Transposed and Impacted lower canine

Note: by convention, when we view patients' images, right and left are reversed so that it appears that you are standing in front of the person looking at them. Any mention of "right" or "left" on this site refers to the patient's right or left. All post-treatment records are taken on the day the braces are removed, unless otherwise noted.

This patient was just under 11 years old when I initially saw him and took his diagnostic records. His pre-treatment panoramic radiograph showed the following remarkable items: both lower wisdom teeth were developing with a forward tip; the lower right canine was erupting between the central and lateral incisors and was impacted (no space available for it to come in); the lower second premolar teeth were erupting tipped towards the back of his mouth and may not be able to dissolve enough of the baby tooth roots to make the baby teeth fall out (the lower primary second molars may need to be extracted).

Pre-Treatment Panoramic xray

He also had an upper right front tooth in crossbite (the upper tooth was inside his lower teeth when he bites down) and his upper canines were erupting outside his arch form. The midlines of both his upper and lower teeth (where the two middle teeth meet relative to the middle of the face) were both off to his right.

Slide of his bite on his right side. You can see the crossbite of the tooth second from the middle on his right.
Slide of his teeth from the front.
Slide of his bite on his left side (at least it's supposed to be).

Treatment options for the lower canine included trying to bring it into proper position, leaving it transposed and trying to create enough space for its eruption and bringing it in, and extracting it. In order to correct the transposition with the lateral incisor, I would have to either move the root of the lateral way to the inside so I could move the canine around it from the outside, or move the root of the lateral way to the outside so I could move the canine around it from the inside. After consulting with an oral surgeon, we determined that the bone was not thick enough in this area to try to correct the transposition without damaging the lateral. The crowding was severe enough that a tooth would need to be removed anyway to gain enough space, so we decided to extract the canine. In order for his bite to fit together on right ride side, I needed to account for the difference in number of size and shape of the remaining teeth that would occur with the extraction of the canine. Since the lower right first premolar was to replace the canine on the lower right, I would need to reshape the first premolar's width to be the same as the canine. A tooth on his upper right would also need to be extracted to allow his molars to fit together properly on that side. An analysis of his tooth sizes showed that the upper right second premolar would be the best tooth to extract here. Although the his upper and lower midlines were off to his right, they were not off enough that his parents and I thought extractions on his left were warranted. His parents were also not concerned enough about his midlines that they wanted me to reduce the widths of some of his teeth on his left to gain space to correct his midlines. Since there would be no space to correct his midlines, we decided to attempt to hold his midlines in their current positions.

We also had to determine when the right time was to start his treatment. He still had some primary teeth left in his upper arch, and I wanted to give the lower primary second molars the chance to fall out by themselves before deciding on the need to extract them. If I put braces on now and had the upper right second premolar removed, the oral surgeon would need to remove a significant amount of bone to get to this tooth since it was still unerupted. This bone loss would compromise the health fo the first molar when I brought it forward to close the space. If I put braces on now and waited for the upper second premolars to erupt, he would have to wear the braces for a much longer period of time than if I wait for them to erupt. We therefore decided to wait until his upper second premolars had erupted before getting started.

When I saw him a year later, both upper second premolars had fully erupted, but the lower primary second molars were not even loose. We now knew that the lower primary second molars were not going to be able to fall out on their own, and these teeth needed to be extracted.

To summarize his treatment plan, he was to have 2 permanent teeth extracted (the upper right second premolar to be able to shift his first molar forward and provide a proper bite relationship on the right side, and the impacted lower canine) and 2 baby teeth extracted. I would reshape the lower right first premolar to a width matching his lower left canine, and attempt to hold his midlines in their current positions.

He wore braces for 22 months. A quarter of a millimeter was removed from the front and back contacts of the lower right first premolar to make it the same width as the lower left canine. As you can see from his smile photo, his midlines were reasonably maintained (his upper and lower midlines are still off to his right, but as you can see from the photo below, in his case it is really not noticeable). His lower wisdom teeth will likely need to be removed in the future.

Post-Treatment Panoramic xray

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