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  1. Margaret Mitchell
  2. Troubleshooting
  3. Thursday, 17 November 2016
Hello. I have noticed on many of my cases the maxillary lateral incisors do not track. I can see 1/2 mm incisal space between the teeth and aligners. I notice this often when there are large centrals and canines. In the clincheck I will ask for larger attachments on the laterals to help the aligners grip the laterals better. I also give the patient chewies by Dentsply to help move the teeth into the aligners. Does anyone seem to see this and have other techniques to help?
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Margaret Mitchell Accepted Answer Pending Moderation
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Hello. I was just curious if anyone has any insight regarding lagging maxillary lateral incisors. I just had another patient this morning with this problem. I used the crimpers to place dimples to encorage the movement. I also told the patient to use the chewies as much as possible to help the teeth move into the aligners.
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  1. more than a month ago
  2. Troubleshooting
  3. # 1
John C. Melucci, DDS Accepted Answer Pending Moderation
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The Munchies are really nice to use, they seat the aligners better and patients like chewing on the 3-4/day. Various firmnesses. Laterals are always trouble, but I’ve noticed since using the Munchies the aligners do seat better.
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  1. more than a month ago
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John C. Melucci, DDS Accepted Answer Pending Moderation
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The Munchies are really nice to use, they seat the aligners better and patients like chewing on the 3-4/day. Various firmnesses. Laterals are always trouble, but I’ve noticed since using the Munchies the aligners do seat better.
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  1. more than a month ago
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Anthony Vondra Accepted Answer Pending Moderation
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Dr Perry E. Jones Accepted Answer Pending Moderation
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Sorry to disagree, but I have found Chewies to be of no value to reduce movement lag. It's VERY hard to imagine that a Chewie is capable of "bending" the aligner plastic to reingage the attachment and somehow secure itself around that same attachment that failed in the first place!! If it's possible to "bend" the plastic with a "Chewie" like object, it would seem that it would have to engage to attachment and then hold that position to extrude the movement lagging tooth. I find that VERY hard to imagine to be a reasonable expectation! If the Chewie is successful to "bend" the plastic at the incisal edge which happens to be the MOST difficult area to "bend", the aligner must then conform to the attachment and stay there long enough ( 22 hrs per day 300 hrs or maybe 150 hrs between aligner change) to resume a proper directed force of sufficient magnitude to execute the desired movement. The attachment in place could not accomplish this movement. How is the Chewie possibly able to bend the plastic and make the previous failed movement successful?
I would welcome before, during and after treatment photos with ONLY Chewies as the force system to reduce movement lag especially with lateral incisors or round teeth such as canines. I'd love to see photo evidence of movement lag where the tooth has an extrusion attachment and let's say 2mm of measurable lag. Impressive, if a Chewie alone can get a lateral back on track with 2mm or so of movement lag.
I can see Munchies may help aligner seating for the entire arch. Expectation of reduction of specific movement lag of a specific tooth such as a maxillary lateral with Chewies is another story!! Love to have a photo series to demonstrate correction movement lag for a lateral incisor with only Chewies!!
YES Movement lag is not uncommon!
Maxillary lateral incisors are especially problematic.
1. They are "V" shaped and so is the aligner!
2. They have a unique concave lingual anatomy.
3. Plastic covers the lingual of the target tooth.
4. The occclusion of the lower opposing teeth are covered by plastic and that plastic fits into the lateral lingual concave surface.
5. Lateral have little proximal undercut and tend to be narrow giving little for the aligner plastic to "grip"
6. Once an attachment "jumps" the aligner reservoir an "intrusion" force is created that tends to further intrude the tooth as the aligner is worn. This effect is due to the aligner plastic material rebound or memory. Like a watermelon seed when squeezed it "squirts" out of your fingers, so does a tooth with a non-fitting attachment when squeezed tend to further intrude away from the aligner NOT extrude magically into the aligner!

It's hard to imagine how a Chewie can overcome the intrusion force created as the memory of the plastic continues to "squeeze" against the now protruding attachment and thus creates the intrusion force.

In my opinion, a much faster and predictable method of solving movement lag is to use a adjunct system with a labial bonded button and and one of the following lingual elastic retention systems:
1. Labial bonded button and full loop elastic/ bonded lingual button for elastic retention
2. Labial bonded button and full loop elastic/ target tooth, lingual cut or notched TAB retention
3. Labial bonded button and full loop elastic/ target tooth, lingual "extended" cut for better elastic hold
4. Labial bonded button and full loop elastic/ target tooth, lingual "KEY HOLE" with slot to hold elastic
5. Labial bonded button and chain elastic (short) target tooth, lingual heated plier custom cut hook
6. Labial bonded button and chain elastic (short) target tooth lingual "mushroom" hook
7. Labial bonded button and chain elastic (short) lingual "slot"

Best,

Perry
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  1. more than a month ago
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Larry Levin Accepted Answer Pending Moderation
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Perry

Would you describe in more detail or show photos of 4 and 5? (The keyhole with slot and the lingual heated plier custom cut hook)
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  1. more than a month ago
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