OBJECTIVETo investigate the soft and hard tissue changes in Class II division 1 patients treated with Tip-Edge plus technique.

METHODSSixteen Class II division 1 patients (7 boys and 9 girls) with mandibular retrusion in permanent dentition were selected and treated with Tip-Edge plus appliance. Lateral cephalometric films were analyzed before and after treatment. The effects were evaluated with Holdaway soft tissues analysis and routine cephalometric analysis methods. The arithmetic mean and standard deviation were calculated for each variable. Paired t-test was performed.

RESULTSThe average treatment time was 16 months. Normal overjet and overbite were established with retroclination of upper incisors and proclination of lower incisors. U1-NA(°) and U1-NA (mm) decreaed by (15.40 ± 5.31)° and (4.16 ± 1.82) mm (P < 0.01). NLA showed an average increase of (-16.60 ± 5.29)° (P < 0.01). Remarkable soft tissue change was noted after the treatment.

CONCLUSIONSThe profile in Class II division 1 patients could be quickly and efficiently improved after treatment with Tip-Edge plus technique.

Adolescent ; Cephalometry ; Child ; Esthetics, Dental ; Female ; Humans ; Male ; Malocclusion, Angle Class II ; diagnostic imaging ; therapy ; Orthodontic Wires ; Orthodontics, Corrective ; instrumentation ; methods ; Radiography, Panoramic

OBJECTIVETo compare the difference between J-hook and micro-implant anchorage in the treatment of patient with bimaxillary protrusion.

METHODSThirty patients with bimaxillary protrusion were divided into two groups (J-hook and micro-implant groups) and treated with MBT appliance. Four first premolars were extracted in all patients. Cephalometric analyses were carried out before and after treatment.

RESULTSIn J-hook group and micro-implant group,computerized cephalometric analysis revealed that before treatment U6C-PP was (12.4 +/- 0.2) mm and (12.5 +/- 0.1) mm, respectively,and after treatment U6C-PP was (12.6 +/- 0.1) mm and (12.8 +/- 0.1) mm,respectively. The difference between J-hook group and microimplant group was significant (P < 0.01). The other differences of cephalometric analyses between J-hook group and micro-implant group was not significant.

CONCLUSIONSBoth J-hook and micro-implant could provide adequate anchorage in the treatment of patients with bimaxillary protrusion.

Adolescent ; Adult ; Child ; Female ; Humans ; Male ; Malocclusion, Angle Class I ; therapy ; Orthodontic Anchorage Procedures ; instrumentation ; Orthodontic Appliances ; Orthodontics, Corrective ; instrumentation ; methods ; Young Adult

OBJECTIVETo evaluate the effect of the preadjusted appliance (Z1 appliance) based on Chinese normal occlusion.

METHODSThirty non-extraction patients were treated with Z1 appliance. No wire bending was made during treatment. The results of these 30 cases had been evaluated by five senior orthodontists. Models were analysed quantitatively to testify and evaluate the efficiency of the appliance.

RESULTSThe average score for post-treatment models was 91.2 (total score was 100). The model measurements indicated that average projective distance on occlusal plane between proximal contact points of adjacent teeth was less than 0.3 mm, which demonstrated good alignment. The prominence of crowns was almost coincident with the data of Chinese normal occlusion. For the average tip of most teeth, there was no statistical difference between the study group and the normal control group. The crown torque variation tendency from anterior to posterior was similar to that in the subjects with normal occlusion. However, the cases treated with Z1 appliance achieved more negative torque in the lower posterior segment.

CONCLUSIONSThe result of the non-extraction patients treated with Z1 appliance was quite satisfied. Wire bending could be reduced during treatment. It was necessary to adjust the crown torque values for lower posterior teeth.

Adolescent ; Asian Continental Ancestry Group ; Child ; Dental Occlusion ; Female ; Humans ; Male ; Orthodontic Appliance Design ; Orthodontic Appliances ; Orthodontics, Corrective ; instrumentation ; methods ; Young Adult

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

OBJECTIVEObserve the clinical effect of removable lingual arch plus auxiliary spring for convenient dental (especially mandibular) arch expansion.

METHODSSeventeen patients with dental arch constriction complicated by mild dental crowding were enrolled in this study, including 9 requiring maxillary arch expansion and 8 necessitating mandibular expansion. The patients were divided to two groups at random for arch expansion with removable lingual arch plus auxiliary spring and with Quad-helix, respectively, and the effect of arch expansion was compared between the two groups.

RESULTSAfter 8 weeks of arch expansion, the average width of U4-U4 and U5-U5 in removable lingual arch group was enlarged by 2.2 mm and 3.0 mm, and that in Quad-helix group by 2.3 mm and 3.5 mm, respectively, showing no significant differences between the two groups (P>0.05). After 12 weeks of treatment, the average width of L4-L4 and L5-L5 in the former group was enlarged by 2.3 mm and 2.5 mm, respectively, significantly greater than that in the latter group (1.0 mm and 1.2 mm, P<0.05).

CONCLUSIONRemovable lingual arch plus auxiliary spring allows significant expansion of the middle segment of the dental arch (bicuspids), and can be more effective than Quad-helix for mandibular arch expansion.

Adolescent ; Child ; Dental Arch ; pathology ; Humans ; Malocclusion ; therapy ; Orthodontic Appliances, Removable ; Orthodontics, Corrective ; methods ; Palatal Expansion Technique ; instrumentation ; Young Adult

OBJECTIVETo evaluate the effects of magnetic Twin-block appliance in the treatment of skeletal class II cases.

METHODSThe magnetic Twin-block appliance was embedded with two pairs of neodymium-iron-boron (Nd(2)Fe(14)B) rare earth permanent magnets in the upper and lower inclined planes of Twin-block appliance. The sample comprised of 13 skeletal class II patients in the late mixed or early permanent dentition treated by magnetic Twin-block appliance. Cephalometric films were taken before and after treatment. Helix CT images of the temporomandibular joint (TMJ) in all patients were examined before treatment (T1), during treatment (4 months after appliance placement, T2), after treatment (T3) and one year after treatment (T4).

RESULTSA double contour image was detected in the superior posterior part of the condylar head on the pseudo-sagittal reconstruction plane pictures of T2 in 11 patients. The double contour image could be observed in most patients as well. This image also exhibited on the pictures of T3 in several patients. On the pictures of T2 and T3 in some patients, interruption of cortical bone and "bifurcation phenomenon" of condyles were shown. Pictures of T1 and T4 were similar and no signs of remodeling of TMJ were observed. Cephalometric analysis revealed significant changes in the maxillofacial structure after treatment. The profile of patients improved.

CONCLUSIONSBone remodeling of condyle occurred during the magnetic Twin-block treatment in class II patients. Magnetic Twin-block appliance was effective in the treatment of the growing skeletal class II patients.

Adolescent ; Bone Remodeling ; Child ; Female ; Humans ; Magnetics ; Male ; Malocclusion, Angle Class II ; physiopathology ; therapy ; Mandibular Condyle ; physiopathology ; Orthodontic Appliances ; Orthodontics, Corrective ; instrumentation ; Treatment Outcome

OBJECTIVE: To evaluate the therapeutic effects of MBT straight wire on extraction case of Class II division I. METHODS: Thirty-six class II division I malocclusion patients were treated with MBT straight wire by extracting 4 bicuspid premolars or 2 maxillary bicuspid premolars. The X-ray cephalograms were analyzed before and after the treatment of MBT straight wire. RESULTS: After the treatment, the overjet was reduced by 6.04 mm (P < 0.01); U1-NA was reduced by 15.43 degrees (P <0.01); and U1-NA (mm) was reduced by 4.71 mm (P <0.01). ANB was significantly reduced (P < 0.05). CONCLUSION MBT straight wire not only shortens the operation but also shows superior effect for Class II division I malocclusion cases.
Adolescent ; Child ; Female ; Humans ; Male ; Malocclusion, Angle Class II ; therapy ; Orthodontic Appliance Design ; Orthodontic Wires ; Orthodontics, Corrective ; instrumentation ; methods

This study is designed to theoretically evaluate the treatment effects of MEAW with tip back bends on the mandible dentition when used as a finishing archwire without elastic and with long class III elastics respectively, and to compare them with those of stainless-steel wire and shape-memory wire. The finite element analysis (FEA) method was adopted and the findings were as follows: (1) In the case of no elastics, the MEAW rotates the second premolar, the first molar and the second molar distally while rotating other teeth mesially, and depresses anterior teeth. However, the stainless-steel wire and the shape-memory wire rotate molars distally while rotating other teeth mesially. Furthermore, they extrude anterior teeth and depress posterior teeth. (2) The MEAW with tip back bends and long class III elastics inclines and rotates posterior teeth more distally than the MEAW with only tip back bends does. In the case of tip back bends and long class III elastics loaded together, the shape-memory wire inclines teeth in greater strength as compared with the stainless-steel wire. (3) The stress level of tooth root is the lowest with MEAW, the highest with stainless-steel wire, and is middle with the shape-memory wire. From these results, it is suggested that: (1) The MEAW therapy technique is effective for leveling the curve of Spee and regulating tooth respectively. (2) The MEAW therapy technique can transfer therapy force efficiently. (3) The MEAW is considered to be suitable for treating openbite malocclusion to make the posterior teeth upright because it effectively rotates teeth distally through the force of posterior bends and long class III elastics. (4) The loaded force on the teeth is more soft and permanent in the MEAW than in the stainless-steel wire and the shape-memory wire.
Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Imaging, Three-Dimensional ; Malocclusion ; therapy ; Orthodontic Appliance Design ; Orthodontic Brackets ; Orthodontic Wires ; Orthodontics, Corrective ; methods ; Tooth Movement Techniques ; instrumentation

OBJECTIVETo analyze the surgical patients treated with straight wire appliance for guidelines of clinical using of the appliance.

METHODSTotally 51 patients from Joint Clinic of Orthodontic Surgery, Peking University School of Stomatology with dentofacial deformities treated with straight wire appliance were analyzed. The patients were aged from 15 years to 34 years 5 months, average 18 years 9 months. Among whom, 16 are males, while the other 35 are females.

RESULTSEighteen patients were treated with extraction of teeth, while other 33 cases were nonextraction case. The duration of average presurgical orthodontic treatment was 13.3 months, and 10.4 months was for postsurgical orthodontic treatment, totally active treatment time was 25.5 months.

CONCLUSIONSStraight wire appliance would benefit a lot for three dimensional control of teeth when doing pre- and post-surgical orthodontic treatment. Good results could be achieved without wire bending.

Adolescent ; Adult ; Female ; Humans ; Male ; Malocclusion, Angle Class II ; therapy ; Malocclusion, Angle Class III ; therapy ; Orthodontic Wires ; Orthodontics, Corrective ; instrumentation ; methods ; Postoperative Care ; Preoperative Care ; Treatment Outcome ; Young Adult

OBJECTIVEThe purpose of this study was to investigate the effects of Fränkel II appliance on the upper airway of children.

METHODSThe subjects consisted of 20 patients with Angle Class II, division I malocclusion (10 males and 10 females). The ages of all cases were ranged in 9-10 years. Each experimental subject was also served as self-control and cephalometric analysis was conducted.

RESULTSCompared with the results of pretreatment, the distance of PNS-Ba, SPP-SPPW, P-T, V-LPW and the Mcnamara line increased remarkably.

CONCLUSIONThe Fränkel II appliance can improve the sagittal dimensions of the upper airway in children.

Cephalometry ; Child ; Female ; Humans ; Male ; Malocclusion, Angle Class II ; pathology ; therapy ; Orthodontic Appliances, Functional ; Orthodontics, Corrective ; instrumentation ; Pharynx ; anatomy & histology ; Radiography ; Respiratory System ; anatomy & histology ; Skull ; diagnostic imaging