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ePaper created 2015-11-17, 15:11:47 | version 1.38.0
Volume 1 | Issue 1/2015 27Journal of Oral Science & Rehabilitation C om pli cati o ns af te r si nu s f lo o r au gme ntati o n from Li, the effective dose from 3D Accuitomo was 54 μSv, while that of CB MercuRay (Hitachi Medical Systems America, Twinsburg, Ohio, U.S.) using a panoramic field of view was 560 μSv.2 Lofthag-Hansen et al. reported that the calculated effective dose of 3D Accuitomo was 52–63 μSv with a volume size of 60 mm in diameter × 60 mm in length, tube voltage of 75 kV and tube current of 4.5–5.5 mA.3 There- fore, postoperative examination of sinus floor augmentation using CBCT appears to be safe when the appropriate CBCT device and parame- tersareselected. Wefoundthatthemaxillarysinusmembrane swelled one week after sinus floor augmenta- tion.Thispreviouslyunknownbiologicalreaction could not be identified on the 2-D radiographs and has not been reported before. The aims of this clinical study were to investigate this post- operative swelling of the maxillary sinus mem- brane using CBCT and to evaluate its complica- tions. Furthermore, methods to prevent these complicationswereconsidered. Materials&methods Selec tion a n d regulatio n of C BC T d ev ic e Inordertolimittheradiationdose,3DAccuitomo was selected and an imaging volume size of 60 mmindiameter×60 mminlengthfortheex- amination ofmaxillaewas chosen. Furthermore, the tube voltage was set at 80 kV and the tube currentat2 mAfor17.5 sofexposuretime.Inthis situation, the calculated effective dose was ap- proximately40 μSv. Informed co n s en t for C BC T s c a n s It was explained to all of the patients that the total radiation dose of five CBCT examinations was approximately 200 μSv and less than half of that of old-type CBCT scans. All of the pa- tients understood the importance of CT evalu- ationsofthesinusflooraugmentationandcon- sented to five CBCT scans over the first year after surgery. Patien ts a n d s urgery The patient population was 112 and consisted of 35malesand77femaleswhorangedinagefrom 25 to 77 years (mean age of 53.5 years). All pa- tients were in good health, and 24 patients (21.4%) were smokers. The standard examina- tionfoundnolocalorsystemiccontraindications to the maxillary sinus floor augmentation. In 20 patients (15.2%), the maxillary sinus floor aug- mentation was performed bilaterally, and the surgerywascarriedoutin132sitesintotal. All of the patients had been referred to our clinicbytheiroriginaldentistsforsinusflooraug- mentation owing to insufficient bone volume of the posteriormaxillae. Maxillarysinusflooraug- mentations were performed by the lateral win- dowtechnique using only beta-tricalcium phos- phate (β-TCP) granules (OSferion, Olympus Terumo Biomaterials, Tokyo, Japan) overthe pe- riod of March 2006 to June 2012. The surgeries were performed bythe same oral surgeon under localanesthesiawithintravenoussedation.After the creation of the lateral window, the maxillary sinus membranewas detachedfromthe surface of the maxillary sinus and elevated. The empty compartment created by elevating the sinus membranewasfilledwithβ-TCPgranulesasthe bonesubstitutematerial. Thesitesweredividedintotwogroupsbased on the extent of lateral window coverage. The lateral window was not completely covered in Group 1 and was completely covered with a tita- nium mesh plate and microscrews or only a re- sorbablebarriermembraneinGroup 2. CB CT e valu ati o n The proportion of the area of the postoperative swelling of the maxillary sinus membrane that occurredoneweekaftersurgeryinrelationtothe remainingsinuscavitywasdeterminedandclas- sifiedintothreetypes(Fig. 1): Type1:Swelling of less than one-third of the re- mainingsinuscavity Type2:Swellingofone-thirdtotwo-thirdsofthe remainingsinuscavity Type3:Swelling of more than two-thirds of the remainingsinuscavity. The degree of buccal migration of the β-TCP granules through the lateral windowwas classi- fiedintothreetypes(Fig. 2): TypeA:Limitedtothelateralwindow TypeB:Limitedtotheadjacenttooth TypeC:Extendingbeyondtheadjacenttooth.