Purpose: With the increased demand for orthodontic treatments in adults, Diastemas have always been an obstacle for either pre or post orthodontic treatment. The purpose of the present investigation is to identify the...Purpose: With the increased demand for orthodontic treatments in adults, Diastemas have always been an obstacle for either pre or post orthodontic treatment. The purpose of the present investigation is to identify the prevalence and location of diastema among patients attending the dental clinics, School of Dental Medicine, University of Nevada, Las Vegas (UNLV). Methods: A retrospective keywords search of the clinical notes of UNLV School of Dental Medicine (SDM) patient charts in AxiUmTM (dental practice management software) was performed using the search terms “diastema” and “midline diastema” to identify the number of cases that clinically presented with diastema from 1/1/2014-9/30/2020. Demographic data were then analyzed using a Chi-square test and compared against Clark County population data. Results: 1182 patients’ records were identified to have one of the search keywords. 56.7% of the patients who presented with diastema were female, 43.1% were male and 0.2% were transgender. 31.5% of patients presenting with diastema were between the ages of 12 and 19. The majority of the diastema cases were in maxillary teeth, followed by diastema in both maxillary and mandibular. The least number of cases had only mandibular diastema. In regards to size, most (look up percent) were mild diastema (1 - 2 mm), followed by moderate (2 mm) and severe (above 2 mm). The reported ethnicity with highest diastema was Hispanic followed by Caucasians and 17% were African Americans. Chi square analysis showed ethnicity results are statistically significant (p Conclusion: Ethnicity and arch are integral predictors for patients who have diastema.展开更多
The dentary diastema of iguanodontians has been considered to be related to its unique jaw mechanism for herbivorous adaptation. The dentary and diastema lengths of iguanodontians were measured and compared to elucida...The dentary diastema of iguanodontians has been considered to be related to its unique jaw mechanism for herbivorous adaptation. The dentary and diastema lengths of iguanodontians were measured and compared to elucidate the evolution of iguanodontian diastema. A gap in ratios between most non-hadrosaurid iguanodontians and hadrosaurids was observed, suggesting that all non- hadrosaurid iguanodontians, expect for Ouranosaurus nigeriensis and Protohadros byrdi, lack a diastema or have a short diastema, although some other taxa have been considered to have a long diastema in previous studies. In non-hadrosaurid iguanodontians, some large-sized forms, such as Iguanodon bernissartensis, Shuangmiaosaurus gilmorei, and possibly Eolambia caroljonesa, had a short diastema through ontogeny, whereas Ouranosaurus nigeriensis and Protohadros byrdi developed a long diastema convergently. The development of a long diastema of hadrosaurine hadrosaurids may be different from that of lambeosaurine hadrosaurids. Some hadrosaurines （Edmontosaurus annectens, Edmontosaurus regalis, and Saurolophus angustirostris） may have developed a long diastema in the subadult stage and showed little elongation of dentary diastema through ontogeny. Lambeosaurines （Corythosaurus casuarius and Lambeosaurus lambei） tend to have a short diastema in the embryonic and subadult stages, and an elongated diastema from the subadult to adult stages.展开更多
目的:评价运用复合树脂分层堆塑技术关闭前牙间隙的修复效果。方法:收集我科2016年9月至2018年11月通过直接法关闭前牙邻面间隙的35名患者的82个树脂修复体为研究对象,术后随访36个月,运用美国公共卫生署(United States Public Health S...目的:评价运用复合树脂分层堆塑技术关闭前牙间隙的修复效果。方法:收集我科2016年9月至2018年11月通过直接法关闭前牙邻面间隙的35名患者的82个树脂修复体为研究对象,术后随访36个月,运用美国公共卫生署(United States Public Health Service,USPHS)改良评价标准进行临床效果评价。结果:单个邻面间隙的平均操作时间为(107.12±9.44)min。术后即刻,28个树脂修复体(34.15%)局部牙龈出现轻度红肿及出血的症状,其中24个树脂修复体在术后2周内症状得到缓解。治疗后36个月,2个树脂修复体(2.44%)边缘与天然牙间出现较明显空隙;1个树脂修复体(1.22%)边缘折断伴表面粗糙度明显增加;1个邻间隙所涉及的2个树脂修复体(2.44%)牙龈红肿较明显。所有患牙在36个月的随访期内均未出现继发龋及术后敏感。结论:复合树脂层塑技术作为关闭前牙邻面间隙的一种可选手段,具有疗效稳定,治疗周期短,费用低等优点,但椅旁操作时间较长且需要定期维护。展开更多
目的:三维重建小鼠牙发育早期牙胚的形态结构,对比无牙区发育不全的牙胚(rudimentary bud 2,R2)与磨牙区第一磨牙(the first molar,M1)牙胚的形态差异。方法:选取胚胎12.5 d(E12.5)及胚胎13.5 d(E13.5)小鼠胚胎头部标本,经冠状面连续石...目的:三维重建小鼠牙发育早期牙胚的形态结构,对比无牙区发育不全的牙胚(rudimentary bud 2,R2)与磨牙区第一磨牙(the first molar,M1)牙胚的形态差异。方法:选取胚胎12.5 d(E12.5)及胚胎13.5 d(E13.5)小鼠胚胎头部标本,经冠状面连续石蜡切片、苏木精-伊红(hematoxylin and eosin,HE)染色后,获取组织学图像数据。图像经Photoshop CC 2018软件处理并配准,用Fiji软件再配准与赋予虚拟CT值后,导入Mimics Research 19.0软件进行三维重建和分析。结果:在重建的三维图像中观察到无牙区R2上皮可向间充质内陷形成蕾状,但其下方无明显的间充质细胞团形成。赋予无牙区R2和磨牙区M1虚拟CT值后,对重建图像进行半定量测量,发现凝聚在无牙区R2蕾状上皮周围的间充质细胞密度较低,凝聚面积较小。此现象可能与无牙区细胞增殖不如磨牙区活跃有关。结论:基于组织学切片的三维重建结果提示,发育早期小鼠无牙区丧失了形成间充质细胞团的能力。展开更多
文摘Purpose: With the increased demand for orthodontic treatments in adults, Diastemas have always been an obstacle for either pre or post orthodontic treatment. The purpose of the present investigation is to identify the prevalence and location of diastema among patients attending the dental clinics, School of Dental Medicine, University of Nevada, Las Vegas (UNLV). Methods: A retrospective keywords search of the clinical notes of UNLV School of Dental Medicine (SDM) patient charts in AxiUmTM (dental practice management software) was performed using the search terms “diastema” and “midline diastema” to identify the number of cases that clinically presented with diastema from 1/1/2014-9/30/2020. Demographic data were then analyzed using a Chi-square test and compared against Clark County population data. Results: 1182 patients’ records were identified to have one of the search keywords. 56.7% of the patients who presented with diastema were female, 43.1% were male and 0.2% were transgender. 31.5% of patients presenting with diastema were between the ages of 12 and 19. The majority of the diastema cases were in maxillary teeth, followed by diastema in both maxillary and mandibular. The least number of cases had only mandibular diastema. In regards to size, most (look up percent) were mild diastema (1 - 2 mm), followed by moderate (2 mm) and severe (above 2 mm). The reported ethnicity with highest diastema was Hispanic followed by Caucasians and 17% were African Americans. Chi square analysis showed ethnicity results are statistically significant (p Conclusion: Ethnicity and arch are integral predictors for patients who have diastema.
文摘The dentary diastema of iguanodontians has been considered to be related to its unique jaw mechanism for herbivorous adaptation. The dentary and diastema lengths of iguanodontians were measured and compared to elucidate the evolution of iguanodontian diastema. A gap in ratios between most non-hadrosaurid iguanodontians and hadrosaurids was observed, suggesting that all non- hadrosaurid iguanodontians, expect for Ouranosaurus nigeriensis and Protohadros byrdi, lack a diastema or have a short diastema, although some other taxa have been considered to have a long diastema in previous studies. In non-hadrosaurid iguanodontians, some large-sized forms, such as Iguanodon bernissartensis, Shuangmiaosaurus gilmorei, and possibly Eolambia caroljonesa, had a short diastema through ontogeny, whereas Ouranosaurus nigeriensis and Protohadros byrdi developed a long diastema convergently. The development of a long diastema of hadrosaurine hadrosaurids may be different from that of lambeosaurine hadrosaurids. Some hadrosaurines （Edmontosaurus annectens, Edmontosaurus regalis, and Saurolophus angustirostris） may have developed a long diastema in the subadult stage and showed little elongation of dentary diastema through ontogeny. Lambeosaurines （Corythosaurus casuarius and Lambeosaurus lambei） tend to have a short diastema in the embryonic and subadult stages, and an elongated diastema from the subadult to adult stages.
文摘目的:评价运用复合树脂分层堆塑技术关闭前牙间隙的修复效果。方法:收集我科2016年9月至2018年11月通过直接法关闭前牙邻面间隙的35名患者的82个树脂修复体为研究对象,术后随访36个月,运用美国公共卫生署(United States Public Health Service,USPHS)改良评价标准进行临床效果评价。结果:单个邻面间隙的平均操作时间为(107.12±9.44)min。术后即刻,28个树脂修复体(34.15%)局部牙龈出现轻度红肿及出血的症状,其中24个树脂修复体在术后2周内症状得到缓解。治疗后36个月,2个树脂修复体(2.44%)边缘与天然牙间出现较明显空隙;1个树脂修复体(1.22%)边缘折断伴表面粗糙度明显增加;1个邻间隙所涉及的2个树脂修复体(2.44%)牙龈红肿较明显。所有患牙在36个月的随访期内均未出现继发龋及术后敏感。结论:复合树脂层塑技术作为关闭前牙邻面间隙的一种可选手段,具有疗效稳定,治疗周期短,费用低等优点,但椅旁操作时间较长且需要定期维护。
文摘目的:三维重建小鼠牙发育早期牙胚的形态结构,对比无牙区发育不全的牙胚(rudimentary bud 2,R2)与磨牙区第一磨牙(the first molar,M1)牙胚的形态差异。方法:选取胚胎12.5 d(E12.5)及胚胎13.5 d(E13.5)小鼠胚胎头部标本,经冠状面连续石蜡切片、苏木精-伊红(hematoxylin and eosin,HE)染色后,获取组织学图像数据。图像经Photoshop CC 2018软件处理并配准,用Fiji软件再配准与赋予虚拟CT值后,导入Mimics Research 19.0软件进行三维重建和分析。结果:在重建的三维图像中观察到无牙区R2上皮可向间充质内陷形成蕾状,但其下方无明显的间充质细胞团形成。赋予无牙区R2和磨牙区M1虚拟CT值后,对重建图像进行半定量测量,发现凝聚在无牙区R2蕾状上皮周围的间充质细胞密度较低,凝聚面积较小。此现象可能与无牙区细胞增殖不如磨牙区活跃有关。结论:基于组织学切片的三维重建结果提示,发育早期小鼠无牙区丧失了形成间充质细胞团的能力。
