AIM:To evaluate the efficacy of retrograde observation of the esophagus, pharynx, larynx and lingual root. METHODS:With the beagle dog under anesthesia, the anterior wall of the stomach was fixed on the abdominal wall...AIM:To evaluate the efficacy of retrograde observation of the esophagus, pharynx, larynx and lingual root. METHODS:With the beagle dog under anesthesia, the anterior wall of the stomach was fixed on the abdominal wall in a similar way to percutaneous endoscopic gastrostomy. The gastrointestinal scope was inserted via a 12 mm laparoscopic port for subsequent retrograde observation from stomach to the oral cavity. RESULTS:With this technique, direct observation of gastric cardia was possible without restriction. The cervical esophagus was dilated well, also allowing clear observation of the hypopharyngo-esophageal junction. If the tongue was manually pulled out forward, observation of the lingual root was possible.CONCLUSION: This procedure is easy and effective for pre-treatment evaluation of the feasibility of endoscopic resection in cases of superficial carcinoma of head and neck.展开更多
目的利用锥形束CT(cone-beam computed tomography,CBCT)研究不同年龄段的下颌第一磨牙独立远中舌根的根管,探讨其增龄性变化,以期为临床根管治疗有所指导。方法选取200例具有独立远中舌根的门诊患者,其中年龄≤40岁者(≤40岁组)100例,...目的利用锥形束CT(cone-beam computed tomography,CBCT)研究不同年龄段的下颌第一磨牙独立远中舌根的根管,探讨其增龄性变化,以期为临床根管治疗有所指导。方法选取200例具有独立远中舌根的门诊患者,其中年龄≤40岁者(≤40岁组)100例,年龄>40岁者(>40岁组)100例。2组均进行CBCT扫描,图像分析包括:1)远中舌根根管口与远中颊根根管口间距(DL-DB)的测量;2)近中舌根根管口与远中舌根根管口间距(ML-DL)的测量;3)远舌根管的近远中向及颊舌向弯曲度及弯曲部位的判定。结果 1)DL-DB间距:≤40岁组为( 3.20±0.85)mm,>40岁组为(3.05±0.76)mm,2组比较差异有统计学意义( P <0.05)。2)ML-DL间距:≤40岁组为(3.74±0.44)mm,>40岁组为(3.69±0.52)mm,2组比较差异无统计学意义( P >0.05)。3)远舌根管颊舌向弯曲度:≤40岁组为(35.5±6.7)°,>40岁组为(37.6±7.2)°,2组比较差异有统计学意义( P <0.05);远舌根管近远中向弯曲度:≤40岁组为(9.1±8.2)°,>40岁组为(9.7±6.1)°,2组比较差异无统计学意义( P >0.05);≤40岁组和>40岁组弯曲部位均绝大多数位于根中1/3。结论下颌第一磨牙随着年龄的增长,DL和DB根管口间距离会缩小,远舌根管弯曲度会增大。展开更多
Orthodontic forces can cause stress and strain concentration and microcracks on tooth root surfaces.This study aimed to analyze whether a lingual orthodontic appliance was more likely to cause root stress concentratio...Orthodontic forces can cause stress and strain concentration and microcracks on tooth root surfaces.This study aimed to analyze whether a lingual orthodontic appliance was more likely to cause root stress concentration and root resorption than the traditional buccal appliance.A finite element model of the root of the maxillary central incisor with straight,buccal,and lingual curvatures was established.A load perpendicular to the tooth surface on the buccal and lingual surfaces of the central incisor was applied,and the stress and strain concentration at the root apex was compared.The stress and strain at the root apex of the lingual cingulum group were lesser than those of the buccal group;little difference was observed between the lingual and buccal clinical crown central augmentation groups.The stress and strain at the root apex of the lingual direction movement group were greater than those of the buccal direction movement group.The direction of the root curvature also influenced the amount of stress and strain at the root apex.The difference in the risk of root resorption between lingual and buccal orthodontics is dependent on the height of the bracket placement.The loading direction of the orthodontic force and direction of the root curvature also affect the stress and strain at the root apex.展开更多
文摘AIM:To evaluate the efficacy of retrograde observation of the esophagus, pharynx, larynx and lingual root. METHODS:With the beagle dog under anesthesia, the anterior wall of the stomach was fixed on the abdominal wall in a similar way to percutaneous endoscopic gastrostomy. The gastrointestinal scope was inserted via a 12 mm laparoscopic port for subsequent retrograde observation from stomach to the oral cavity. RESULTS:With this technique, direct observation of gastric cardia was possible without restriction. The cervical esophagus was dilated well, also allowing clear observation of the hypopharyngo-esophageal junction. If the tongue was manually pulled out forward, observation of the lingual root was possible.CONCLUSION: This procedure is easy and effective for pre-treatment evaluation of the feasibility of endoscopic resection in cases of superficial carcinoma of head and neck.
文摘目的利用锥形束CT(cone-beam computed tomography,CBCT)研究不同年龄段的下颌第一磨牙独立远中舌根的根管,探讨其增龄性变化,以期为临床根管治疗有所指导。方法选取200例具有独立远中舌根的门诊患者,其中年龄≤40岁者(≤40岁组)100例,年龄>40岁者(>40岁组)100例。2组均进行CBCT扫描,图像分析包括:1)远中舌根根管口与远中颊根根管口间距(DL-DB)的测量;2)近中舌根根管口与远中舌根根管口间距(ML-DL)的测量;3)远舌根管的近远中向及颊舌向弯曲度及弯曲部位的判定。结果 1)DL-DB间距:≤40岁组为( 3.20±0.85)mm,>40岁组为(3.05±0.76)mm,2组比较差异有统计学意义( P <0.05)。2)ML-DL间距:≤40岁组为(3.74±0.44)mm,>40岁组为(3.69±0.52)mm,2组比较差异无统计学意义( P >0.05)。3)远舌根管颊舌向弯曲度:≤40岁组为(35.5±6.7)°,>40岁组为(37.6±7.2)°,2组比较差异有统计学意义( P <0.05);远舌根管近远中向弯曲度:≤40岁组为(9.1±8.2)°,>40岁组为(9.7±6.1)°,2组比较差异无统计学意义( P >0.05);≤40岁组和>40岁组弯曲部位均绝大多数位于根中1/3。结论下颌第一磨牙随着年龄的增长,DL和DB根管口间距离会缩小,远舌根管弯曲度会增大。
基金This work was supported by the National Natural Science Foundation of China(No.U20A20390 and 11827803).
文摘Orthodontic forces can cause stress and strain concentration and microcracks on tooth root surfaces.This study aimed to analyze whether a lingual orthodontic appliance was more likely to cause root stress concentration and root resorption than the traditional buccal appliance.A finite element model of the root of the maxillary central incisor with straight,buccal,and lingual curvatures was established.A load perpendicular to the tooth surface on the buccal and lingual surfaces of the central incisor was applied,and the stress and strain concentration at the root apex was compared.The stress and strain at the root apex of the lingual cingulum group were lesser than those of the buccal group;little difference was observed between the lingual and buccal clinical crown central augmentation groups.The stress and strain at the root apex of the lingual direction movement group were greater than those of the buccal direction movement group.The direction of the root curvature also influenced the amount of stress and strain at the root apex.The difference in the risk of root resorption between lingual and buccal orthodontics is dependent on the height of the bracket placement.The loading direction of the orthodontic force and direction of the root curvature also affect the stress and strain at the root apex.
