Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2015-11-12, 17:51:05 | version 1.38.0
I literature review _ current publications cortical thickness, facial and palatal tissue thickness and alveolar crest width. The bone and tissue thick- nessweremeasuredatthreelocations:cervical,mid- dle and apical. In the cervical areas, strong correla- tions were found between the labial bone thickness andcorrespondingsofttissue,palatalbonethickness and corresponding soft thickness as well as a corre- lation between bone thickness and bucco-palatal socketdimensions(widersocketsmayassociatewith thicker labial cortices). The authors found no correla- tion between the position of the maxillary central in- cisor (forwardly inclined, normal or backwardly in- clined) in the socket to the thickness of cortical bone in the cervical area. The majority of teeth (64%) had proclined roots compared to 30% having normally positioned roots, with the proclined teeth having a lower thickness of bone on the palatal in the apical area. As for the facial bone, this study demonstrated that36.7%hadlabialbonethicknessgreaterorequal than 1mm, whereas 63% had < 1mm of bone. Whilenocorrelationwasfoundbetweentheposi- tionofthetoothinthealveolusandthelabialcortical bone thickness, the tooth position does have signifi- cant implications for implant placement and under- scorestheimportanceCBCTanalysispriortotoothex- traction. The position of the tooth in the socket can dictatetheimplanttrajectoryandthiswill,inturn,be affectedifgraftingisneeded,aswellasiftheimplant will be cement vs screw retained. _“Angulations of anterior teeth with reference to the alveolar bone measured by CBCT in a Chinese population” by S. Zhang, X. Shi, H. Liu. (Implant Dent. 2015 Aug;24(4):397–401) Whenplacingimmediateimplantsinthemaxillary anterior region the position of the tooth within the alveolus must be evaluated prior to implant place- ment. Sagittal slices from CBCT are a cost effective way to do this with low dose radiation. This study evaluatedtheangulationsofupperandlowerante- rior teeth with respect to alveolar bone in a Chinese population. Sectionalslicescontainingmaxillaryandmandibu- lar central incisors, maxillary and mandibular lateral incisors and maxillary and mandibular canines were analysed to compare the angulation of the root rela- tivetothebonyhousingitself(Fig.3).Thestudyfound that maxillary anterior teeth were closer to the labial alveolar surface and therefore more divergent to the alveolus itself (17.65 degrees for the central incisor, 18.79 degrees for the lateral and 23.82 degrees for the canine). The mandibular incisors, however, were usually less than 8 degrees difference from the alve- olus itself. Measurements of the maxillary alveolar bone were measured in three places: crestal, midroot and apical. What was noteworthy was that at the midrootlevel,thelabialthicknesswaslessthan1mm in 77–90%; 42.4% of maxillary canine teeth were lessthan5mmandalmostallmaxillaryanteriorteeth had labial thicknesses less than 2mm. The authors suggest these numbers as a plausible explanation to thehigherfrequencyofperforationatthemidrootlevel. Given the greater incidence of the maxillary roots being closer to the labial plate the implant would be placed with a more labial inclination to access the available palatal bone necessitating the need of an- gled abutment. Conversely, because the mandibular incisors are closer in angulation to the alveolar bone itismorelikelyastraightabutmentcanbeused.CBCT is, therefore, instrumental in treatment planning im- mediateimplantsintheanteriorregionpriortotooth extraction._ Fig. 3_ Sagittal section of maxillary and mandibular incisors. The thin white line is the long axis of the tooth and the thick white line in the long axis of the alveolus. “Angulations of anterior teeth with reference to the alveolar bone measured by CBCT in a Chinese population” by S. Zhang, X. Shi, H. Liu. (Implant Dent. 2015 Aug;24(4):397–401) 08 I cone beam4_2015 Dr Barry Kaplan,Prosthodontist,Bloomfield, NJ,USA.Past President of the NJ Section of the American College of Prosthodontists,Fellow of the International Congress of Oral Implantologists (ICOI). www.kaplandentistrynj.com cone beam_about the author Fig. 2_Sagittal slice of maxillary anterior tooth demonstrating sufficient palatal bone for fixation. “Three-dimensional evaluation of alveolar bone and soft tissue dimensions of maxillary central incisors for immediate implant placement: A CBCT assisted analysis” by M.G. Kheur, N.R. Kantharia, S.M Kheur, A. Acharya, B. Le, T. Sethi (Implant Dent. 2015 Aug;24(4):407–15) Fig. 2 Fig. 3