Break Through Retention

We gave you the wisdom of retention in our previous posts. Now it’s time to wrap it up with some bonus thoughts and tips on settling, phase 1 retention, and eruption of  third molars.

Settling During Retention

When orthodontic appliances are removed and we make retainers immediately after treatment, we hold the dentition in an artificial position which was created with the finishing wires or aligners.

After debond, the dynamic nature of dentition will result in occlusal “settling” which allows for an improved intercuspation as long as all your finishing criteria are met and the teeth are in the right spot. You can think of the following strategies to allow the dentition to settle in a natural, physiologic occlusion:

  1. Finishing in light wires will allow for most of settling to occur prior to debond.
  2. Using retainers without any occlusal coverage like Hawley or wrap retainers (ie- not essix-style retainers)
  3. Making removable retainers 1-2 weeks post-debond. If you plan on bonding a fixed retainer for the anterior segment, bond it right away especially if the patient started with a diastema or severe crowding.

Bonus Tip: when patients go to part-time retainer wear there is constant movement of the teeth from the artificial position to the settled position and can cause “retainer mobility”.

Early Treatment Retention

Once the objectives of early treatment are achieved, the patient’s dentition goes through significant changes until comprehensive treatment: teeth exfoliate, erupt and drift constantly. This brings additional challenges while we need to retain transverse dimension, alignment and spaces.

You can think of the following strategies for retention while waiting for phase 2:

  1. In the maxilla, Hawley retainers with Adam’s clasps on permanent molars and labial bow across incisors is preferred (a “2×4” retainer). C-clasps are not that retentive on children with short clinical crowns. Make sure to adjust acrylic as needed to accommodate eruption of 4s and 5s.
  2. Another option for maxillary arch is a Nance if holding spaces and preventing U6s from slipping forward are a huge priority. The downside is that the palate becomes irritated over time.
  3. In the mandibular arch, a lower fixed retainer 2-2 or a lower lingual holding arch are preferred. LLHA is good for holding arch length. You can use both at the same time if necessary.

 

Bonus Tip: You can leave the bands on for HG wear in class II skeletal patients.

Bonus Tip: You can incorporate a bite plate in patients with deep bite.

Wisdom Teeth and Incisor Crowding

Our patients ask us many times: “My wisdom teeth are coming in and my lower teeth are getting crowded, should I take them out?”

The answer is: Not necessarily. It is controversial and there is no clear evidence to show that third molars are causing late incisor crowding.

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The recommendation for mandibular third molar removal with the objective of alleviating or preventing mandibular incisor irregularity may not be justified.(2)


Have you read “The Wisdom of Retention” Part 1 and Part 2 yet? Those posts cover techniques, indications, bonded retainers, removable retainers…you name it, we got you covered. Enjoy!


Authors:

Fedora and Mina

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References:

  1. Long-term post-treatment changes measured by the American Board of Orthodontics objective grading system. Nett BC, GJ Huang. AJODO,2005 Apr;127(4):444-50.

  2. A long-term study of the relationship of third molars to changes in the mandibular dental arch. Ades, Amin G. et al. American Journal of Orthodontics and Dentofacial Orthopedics , Volume 97 , Issue 4 , 323 – 335


Disclaimer:

Please consider that the preceding article expresses general opinions and thoughts of the author(s), and should not be construed as explicit treatment recommendations for a specific patient. The evidence is constantly changing, and readers are encouraged to continuously update their knowledge base. The post is meant to inform the reader of what is available in the specialty literature at time of publishing.  

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