OBJECTIVE: To assess the efficacy of bone anchorage and maxillary facemask protraction devices in treating skeletal class Ⅲ malocclusion in adolescents. METHODS: Articles relating to the use of bone anchorage and maxillary facemask protraction devices for treating skeletal class Ⅲ malocclusion in adolescents were searched from the databases of Cochrane Library, PubMed, EmBase, CNKI, and Wanfang database. Several inclusion and exclusion criteria were developed for the article screening. The clinical data were extracted, and the quality of the selected articles was evaluated. A Meta-analysis of SNA, SNB, ANB, ANS-Me, Wits, and U1-PP change was performed by using RevMan 5.3. RESULTS: Seven studies (264 patients) were included in the Meta-analysis. Among these studies, three were randomized controlled trials, and four were non-randomized controlled trials. Compared with the maxillary facemask protraction device group, the bone ancho-rage device group had higher SNA changes and lower ANS-Me, Wits, and U1-PP changes (P<0.05). No significant differences were observed in the SNB and ANB changes between these two groups. CONCLUSIONS Compared with the maxillary facemask protraction device, the bone anchorage device can increase the extent of protraction of the maxilla and has better controls for the labial inclination of the maxillary anterior teeth in treating skeletal class Ⅲ malocclusion among adolescents. However, additional high-quality randomized controlled trials must be performed to verify the results.
Adolescent ; Cephalometry ; Extraoral Traction Appliances ; Humans ; Malocclusion, Angle Class III ; Maxilla ; Palatal Expansion Technique

Child ; Extraoral Traction Appliances ; Humans ; Molar ; Orthodontic Wires ; Orthodontics, Interceptive ; instrumentation ; Prognosis ; Time Factors ; Tooth Crown ; surgery ; Tooth Eruption, Ectopic ; surgery ; therapy ; Tooth Movement Techniques ; instrumentation ; methods

OBJECTIVETo evaluate the soft profile and hard tissue changes after maxillary protraction with skeletal anchorage implant in treatment of Class III malocclusion during growth period.

METHODS18 patients with skeletal Class III malocclusion were treated with maxillary protraction for about 9 months, (3.5 +/- 0.1) N, with skeletal anchorage implant and face mask. Cephalometric records were analyzed to assess the changes of maxillo-facial structure of the hard and soft tissue before and after treatment.

RESULTSAll patients' Class III profiles were corrected. Maxillary growth increased, chin clockwise rotated, facial convexity angle increased, lower lip protrusion decreased. Facial vertical height ratio, nasolabial angle, upper lip protrusion and mentolabial sulcus changed unconspicuously. Upper incisors kept in sites, lower incisor upright, maxilla moved forwards. SNA, ANB significantly increased. SNB decreased and the mandible clockwise rotated.

CONCLUSIONThe maxilla is effectively protracted without significant rotation by using skeletal anchorage implant. The undesired effects of conventional protraction therapies, such as labial tilt of upper anterior teeth and extrusion of the maxillary molars, are reduced or eliminated with skeletal anchorage implant. These effects can conspicuously correct profiles of the patients with skeletal Class III malocclusion, make the profile more harmonious and aesthetic.

Cephalometry ; Chin ; Extraoral Traction Appliances ; Face ; Humans ; Incisor ; Lip ; Malocclusion, Angle Class III ; Mandible ; Maxilla ; Molar

OBJECTIVE: The purpose of this prospective study was to evaluate the dentofacial effects of conventional and modified facemask therapies with rapid maxillary expansion, in a group of Class III patients; and compared with an untreated control group. METHODS: The conventional facemask group (Group 1) comprised of 24 patients, 13 girls and 11 boys (mean age, 9.2 +/- 1.4 years); the modified facemask treatment group (Group 2) comprised of 24 patients, 12 girls and 12 boys (mean age, 9.3 +/- 1.6 years); and the control group (Group 3) comprised of 21 subjects, 11 girls and 10 boys (mean age, 9.8 +/- 1.9 years). Treatment and control changes within the groups and the differences between the groups were analyzed statistically. Intra-group comparisons were evaluated using the non-parametric Wilcoxon's test and intergroup changes were analyzed using the Kruskal-Wallis test. The statistical significance of intergroup differences was further assessed with the Mann-Whitney test for independent samples and applying Bonferroni's correction (p < 0.016). RESULTS: In group 1, SNB changes were less than the control. There were increases in SNA, ANB, SN-MP, A to N perp and Upper lip to E plane. In group 2, SNB, U1-NA (mm) U1-NA (degrees) and Pog to N perp (mm) changes were less than the control. There were increases in SNA, ANB, SN-MP, A to N perp and Upper lip to E plane. CONCLUSIONS: Modified facemask appliance can be used effectively in Class III patients with a retrognathic maxilla. Facemask therapies with expansion resulted in an anterior advancement and translation of maxilla without rotation; and the mandible moved downward and backward in both treatment groups.
Cephalometry ; Extraoral Traction Appliances ; Humans ; Lip ; Malocclusion ; Malocclusion, Angle Class III ; Mandible ; Maxilla ; Palatal Expansion Technique ; Prospective Studies

OBJECTIVETo evaluate the effectiveness of treatment with maxillary protraction with or without rapid palatal expansion (RPE) for skeletal Class III malocclusion in mixed dentition.

METHODSA total of 31 children with Class III malocclusion in mixed dentition were selected, and 15 (group A) received maxillary protraction treatment with RPE, the other 16 (group B) received maxillary protraction without RPE. Cephalometric films were taken before and after treatment, and traditional and Pancherz analysis were used.

RESULTSThe average duration of treatment was 10.14 months in group A and 9.77 months in group B respectively (P>0.05). According to Pancherz analysis, maxillary basal bone moved forwards by 2.99 mm in group A and 3.33 mm in group B respectively (P>0.05), mandibular basal bone moved backwards by 0.07 mm in group A, while forwards by 0.80 mm in group B (P>0.05), the overjet increased by 4.51 mm in group A and 6.37 mm in group B respectively (P<0.05), and the molar relationship improved by 4.97 mm in group A and 4.73 mm in group B respectively (P>0.05). The effects were clinically satisfactory in the both groups. Lower molar moved forwards by 1.18 mm in basal bone in group A, while backwards by 1.20 mm in group B (P<0.05). Traditional cephalometric analysis showed no statistic differences between the two groups except that upper incisior showed greater procline in group B than in group A (P<0.05).

CONCLUSIONThe study shows that maxillary protraction treatment, with or without RPE, is clinically satisfactory to correct early skeletal Class III malocclusion.

Cephalometry ; Child ; Extraoral Traction Appliances ; Female ; Humans ; Male ; Malocclusion, Angle Class III ; Mandible ; Maxilla ; Molar ; Palatal Expansion Technique

OBJECTIVE: To determine the effect of simulated protraction after maxillary fissure repair on stress and shift of maxillary bone and to provide the scientific evidence for treatment of maxilla in patients with cleft lip and palate. METHODS: Based on the establishment of 3-dimensional finite element model of maxilla with cleft lip and palate, we used ANSYS 10.0 software to simulate protraction, repair fissures of maxillary bone, and then analyzed the change of maxillary stress and shift. RESULTS: The maxillary fissures could be enlarged by protraction without reparation of maxillary. Obvious motion was observed on the uninjured side, with 500 g/per lateral protraction and 30 degree protraction angle. The major principal stress and von Mises stress of craniofacial bone distributed evenly under protraction after fissure repair. CONCLUSION The maxillary fissures have an enlarged trend by protraction without repair.The protraction treatment benefits the development of maxillary bone after repairing maxillary fissure.
Biomechanical Phenomena ; Cleft Lip ; therapy ; Cleft Palate ; therapy ; Extraoral Traction Appliances ; Finite Element Analysis ; Humans ; Imaging, Three-Dimensional ; Malocclusion ; therapy ; Maxilla ; physiology ; Retrognathia ; therapy

OBJECTIVE: To determine the rule of simulated protraction and palate expansion on shift of maxillary bone,and to supply the scientific data for treating maxilla in patients with cleft lip and palate. METHODS: Based on the establishment of 3-dimensional finite element model of maxilla with cleft lip and palate, we used ANSYS 10.0 software to simulate protraction and expand fissures of palate, and analyzed the changes of maxillary shift. RESULTS: After the simulated protraction and pa-late expansion,an upward, forward, and outward growth occurred on maxilla, and the normal lateral bow had no internal shrinkage as well as the abnormal one. CONCLUSION Combined palate expansion with maxillary protraction treatment in patients with cleft lip and palate tend to improve the development of maxillary bone.
Biomechanical Phenomena ; Cleft Lip ; therapy ; Cleft Palate ; therapy ; Extraoral Traction Appliances ; Finite Element Analysis ; Humans ; Imaging, Three-Dimensional ; Malocclusion ; therapy ; Maxilla ; physiology ; Palatal Expansion Technique ; Retrognathia ; therapy

OBJECTIVERetention elements were added in the removable reverse headgear appliances in order to achieve better treatment effects of skeletal Class III malocclusion.

METHODSEighteen patients who needed treatments with reverse headgear appliances were randomly and equally divided into two groups with traditional type of retention elements (T group) and modified type of retention elements (M group) respectively. For the modified type appliances, an adams clasp was added in the position of central incisors on the basis of the traditional type. The minimum dislocating force for both types was measured with the same forcemeter in the first and second visit, respectively. The occurrence of dislocation caused by traction was recorded during the visits of the first three months.

RESULTSThe M group showed significantly greater retention than the T group. The minimum dislocating force for M group was larger in the first and second visit (P<0.01, P<0.001). Furthermore, during the first three months, two times of dislocation occurred in M group while it was nine times for T group, indicating great difference in retention (P< 0.05).

CONCLUSIONAdding an adams clasp in the position of upper central incisors could effectively prevent the downward dislocation of the appliance when traction force was applied. Accordingly, the therapeutic efficacy was greatly improved.

Extraoral Traction Appliances ; Female ; Humans ; Incisor ; Male ; Malocclusion, Angle Class II ; Malocclusion, Angle Class III ; Tooth ; Tooth Movement Techniques

OBJECTIVE: To determine the effective rule of protraction in different directions,strains, and shifts of maxillary bone,and to supply the scientific data for treatment of the maxilla in patients with cleft lip and palate. METHODS: " Based on the establishment of 3-dimensional finite element model of maxilla with cleft lip and palate,ANSYS 10.0 software was used to simulate protraction,and then we analyzed the change of maxillary stress and shift in the same force of traction in different directions. RESULTS: With 500 g per lateral protraction and the protraction angle from 20 degree to 45 degree,the maxillary shifted upward, forward, and outward, and the shape of maxillary plate bow showed internal shrinkage. There was a close relation between the internal shrinkage and the direction of protraction. The smaller the angle between the direction of protraction and the functional occlusion plane,the larger the internal shrinkage of tooth bow. The larger the angle between the direction of protraction and the functional occlusion plane,the smaller the internal shrinkage of tooth bow. CONCLUSION With protraction,the maxilla grows upward, forward, and outward, and the maxillary palate shinks internally. There is a close relation between the direction of protraction and the range of internal shrinkage.
Biomechanical Phenomena ; Cleft Lip ; therapy ; Cleft Palate ; therapy ; Extraoral Traction Appliances ; Finite Element Analysis ; Humans ; Imaging, Three-Dimensional ; Malocclusion ; therapy ; Maxilla ; physiology ; Retrognathia ; therapy

Child ; Dental Implantation, Endosseous ; Extraoral Traction Appliances ; Humans ; Male ; Malocclusion, Angle Class III ; therapy ; Maxilla ; abnormalities ; Orthodontic Anchorage Procedures ; instrumentation ; Orthodontic Appliance Design ; Orthodontics, Corrective ; instrumentation