High-pull Chincup Research Articles

Stability of anterior open bite treatment with bonded spurs associated with high-pull chincup.

To evaluate the stability of anterior open bite (AOB) treatment with bonded spurs associated with high-pull chincup (BS/HPCC). The experimental group consisted of 25 Class I AOB patients (15 female, 10 male) treated with BS/HPCC for 1year. Cephalograms were analysed at pre-treatment (T1), post-treatment (T2) and at the 3-year post-treatment (T3) stage with the patients mean ages of 8.10, 9.14 and 12.18years, respectively. The control group consisted of 23 subjects (13 female, 10 male) with normal occlusion, with comparable ages at the 3 stages (8.45, 9.45 and 12.50years at T1, T2 and T3, respectively). T tests were used for intergroup comparisons at T1 and to compare the changes during the 3-year post-treatment period (T2-T3). Intragroup comparison in the treated group was evaluated with dependent t tests between T1 and T2. Correlations between the overbite changes in the T2-T3 period, the pre-treatment AOB severity and the amount of correction achieved during treatment were evaluated with Pearson's correlation coefficient. No statistically significant relapse of the AOB was found at T3. Only 1 patient had a clinically significant AOB relapse. Neither the pre-treatment AOB severity nor the amount of correction was related to overbite changes during the 3-year post-treatment period. There was no statistically significant relapse of the AOB, and the clinical stability of AOB correction 3-year post-treatment was of 96%.

Orthodontic and orthopaedic treatment for anterior open bite in children.

Anterior open bite occurs when there is a lack of vertical overlap of the upper and lower incisors. The aetiology is multifactorial including: oral habits, unfavourable growth patterns, enlarged lymphatic tissue with mouth breathing. Several treatments have been proposed to correct this malocclusion, but interventions are not supported by strong scientific evidence. The aim of this systematic review was to evaluate orthodontic and orthopaedic treatments to correct anterior open bite in children. The following databases were searched: the Cochrane Oral Health Group's Trials Register (to 14 February 2014); the Cochrane Central Register of Controlled Trials (CENTRAL)(The Cochrane Library 2014, Issue 1); MEDLINE via OVID (1946 to 14 February 2014); EMBASE via OVID (1980 to 14 February 2014); LILACS via BIREME Virtual Health Library (1982 to 14 February 2014); BBO via BIREME Virtual Health Library (1980 to 14 February 2014); and SciELO (1997 to 14 February 2014). We searched for ongoing trials via ClinicalTrials.gov (to 14 February 2014). Chinese journals were handsearched and the bibliographies of papers were retrieved. All randomised or quasi-randomised controlled trials of orthodontic or orthopaedic treatments or both to correct anterior open bite in children. Two review authors independently assessed the eligibility of all reports identified. Risk ratios (RRs) and corresponding 95% confidence intervals (CIs) were calculated for dichotomous data. The continuous data were expressed as described by the author. Three randomised controlled trials were included comparing: effects of Frankel's function regulator-4 (FR-4) with lip-seal training versus no treatment; repelling-magnet splints versus bite-blocks; and palatal crib associated with high-pull chincup versus no treatment.The study comparing repelling-magnet splints versus bite-blocks could not be analysed because the authors interrupted the treatment earlier than planned due to side effects in four of ten patients.FR-4 associated with lip-seal training (RR = 0.02 (95% CI 0.00 to 0.38)) and removable palatal crib associated with high-pull chincup (RR = 0.23 (95% CI 0.11 to 0.48)) were able to correct anterior open bite.No study described: randomisation process, sample size calculation, there was not blinding in the cephalometric analysis and the two studies evaluated two interventions at the same time. These results should be therefore viewed with caution. There is weak evidence that the interventions FR-4 with lip-seal training and palatal crib associated with high-pull chincup are able to correct anterior open bite. Given that the trials included have potential bias, these results must be viewed with caution. Recommendations for clinical practice cannot be made based only on the results of these trials. More randomised controlled trials are needed to elucidate the interventions for treating anterior open bite.

Evaluation of the stability of open bite treatment using a removable appliance with palatal crib combined with high-pull chincup

OBJECTIVE: The aim of this prospective study was to cephalometrically analyze the stability of dentoalveolar and skeletal changes produced by a removable appliance with palatal crib associated to high-pull chincup in individuals with anterior open bite treated for 12 months, and compare them to individuals with similar malocclusion and age, not submitted to orthodontic treatment, also followed for the same period. METHODS: Nineteen children with a mean age of 9.78 years old treated for 12 months with a removable appliance with palatal crib associated with chincup therapy were evaluated after 15 months (post-treatment period) and compared with a control group of 19 subjects with mean age of 9.10 years with the same malocclusion that was followed-up for the same period. Seventy-six lateral cephalograms were evaluated at T1 (after correction) and T2 (follow-up) and cephalometric variables were analyzed by statistical tests. RESULTS: The results did not show significant skeletal, soft tissue or maxillary dentoalveolar changes. Overall, treatment effects on the experimental group were maintained at T2 evaluation with an increase of 0.56 mm in overbite. Overjet and maxillary incisors/molars position (vertical and sagittal) remained essentially unchanged during the study period. Only mandibular incisors showed significant changes (labial inclination and protrusion) compared to control group. CONCLUSIONS: Thus, it can be concluded that the early open bite treatment with a removable appliance and palatal crib associated with high-pull chincup therapy provided stability of 95%.

Treatment effects of bonded spurs associated with high-pull chincup therapy in the treatment of patients with anterior open bite

The aim of this prospective clinical study was to investigate the cephalometric changes produced by bonded spurs associated with high-pull chincup therapy in children with Angle Class I malocclusion and anterior open bite. Thirty patients with an initial mean age of 8.14 years and a mean anterior open bite of -3.93 mm were treated with bonded spurs associated with chincup therapy for 12 months. An untreated control group of 30 subjects with an initial mean age of 8.36 years and a mean anterior open bite of -3.93 mm and the same malocclusion was followed for 12 months for comparison. Student t tests were used for intergroup comparisons. The treated group demonstrated a significantly greater decrease of the gonial angle, and increase in overbite, palatal tipping of the maxillary incisors, and vertical dentoalveolar development of the maxillary and mandibular incisors compared with the control group. The association of bonded spurs with high-pull chincup therapy was efficient for the correction of the open bite in 86.7% of the patients, with a 5.23-mm (SD, ±1.69) overbite increase.

Chin cup treatment outcomes in skeletal Class III dolicho- versus nondolichofacial patients.

This study examines cephalometric differences and sex differences in the long-term outcome of chin cup treatments of Class III subjects with two facial patterns. Seventeen nondolichofacial and 16 dolichofacial Class III male patients and 16 nondolichofacial and 16 dolichofacial female patients were treated by either bicuspid extraction or nonextraction. Rapid palatal expansion without maxillary protraction was performed on 11 male cases and 15 female cases. The borderline between the two groups was drawn either at 39 degrees mandibular plane angle or 132 degrees (male subjects) or 130 degrees (female subjects) gonial angle. Dolichofacial subjects were treated with either an occipital or a high-pull chin cup force during the first two years, followed by high-pull force during night-time wear for the subsequent three years. All treated cases showed excellent results in the retention records with acceptable posterior occlusion as well as excellent skeletal and soft-tissue profiles. In addition, patient compliance was excellent. The treatment outcomes of the two groups showed significant improvement of the skeletal Class III malocclusion. This study indicated that the treatment period and wear time of the chin cup appliance in nondolichofacial (mostly mesiofacial pattern) patients could be shorter than those of dolichofacial patients. Although all subjects showed significant improvement in the Class III malocclusion, the treatment outcome in the two groups maintained the original characteristic skeletal morphology at retention.

Treating anterior open bite

The Cochrane Central Register of Controlled Trials, Medline, Embase, LILACS (Latin American & Caribbean Health Sciences Literature) , Brazilian Bibliography of Odontology and SciELO. Ten Chinese journals were searched by hand and the bibliographies of papers were retrieved. Randomised controlled trials (RCT) or quasi-RCT of orthodontic or orthopaedic treatments or both to correct anterior open bite in children were included. Two review authors independently assessed the eligibility of all reports identified. Risk ratios (RR) and corresponding 95% confidence intervals (CI) were calculated for dichotomous data. The continuous data were expressed as described by the author. Twenty-eight trials were potentially eligible, but only three RCT were included comparing treatments as follows: effects of Frankel's function regulator-4 (FR-4) with lip-seal training versus no treatment; repelling-magnet splints versus bite-blocks; and palatal crib associated with high-pull chincup versus no treatment. The study comparing repelling-magnet splints versus bite-blocks could not be analysed because the authors interrupted the treatment earlier than planned because of side-effects in four out of 10 patients. FR-4 associated with lip-seal training (RR, 0.02; 95% CI, 0.00-0.38) and removable palatal crib associated with high-pull chincup (RR, 0.23; 95% CI, 0.11-0.48) were able to correct anterior open bite. No study described the randomisation process nor sample size calculation; there was not blinding in the cephalometric analysis; and the two studies also evaluated two interventions at the same time. There is weak evidence that the interventions FR-4 with lip-seal training and palatal crib associated with high-pull chincup are able to correct anterior open bite. Given that the trials included have potential bias, these results must be viewed with caution. Recommendations for clinical practice cannot be made based only on the results of these trials. More RCT are needed to elucidate the interventions for treating anterior open bite.

Anterior open bite treated with a palatal crib and high-pull chin cup therapy. A prospective randomized study

The aim of this prospective randomized clinical study was to cephalometrically investigate the dentoalveolar and soft tissue changes produced by a removable appliance with a palatal crib associated with high-pull chin cup therapy in children with an Angle Class I anterior open bite (AOB) malocclusion. Thirty children (8 males and 22 females) with an initial mean age of 8.3 years and a mean AOB of 4.1 mm were treated with a removable appliance composed of a palatal crib associated with chin cup therapy for 12 months. A control group of 30 individuals (7 males and 23 females) closely matched for age, initial mean age 8.6 years, gender, and ethnicity with a mean AOB of 4.6 mm was followed without treatment. The measurements (means and standard deviations) were statistically analysed using a paired t-test. The results showed no significant differences in the level of molar eruption or in lower anterior face height, suggesting that the vertical control expected from the chin cup therapy did not occur. Dentoalveolar changes at the anterior region were evident, with statistically significant extrusion, retrusion, and lingual tipping of the maxillary and mandibular incisors (P < or = 0.05). However, these hard tissue changes did not imply soft tissue changes and the variables related to the soft profile were not statistically significantly different between the groups. The dentoalveolar changes at the anterior region of the dental arches were mainly responsible for closure of the AOB in patients treated in the mixed dentition.

A prospective study of the treatment effects of a removable appliance with palatal crib combined with high-pull chincup therapy in anterior open-bite patients

The aim of this prospective clinical study was to cephalometrically investigate the dentoalveolar and skeletal changes produced by a removable appliance with palatal crib associated with high-pull chincup therapy in children with Angle Class I anterior open-bite malocclusions. Thirty children with initial mean age of 8.61 years and mean anterior open bite of 4.01 mm were treated with removable appliances with palatal crib associated with chincup therapy for 12 months. A control group of 30 subjects with initial mean age of 8.33 years and mean anterior open bite of 3.95 mm with the same malocclusion was followed for 12 months for comparison. The removable appliance with palatal crib combined with vertical chincup did not yield significant changes in maxillary and mandibular skeletal components, maxillomandibular relationship, or vertical facial pattern. Overall, effects in the treated group were exclusively dentoalveolar. Open bite in the treatment group showed a mean closure of 5.01 mm (SD +/- 1.73). The association of high-pull chincup therapy with a removable appliance and palatal crib provided no positive skeletal influence on the vertical facial pattern of patients treated for open bite in the mixed dentition.

Early treatment of vertical skeletal dysplasia: The hyperdivergent phenotype

This cephalometric study evaluated an early nonextraction treatment approach for patients with severe vertical skeletal dysplasia and maxillary transverse constriction. Thirty-eight patients, 8.2 years (± 1.2 years) of age, were treated for 1.3 years (± 0.3 years) with lip seal exercises, a bonded palatal expander appliance, and a banded lower Crozat/lip bumper. The bonded palatal expander functioned as a posterior bite-block and was fixed in place throughout treatment. Patients with poor masticatory muscle force (79%) wore a high-pull chincup 12 to 14 hours per day. A control group was matched for age, sex, and mandibular plane angle. Treatment changes for chincup and other patients were not significantly different. Overall, treatment significantly enhanced condylar growth, altered it to a more anterosuperior direction, and produced “true” forward mandibular rotation 2.7 times greater than control values. Posterior facial height increased significantly more in patients than in controls, and the maxillary molars showed relative intrusion. In treated patients, articular angle increased, gonial angle decreased, and the chin moved anteriorly twice as much as in controls. Treatment also led to increased overbite and decreased overjet. Maxillary and mandibular expansion did not cause the mandibular plane angle to increase. The 16 patients with openbite malocclusions exhibited a 2.7 mm increase in overbite and inhibition of growth in anterior lower facial height. The aggregate of individual changes demonstrates a net improvement, indicating this treatment approach may be suited for hyperdivergent patients with skeletal discrepancies in all 3 planes of space. (Am J Orthod Dentofacial Orthop 2000;118:317–27)

Control of vertical dimension during rapid palatal expansion using a high-pull chin cup

Control of vertical dimension during rapid palatal expansion using a high-pull chin cup

Stress distribution under high-pull extraoral chin cup traction. A photoelastic study.

Birefringent materials were employed in the fabrication of a model of a human skull with distinct simulants for teeth, bone, and periodontal ligaments. The following observations were made subsequent to the application of force to this model with an extraoral high-pull chin cup: 1. Reciprocal stresses were observed in the posterior portion of the glenoid fossa and the contacting posterior part of the head of the condyle. 2. A tension coil spring representing the external pterygoid muscle applied reciprocal stresses at its insertions in the lateral pterygoid plate on the greater wing of the sphenoid and the anterior aspect of the head of the condyle. 3. Stresses were seen to radiate from the roots and apices of both the maxillary and mandibular posterior teeth. 4. A distinct concentration of stress was noted in the retromolar area of the mandible, away from the dentition, indicating a bending stress. 5. The posterior half of the sigmoid notch, below the anterior aspect of the head of the condyle, displayed a heavy band of stresses. 6. Selected sectioning of the mandible substantiated observations made from the intact hemimandible and also showed evidence of bending in the area corresponding to the head and neck of the condyle.