Angle Orthodontist最新文献

Objectives: To evaluate treatment effects in Class II patients using infrazygomatic crest (IZC) miniscrews (MS).

Materials and methods: A prospective sample of 25 adolescents (14 females and 11 males; mean age: 13.6 ± 1.5 years) who underwent maxillary dentition distalization treatment with IZC MSs were recruited. Lateral cephalograms and digital models at the beginning of treatment (T1) and after Class II molar correction (T2) were obtained. To compare cephalometric and digital model changes, paired t-test and Wilcoxon test were used. A significance level of 5% was used.

Results: All patients achieved Class II molar correction over a mean period of 7.7 ± 2.5 months. The IZC MS therapy provided 4 mm of distalization; there was 1.2 mm of intrusion of the first molar with 11.2° distal tipping. The maxillary incisors were retracted 4.7 mm and tipped lingually 13.4°. Overjet and overbite showed a reduction of 3.6 mm and 2.4 mm, respectively. The occlusal plane rotated clockwise 2.8°. The upper lip was retracted by 1 mm and the nasolabial angle increased 5.1°. There was an increase in the interpremolar and intermolar distances.

Conclusions: Total arch distalization of the maxillary dentition using IZC MS was effective in the treatment of Class II malocclusions.

Objectives: To evaluate and compare the efficiency of orthodontic treatment and surgical uprighting of first and second mandibular molars.

Materials and methods: An electronic literature search in PubMed, Science Direct, Embase, Scopus, Web of Science, Cochrane Library, LILACS, and Google Scholar, as well as a hand search was conducted by two independent researchers to identify relevant articles up to January 2022. In addition, a manual search was done that included article reference lists, grey literature, and dissertations. The risk of bias of the included prospective and retrospective studies was assessed with the Risk Of Bias Tool In Non-randomized Studies of Interventions (ROBINS-I) assessment tool.

Results: A total of six nonrandomized clinical trials (non-RCT) evaluating the efficiency of mandibular molar orthodontic and/or surgical uprighting were included. The quality analysis showed certain defects of the Non-RCTs included and, according to the criteria used, the majority of the articles were judged to be of moderate quality.

Conclusions: Based on the evidence, orthodontic and surgical uprighting appear to be effective treatment methods for mandibular molars. Surgical uprighting may be associated with more complications than orthodontic uprighting. However, the existing literature on the subject is limited, heterogeneous, and methodologically limited. Therefore, the outcomes should be interpreted carefully.

Objectives: To describe pre- and post-alveolar bone graft (ABG) practice protocols of orthodontists associated with American Cleft Palate-Craniofacial Association-approved cleft and cleft/craniofacial teams.

Materials and methods: Electronic survey responses from team orthodontists were evaluated regarding pre-ABG orthodontic treatment type(s), timing of post-ABG imaging and post-ABG orthodontic treatment, and craniofacial orthodontic fellowship training status of the team orthodontists. A P value of <.05 was considered significant.

Results: Of 31 responding orthodontists, 54.8% had fellowship training and 45.2% did not. Pre-ABG orthodontic preparation ranged from solely maxillary expansion for alveolar segment alignment (35.5%) to a combination of maxillary expansion for both alveolar segment alignment and posterior crossbite correction, anterior tooth alignment, and anterior crossbite correction (19.4%). Most captured post-ABG radiographs prior to orthodontic tooth movement (90.3%). Orthodontists began treatment at least 6 months (35.5%), 2-4 months (32.3%), or 4-6 months (29%) post-ABG. No significant differences were found when comparing fellowship subgroups. In addition, 47.1% of fellowship-trained orthodontists deferred post-ABG orthodontic treatment to at least 6 months post-operatively, vs 21.4% of non-fellowship trained orthodontists (P = .14).

Conclusions: A large variation in approaches is evident in pre-ABG orthodontic treatment types and timing of post-ABG treatment. Post-operative imaging is pursued by most orthodontists to assess graft status prior to initiating orthodontic treatment. Additional clinical research is needed to support providers in their decision-making with regard to evidence-based approaches.

Objectives: To investigate and compare the transfer accuracy of five different surgical guides (SGs) for the insertion of orthodontic mini-implants (OMIs) in the anterior palate.

Materials and methods: Stereolithographic files of 10 maxillary patient models and their corresponding lateral cephalograms were virtually matched and used for planning the position of two parallel OMIs in the paramedian region of the anterior palate. For each patient model, three 3-dimensional (3D)-printed and two conventional SGs were manufactured from different materials, and a total of 96 OMIs were transferred to the anterior palates of the respective 50 molded resin models. The planned (T0) and the actual (T1) OMI positions were analyzed and compared after superimposition of the digitized models. The deviations between the OMI positions in T0 and T1 were described as the distance between the head and the tip, respectively, of each OMI in millimeters and the deviating angle between the OMI axes for each patient and SG.

Results: The conventionally manufactured SGs of Pattern Resin LS (GC Europe N.V., Leuven, Belgium) showed the highest linear and angular transfer accuracy for the insertion of OMIs. The highest deviations were found with the SGs made of IMPRIMO LC Splint (3D-printed; Scheu-Dental, Iserlohn, Germany) and Memosil 2 (conventional SG; Kulzer, Hanau, Germany).

Conclusions: The 3D-printed SGs did not reach the accuracy of the conventional SGs made of Pattern Resin but may provide sufficient accuracy for palatal OMI placement.

A patient with a Class II division 2 malocclusion is presented, illustrating the application of a modified double J retractor (DJR) and palatal miniscrews along with clear aligners to correct the malocclusion and normalize the incisor torque. In terms of incisor torque recovery, a nonextraction approach might be a good choice if the Class II correction could be successfully achieved with total arch distalization. When maxillary molar distalization was limited by anatomical boundaries, the treatment plan was changed to bilateral maxillary first premolar extractions, which led to even more retroclination of the maxillary incisors after space closure. Anterior interdental miniscrews were used to intrude the maxillary incisors. A modified DJR and palatal miniscrews were used to regain torque and achieve palatal root movement of the maxillary incisors. The treatment effects and biomechanical designs were evaluated for torque recovery of the retroclined maxillary incisors.

Objectives: To investigate the relationship between circummaxillary sutures and miniscrew-assisted rapid palatal expansion (MARPE) success in adult male patients and to evaluate the correlation between the width of the sutures and the maxilla expansion ratio.

Materials and methods: This retrospective study comprised 40 adult male patients treated with MARPE divided into a separation group (N = 20, mean age, 21.9 years) consisting of subjects with midpalatal suture opening and a nonseparation group (N = 20, mean age, 21.7 years) consisting of subjects with no midpalatal suture opening. Cone-beam computed tomography images were obtained before MARPE expansion for both groups and after expansion for the separation group. Vertical and horizontal skeletal relationships, palate length, and widths of 10 circummaxillary sutures before expansion were compared. The correlation between maxilla expansion ratio (jackscrew expansion to maxillary expansion ratio) and circummaxillary suture widths was also analyzed in the separation group.

Results: There were no significant differences in age, vertical and horizontal skeletal relationships, and palate length between the two groups. Zygomaticomaxillary, pterygomaxillary, midpalatal, and transverse palatine sutures showed significantly greater width in the separation group (P < .05). The zygomaticomaxillary suture showed the greatest difference (Δ = 0.36 mm) between the groups. The zygomaticomaxillary and pterygomaxillary sutures showed significant positive correlation with the maxilla expansion ratio (P < .01).

Conclusions: In adult male patients, greater circummaxillary suture widths before MARPE expansion, especially zygomaticomaxillary and pterygomaxillary sutures, resulted in a better chance of successful suture separation and more maxillary expansion.

Objectives: To perform an in vitro qualitative and quantitative evaluation of the enamel surface (by scanning electronic microscopy [SEM] and measuring polishing time and roughness analysis, respectively) among four methods to remove remaining orthodontic adhesive after bracket debonding.

Materials and methods: Forty-one human premolars were randomly divided into four groups (n = 10) according to the adhesive remnant removal method and one tooth was used as control: Group 1 (G1): Enhance (Dentsply, Milford, USA); Group 2 (G2): Fiberglass (TDV, Pomerode, Brazil); Group 3 (G3): DU10CA-Ortho (Dian Fong Industrial, Shenzhen, China); Group 4 (G4): Sof-Lex Pop-On (3M ESPE, Seefeld, Germany). Roughness was measured before bonding and after complete removal of the remaining adhesive (Ra2). SEM analysis was performed on one sample of each group after adhesive removal and polishing. The time required for adhesive remnant removal and polishing was measured in all groups. Analysis of variance and Tukey post hoc for pairwise comparison was applied to compare polishing times among groups and analysis of covariance was used to compare Ra2 means.

Results: Comparison between groups show that G4 presented the lowest Ra2 mean (0.43 μm)c followed by G3 (0.71 μm)ac, G1 (1.06 μm)ab, and G2 (1.21 μm)b - different letters, statistically different at P ≤ 0,05. In addition, Fiberglass was more time-consuming for adhesive remnant removal than other methods (P ≤ .05). SEM analysis showed that some enamel damage occurred for all methods.

Conclusions: All methods were able to remove the remaining adhesive and polish the enamel. The DU10CA-Ortho and Sof-Lex methods promoted better polishing of the enamel surface and exhibited a similar time-consuming process.

Objectives: To elucidate the relationships and factors affecting the proximity between the incisive canal (IC) and maxillary central incisors and to predict the probable outcomes after anterior tooth retraction using cone beam computed tomography (CBCT).

Materials and methods: Retrospective CBCT data taken before and after maxillary anterior retraction in 36 patients were used in this study. The incisive canal length (ICL), maxillary central incisor length (TL), angles between the palatal plane and axes of the maxillary alveolar border (θ1), IC (θ2), and maxillary central incisor (θ3), retraction distance (TDE), distance from the maxillary central incisors to the IC (D), cross-sectional area of the IC (CSA), and volume of the IC were evaluated. Comparison of the parameters between contact and noncontact groups were examined. Logistic regression was performed to analyze the probable outcome prediction.

Results: All parameters significantly decreased after anterior retraction, except for the ICL. Eighteen roots in 12 patients contacted the IC. The θ1, θ2, θ3, and D values at all levels were significantly lower, whereas the TDE, midlevel and oral opening CSA, and volume were significantly higher in the contact group compared with the noncontact group. The larger the pretreatment θ1 and θ3 were, the higher was the chance of incisors not contacting the IC.

Conclusions: Maxillary central incisors not contacting the IC after anterior retraction was positively associated with larger degrees of pretreatment maxillary alveolar bone angle and maxillary central incisor angle.

Objectives: To determine recognition ability and the levels of esthetic tolerance of deep bite and anterior open bite (AOB) among laypeople and investigate the factors affecting levels of tolerance.

Materials and methods: Using a questionnaire, laypeople (N = 100) were examined, and overbite was measured. They were tested for whether they recognized deep bite and AOB. Esthetic tolerance thresholds for deep bite and AOB were selected by incremental depiction in grayscale images. Stepwise logistic regression analyses were used to quantify the effect of recognition and other factors (age, sex, education level, occupation, history of orthodontic treatment, interest in orthodontic treatment or retreatment, and overbite presence) affecting the tolerance of overbite problems (α = 0.05).

Results: Of the participants, 55% and 94% recognized deep bite and AOB, respectively. Participants with a deep bite were significantly more likely to esthetically tolerate deep bite compared with those without a deep bite (odds ratio [OR], 3.57; 95% confidence interval [CI], 1.29-9.89). Participants who recognized a deep bite problem had significantly lower esthetic tolerance to deep bite compared with participants who did not recognize a deep bite (OR, 0.17; 95% CI, 0.06-0.45). None of the other eight chosen factors significantly affected the tolerance level of AOB (P > .05).

Conclusions: Participants with a deep bite or those who did not recognize a deep bite had significantly higher esthetic tolerance of deep bite than those without or those who recognized the problem (P < .05).

Objectives: To evaluate the axial and dimensional changes of the condylar head after orthognathic surgery, including Le Fort I and bilateral sagittal split ramus osteotomies, and to assess condylar remodeling through three-dimensional (3D) surface superimposition.

Materials and methods: Twenty-four patients (15 females, 9 males; mean age: 32.22 ± 6.92 years) with skeletal Class III deformity were included in the study. Cone-beam computed tomography data obtained in the preoperative (T0) and postoperative (T1) periods were examined using Mimics and 3-Matic software. The height, depth, and width of the condylar head and its angular changes were measured. The volumes of the 3D reconstructed models were calculated, and remodeling amounts were evaluated through regional surface superimposition. Statistical significance was set at P < .05.

Results: Following the surgery, there was a significant decrease in the size of condyles (P < .05). An inward rotation of the condyles was found in the axial plane (T0: 79.60 ± 6.01°, T1: 76.6 ± 6.48°, P < .05). The maximum resorption, maximum apposition, mean remodeling, and mean absolute remodeling were -2.63 ± 1.23 mm, 1.15 ± 0.4 mm, -0.30 ± 0.34 mm, and 0.73 ± 0.43 mm, respectively. No correlation was found between the angular changes and remodeling parameters or linear and volumetric changes of the condylar head (P > .05).

Conclusions: Condyles undergo a remodeling process with a resorptive character following orthognathic surgery, without clinically significant effects in the present study.