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I 21 report _ inferior alveolar nerve I implants3_2010 Operativeprocedures After carrying out an insertion of the jaw ridge andthepreparationofthemucoperiostealflap,the mental foramen can be shown. This is important and enables orientation when positioning the lat- eral bone incision. The horizontal incision line starts approximately 3–5 mm distal of the fora- men. The incision depth depends on the route of theinferioralveolarnervedistalfromtheforamen. Piezo surgery is recommended for the preparation of the bone incision and the latter preparation of the inferior alveolar nerve because it guarantees maximum safety for the soft tissue, while at the sametimetheriskofnerveirritationcanalsobere- duced. After the removal of the buccal corticalis the nerve can be prepared in the cancellous bone. Usageofthediamond-coatedpartofthePiezode- vice is recommended for this procedure. After preparation, the nerve will be encircled with ethiloop silicone slinga . The preparation of the nerve is followed by the insertion of the implant. In order to obtain suffi- cient primary stability, there must still remain enough bone in the buccal area after the prepara- tion of the cavity. If there is not enough bone left, the buccal bone lamella may break during inser- tion,whichmightendangertheprimarystabilityof the implant. The preparation of the counter corti- calisisalsosuggested,providedthattheimplantis long enough. A previously manufactured—by meansof3-Ddiagnosis—orientationtemplate,can beusedforthebucco-lingualandmesio-distalpo- sitioning of the implant. The nerve can be repositioned directly on the implant (in this case a CAMLOG Srewline, 4,3 x 13 mm, was used, Fig. 10 and 11) without taking anyfurthermeasures.Someauthors(Rosenquist11 , Friberg4 ) state that the contact with sharp thread edges often causes chronic irritation. Use of im- plants with a low incisive thread is therefore rec- ommended in order to avoid nerve irritation. After repositioning the nerve the bone cavity will be filled with bone chips, which were obtained by grindingthebuccalcompactbone.Afterwards,the cavity will be covered with the collagen mem- braneb , which will be fixed with membrane nailsc . The wound is carefully closed with successive sin- gle interrupted suturesd .After a waiting period of three months, the fixed prosthetic restoration can be done. During this time the operative site should not be irritated. _Discussion The lateralization of the inferior alveolar nerve offers patients the possibility of obtaining a fixed prosthesisinthemandible,providedthattheyhave a conservable anterior residual dentition and a free-end situation. Thisissometimestheonlyfeasibleprocedureto helppatientsobtainafixedprosthesis,especiallyin those cases where there is only very little residual bone height depth left due to the route of the in- ferioralveolarnerveratherthanatrophy.Otherad- vantages are the fixation in the pre-existing bone, and the one site surgery, which make augmenta- tive procedures unnecessary. This also avoids the disadvantagesofotherproceduresforexamplethe risk of resorption. The evaluation values for im- plant survival rates are similar to those for stan- dard implantations. However, there are two rea- sons that might advise against a lateralization of the inferior alveolar nerve: (i) the complicated sur- gical technique requires a skilled surgeon and (ii) the risk of nerve irritation. Patients have to consider 6–8 weeks of lasting paresthesia of the mental nerve, and the possibil- ityofapermanentparesthesiacannotbeexcluded. It is therefore of utmost importance to inform the patient in detail beforehand. A rather rarely-oc- curring complication is a mandibular fracture in the area of the bony window. In 10 of the 11 later- alizationsurgeriescarriedoutintheauthorsclinic, the function of the mental nerve was completely recovered within 6–8 weeks. In one case, one pa- tient still suffers from permanent paresthesia, though it does not disturb much. However, even this patient would again decide upon this surgery insteadofchoosingaremovablemandibularpros- thesis as alternative solution. No case of implant losscanbereported.Inallcases,thefixedimplant- supported prosthesis could be manufactured ac- cording to the previous planning._ Editorial note: The literature list can be requested fromtheauthor. Dr Bernd Quantius MSc Giesenkirchener Str.40 41238 Mönchengladbach,Germany E-mail:B.Quantius@drquantius.de _contact implants a Ethiloop—Ethicon b Bio-Gide—Geistlich Biomaterials c Frios Membrannägel—DENTSPLY Friadent d Ethibond Excel 4-0—Ethicon