However, when determining the arc of closure, a single intermaxillary contact was found (tooth #18 with tooth #48) and anterior and posterior open bite, a bilateral Class II occlusion and an anterior shift into intercuspal position (Figs. 5a–c).
Because the occlusal scheme would have not allowed for minimally invasive prosthetic restoration, the patient was referred for orthodontics first. As the patient was not bothered by the facial asymmetry, and her facial and skeletal balance were satisfactory, she declined orthognathic surgery and opted for an orthodontic and prosthodontic solution for her deteriorating dentition.
After orthodontic case analysis and interdisciplinary discussion with the prosthodontist, the following treatment objectives were established: levelling of the gingival margins of the maxillary incisors and canines, intrusion of the overerupted maxillary molars, reduction of the Class II occlusion and overjet, levelling of the mandibular occlusal plane and uprighting of the mandibular second molars, removing the premature contacts and allowing for multiple, stable intermaxillary contacts in the registered arc of closure.
Sometimes, after removing premature posterior contacts by extraction of third molars and/or intrusion of terminal molars, the mandible autorotates into a Class I occlusion, making the orthodontic strategy clear: vertical control. That is why, on the registered and mounted casts, we removed the mandibular second (which would have been intruded using the existing implant-supported crowns) and third molars in order to see whether we would obtain any change in the sagittal intermaxillary relationship (Figs. 6a–c). Unfortunately, this quick treatment simulation showed us that vertical control would not be enough and that sagittal correction biomechanics would also need to be considered.
The best anchorage in orthodontics is skeletal anchorage. In the mandible, the implants would be used for intrusion and uprighting of the second molars, and in the maxilla, we had planned to use orthodontic mini-implants to intrude the overerupted first molars 4,5 and for en masse distalisation of the maxillary arch into a Class I occlusion.
After the treatment strategy was decided on, an orthodontic digital set-up (Figs. 7a–c) was created and discussed with the prosthodontist and then with the patient so that she could better understand and visualise the need for treatment and the restoration requirements after orthodontics. This step was very important for the interdisciplinary treatment, as the patient needed to understand that, in order to reach the desired aesthetic and functional result, she needed to complete both orthodontic and prosthodontic treatment.
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