目的 探讨基于局部或全局特征点的3D牙模配准比对结果差异。方法 间隔6个月两次采集30名志愿者的上颌口内扫描模型(共60例),通过Geomagic Control X软件分别实施局部和全局特征点配准,计算配准后对应特征点间均方根(root mean square, R...目的 探讨基于局部或全局特征点的3D牙模配准比对结果差异。方法 间隔6个月两次采集30名志愿者的上颌口内扫描模型(共60例),通过Geomagic Control X软件分别实施局部和全局特征点配准,计算配准后对应特征点间均方根(root mean square, RMS)距离。将个体内牙模配准记为匹配组,将个体间牙模配准记为不匹配组,采用Mann-Whitney U检验分析组间差异。结果 两种配准方式下,匹配组的RMS距离均显著低于不匹配组(P<0.05),且组间RMS值分布不重叠。但局部特征点配准的RMS值不重叠区间(0.21~0.72 mm)略窄于全局特征点配准(0.18~0.79 mm)。结论 不重叠的RMS值区间表明两种3D牙模配准方法均具备个体识别潜力,但局部特征点配准的判别阈值区间相对较窄。展开更多
<b>Introduction:</b> Digital models showed promising results for orthodontic diagnosis and treatment planning. Digital models can be obtained from alginate impressions as well as direct intra-oral scanners...<b>Introduction:</b> Digital models showed promising results for orthodontic diagnosis and treatment planning. Digital models can be obtained from alginate impressions as well as direct intra-oral scanners. Studies assessing the accuracy of digital models have shown digital models to be valid, clinically acceptable, and more quickly obtainable. With the advent of new scanners with better scanning technology researches are necessary to evaluate their accuracy and reliability. <b>Aim of Study:</b> To evaluate the diagnostic accuracy of 3D digital models obtained through intraoral and extraoral scanning modalities to the reference gold standard plaster model. <b>Material & Methods:</b> Twenty-four adult male and female subjects were randomly selected for this study. The intraoral scanners evaluated in this study were Sirona (CEREC Omnicam) and 3 shape (TRIOS 3), while the laboratory scanners used were Sirona (inEos X5), and 3 shape (D850). Intra-oral scanning of the subjects and extra-oral scanning of their alginate impressions, plaster models of the alginate impression, rubber base impression, and plaster model of their rubber base impression were done. Linear dental measurements included intermolar width, interpremolar width, intercanine width, mesiodistal width of the 1<sup>st</sup> permanent molar, 1<sup>st</sup> premolar, canine and central incisor and arch width. All data were collected, tabulated and subjected to statistical analysis. <b>Results:</b> Small differences between the plaster and digital models were observed. Intra-observer reliability analysis for 14 out of the 16 measurements showed that all variables exhibited good to excellent reliability. <b>Conclusions: </b>There was no difference between the digitization using the intraoral scanner or the laboratory scanner. The most accurate digitization technique was the 3 Shape laboratory scanner of the cast of the alginate impression. The inEos X5 showed the highest error of digitization of the alginate and rubber base impressions.展开更多
Retropharyngeal abscess (RPA) is an uncommon disease entity that typically occurs in children under 5 years of age, which has the potential to cause upper airway obstruction. Upper respiratory tract infection is the m...Retropharyngeal abscess (RPA) is an uncommon disease entity that typically occurs in children under 5 years of age, which has the potential to cause upper airway obstruction. Upper respiratory tract infection is the most common predisposing factor to RPA in children while cervical spine tuberculosis and trauma are the major aetiological factors in the adult. We report a case of a 21-year-old Nigerian farmer with giant retropharyngeal abscess following fish bone throat injury causing life-threatening upper airway obstruction. The patient responded well to emergency tracheostomy, intraoral surgical drainage and empirical antibiotic therapy. We highlight the diagnostic and therapeutic challenges of managing such a patient.展开更多
文摘<b>Introduction:</b> Digital models showed promising results for orthodontic diagnosis and treatment planning. Digital models can be obtained from alginate impressions as well as direct intra-oral scanners. Studies assessing the accuracy of digital models have shown digital models to be valid, clinically acceptable, and more quickly obtainable. With the advent of new scanners with better scanning technology researches are necessary to evaluate their accuracy and reliability. <b>Aim of Study:</b> To evaluate the diagnostic accuracy of 3D digital models obtained through intraoral and extraoral scanning modalities to the reference gold standard plaster model. <b>Material & Methods:</b> Twenty-four adult male and female subjects were randomly selected for this study. The intraoral scanners evaluated in this study were Sirona (CEREC Omnicam) and 3 shape (TRIOS 3), while the laboratory scanners used were Sirona (inEos X5), and 3 shape (D850). Intra-oral scanning of the subjects and extra-oral scanning of their alginate impressions, plaster models of the alginate impression, rubber base impression, and plaster model of their rubber base impression were done. Linear dental measurements included intermolar width, interpremolar width, intercanine width, mesiodistal width of the 1<sup>st</sup> permanent molar, 1<sup>st</sup> premolar, canine and central incisor and arch width. All data were collected, tabulated and subjected to statistical analysis. <b>Results:</b> Small differences between the plaster and digital models were observed. Intra-observer reliability analysis for 14 out of the 16 measurements showed that all variables exhibited good to excellent reliability. <b>Conclusions: </b>There was no difference between the digitization using the intraoral scanner or the laboratory scanner. The most accurate digitization technique was the 3 Shape laboratory scanner of the cast of the alginate impression. The inEos X5 showed the highest error of digitization of the alginate and rubber base impressions.
文摘Retropharyngeal abscess (RPA) is an uncommon disease entity that typically occurs in children under 5 years of age, which has the potential to cause upper airway obstruction. Upper respiratory tract infection is the most common predisposing factor to RPA in children while cervical spine tuberculosis and trauma are the major aetiological factors in the adult. We report a case of a 21-year-old Nigerian farmer with giant retropharyngeal abscess following fish bone throat injury causing life-threatening upper airway obstruction. The patient responded well to emergency tracheostomy, intraoral surgical drainage and empirical antibiotic therapy. We highlight the diagnostic and therapeutic challenges of managing such a patient.
