Within the framework of treatment planning for missing teeth, the fundamental question is how to offer long-term solutions. One option is to close the space with a prosthetic restoration such as a dental implant or fixed or removable partial denture. Another option is orthodontic space closure, which makes it possible to avoid further tooth preparation, thus reducing the tooth substance required, or even generate new bone through the tooth movement into the gap due to the interdental fibres. Compared to space opening, however, space closure has far greater requirements in terms of anchorage. Preservation of the sagittal vertical overlap and adjustment of the dental midlines often necessitates use of skeletal anchorage, especially in cases of dental asymmetry. The present case report demonstrates a complex treatment using aligner orthodontics in combination with the Mesialslider (TADMAN, Gunningen, Germany) after loss of a maxillary molar, including a mandibular incisor extraction approach, closure of anterior open bite and solving of unilateral reverse articulation. Keywords: aligner orthodontics, anterior open bite, incisor extraction, Invisalign, Mesialslider, mini-implants, molar extraction, reverse articulation, skeletal anchorage, space closure