Question:

I have a strange case where the pt claims he developed an open bite because 12 moved lingually. I haven't seen him in 10 years, and back then he had a slight class III tendency. He is 31 now. https://shub.invisalign.com/cc-cloud/latest/index.html?locale=en_US&user=user&ccModIntegrity=false&configUrl=%2Fconfig%2Fscsl_cc_cloud&ccId=451030

Answer:

This is a case involving an adult patient, 31 years old, presenting with significant crowding, a class III tendency, and a concern that tooth 1-2 has moved lingually. The primary issue is whether to focus on cross-bite correction and see how the bite adjusts before moving forward with other treatment.

One key concern is that the patient has retained wisdom teeth and a narrow arch, causing the wisdom teeth to bite heavily on their palatal cusps. This occurs because the teeth have reached the limit of possible expansion. The 6th teeth (first molars) still have room for further expansion, as do the 4th and 5th teeth (premolars). However, the 8th teeth (third molars) are positioned as far buccally as possible, hitting biological constraints that limit any additional expansion.

The first challenge is the limited likelihood of expanding the wisdom teeth. The second challenge is that the wisdom teeth lack attachments, making it difficult to achieve successful expansion even if attempted. To resolve this, attachments would need to be placed at their maximum thickness, but their current orientation is not ideal, as they are beveled towards the gingiva. Both upper and lower attachments should be modified to ensure no bevel towards the gingiva, allowing for optimal thickness.

Because of these limitations, the recommendation is not to expand the second or third molars (wisdom teeth) further. Instead, it is advised to leave the wisdom teeth in place and mark them as "unmovable" in the treatment plan. While this may leave the patient with less-than-ideal occlusion on the third molars, adjustments could be made using a burr to fine-tune the occlusion slightly if necessary. However, extraction of the wisdom teeth is not recommended.

For the first and second molars, it is suggested to focus on bite settling. The attachments on the molars should be reoriented to achieve better buccal root torque. The current number of aligner trays is 17, but this should be increased, with a recommendation for around 40 aligners and weekly changes.

The extraction of a lower incisor is acceptable and can be addressed later to ensure the roots are positioned correctly. On the upper arch, it is recommended to aim for complete correction rather than stopping mid-treatment. Spacing should be added around the lateral incisor (tooth 1-2), with a request to the technicians to maintain 0.3 mm of space before the lateral incisor starts moving buccally. This space should be maintained throughout the process to ensure proper alignment. The lower arch can also be set to an ideal position.

Currently, the roots of teeth 32 and 41 (lower incisors) are converging, but the lower incisor extraction is consistent with the treatment plan. The space between the roots could be closed entirely, but the roots should remain slightly more mesial. The CVCT integration would show the roots almost touching, so it is important to get them straightened and in the correct position. The goal is to use around 40 aligners to achieve proper positioning for all the teeth.

Given the wear on tooth 1-2, aligning the gingival margins with tooth 2-2 and considering a restorative solution would provide a nice aesthetic outcome. However, the 0.3 mm of space should be maintained for future treatment adjustments. During the next clincheck, this space could be closed easily and consistently.

If occlusion issues arise in the posterior after expansion, vertical elastics can be used to help settle the teeth into position. However, it is expected that the wisdom teeth will have poor overall occlusion due to the biological constraints, and some equilibration may be necessary.