Non-compliant upper molar mesialization using palatal mini-implants and the Mesialslider appliance

Unilateral or bilateral missing upper teeth are diagnosed quite frequently: Congenitally missing lateral incisors / second bicuspids, extremely displaced canines or a severe trauma of a central incisor are potential findings that result in a reduced upper dentition. Especially the prevalence of missing maxillary lateral incisors is quite high (0.8 to 2%). The two major treatment approaches are space closure and space opening to allow prosthodontic replacements either with a fixed prosthesis or single-tooth implant. Both of these treatment approaches may potentially compromise aesthetics, periodontal health, and function. Single-tooth dental implants in the maxillary anterior region have the highest risk of esthetic complications from infra-positioning due to continuing growth and the continuing eruption of adjacent teeth. In many cases, space closure to the mesial seems to be the favourable treatment goal, since treatment already can be completed as soon as the dentition is complete. Thus, a second orthodontic treatment to upright tipped adjacent roots before insertion of a dental implant can be avoided. Canine substitutions can be accomplished with good aesthetic outcomes by tooth reshaping and positioning, bleaching and porcelain veneers. The more mesial the missing tooth is the higher will be the demands for anchorage, which can be realized by reverse headgear or class III elastics. However, both anchorage modalities require a high level of compliance and may cause some unwanted side effects such as TMJ problems or retrusion of lower teeth on case of class III elastics. With the goal to achieve a more reliable anchorage, the use of mini-implants has increased over the last couple of years. However, buccally inserted mini-implants are in the path of moving teeth. As a consequence, the palatal area seems advantageous, since all teeth can be moved without any interference with TADs. The Mesialslider enables clinicians to mesialize upper molars and thus close upper spaces unilaterally or bilaterally. In addition, even contralateral distalization is possible (Mesial-Distalslider).