Introduction: The stability of orthodontic brackets throughout orthodontic treatment plays a critical role in the treatment’s effectiveness. The present in vitro study was designed to assess the impact of various die...Introduction: The stability of orthodontic brackets throughout orthodontic treatment plays a critical role in the treatment’s effectiveness. The present in vitro study was designed to assess the impact of various dietary components on the performance of orthodontic brackets. Methods: Metal orthodontic brackets were bonded to 66 extracted anterior teeth divided into groups based on the solution type: Milk, Gatorade, Cold Coffee, and a control group using water. Each group consisted of 20 teeth except for the control group, which included six teeth. The bracketed teeth were submerged in their respective solutions for 15 minutes three times daily at different intervals to mimic an in vivo environment and were stored in artificial saliva at room temperature (23?C). The specimens underwent artificial aging through 10,000 cycles of thermocycling (representing one clinical year) between 5?C and 55?C. Shade measurements were taken using a VITA Easy Shade device, capturing the classic shade and L*, a*, and b* values. Delta E values were calculated immediately post-bonding and after 7 days, 1 month, 1, and 2 clinical years. The shear bond strength of each bracket was measured using an ultra-tester machine. Results: After two clinical years, significant differences in ΔE color values were observed across all groups, with the most substantial change noted in teeth immersed in cold coffee. Brackets submerged in milk demonstrated lower shear bond strength than other solutions, whereas the control group exhibited the highest shear bond strength (P = 0.01). Conclusion: The study indicates that dietary components significantly influence tooth color stability and the shear bond strength of orthodontic brackets, underscoring the importance of considering these factors in orthodontic treatment planning.展开更多
A simple overview of daily orthodontic practice involves use of brackets, wires and elastomeric modules. However, investigating the underlying effect of orthodontic forces shows various molecular and cellular changes....A simple overview of daily orthodontic practice involves use of brackets, wires and elastomeric modules. However, investigating the underlying effect of orthodontic forces shows various molecular and cellular changes. Also, orthodontics is in close relation with dentofacial orthopedics which involves bone regeneration. In this review current and future applications of stem cells(SCs) in orthodontics and dentofacial orthopedics have been discussed. For craniofacial anomalies, SCs have been applied to regenerate hard tissue(such as treatment of alveolar cleft) and soft tissue(such as treatment of hemifacial macrosomia). Several attempts have been done to reconstruct impaired temporomandibular joint. Also, SCs with or without bone scaffolds and growth factors have been used to regenerate bone following distraction osteogenesis of mandibular bone or maxillary expansion. Current evidence shows that SCs also have potential to be used to regenerate infrabony alveolar defects and move the teeth into regenerated areas. Future application of SCs in orthodontics could involve accelerating tooth movement, regenerating resorbed roots and expanding tooth movement limitations. However, evidence supporting these roles is weak and further studies are required to evaluate the possibility of these ideas.展开更多
The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not be...The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too.展开更多
BACKGROUND In the clinical scenario,adult patients with periodontal diseases and dental malformation,characterized by dental crowding in lower anterior teeth with the thin biotype,often require orthodontic treatment.T...BACKGROUND In the clinical scenario,adult patients with periodontal diseases and dental malformation,characterized by dental crowding in lower anterior teeth with the thin biotype,often require orthodontic treatment.This case report aimed to evaluate the clinical and radiographic outcomes of periodontally accelerated osteogenic orthodontics(PAOO)combined with autologous platelet-rich fibrin(PRF)in an adult patient with class I malocclusion along with dental crowding,a thin periodontal biotype,and buccal plate deficiency.CASE SUMMARY A 32-year-old female complaining of dental crowding and gingival bleeding was referred to the orthodontic clinic.The patient underwent periodontal risk assessment prior to orthodontic treatment.She was diagnosed with a high risk of gingival recession due to dental crowding,root prominence,loss of buccal plates,and a thin gingival tissue biotype.The treatment regimen included PAOO combined with autologous PRF for alveolar augmentation and interproximal enamel reduction for moderate dental crowding.Clinically,PAOO-assisted orthodontic tooth movement in this case showed enhanced periodontium remodeling.Radiographic outcomes also showed statistically significant improvements(P<0.01)in the mandibular buccal alveolar bone.CONCLUSION This case report suggests the combination of autologous PRF with PAOO to enhance bone augmentation and long-term tissue support in adult orthodontic patients with periodontal disease.展开更多
Anchorage is an important factor in orthodontics and must be properly managed for a successful treatment outcome. Orthodontists have historically used many devices to prevent unwanted tooth movement. The use of minisc...Anchorage is an important factor in orthodontics and must be properly managed for a successful treatment outcome. Orthodontists have historically used many devices to prevent unwanted tooth movement. The use of miniscrews as a source of skeletal anchorage has become routine in present-day orthodontic practice. Skeletal anchorage opens up alternative treatments, to borderline surgery patients for example, who can now be treated by taking advantage of the biomechanical properties of miniscrews. Because they are bone-borne and provide excellent control over tooth movement in the three spatial planes of movement, mini-implants can be used to serve many purposes in addition to anchorage. Therefore, a variety of successful mini-implant appliances are explained in relation to the three planes of movement: sagittal, vertical, and transverse. The aim of this review is to illustrate the clinical versatility of miniscrews in the three spatial planes of malocclusion in orthodontic and orthopedic management and to define clinical guidelines for the selection, application and biomechanics of mini-implants.展开更多
Bilateral Controversy in orthodontic science is widely present in different patterns;one of the most common is the debate between early versus late orthodontic treatment. This paper is going to demonstrate two clinica...Bilateral Controversy in orthodontic science is widely present in different patterns;one of the most common is the debate between early versus late orthodontic treatment. This paper is going to demonstrate two clinical cases of class III malocclusion which are treated orthodontically, one in early mixed dentition and the other in permanent dentition. The face is highly capable to adapt to the changes achieved by orthodontics provided the earlier treatment begins, the more the face adapts to our standards;the later treatment begins, the more our standards have to adapt to the face.展开更多
Dental biofilm is the initiating factor of oral diseases,such as periodontitis and caries.Orthodontic treatment could alter the microbiome structure balance,and increase the risk of such diseases.Furthermore,fixed app...Dental biofilm is the initiating factor of oral diseases,such as periodontitis and caries.Orthodontic treatment could alter the microbiome structure balance,and increase the risk of such diseases.Furthermore,fixed appliances can induce temporary changes in the microbiome community,and the changes that clear aligners bring are smaller by comparison.Temporary anchorage devices(TADs)are skeletal anchorages that are widely used in orthodontic treatment.Microorganisms affect the occurrence and development of inflammation surrounding TADs.At present,existing researches have verified the existence of plaque biofilm on the surface of TADs,but the formation of plaque biofilm and plaque composition under different stable conditions have not been fully understood.The development of high-throughput sequencing,molecular biology experiments,and metabonomics have provided new research ideas to solve this problem.They can become an effective means to explore the microbiome surrounding TADs.展开更多
This case presents an unusual transposition of an impacted canine on the central incisor that provides a multidisciplinary approach to its resolution. The patient comes to the consultation for mobility of the central ...This case presents an unusual transposition of an impacted canine on the central incisor that provides a multidisciplinary approach to its resolution. The patient comes to the consultation for mobility of the central incisor. Clinically, tooth mobility was confirmed with tooth crowding and persistence of the temporary canine. Cone beam tomography (CBCT) observed the atypical position of the permanent canine that caused root resorption of the ipsilateral central incisor and the need to extract both teeth. The conservative treatment of the bone structures during the dental enucleation of the impacted canine carried out by odontosection and the immediate bone grafting of the defect projected an acceptable regeneration of the bone volume for the insertion of the implant. The orthodontic treatment managed to correct the bite, position the upper premolar in the place of the canine tooth and maintain the space to place the implant in the central incisor. The three-year follow-up shows maintenance of the peri-implant crestal bone level, the success of orthodontic treatment with recovery of the patient’s function and aesthetics.展开更多
Objective:To investigate the clinical efficacy of periodontal sequence in combination with orthodontic treatment of patients with periodontitis.Methods:Retrospective analysis of periodontitis patients(54 cases)treated...Objective:To investigate the clinical efficacy of periodontal sequence in combination with orthodontic treatment of patients with periodontitis.Methods:Retrospective analysis of periodontitis patients(54 cases)treated at our hospital between February 2018 and June 2019.The clinical data of all the enrolled participants were subjected to periodontal serial combined orthodontic treatment,and all the registered participants were observed at the initial consultation,periodontal serial treatment1 Periodontal parameters at the end of months and at the end of orthodontic treatment,serial periodontal treatment and orthodontic treatment for all enrolled individuals,x-rays and Oral examinations were performed,and the results were analyzed.Results:Compared to the initial visit,all enrolled individuals had a higher plaque index(PLI)after 1 month of periodontal treatment and at the end of orthodontic treatment.Bleeding index(BI),periodontal probe depth(PD),and periodontal attachment loss(CAL)levels were all lower than those detected at the initial visit.The difference was statistically significant(P<0.05);after serial periodontal treatment and orthodontic treatment,the x-ray results showed that the patients’Alveolar bone resorption or regeneration ceased;The results of the oral examination showed that the patient’s occlusal relationship improved significantly and basically returned to normal.Status,a masticatory function was significantly improved,and individual tooth loosening due to occlusal trauma was improved considerably.Conclusion:The combination of periodontal sequence and orthodontic treatment of patients with periodontitis is beneficial to enhance periodontal parameters,improve occlusal relationships,and improve masticatory function.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
Whether medicine is a science remains a philosophical question. Yet undeniably advances in science have revolutionarily influenced almost every aspect of medicine including dentistry. It is now exactly one hundred yea...Whether medicine is a science remains a philosophical question. Yet undeniably advances in science have revolutionarily influenced almost every aspect of medicine including dentistry. It is now exactly one hundred years from Edward H. Angle introduced fixed orthodontic appliances in the early 1900s and established orthodontics as the first dental specialty. Orthodontics has come a long way during its first century. Looking forward to all the challenges and opportunities, it is now time to reflect what science has given to our profession, what for gap still exists between the science and practice in orthodontics, and how we can make science more available to our practice in future.展开更多
Background Enamel decalcification in orthodontics is a concern for dentists and methods to remineralize these lesions are the focus of intense research. The aim of this study was to evaluate the remineralizing effect ...Background Enamel decalcification in orthodontics is a concern for dentists and methods to remineralize these lesions are the focus of intense research. The aim of this study was to evaluate the remineralizing effect of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) nanocomplexes on enamel decalcification in orthodontics. Methods Twenty orthodontic patients with decalcified enamel lesions during fixed orthodontic therapy were recruited to this study as test group and twenty orthodontic patients with the similar condition as control group. GC Tooth Mousse, the main component of which is CPP-ACP, was used by each patient of test group every night after tooth-brushing for six months. For control group, each patient was asked to brush teeth with toothpaste containing 1100 parts per million (ppm) of fluoride twice a day. Standardized intraoral images were taken for all patients and the extent of enamel decalcification was evaluated before and after treatment over this study period. Measurements were statistically compared by t test. Results After using CPP-ACP for six months, the enamel decalcification index (EDI) of all patients had decreased; the mean EDI before using CPP-ACP was 0.191+0.025 and that after using CPP-ACP was 0.183+0.023, the difference was significant (t=5.169, P 〈0.01). For control group, the mean EDI before treatment was 0.188±0.037 and that after treatment was 0.187±0.046, the difference was not significant (t=1.711, P 〉0.05). Conclusion CPP-ACP can effectively improve the demineralized enamel lesions during orthodontic treatment, so it has some remineralization potential for enamel decalcification in orthodontics.展开更多
The malalignment of teeth is treated classically by metal braces with alloy wires,which has an unfavorable influence on the patients appearance during the treatment.With the development of digitization,computer simula...The malalignment of teeth is treated classically by metal braces with alloy wires,which has an unfavorable influence on the patients appearance during the treatment.With the development of digitization,computer simulation and three-dimensional(3D)printing technology,herein,a modern treatment was tried using clear polymeric aligners,which were fabricated by molding polyurethane films via thermoforming on the 3D-printed personalized dental models.The key parameters of photocurable 3D printing of dental models and the mechanical properties of the clear aligner film material were examined.The precision of a 3D-printed dental model mainly relied on characteristics of photocurable resin,the resolution of light source and the exposure condition,which determined the eventual shape of the molded clear aligner and thus the orthodontic treatment efficacy.The biocompatibility of the polyurethane filmmaterial was confirmed through cytotoxicity and hemolysis tests in vitro.Following a series of 3D-printed personalized dental models and finite element analysis to predict and plan the fabrication and orthodontic processes,corresponding clear aligners were fabricated and applied in animal experiments,which proved the efficacy and biocompatibility in vivo.Clinical treatments of 120 orthodontic cases were finally carried out with success,which highlights the advantage of the clear aligners as an esthetic,compatible and efficient appliance.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Introduction: The stability of orthodontic brackets throughout orthodontic treatment plays a critical role in the treatment’s effectiveness. The present in vitro study was designed to assess the impact of various dietary components on the performance of orthodontic brackets. Methods: Metal orthodontic brackets were bonded to 66 extracted anterior teeth divided into groups based on the solution type: Milk, Gatorade, Cold Coffee, and a control group using water. Each group consisted of 20 teeth except for the control group, which included six teeth. The bracketed teeth were submerged in their respective solutions for 15 minutes three times daily at different intervals to mimic an in vivo environment and were stored in artificial saliva at room temperature (23?C). The specimens underwent artificial aging through 10,000 cycles of thermocycling (representing one clinical year) between 5?C and 55?C. Shade measurements were taken using a VITA Easy Shade device, capturing the classic shade and L*, a*, and b* values. Delta E values were calculated immediately post-bonding and after 7 days, 1 month, 1, and 2 clinical years. The shear bond strength of each bracket was measured using an ultra-tester machine. Results: After two clinical years, significant differences in ΔE color values were observed across all groups, with the most substantial change noted in teeth immersed in cold coffee. Brackets submerged in milk demonstrated lower shear bond strength than other solutions, whereas the control group exhibited the highest shear bond strength (P = 0.01). Conclusion: The study indicates that dietary components significantly influence tooth color stability and the shear bond strength of orthodontic brackets, underscoring the importance of considering these factors in orthodontic treatment planning.
文摘A simple overview of daily orthodontic practice involves use of brackets, wires and elastomeric modules. However, investigating the underlying effect of orthodontic forces shows various molecular and cellular changes. Also, orthodontics is in close relation with dentofacial orthopedics which involves bone regeneration. In this review current and future applications of stem cells(SCs) in orthodontics and dentofacial orthopedics have been discussed. For craniofacial anomalies, SCs have been applied to regenerate hard tissue(such as treatment of alveolar cleft) and soft tissue(such as treatment of hemifacial macrosomia). Several attempts have been done to reconstruct impaired temporomandibular joint. Also, SCs with or without bone scaffolds and growth factors have been used to regenerate bone following distraction osteogenesis of mandibular bone or maxillary expansion. Current evidence shows that SCs also have potential to be used to regenerate infrabony alveolar defects and move the teeth into regenerated areas. Future application of SCs in orthodontics could involve accelerating tooth movement, regenerating resorbed roots and expanding tooth movement limitations. However, evidence supporting these roles is weak and further studies are required to evaluate the possibility of these ideas.
文摘The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too.
基金Supported by Natured Science Foundation of Anhui Province,No.1908085MH255.
文摘BACKGROUND In the clinical scenario,adult patients with periodontal diseases and dental malformation,characterized by dental crowding in lower anterior teeth with the thin biotype,often require orthodontic treatment.This case report aimed to evaluate the clinical and radiographic outcomes of periodontally accelerated osteogenic orthodontics(PAOO)combined with autologous platelet-rich fibrin(PRF)in an adult patient with class I malocclusion along with dental crowding,a thin periodontal biotype,and buccal plate deficiency.CASE SUMMARY A 32-year-old female complaining of dental crowding and gingival bleeding was referred to the orthodontic clinic.The patient underwent periodontal risk assessment prior to orthodontic treatment.She was diagnosed with a high risk of gingival recession due to dental crowding,root prominence,loss of buccal plates,and a thin gingival tissue biotype.The treatment regimen included PAOO combined with autologous PRF for alveolar augmentation and interproximal enamel reduction for moderate dental crowding.Clinically,PAOO-assisted orthodontic tooth movement in this case showed enhanced periodontium remodeling.Radiographic outcomes also showed statistically significant improvements(P<0.01)in the mandibular buccal alveolar bone.CONCLUSION This case report suggests the combination of autologous PRF with PAOO to enhance bone augmentation and long-term tissue support in adult orthodontic patients with periodontal disease.
文摘Anchorage is an important factor in orthodontics and must be properly managed for a successful treatment outcome. Orthodontists have historically used many devices to prevent unwanted tooth movement. The use of miniscrews as a source of skeletal anchorage has become routine in present-day orthodontic practice. Skeletal anchorage opens up alternative treatments, to borderline surgery patients for example, who can now be treated by taking advantage of the biomechanical properties of miniscrews. Because they are bone-borne and provide excellent control over tooth movement in the three spatial planes of movement, mini-implants can be used to serve many purposes in addition to anchorage. Therefore, a variety of successful mini-implant appliances are explained in relation to the three planes of movement: sagittal, vertical, and transverse. The aim of this review is to illustrate the clinical versatility of miniscrews in the three spatial planes of malocclusion in orthodontic and orthopedic management and to define clinical guidelines for the selection, application and biomechanics of mini-implants.
文摘Bilateral Controversy in orthodontic science is widely present in different patterns;one of the most common is the debate between early versus late orthodontic treatment. This paper is going to demonstrate two clinical cases of class III malocclusion which are treated orthodontically, one in early mixed dentition and the other in permanent dentition. The face is highly capable to adapt to the changes achieved by orthodontics provided the earlier treatment begins, the more the face adapts to our standards;the later treatment begins, the more our standards have to adapt to the face.
基金supported by the Beijing Municipal Science&Technology Commission(No.Z171100001017128)National Program for Multidisciplinary Cooperative Treatment on Major Diseases(No.PKUSSNMP-202013)+1 种基金National Natural Science Foundation of China(No.81671015)China Postdoctoral Science Foundation(No.2020M680263).
文摘Dental biofilm is the initiating factor of oral diseases,such as periodontitis and caries.Orthodontic treatment could alter the microbiome structure balance,and increase the risk of such diseases.Furthermore,fixed appliances can induce temporary changes in the microbiome community,and the changes that clear aligners bring are smaller by comparison.Temporary anchorage devices(TADs)are skeletal anchorages that are widely used in orthodontic treatment.Microorganisms affect the occurrence and development of inflammation surrounding TADs.At present,existing researches have verified the existence of plaque biofilm on the surface of TADs,but the formation of plaque biofilm and plaque composition under different stable conditions have not been fully understood.The development of high-throughput sequencing,molecular biology experiments,and metabonomics have provided new research ideas to solve this problem.They can become an effective means to explore the microbiome surrounding TADs.
文摘This case presents an unusual transposition of an impacted canine on the central incisor that provides a multidisciplinary approach to its resolution. The patient comes to the consultation for mobility of the central incisor. Clinically, tooth mobility was confirmed with tooth crowding and persistence of the temporary canine. Cone beam tomography (CBCT) observed the atypical position of the permanent canine that caused root resorption of the ipsilateral central incisor and the need to extract both teeth. The conservative treatment of the bone structures during the dental enucleation of the impacted canine carried out by odontosection and the immediate bone grafting of the defect projected an acceptable regeneration of the bone volume for the insertion of the implant. The orthodontic treatment managed to correct the bite, position the upper premolar in the place of the canine tooth and maintain the space to place the implant in the central incisor. The three-year follow-up shows maintenance of the peri-implant crestal bone level, the success of orthodontic treatment with recovery of the patient’s function and aesthetics.
文摘Objective:To investigate the clinical efficacy of periodontal sequence in combination with orthodontic treatment of patients with periodontitis.Methods:Retrospective analysis of periodontitis patients(54 cases)treated at our hospital between February 2018 and June 2019.The clinical data of all the enrolled participants were subjected to periodontal serial combined orthodontic treatment,and all the registered participants were observed at the initial consultation,periodontal serial treatment1 Periodontal parameters at the end of months and at the end of orthodontic treatment,serial periodontal treatment and orthodontic treatment for all enrolled individuals,x-rays and Oral examinations were performed,and the results were analyzed.Results:Compared to the initial visit,all enrolled individuals had a higher plaque index(PLI)after 1 month of periodontal treatment and at the end of orthodontic treatment.Bleeding index(BI),periodontal probe depth(PD),and periodontal attachment loss(CAL)levels were all lower than those detected at the initial visit.The difference was statistically significant(P<0.05);after serial periodontal treatment and orthodontic treatment,the x-ray results showed that the patients’Alveolar bone resorption or regeneration ceased;The results of the oral examination showed that the patient’s occlusal relationship improved significantly and basically returned to normal.Status,a masticatory function was significantly improved,and individual tooth loosening due to occlusal trauma was improved considerably.Conclusion:The combination of periodontal sequence and orthodontic treatment of patients with periodontitis is beneficial to enhance periodontal parameters,improve occlusal relationships,and improve masticatory function.
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.
文摘Whether medicine is a science remains a philosophical question. Yet undeniably advances in science have revolutionarily influenced almost every aspect of medicine including dentistry. It is now exactly one hundred years from Edward H. Angle introduced fixed orthodontic appliances in the early 1900s and established orthodontics as the first dental specialty. Orthodontics has come a long way during its first century. Looking forward to all the challenges and opportunities, it is now time to reflect what science has given to our profession, what for gap still exists between the science and practice in orthodontics, and how we can make science more available to our practice in future.
文摘Background Enamel decalcification in orthodontics is a concern for dentists and methods to remineralize these lesions are the focus of intense research. The aim of this study was to evaluate the remineralizing effect of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) nanocomplexes on enamel decalcification in orthodontics. Methods Twenty orthodontic patients with decalcified enamel lesions during fixed orthodontic therapy were recruited to this study as test group and twenty orthodontic patients with the similar condition as control group. GC Tooth Mousse, the main component of which is CPP-ACP, was used by each patient of test group every night after tooth-brushing for six months. For control group, each patient was asked to brush teeth with toothpaste containing 1100 parts per million (ppm) of fluoride twice a day. Standardized intraoral images were taken for all patients and the extent of enamel decalcification was evaluated before and after treatment over this study period. Measurements were statistically compared by t test. Results After using CPP-ACP for six months, the enamel decalcification index (EDI) of all patients had decreased; the mean EDI before using CPP-ACP was 0.191+0.025 and that after using CPP-ACP was 0.183+0.023, the difference was significant (t=5.169, P 〈0.01). For control group, the mean EDI before treatment was 0.188±0.037 and that after treatment was 0.187±0.046, the difference was not significant (t=1.711, P 〉0.05). Conclusion CPP-ACP can effectively improve the demineralized enamel lesions during orthodontic treatment, so it has some remineralization potential for enamel decalcification in orthodontics.
基金supports from NSF of China(grants No.52130302,21961160721)National Key R&D Program of China(grant No.2016YFC1100300)。
文摘The malalignment of teeth is treated classically by metal braces with alloy wires,which has an unfavorable influence on the patients appearance during the treatment.With the development of digitization,computer simulation and three-dimensional(3D)printing technology,herein,a modern treatment was tried using clear polymeric aligners,which were fabricated by molding polyurethane films via thermoforming on the 3D-printed personalized dental models.The key parameters of photocurable 3D printing of dental models and the mechanical properties of the clear aligner film material were examined.The precision of a 3D-printed dental model mainly relied on characteristics of photocurable resin,the resolution of light source and the exposure condition,which determined the eventual shape of the molded clear aligner and thus the orthodontic treatment efficacy.The biocompatibility of the polyurethane filmmaterial was confirmed through cytotoxicity and hemolysis tests in vitro.Following a series of 3D-printed personalized dental models and finite element analysis to predict and plan the fabrication and orthodontic processes,corresponding clear aligners were fabricated and applied in animal experiments,which proved the efficacy and biocompatibility in vivo.Clinical treatments of 120 orthodontic cases were finally carried out with success,which highlights the advantage of the clear aligners as an esthetic,compatible and efficient appliance.
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.