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industry | 27 3 2016 implants Fig. 3: Pre-operative clinical aspect of the anterior alveolar ridge. Fig. 4: After elevation of the mucoperiostal flap, the sharp-edged alveolar ridge becomes visible. Fig. 5: Preparation of the osseous graft with the microsaw. Fig. 6: Detachment of the graft with a chisel. Diagnostic procedures In cases of long-term edentulism, the dental sur- geon is almost always confronted with a reduced bone volume, representing both a major challenge and a significant demand for the use of diagnostic imaging methods prior to augmentation and im- planttreatment.ConventionalX-rayimagescontain onlyatwo-dimensionalinformationconcerningthe vertical height of the alveolar bone. Therefore, they represent an insufficient method for the apprecia- tion of the horizontal bony dimensions.4 In compar- ison, three-dimensional (3-D) diagnostic tools like cone beam computed tomography (CBCT) offer the advantage of the visualisation of the so called ‘z-axis’, representing the bone volume in the hori- zontal, i.e. bucco-lingual dimension of the alveolar crest respectively. A proper treatment planning and theuseof3-Ddiagnosisarethereforecrucialparam- eters for a predictable and sustainable final treat- ment outcome in implant therapy, especially in pa- tient cases with severe resorption of the jawbone, like in our presented patient case. The oral examination and the CBCT-Scan (SCANORA, SOREDEX, Schutterwald, Germany) re- vealed a distinct bone resorption in the lower jaw, showing a more pronounced horizontal atrophy in theanteriorpartofthemandible(Figs.2&3).Accord- ingtotheclinicalmeasurementsandthevaluesofthe 3-D CBCT scan, the interforaminal vertical bone height was between 22.0–25.0 mm. The horizontal bone volume amounted to between 1.0–3.0 mm in the implantation zone. The CBCT–Scan revealed a horizontal crestal bone thickness of 1.09 mm in re- gion 32, and 1.74 mm in region 44. Treatment planning and augmentation procedure After patient-consultation, we opted for a two- stage surgery with an intraorally harvested autoge- nousbone-graftandadelayedimplanttreatmentaf- ter a healing period of at least four months. As the vertical dimension of the implant region appeared to be sufficient enough for placement of implants with astandardlength,wedecidedtocutoff5.0 mmofthe thin and sharp-edged alveolar ridge by osteotomy, in order to create an autogenous lateral onlay bone- graft for horizontal augmentation in the anterior al- veolar ridge. This protocol comprised in our view the advantage of the avoidance of donor morbidity, be- cause the donor site was the receptor site as well. Af- ter creation and mobilisation of the mucoperiostal flap,theverythinandsharpedgeoftheatrophiedal- veolar crest became visible (Fig. 4). The osteotomy of the bone was performed with a saw (Bone splitting system, Helmut Zepf Medizintechnik GmbH, Seitin- gen-Oberflacht, Germany; Fig. 5). Subsequently, the graft was detached from the anterior mandible with chisel (Bone splitting system, Helmut Zepf, Medizin- technik GmbH, Seitingen-Oberflacht, Germany; Fig. 6) and a cortico-cancellous bone block was ob- tained (Fig. 7). The bone graft was fixed at the buccal sideoftheanteriormandible(region34–44)withfour 8.0 mm long titanium microscrews (Storz am Mark GmbH, Emmingen-Liptingen, Germany; Fig. 8). A combination of autogenous bone chips and particu- lated xenograft (BEGO OSS, BEGO Implant Systems, Bremen,Germany)wasplacedinthesmallremaining space between the bone block and the alveolar pro- cessus, as well as around and on the bone graft. The augmented site was covered with a platelet rich in Fig. 4 Fig. 6 Fig. 3 Fig. 5 32016