Читать книгу Bone and Soft Tissue Augmentation in Implantology - Группа авторов - Страница 65

Targeted implant therapy requires a precise survey of the treatment-relevant, individual patient findings, especially when severe bone loss is present. Due to the exact knowledge of the anamnesis and the anatomical structures, patients can be provided with a sufficient alveolar crest for the intended implant placement to achieve an appropriate prosthetic restoration. Different grafting procedures are available, their use depending on the soft tissue situation, the defect configuration, and the desires of the patient. In the atrophied edentulous maxilla, the surgical part of hard and soft tissue augmentation can be less invasive in case of a removable definitive restoration compared with a fixed restoration. In this situation, the goal of the bone grafting procedure is to provide enough bone volume for the insertion of implants. In case of a planned fixed restoration, there are additional goals apart from the aim of inserting the implant, which include having a significant volume of bone and soft tissue to guarantee an esthetic restoration with definitive crowns of a normal length and adequate soft tissue volume, margins, and papillae.

It is important to pay special attention in cases of reconstructions in the esthetic area. In some situations, there is a need for preoperative orthodontic treatment to create sufficient space for a symmetric restoration without injury to the neighboring teeth, something which is not always easy. In such a situation, where the orthodontic treatment was not able to fulfill the expected result, alternatives need to be discussed with the patient (Fig 2-28a to k).

Precise preoperative diagnostics allow for the exact positioning of implants even under difficult anatomical conditions. Especially in the situation with looseness of the vertical dimension, e.g. in the case of hypodontia, the planning as well as the surgical guide must be the result of teamwork between the surgeon, prosthodontist, and dental technician (Fig 2-29a to y). In routine cases, the use of tooth-borne orientation guides on the basis of a 2D radiologic diagnosis is sufficient.

Fig 2-27a Pronounced atrophy in the mandibular bilateral free-end situation after long-term restoration with removable dentures.

Fig 2-27b Three-dimensional illustration of the necessary autologous graft for implant insertion into the mandible. It was planned to harvest bone grafts from the iliac crest due to the poor bone volume of the mandibular external oblique line.

Fig 2-27c A surgical guide based on CBCT data for optimum utilization of the grafted bone 3 months after vertical augmentation using transplants from the iliac crest.

Fig 2-27d Insertion of three implants in the left mandible in a fully regenerated iliac crest graft. Another four implants were inserted in the grafted right mandible.

Fig 2-27e Definitive prosthetic restoration.

Fig 2-27f Control radiograph 2 years postoperatively.

Fig 2-28a Persistent primary teeth in the absence of the right and left mandibular central incisors. Despite many years of orthodontic treatment, it was not possible to obtain sufficient space for two implants.

Fig 2-28b Clinical situation 4 weeks after extraction of the primary teeth.

Fig 2-28c Severe atrophy of the alveolar ridge.

Fig 2-28d A bone block is harvested from the apical region of the chin with a micro saw.

Fig 2-28e Removal of the bone block with a thin chisel.

Fig 2-28f Longitudinal split of the bone block into two thin blocks.

Fig 2-28g Insertion of one implant after bone spreading and grafting of one of the blocks on the vestibular side to support the mobile and thin vestibular bone wall.

Fig 2-28h Replantation of the second bone block back in its original donor site.

Fig 2-28i Control radiograph 4 months postoperatively.

Fig 2-28j Clinical situation 6 months postoperatively after conditioning the soft tissue with the temporary restoration.

Fig 2-28k Clinical situation after definitive prosthetic restoration with a pontic for the left central incisor supported by the implant of the right central incisor.

The use of 3D imaging, especially with prepared radiopaque, prosthetically oriented structures or the superimposition of digitally generated prosthetic proposals, allows for the detailed planning from the anatomical and prosthetic points of view.⁶⁶

Finally, a greater planning effort is rewarded by fewer prosthetic and laboratory/technical complications or problems for a precise implant placement in order to achieve an optimal prosthetic restoration after an extensive grafting procedure. Despite the intensive preoperative diagnostics, it is necessary to pay close attention to the recommended protocols in order to avoid complications and failures.⁹⁶

Fig 2-29a Multiple hypodontia in the maxilla and mandible of a 19-year-old female patient.

Fig 2-29b Clinical situation with a relatively high smile line and a slightly reduced vertical dimension.

Fig 2-29c Intraoral situation documenting a looseness of the vertical dimension.

Fig 2-29d Severe alveolar ridge atrophy in the anterior mandible.

Fig 2-29e Clinical situation 3 weeks after extraction of the primary teeth in the maxilla.

Fig 2-29f Diagnostic wax-up for the maxilla.

Fig 2-29g Following the wax-up, a vertical bone augmentation is not necessary in the right maxilla.

Fig 2-29h Wax-up of the left maxilla shows the extent of the required vertical bone augmentation.

Fig 2-29i Slight increase of the vertical bite dimension with temporary restorations and composite reconstructions on the remaining teeth.

Fig 2-29j Panoramic radiograph with surgical templates: the vertical bone atrophy is clearly visible in the premolar area of the left maxilla.

Fig 2-29k Vertical bone deficit in the left maxilla.

Fig 2-29l Vertical bone augmentation with simultaneous insertion of two XiVE implants.

Fig 2-29m Insertion of a 3-mm XiVE implant at the area of the right lateral incisor.

Fig 2-29n Extremely thin alveolar ridge in the anterior mandible.

Fig 2-29o Bone harvesting apical of the atrophied alveolar ridge.

Fig 2-29p Bone block grafting in the anterior mandible.

Fig 2-29q Insertion of four XiVE implants with a 3-mm diameter in the grafted area 3 months postoperatively.

Fig 2-29r Panoramic radiograph 4 years postoperatively.

Fig 2-29s Clinical situation 4 years postoperatively. Thin mucosa region (41 and 42) was later augmented using a connective tissue graft.

Fig 2-29t Clinical situation of the restored implants in the left maxilla.

Fig 2-29u Control radiograph 4 years postoperatively of the restored implants in the vertically grafted left maxilla.

Fig 2-29v Clinical situation in the right maxilla 4 years postoperatively.

Fig 2-29w Control radiograph 16 years postoperatively demonstrating a stable peri-implant bone level.

Fig 2-29x Clinical appearance of the restored implants in the right maxilla 16 years postoperatively.

Fig 2-29y Similar stability in the left maxilla.