Craniofacial growth series最新文献

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REGISTRATION OF ORTHODONTIC DIGITAL MODELS. 正畸数字模型注册。

Craniofacial growth series Pub Date : 2011-01-01

Dan Grauer, Lucia H Cevidanes, Donald Tyndall, Martin A Styner, Patrick M Flood, William R Proffit

{"title":"REGISTRATION OF ORTHODONTIC DIGITAL MODELS.","authors":"Dan Grauer, Lucia H Cevidanes, Donald Tyndall, Martin A Styner, Patrick M Flood, William R Proffit","doi":"","DOIUrl":"","url":null,"abstract":"Current methods to assess outcomes and change in orthodontics are comparison of photographs, cephalometric measurements and superimpositions, and comparisons/measurements on dental casts. Digital models are a relatively new records modality in orthodontics. They offer numerous advantages in terms of storage space, spatial registration and superimposition. The purpose of this chapter is to determine the reproducibility of: 1) establishing occlusion of independently scanned digital models; and 2) registering digital models obtained after treatment on their homologous digital model setups produced before treatment. Reliability of both procedures was assessed with two random samples of five patient's models. In both experiments, three replicate positionings of the models per patient were created and variability in position was evaluated by the maximum surface difference between replicates, and the standard deviation of the surface distances between replicates respectively. Based on the data obtained, we concluded that it is reliable to register independently scanned models to a scanned surface of the models in occlusion. Surface-to-surface registration of final orthodontic digital models to planned setup models also is reproducible.","PeriodicalId":91238,"journal":{"name":"Craniofacial growth series","volume":"48 ","pages":"377-391"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4636130/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144183637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

CONDYLAR RESORPTION IN PATIENTS WITH TMD. tmd患者的髁突骨吸收。

Craniofacial growth series Pub Date : 2009-03-01

Lucia H Cevidanes, David G Walker, Martin Styner, Pei Feng Lim

{"title":"CONDYLAR RESORPTION IN PATIENTS WITH TMD.","authors":"Lucia H Cevidanes, David G Walker, Martin Styner, Pei Feng Lim","doi":"","DOIUrl":"","url":null,"abstract":"The objective of this study is to determine the nature of the difference between condyle morphology of osteoarthritic temporomandibular joint (TMJ) and non-osteoarthritic TMJ, using 3D surface models constructed from cone-beam CT (CBCT) images. Three-dimensional Shape Correspondence was used to localize and quantify condylar morphological differences of 20 patients with RDC/TMD group III (arthralgia, arthritis, arthrosis) compared to 40 asymptomatic subjects. Three-dimensional models of right and left condyles for each subject were constructed from CBCT images and shape analysis performed using the publicly available SPHARM-PDM software. The right and left condyles were normalized using rigid Procrustes alignment to an overall mean condylar surface per group. The mean differences between groups were compared using the Hotelling T2 analysis with permutation-test derived p-values, corrected for False Discovery Rate. The differences between the group mean surfaces were visualized with color-coded magnitude and difference vectors. The condylar morphology of the TMD group was statistically significantly different from the asymptomatic group (p = 0.05, average surface distance differences of 1.9 mm for the right condyles and 2.3 mm for the left condyles). The average condylar morphology in the TMD patients showed resorption of the anterior surface of the lateral pole and flattening of the articular surface compared to the mean morphology in asymptomatic subjects. The condylar morphology and condylar dimensions of the TMD patients were different, on average, from those of the asymptomatic subjects. The preliminary findings in this cross-sectional study will lead to future investigations to elucidate osteoarthritic changes in TMD and their role in the pathophysiology of TMD. Supported by NIDCR DE017727.","PeriodicalId":91238,"journal":{"name":"Craniofacial growth series","volume":"46 ","pages":"147-157"},"PeriodicalIF":0.0,"publicationDate":"2009-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4636206/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144180622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tractional Forces, Work and Energy Densities in the Human TMJ. 人类颞下颌关节牵引力、功和能量密度。

Craniofacial growth series Pub Date : 2009-03-01

Jeffrey C Nickel, Laura R Iwasaki, Luigi M Gallo, Sandro Palla, David B Marx

{"title":"Tractional Forces, Work and Energy Densities in the Human TMJ.","authors":"Jeffrey C Nickel, Laura R Iwasaki, Luigi M Gallo, Sandro Palla, David B Marx","doi":"","DOIUrl":"","url":null,"abstract":"The role of mechanics in degenerative joint disease of the temporomandibular joint (TMJ) is largely unknown. Objectives were to: 1) develop an empirical model to relate variables of cartilage mechanics and tractional forces; and 2) use the empirical model to estimate tractional forces for calculations of work done (mJ) and energy densities (mJ/mm3) in living human TMJs. Sixty-four porcine discs were statically, then dynamically loaded. Aspect ratios and velocities of stress-fields, compressive strains, and tractional forces were recorded and fit to a quadratic equation to derive the empirical model. Aspect ratios and velocities of stress-fields and cartilage thicknesses then were measured via dynamic stereometry in 15 humans with healthy TMJs and 11 with TMJ disc displacement. These data were used in the empirical model to estimate tractional forces for each TMJ, and then mechanical work done and energy densities were calculated. Mechanical work (mJ) was on average 20 times greater in TMJs with disc displacement than in healthy TMJs (P<0.02). TMJs with disc displacement showed 350% more mechanical work (mJ) and 180% higher energy densities in women compared to men (P<0.02). A power analysis (α=0.05, β=0.90) indicated that 40 women and 40 men would be required to detect a 50% difference in TMJ energy densities between genders. Mechanical work was significantly higher (P≤0.05) in TMJs with disc displacement compared to healthy TMJs, and mechanical work done and energy densities were significantly higher (P≤0.05) in TMJs with disc displacement in women compare to men.","PeriodicalId":91238,"journal":{"name":"Craniofacial growth series","volume":"46 ","pages":"427-450"},"PeriodicalIF":0.0,"publicationDate":"2009-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4636121/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144181397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0