The purpose of this study was to evaluate whether the cranial and circumaxillary sutures react differently to maxillary expansion （ME） and alternate maxillary expansions and constrictions （Alt-MEC） in a rat model....The purpose of this study was to evaluate whether the cranial and circumaxillary sutures react differently to maxillary expansion （ME） and alternate maxillary expansions and constrictions （Alt-MEC） in a rat model. Twenty-two male Sprague-Dawley rats （6 weeks old） were used and divided into three groups. In ME group （n=9）, an expander was activated for 5 days. In Alt-MEC group （9 animals）, an al- ternate expansion and constriction protocol （5-day expansion and 5-day constriction for one cycle） was conducted for 2.5 cycles （25 days total）. The control group comprised 4 animals with no appliances used, each of two sacrificed on day 5 and day 25 respectively. Midpalatal suture expansion or constriction levels were assessed qualitatively and quantitatively by bite-wing X-rays and cast models. Distances between two central incisors and two maxillary first molars were measured on cast models after each activation. Circumaxillary sutures （midpalatal, maxillopalatine, premaxillary, zygomaticotemporal and frontonasal suture） in each group were characterized histologically. Results showed that midpalatal suture was wid- ened and restored after each expansion and constriction. At the end of activation, the widths between both central incisors and first molars in Alt-MEC group were significantly larger than those in ME group （P〈0.05）. Histologically, all five circumaxillary sutures studied were widened in multiple zones in Alt- MEC group. However, only midpalatal suture was expanded with cellular fibrous tissue filling in ME group. Significant osteoclast hyperplasia was observed in all circumaxillary sutures after alternate expan- sions and constrictions, but osteoclast count increase was only observed in midpalatal suture in ME group. These results suggested that cranial and circumaxillary sutures were actively reconstructed after Alt-MEC, while only midpalatal suture had active reaction after ME.展开更多
Objective:To explore the effect of maxillary expansion on orthodontics.Methods:Eight beagle dogs were randomly divided into two groups,with 4 dogs in each group.Dogs in group1 were executed immediately and received th...Objective:To explore the effect of maxillary expansion on orthodontics.Methods:Eight beagle dogs were randomly divided into two groups,with 4 dogs in each group.Dogs in group1 were executed immediately and received the direct physical measurement.The magnetic expansion appliance was used in group 2 for the maxillary expansion.After the expansion,the model was taken again and they were executed after cone beam CT(CBCT) scanning.The model measurement method was adopted in group 1 to measure the dental measurement indicators and width of base bone arch.The CBCT measurement method was employed to measure the above dental indicators and bone indicators.The difference in the indicators measured by different methods was compared and analyzed.Results:Before the expansion,there was no significant difference in the bone measurement indicators between the CBCT measurement method and direct physical measurement method.After the expansion,there was no significant difference in indicators between the CBCT measurement method and direct physical measurement.But there was significant difference among the model measurement method,CBCT measurement method and direct physical measurement method.There was the significant difference in the dental indicators between the CBCT measurement method and model measurement,as well as the bone indicators of posterior marginal spacing of greater palatine foramen,posterior marginal spacing of incisive foramen,width of base bone arch and spacing of implant anchorage.Conclusions:There is no significant difference between the effect of CBCT measurement method and direct physical measurement method,but CBCT is significantly better than the model measurement.展开更多
BACKGROUND Palatal expansion treatment has been used to expand the constricted maxillary arch and has become a routine procedure in orthodontic practice over the past decades.However,the long-term stability of expansi...BACKGROUND Palatal expansion treatment has been used to expand the constricted maxillary arch and has become a routine procedure in orthodontic practice over the past decades.However,the long-term stability of expansion in the permanent dentition without a surgical approach is uncertain.CASE SUMMARY We present the case of a 15-year-old boy with Class II malocclusion and constricted arches.The patient was treated with rapid palatal expansion(RPE)followed by a fixed orthodontic appliance.A 7-year follow-up evaluation was performed by analyzing cephalometric radiographs,plaster models,and photographs.The patient’s constricted maxillary and mandibular arches were relived after the expansion treatment.A Class I occlusion and normal arch form were established and maintained in the long-term.CONCLUSION RPE treatment is successful in solving constricted dental arch in the permanent dentition without a surgical approach.Permanent retention and even occlusal contact help prevent long-term relapse.展开更多
目的·利用锥形束计算机断层扫描(cone-beam computed tomography,CBCT)技术分析中国人群中翼腭缝(pterygopalatine suture,PPS)的解剖及宏观形态特征,并初步探讨其发育模式及其与矫正上颌发育不足之间的关联。方法·纳入2023年...目的·利用锥形束计算机断层扫描(cone-beam computed tomography,CBCT)技术分析中国人群中翼腭缝(pterygopalatine suture,PPS)的解剖及宏观形态特征,并初步探讨其发育模式及其与矫正上颌发育不足之间的关联。方法·纳入2023年7月—8月在上海交通大学医学院附属第九人民医院拍摄的134例CBCT影像资料,根据年龄分为6组。以PPS标志点为依据,计算得出PPS整体的横向位置(transverse position of PPS,X_(PPS)),PPS整体的矢状向位置(sagittal position of PPS,Y_(PPS)),以及PPS的锥突嵌入角(insertion angle of PPS,IAP)、锥突嵌入宽度(insertion width of pyramidal process,IWP)和锥突嵌入深度(insertion depth of pyramidal process,IDP),并通过多平面观察确定翼上颌联合情况。采用回归分析评估各参数与年龄、性别的相关性,并通过两两比较确定参数变化的稳定年龄段。采用配对t检验及配对χ^(2)检验分析双侧参数的差异性。结果·Y_(PPS)、IDP与年龄无显著相关性,而X_(PPS)、IAP、IWP、翼上颌连接的发生率均与年龄呈显著正相关(P<0.01)。性别差异仅在X_(PPS)中显著,男性大于女性(P<0.01)。参数的年龄变化趋势分析表明:X_(PPS)在组1(6岁≤年龄<9岁)和组2 (9岁≤年龄<12岁)间差异显著(女性:P=0.006;男性:P=0.004);IAP在组2与组3 (12岁≤年龄<15岁)间差异显著(P=0.042),98.5%样本的IAP大于45°;IWP在组1与组3间差异显著(P=0.016);翼上颌联合情况在组1、2、3间差异显著(组1、2间P<0.001,组2、3间P=0.037,组1、3间P<0.001),成人发生率高于90%。各项指标双侧比较均未见统计学差异。结论·6岁以后Y_(PPS)及IDP未表现出明显改变,上颌骨与翼突趋于融合。PPS整体横向位置在12岁左右趋于稳定,而IAP及IWP持续增长,至15岁左右达到稳定且翼腭缝锥突嵌入翼切迹的方向偏向矢状向。展开更多
通过Geomagic Studio 2015软件建立包括上颌牙齿、牙槽骨、牙周膜以及无托槽隐形矫治器的三维有限元模型。分析添加0°、5°、10°转矩的过矫治后,后牙移动趋势、位移以及牙周膜的应力分布情况。结果显示,添加10°根颊...通过Geomagic Studio 2015软件建立包括上颌牙齿、牙槽骨、牙周膜以及无托槽隐形矫治器的三维有限元模型。分析添加0°、5°、10°转矩的过矫治后,后牙移动趋势、位移以及牙周膜的应力分布情况。结果显示,添加10°根颊向转矩时第一前磨牙、第二前磨牙、第一磨牙、第二磨牙水平向冠根位移差最小。表明使用无托槽隐形矫治器扩弓时,后牙添加10°根颊向转矩时后牙更趋向于整体移动。展开更多
基金supported by Peking University School of Stomatology Youth Scientific Research Fund of China(No.PKUSS20120113)
文摘The purpose of this study was to evaluate whether the cranial and circumaxillary sutures react differently to maxillary expansion （ME） and alternate maxillary expansions and constrictions （Alt-MEC） in a rat model. Twenty-two male Sprague-Dawley rats （6 weeks old） were used and divided into three groups. In ME group （n=9）, an expander was activated for 5 days. In Alt-MEC group （9 animals）, an al- ternate expansion and constriction protocol （5-day expansion and 5-day constriction for one cycle） was conducted for 2.5 cycles （25 days total）. The control group comprised 4 animals with no appliances used, each of two sacrificed on day 5 and day 25 respectively. Midpalatal suture expansion or constriction levels were assessed qualitatively and quantitatively by bite-wing X-rays and cast models. Distances between two central incisors and two maxillary first molars were measured on cast models after each activation. Circumaxillary sutures （midpalatal, maxillopalatine, premaxillary, zygomaticotemporal and frontonasal suture） in each group were characterized histologically. Results showed that midpalatal suture was wid- ened and restored after each expansion and constriction. At the end of activation, the widths between both central incisors and first molars in Alt-MEC group were significantly larger than those in ME group （P〈0.05）. Histologically, all five circumaxillary sutures studied were widened in multiple zones in Alt- MEC group. However, only midpalatal suture was expanded with cellular fibrous tissue filling in ME group. Significant osteoclast hyperplasia was observed in all circumaxillary sutures after alternate expan- sions and constrictions, but osteoclast count increase was only observed in midpalatal suture in ME group. These results suggested that cranial and circumaxillary sutures were actively reconstructed after Alt-MEC, while only midpalatal suture had active reaction after ME.
基金supported by National Natural Science Foundation of China(81160138)
文摘Objective:To explore the effect of maxillary expansion on orthodontics.Methods:Eight beagle dogs were randomly divided into two groups,with 4 dogs in each group.Dogs in group1 were executed immediately and received the direct physical measurement.The magnetic expansion appliance was used in group 2 for the maxillary expansion.After the expansion,the model was taken again and they were executed after cone beam CT(CBCT) scanning.The model measurement method was adopted in group 1 to measure the dental measurement indicators and width of base bone arch.The CBCT measurement method was employed to measure the above dental indicators and bone indicators.The difference in the indicators measured by different methods was compared and analyzed.Results:Before the expansion,there was no significant difference in the bone measurement indicators between the CBCT measurement method and direct physical measurement method.After the expansion,there was no significant difference in indicators between the CBCT measurement method and direct physical measurement.But there was significant difference among the model measurement method,CBCT measurement method and direct physical measurement method.There was the significant difference in the dental indicators between the CBCT measurement method and model measurement,as well as the bone indicators of posterior marginal spacing of greater palatine foramen,posterior marginal spacing of incisive foramen,width of base bone arch and spacing of implant anchorage.Conclusions:There is no significant difference between the effect of CBCT measurement method and direct physical measurement method,but CBCT is significantly better than the model measurement.
基金Supported by the National Natural Science Foundation of China No.81970909(to Liu DW),No.51903003(to Yu TT)the New Clinical Technology Fund of PKUSS,No.PKUSSNCT-11A07(to Liu DW)Peking University Medicine Seed Fund for Interdisciplinary Research,No.BMU2018MX007(to Liu DW).
文摘BACKGROUND Palatal expansion treatment has been used to expand the constricted maxillary arch and has become a routine procedure in orthodontic practice over the past decades.However,the long-term stability of expansion in the permanent dentition without a surgical approach is uncertain.CASE SUMMARY We present the case of a 15-year-old boy with Class II malocclusion and constricted arches.The patient was treated with rapid palatal expansion(RPE)followed by a fixed orthodontic appliance.A 7-year follow-up evaluation was performed by analyzing cephalometric radiographs,plaster models,and photographs.The patient’s constricted maxillary and mandibular arches were relived after the expansion treatment.A Class I occlusion and normal arch form were established and maintained in the long-term.CONCLUSION RPE treatment is successful in solving constricted dental arch in the permanent dentition without a surgical approach.Permanent retention and even occlusal contact help prevent long-term relapse.
文摘目的·利用锥形束计算机断层扫描(cone-beam computed tomography,CBCT)技术分析中国人群中翼腭缝(pterygopalatine suture,PPS)的解剖及宏观形态特征,并初步探讨其发育模式及其与矫正上颌发育不足之间的关联。方法·纳入2023年7月—8月在上海交通大学医学院附属第九人民医院拍摄的134例CBCT影像资料,根据年龄分为6组。以PPS标志点为依据,计算得出PPS整体的横向位置(transverse position of PPS,X_(PPS)),PPS整体的矢状向位置(sagittal position of PPS,Y_(PPS)),以及PPS的锥突嵌入角(insertion angle of PPS,IAP)、锥突嵌入宽度(insertion width of pyramidal process,IWP)和锥突嵌入深度(insertion depth of pyramidal process,IDP),并通过多平面观察确定翼上颌联合情况。采用回归分析评估各参数与年龄、性别的相关性,并通过两两比较确定参数变化的稳定年龄段。采用配对t检验及配对χ^(2)检验分析双侧参数的差异性。结果·Y_(PPS)、IDP与年龄无显著相关性,而X_(PPS)、IAP、IWP、翼上颌连接的发生率均与年龄呈显著正相关(P<0.01)。性别差异仅在X_(PPS)中显著,男性大于女性(P<0.01)。参数的年龄变化趋势分析表明:X_(PPS)在组1(6岁≤年龄<9岁)和组2 (9岁≤年龄<12岁)间差异显著(女性:P=0.006;男性:P=0.004);IAP在组2与组3 (12岁≤年龄<15岁)间差异显著(P=0.042),98.5%样本的IAP大于45°;IWP在组1与组3间差异显著(P=0.016);翼上颌联合情况在组1、2、3间差异显著(组1、2间P<0.001,组2、3间P=0.037,组1、3间P<0.001),成人发生率高于90%。各项指标双侧比较均未见统计学差异。结论·6岁以后Y_(PPS)及IDP未表现出明显改变,上颌骨与翼突趋于融合。PPS整体横向位置在12岁左右趋于稳定,而IAP及IWP持续增长,至15岁左右达到稳定且翼腭缝锥突嵌入翼切迹的方向偏向矢状向。
文摘通过Geomagic Studio 2015软件建立包括上颌牙齿、牙槽骨、牙周膜以及无托槽隐形矫治器的三维有限元模型。分析添加0°、5°、10°转矩的过矫治后,后牙移动趋势、位移以及牙周膜的应力分布情况。结果显示,添加10°根颊向转矩时第一前磨牙、第二前磨牙、第一磨牙、第二磨牙水平向冠根位移差最小。表明使用无托槽隐形矫治器扩弓时,后牙添加10°根颊向转矩时后牙更趋向于整体移动。
