Mesial sliders & aligners in the posterior region

Introduction: Gap closure as an orthodontic challenge

When teeth are missing in the upper jaw, the question arises as to the best possible treatment: prosthetic replacement using implants or bridges or orthodontic gap closure. The advantage of gap closure lies in the possibility of generating bone in the area of the gap through tooth movement and thus compensating for atrophy in the jawbone. However, gap closure requires a high level of anchorage, especially in asymmetrical tooth situations. Classic intermaxillary elastics are highly dependent on patient compliance and can cause undesirable side effects.

Aligners as an alternative to the multi-bracket technique?

Aligners offer esthetic and hygienic advantages over fixed braces. However, they are not yet able to achieve complete mesialization of molars without additional support. Scientific studies on these biomechanical limitations are still pending.

Skelettale Verankerung durch Mini-Implantate

Mini-implants have established themselves as reliable anchoring systems in orthodontics. While earlier methods used interradicular insertions, mini-implants have proven to be more stable in the anterior palate. This is where the mesial slider is used, which ensures controlled and physical tooth movement. The combination of aligner therapy and skeletally anchored mesial sliders enables targeted tooth movement with minimal side effects.

The CAD/CAM mesial slider: Digital workflow for precise planning

Traditionally, the mesial slider was fabricated in the laboratory. Today, advances in digital manufacturing (CAD/CAM) allow for more precise fabrication using intraoral scans and additive manufacturing techniques such as selective laser sintering (SLS). Virtual planning allows mini-implants and the mesial slider to be inserted in a single session.

The Benefit Direct System: Appliance First approach

One innovative approach is the appliance first-principle, in which the mesial slider is inserted first and the mini-implants are then added for anchoring. This is made possible by a special double-barreled internal thread that allows a stable-angle connection between the implant and the appliance. Stability is maintained even with an insertion misalignment of up to 15°.

Clinical example: Gap closure in a 48-year-old female patient

A patient with a tooth 26 that was not worth preserving and bimaxillary anterior protrusions was treated with aligners and mesial sliders. After digital planning via the portal TADMAN.de portal, the mini-implants were inserted and the appliance fitted in a single session. Despite initial inflammation due to suboptimal oral hygiene, the gaps were successfully closed after two years and the treatment was completed after 2.5 years.

Discussion and conclusion

Gap closure offers long-term benefits such as bone preservation and better distribution of dental forces in the jaw. However, it is more demanding than gap opening and requires stable anchorage. Skeletally anchored appliances such as the mesial slider are an effective solution, especially in combination with aligners. The digital workflow significantly improves planning and patient acceptance.

Source:

Wilmes, B., Funke, J., Schupp, W., Haubrich, J., & Drescher, D. (2021). Mesial sliders & aligners for gap closure in the posterior region. J. Compr. Dentof. Orthod. + Orthop. (COO) Umf. Dentof. Orthod. and Orthodontics (UOO), 3-4, 2021.