The aim of this retrospective study was to quantitatively evaluate the treatment effects of in- trusion of overerupted maxillary molars using miniscrew implant anchorage and to investigate the apical root resorption a...The aim of this retrospective study was to quantitatively evaluate the treatment effects of in- trusion of overerupted maxillary molars using miniscrew implant anchorage and to investigate the apical root resorption after molar intrusion. The subjects included 30 patients whose average ages were 35.5±9.0 years. All patients had received intrusion treatments for overerupted maxillary molars with miniscrew anchorage. There were 38 maxillary first molars and 26 maxillary second molars to be in- truded. Two miniscrews were inserted in the buccal and palatal alveolar bone mesial to the overerupted molar. Force of 100-150 g was applied by the elastic chains between screw head and attachment on each side. Lateral cephalograms and panoramic radiographs taken before and after intrusion were used to evaluate dental changes and root resorption of molars. Only 6 of the 128 miniscrews failed. The first and second molars were significantly intruded by averages of 3.4 mm and 3.1 mm respectively （P〈0.001）. The average intrusion time was more than 6 months. The crown of the molars mesially tilted by averages of 3.1 degrees and 3.3 degrees （P〈0.001） for first and second molars. The amounts of root resorption were 0.2-0.4 mm on average. The intrusion treatment of overerupted molars with miniscrew anchorages could be used as an efficient and reliable method to recover lost restoration space for pros- thesis. Radiographically speaking, root resorption of molars was not clinically significant after applica- tion of intrusive forces of 200 to 300 g.展开更多
Miniscrews offer a reliable alternative for anchorage during orthodontic treatment,particularly for non-cooperative patients or periodontal patients with alveolar bone loss.The study aims at assessing the correlation ...Miniscrews offer a reliable alternative for anchorage during orthodontic treatment,particularly for non-cooperative patients or periodontal patients with alveolar bone loss.The study aims at assessing the correlation of various clinical indicators with the success or failure of miniscrews used for anchorage during orthodontic treatment.Thirty-four consecutive patients with a cumulative total of 82 miniscrews implanted participated in the study.Generalized Estimating Equations were used to assess the correlation of various factors with success rates.The miniscrew was considered the unit of analysis clustered within site and within patient.The overall success rate of miniscrews was 90.2%.For every additional miniscrew used in a patient＇s oral cavity,the success rate was reduced by 67%.Retromandibular triangle and palatal placement and in movable mucosa resulted in lower success rate.The miniscrew length and diameter were found to correlate with success rates.Orthodontic force applied on miniscrews for uprighting purposes showed a lower success rate than that used for retraction.This study revealed that miniscrews present high success rates.The number of miniscrews used per patient,the miniscrew site placement,the soft tissue type of placement,the miniscrew length and diameter as well as the orthodontic force applied on the miniscrew showed significant correlation with success rates.展开更多
The purpose of this study was to investigate the cortical bone thickness of the inter-dental area of both jaws for orthodontic miniscrew placement. The cone-beam computerized tomography images of 32 non-orthodontic ad...The purpose of this study was to investigate the cortical bone thickness of the inter-dental area of both jaws for orthodontic miniscrew placement. The cone-beam computerized tomography images of 32 non-orthodontic adults with normal occlusion were taken to measure the cortical bone thick- ness in both.jaws. One-way analysis of variance （ANOVA） was used to analyze the differences in cortical bone thickness. Buccal cortical bone in the mandible was thicker than that in the maxilla. In the maxilla, cortical bone thickness was thicker in the buccal side than in the palatal side. Buccal cortical bone thickness in the mandible was thickest at the site distal to the first molar, and in the maxilla it was thickest at the site mesial to the first molar, while in the palatal side of maxilla it was thickest at the site mesial to the second premolar. The changing pattern of cortical bone thickness varies at different sites. In the buccal side of maxilla, the thinnest cortical bone thickness was lbund to be at 4 mm level from the alveolar crest, while the thickest was at 10 mm level （except for the site mesial to the first premolar）. The buccal cortical bone thickness at the sites mesial or distal to the first molar in the mandible and palatal cortical bone thickness of maxilla tended to increase with increasing distance from the alveolar bone.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
文摘The aim of this retrospective study was to quantitatively evaluate the treatment effects of in- trusion of overerupted maxillary molars using miniscrew implant anchorage and to investigate the apical root resorption after molar intrusion. The subjects included 30 patients whose average ages were 35.5±9.0 years. All patients had received intrusion treatments for overerupted maxillary molars with miniscrew anchorage. There were 38 maxillary first molars and 26 maxillary second molars to be in- truded. Two miniscrews were inserted in the buccal and palatal alveolar bone mesial to the overerupted molar. Force of 100-150 g was applied by the elastic chains between screw head and attachment on each side. Lateral cephalograms and panoramic radiographs taken before and after intrusion were used to evaluate dental changes and root resorption of molars. Only 6 of the 128 miniscrews failed. The first and second molars were significantly intruded by averages of 3.4 mm and 3.1 mm respectively （P〈0.001）. The average intrusion time was more than 6 months. The crown of the molars mesially tilted by averages of 3.1 degrees and 3.3 degrees （P〈0.001） for first and second molars. The amounts of root resorption were 0.2-0.4 mm on average. The intrusion treatment of overerupted molars with miniscrew anchorages could be used as an efficient and reliable method to recover lost restoration space for pros- thesis. Radiographically speaking, root resorption of molars was not clinically significant after applica- tion of intrusive forces of 200 to 300 g.
文摘Miniscrews offer a reliable alternative for anchorage during orthodontic treatment,particularly for non-cooperative patients or periodontal patients with alveolar bone loss.The study aims at assessing the correlation of various clinical indicators with the success or failure of miniscrews used for anchorage during orthodontic treatment.Thirty-four consecutive patients with a cumulative total of 82 miniscrews implanted participated in the study.Generalized Estimating Equations were used to assess the correlation of various factors with success rates.The miniscrew was considered the unit of analysis clustered within site and within patient.The overall success rate of miniscrews was 90.2%.For every additional miniscrew used in a patient＇s oral cavity,the success rate was reduced by 67%.Retromandibular triangle and palatal placement and in movable mucosa resulted in lower success rate.The miniscrew length and diameter were found to correlate with success rates.Orthodontic force applied on miniscrews for uprighting purposes showed a lower success rate than that used for retraction.This study revealed that miniscrews present high success rates.The number of miniscrews used per patient,the miniscrew site placement,the soft tissue type of placement,the miniscrew length and diameter as well as the orthodontic force applied on the miniscrew showed significant correlation with success rates.
文摘The purpose of this study was to investigate the cortical bone thickness of the inter-dental area of both jaws for orthodontic miniscrew placement. The cone-beam computerized tomography images of 32 non-orthodontic adults with normal occlusion were taken to measure the cortical bone thick- ness in both.jaws. One-way analysis of variance （ANOVA） was used to analyze the differences in cortical bone thickness. Buccal cortical bone in the mandible was thicker than that in the maxilla. In the maxilla, cortical bone thickness was thicker in the buccal side than in the palatal side. Buccal cortical bone thickness in the mandible was thickest at the site distal to the first molar, and in the maxilla it was thickest at the site mesial to the first molar, while in the palatal side of maxilla it was thickest at the site mesial to the second premolar. The changing pattern of cortical bone thickness varies at different sites. In the buccal side of maxilla, the thinnest cortical bone thickness was lbund to be at 4 mm level from the alveolar crest, while the thickest was at 10 mm level （except for the site mesial to the first premolar）. The buccal cortical bone thickness at the sites mesial or distal to the first molar in the mandible and palatal cortical bone thickness of maxilla tended to increase with increasing distance from the alveolar bone.
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.
