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January-February 2017 | No. 1, Vol. 7 PUBLISHED IN DUBAI www.dental-tribune.me ÿPageD2 Augmentation and implant treatment Two-stage surgery in the severely resorbed edentulous mandible ByDrMarkoNikolic,Croatia Introduction An adequate bone volume at the future implant site is a prerequisite for ideal implant placement and im- plant success. A residual bone with a vertical dimension less than 5.0mm indicates a cut-off point and implies the need of additional augmenta- tion procedures in connection with implant insertion, whereas higher valuesofthealveolarcrest≥5.0mm are considered to be sufficient for treatment with standard-diameter implants without the urgent need of any horizontal bone augmentation.1 Distant donor sites like the anterior andposterioriliaccrestandintraoral areas like the retromandibular and theinterforaminalregionofthechin are common sources for harvesting autogenous bone-grafts. Depend- ing from the donor site, patient and surgeon should be aware of the pos- sible confrontation with various advantages but also disadvantages when harvesting the bone. Harvest- ing bone from the iliac crest requires patient hospitalisation, and surgery under general anaesthesia, whereas intraoralboneharvestingcanbeper- formed ambulatory and under local anaesthesia.2,3 The main problem with autogenous bone grafting is represented by the high risk of patient morbidity, caus- ing pain, swelling, and healing prob- lemsatthedonorsite.3 The aim of this case presentation is to demonstrate a predictable, two- stageoperatingprotocolforthehori- zontal augmentation of the severely resorbed, edentulous anterior man- dible with an autogenous bone graft, harvested from the crestal alveolar ridge at implant site, in order to cre- ate a sufficient bone volume for the later implant therapy, without do- normorbidityforthepatient. Patientdata The 47-year-old male patient visited our dental office in order to renew his old and poor fitting prostheses in the lower and in the upper jaw. The remaining five teeth 32–43 in the front of the lower jaw had been removed three months previously due to a chronic periodontitis in our dental practice. Nearly all remaining teeth in the upper and the lower jaw showedsignificantsignsofprogredi- ent chronical periodontitis, insuffi- cient root treatments and prosthetic suprastructures as well (Fig. 1). The medical history of the patient was without any significant pathological findings. Diagnosticprocedures Incasesoflong-termedentulism,the dental surgeon is almost always con- frontedwithareducedbonevolume, representing both a major challenge and a significant demand for the use of diagnostic imaging methods prior to augmentation and implant treatment. Conventional X-ray im- agescontainonlyatwo-dimensional information concerning the vertical height of the alveolar bone. There- fore, they represent an insufficient method for the appreciation of the horizontalbonydimensions.4 In comparison, 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 horizontal, i.e. bucco-lingual dimension of the alveolar crest respectively. A proper treatment planning and the use of 3-D diagnosis are therefore crucial parameters for a predictable and sustainablefinaltreatmentoutcome in implant therapy, especially in pa- tient cases with severe resorption of the jawbone, like in our presented patientcase. The oral examination and the CBCT- Scan(SCANORA,SOREDEX,Schutter- wald, Germany) revealed a distinct bone resorption in the lower jaw, showing a more pronounced hori- zontalatrophyintheanteriorpartof themandible(Figs.2&3). According to the clinical measure- ments and the values of the 3-D CBCT scan, the interforaminal verti- cal bone height was between 22.0– 25.0mm. The horizontal bone volume amounted to between 1.0–3.0mm in the implantation zone. The CBCT– Scan revealed a horizontal crestal bone thickness of 1.09mm in region 32,and1.74mminregion44. Treatment planning and aug- mentationprocedure After patient-consultation, we opt- ed for a twostage surgery with an intraorally harvested autogenous bone-graft and a delayed implant treatment after a healing period of at least four months. As the vertical dimension of the implant region ap- peared to be sufficient enough for placement of implants with a stand- ard length, we decided to cut off 5.0mm of the thin and sharp-edged alveolarridgebyosteotomy,inorder tocreateanautogenouslateralonlay bone-graft for horizontal augmen- tation in the anterior alveolar ridge. This protocol comprised in our view the advantage of the avoidance of donor morbidity, because the donor site was the receptor site as well. Af- ter creation and mobilisation of the mucoperiostalflap,theverythinand sharp edge of the atrophied alveolar crestbecamevisible(Fig.4). The osteotomy of the bone was per- formed with a saw (Bone splitting system, Helmut Zepf Medizintech- nik GmbH, Seitingen-Oberflacht, Germany;Fig.5). Subsequently, the graft was de- tached from the anterior mandi- ble with chisel (Bone splitting sys- tem, Helmut Zepf, Medizintechnik GmbH, SeitingenOberflacht, Germa- ny; Fig. 6) and a cortico-cancellous bone block was obtained (Fig. 7). The bone graft was fixed at the buccal side of the anterior mandible (re- Fig.1:Pre-operativepanoramicX-ray:poorperiodontalandprostheticconditions. Figs. 2a & b: Pre-operative CBCT: aspect of the extremely horizontally resorbed alveolar ridgesof theanteriorpart of themandible. rotary Instruments SWITZERLAND JOTA JOTA AG Rotary Instruments Hirschensprungstrasse 2, 9464 Rüthi, Switzerland Phone +41 (0)71 767 79 99, Fax +41 (0)71 767 79 97 info@jota.ch, www.jota.ch SWITZERLAND jota instruments YOUR RELIABLE PARTNER FROM SWITZERLAND Proximity to customers, global presence and innovations have been components of Jota AG’s success for more than 100 years. Jota is a trusted manufacturer of rotary instruments and the first- choice partner for severel hundred wholesalers and hundreds of thousands of users around the world. Jota presents its new PERI-IMPLANTITIS Kit No. 1912 according to PD Dr. Philipp Sahrmann, University of Zurich. On our website www. jota.ch you will find further information and discover the range of products and services we offer. NEW JOTA KIT 1912 products and services we offer. 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