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PURPOSE: The purpose of this study was to evaluate the validity of reference points for edentulous patient by examining the correlation of teeth and face, and intraoral anatomic landmarks. MATERIALS AND METHODS: We examined a facial outline, length, bizygomatic width, nasion - gnathion length, glabella - nasion distance in 270 men and 280 women satisfied with inclusion criteria from Seoul National School of Dentistry. The shape of maxillary central incisor, mesiodistal crown width and length of maxillary 6 incisors, distance from incisive papilla to labial surface of maxillary central incisor, and perpendicular distance from incisive papilla to intercanine line were measured in the stone model. We analyzed the ratio and relevant relation statistically. RESULTS: The probability on having the same shape of face and the relative same shape maxillary incisor was 55.56% and 46.43% for men and women. The facial length proved to be a more valuable measurement in women in the tooth selection. The ratio of bizygomatic width to mesiodistal width of maxillary central incisor, and the ratio of bizygomatic width to width of maxillary 6 incisors were 16.8 : 1 and 3.0 : 1 and were positively correlated with each other. The distance of the canines from the maxillary incisal papilla was 1.33+/-1.28 mm. The distance between the center of the incisal papilla and the labial surface of their maxillary central incisor was 9.23+/-1.20 mm. CONCLUSION: It was showed that anatomical reference points in tooth selection and arrangement for edentulous patient are useful and have validity in our limited study.
Subject(s)
Female , Humans , Male , Anatomic Landmarks , Crowns , Dentistry , Incisor , Palate , Seoul , ToothABSTRACT
Objective To construct the digital pituitary adenoma image and explore the value of simulation of single nostril-transsphenoidal surgery.Methods Thirty patients with pituitary adenoma,admitted to our hospital from October 2009 to March 2011,were performed single nostril-transsphenoidal surgery; thin slice images of preoperative examinations included computed tomography and magnetic resonance imaging were imported into Dextroscope workstation to construct digital pituitary adenoma image; the related anatomic structures of surgical approach were observed and the procedures were formulated and performed.Results Models based on three-dimensional shapes could show the related anatomical structures dynamically and stereoscopically and simulate the operation processrepeatedly.The preoperative planning indicators in the anatomic segment of nasal,anterior sphenoidal wall,basilar pituitary fossa and structures around the tumor were completed.The anatomic characteristics of simulated surgery were consistent with the real operation.Conclusions The digital models can provide some individual anatomic information to develop the preoperative planning programs for single nostril-transsphenoidal surgery,which can facilitate the work of operation and avoid injuring the important anatomical structures.
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Objective To study the anatomic characteristics of Zuckerkandl's tubercle (ZT) and its clinical relevance as an anatomic landmark of the recurrent laryngeal nerve (RLN) in thyroid surgery.Methods This study involved 147 (106 with benign thyroid diseases and 41 with malignancies) patients who underwent thyroidectomy.ZT was measured and classified based on the Pelizzo classification.The relationship between ZT and the RLN and the relationship between the RLN and the inferior thyroid artery were recognized and classified.Results 233 (107 left and 126 right) thyroid gland lobes were dissected and ZT was identified in most patients (left in 93.5％ and right in 96.0％).The distribution of ZT according to grade was as follows:Grade 0,left 16.0％ and right 13.2％ ; Grade Ⅰ,left 32.0％ and right 27.3％ ; Grade Ⅱ,left 46.0％ and right 44.6％ ; Grade Ⅲ,left 6.0％ and right 14.9％.There was no significant difference on classification between the left-sided and right-sided ZTs.In terms of the relationship between the ZT and the RLN,it was classified as follows:Type A,left 92.9％ and right 93.3％ ; Type B:left 0 and right 0; Type C:left 7.1％ and right 6.7％.Similarly,there was no significant difference between the left sided and the right sided.The ZT grade was correlated with the course of the RLN:the higher the ZT grade was (that is,the greater the size of the ZT),the more often was the course of RLN behind the back of the ZT; the lower the ZT grade (that is,the smaller the size of the ZT),the more often was the course of RLN running by the lateral of the ZT.Considering the incidence of being dangerous type of RLN,the right sided (19.0％) was higher than the left sided (8.3％).The relationship between the ZT and the RLN does not relate to RLN course across the inferior thyroid artery.Conclusions As an important anatomic landmark,the ZT is essential for locating and dissecting the RLN during thyroid surgery,and its classification is a guide to RLN dissection and preservation.
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INTRODUCTION: Accurate diagnosis and treatment planning are very important for orthognathic surgery. A small error in diagnosis can cause postoperative functional and esthetic problems. Pre-existing 2-dimensional (D) chephalogram analysis has a high likelihood of error due to its intrinsic and extrinsic problems. A cephalogram can also be inaccurate due to the limited anatomic points, superimposition of the image, and the considerable time and effort required. Recently, an improvement in technology and popularization of computed tomography (CT) provides patients with 3-D computer based cephalometric analysis, which complements traditional analysis in many ways. However, the results are affected by the experience and the subject of the investigator. MATERIALS AND METHODS: The effects of the sources human error in 2-D cephalogram analysis and 3-D computerized tomography cephalometric analysis were compared using Simplant CMF program. From 2008 Jan to 2009 June, patients who had undergone CT, cephalo AP, lat were investigated. RESULTS: 1. In the 3 D and 2 D images, 10 out of 93 variables (10.4%) and 11 out 44 variables (25%), respectively, showed a significant difference. 2. Landmarks that showed a significant difference in the 2 D image were the points frequently superimposed anatomically. 3. Go Po Orb landmarks, which showed a significant difference in the 3 D images, were found to be the artificial points for analysis in the 2 D image, and in the current definition, these points cannot be used for reproducibility in the 3 D image. CONCLUSION: Generally, 3-D CT images provide more precise identification of the traditional cephalometric landmark. Greater variability of certain landmarks in the mediolateral direction is probably related to the inadequate definition of the landmarks in the third dimension.