spaces would close fast. A 102 degree intercisal angle and a +8 Lower 1APo confirmed that she had protrusion, which was her chief complaint. After doing a wrist and CVM analysis, we determined that she was nearing the end of her growth, as she was close to Stage 4 of the growth curve.

 

Precisely analyzing occlusion from digital model measuring

Looking at the projected outcome (in purple), via IPSoft’s VTO tool

After comparing a few treatment options and visualizing their effects, we decided to extract the rest of her 4s with moderate anchorage on both arches to reduce her protrusion and fix her midline shift.

Treatment

We extracted Yolin’s remaining 4s (14, 34, and 44) to balance her out. I treated her with a customized IP Appliance®, using a medium ovoid archwire shape to keep the archform, provide a small amount of expansion, and move the teeth between the buccal cortical plates. Rotations were diagnosed in 13 of her teeth, and custom IP rotation brackets were applied to have more efficient correction. To close her open bite early on, I also placed Li upper and lower torque brackets with an open bite position.

For her upper arch mechanics, I placed a TPA on an 18x25 nitie wire to prevent the loss of molar anchorage. When the 14 was extracted, we placed a 19x25 stainless steel wire with a nite open coil using steel ties to move the 13 back by 3mm. We then laced and used a chain to walk her upper midline. After her midline was centered, I changed both arches to a 19x25 keyhole wire and used 9mm of closing coils to close the spaces with Step 3 forces until her spaces were closed.

We decided to use a non-compliant treatment plan with closing coils so we didn’t have to worry about her remembering to use rubber bands to fix her open bite or her asymmetry. Yolin kept up her hygiene well. However, we wanted to control the treatment and didn’t want to leave her results to chance, and this worked out well.

How did Yolin’s case turn out?

I am quite happy with Yolin’s outcome. After two years of treatment, we were able to get her into an ideal Class I molar and canine relationship on both sides. Her lateral open bite closed and her bite looked great.  More importantly though, I’ve noticed how much more confident and social Yolin has become.

Treatment results:

  • Fixed canine relationship to become Class I
  • Both archforms now well formed
  • Open bite has closed properly
  • Reduced protrusion with 4mm and 3mm of retraction of the upper and lower incisors
  • Happy patient and family

Dentists often find that midline shift can be one of the trickiest problems to fix in orthodontic cases. But after doing several asymmetric cases like this (and learning from my mistakes), I’ve realized that if you stick to what you’re taught, it’s actually quite easy and can be efficient. Yolin’s actual results are very similar to what we predicted on the VTOs. The upper incisor went back and down 4mm and the lower incisor moved back 3mm as predicted.

Prediction

Actual

 

Yolin had always been friendly. She transformed into a social butterfly!

Yolin and her mom were very happy with the results. Yolin told me that she’s very proud of her smile and can now smile with confidence. Her mum told us how happy she was that Yolin is smiling now in pictures. She even admits that Yolin has become addicted to selfies.

This is why I love being a dentist.