Early treatment of a Class II Division 1 retruded mandible: Long-term stability

Purpose: To evaluate the muscle response in order to determine the mechanism of neuromuscular adaptations with Forsus Fatigue Resistant DeviceTM which has greater elasticity and flexibility; allows greater range of movement of mandible; is available in pre fabricated assembly of springs, tubes and rods and is a simple, effective and reliable corrective appliance that benefits not only growing patients but also malocclusions that previously required extractions, headgears and surgery. Method: Bilateral EMG activity from anterior temporalis and masseter muscles was monitored longitudinally on 10 young growing females with Class II Division 1 malocclusion to determine changes in postural, swallowing, and maximal voluntary clenching over an observation period of 6 months. Results: There was a significant decrease in the muscle activity at one month after Forsus Fatigue Resistant DeviceTM insertion during swallowing of saliva and maximal voluntary clenching which gradually returned to pre treatment levels at the end of six months.Conclusion: This study suggests that Forsus Fatigue Resistant DeviceTM should be given for at least six months to allow for adequate neuromuscular adaptations to occur for long term stability of the result.

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Class II treatment in early mixed dentition with the eruption guidance appliance: effects and long-term stability

European Journal of Orthodontics ◽

10.1093/ejo/cjz092 ◽

2019 ◽

Vol 42 (2) ◽

pp. 151-156 ◽

Cited By ~ 1

Author(s):

Katri Keski-Nisula ◽

Leo Keski-Nisula ◽

Juha Varrela

Keyword(s):

Treatment Group ◽

Class Ii ◽

Post Treatment ◽

Mixed Dentition ◽

Term Stability ◽

Long Term Stability ◽

Class Ii Treatment ◽

Significant Correction ◽

The Mean

Summary Objectives Our aim was to analyse dentoskeletal effects and long-term stability of Class II treatment carried out with an eruption guidance appliance (EGA) in early mixed dentition. Materials and methods Sixty-five Class II patients (38 females and 27 males), treated with an EGA in early mixed dentition, were compared with 58 children (26 females and 32 males) with untreated Class II malocclusion. The mean age in the treatment group at the start (T1) and end of treatment (T2) was 5.4 years (±0.4) and 8.5 years (±0.9), respectively, and at the final examination in the early permanent dentition (T3) 16.7 years (±0.4). In the control group, the mean age at T1 and T2 were 5.1 years (±0.5) and 8.4 years (±0.5), respectively. The independent and dependent sample t-tests, Chi-square test, and Fisher’s test were used in the statistical evaluation. Results In the treatment group, the frequency of Class II decreased from 100 to 14% during the treatment (T1–T2) and a significant correction took place in all occlusal variables. At T2, the treatment and control groups showed statistically significant differences (P < 0.05) in all occlusal variables. In the treated children, mandibular length increased 5 mm more (P < 0.001) from T1 to T2 compared to the control children, and the ANB angle became significantly smaller (P = 0.006). During the post-treatment period (T2–T3), the frequency of Class II in the treatment group decreased from 14 to 2% (P < 0.05), overbite increased from 2.2 to 3.1 mm (P < 0.05), and lower crowding increased from 2to 14% (P < 0.05). Post-treatment changes in overjet and upper crowding were not statistically significant. At T3, the mean values of the SNA, SNB, and ANB angles were 83.0° (SD 3.9°), 81.3° (SD 3.8°), and 2.4° (SD 1.5°), respectively. Conclusions A clinically significant correction of the molar relationship, overjet, overbite, incisor alignment, and growth enhancement of the mandible were observed after treatment in early mixed dentition. The treatment results remained largely stable in the early permanent dentition. However, an increase was observed in overbite and lower crowding. None of the children treated in early mixed dentition needed a second treatment phase.

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Development and validation of a prediction model for long-term unsuccess of early treatment of Class III malocclusion

European Journal of Orthodontics ◽

10.1093/ejo/cjz031 ◽

2019 ◽

Vol 42 (2) ◽

pp. 200-205 ◽

Cited By ~ 5

Author(s):

Bernardo Quiroga Souki ◽

Michele Nieri ◽

Chiara Pavoni ◽

Helena Maria Pavan Barros ◽

Tarcisio Junqueira Pereira ◽

...

Keyword(s):

Logistic Regression ◽

Prediction Model ◽

Early Treatment ◽

Class Iii ◽

Term Stability ◽

Long Term Stability ◽

Unsuccessful Treatment ◽

Lateral Cephalograms ◽

Bivariate Logistic Regression

Summary Aim To develop and validate a prediction model to forecast long-term stability of early treatment with rapid maxillary expansion (RME) and facemask (FM) in a large sample of Class III growing patients. Methods The Brazilian Group (BG) consisted of 73 consecutively treated Caucasian Class III patients (41 females and 32 males). Mean age at T0 (before treatment) was 7.1 ± 1.6 years, while mean age at T1 (long-term follow-up) was 21.8 ± 3.2 years. The Italian Group (IG, validation cohort) comprised 28 consecutively treated Caucasian Class III patients (14 females and 14 males, mean age at T0 9.0 ± 1.3 years and mean age at T1 18.2 ± 1.4 years). Cephalometric analysis was performed on lateral cephalograms at T0. Gender and cephalometric variables, chronologic age, and dentition phase at T0 were used as predictors for long-term unsuccessful treatment at T1. All predictors for unsuccessful treatment in the BG were subjected to bivariate logistic regression. Only those statistically significant predictors in the bivariate logistic regression entered mixed stepwise logistic regression with P = 0.05 to enter and to leave. The validity of the prediction model derived from the BG was then tested on the IG. Results The prediction model consisted of only one cephalometric variable: the angle between the Condylar Axis and the Mandibular Plane (CondAx–MP) (odds ratio: 1.52, 95% confidence interval: 1.25–1.85, P < 0.0001). Unsuccessful treatment at T1 was predicted for values of CondAx–MP at T0 greater than the cut-off value of 147.8 degrees. BG patients predicted incorrectly were 3 out of 22 for the unsuccessful cases and 1 out of 51 for the successful cases. Therefore, accuracy was 0.95, sensitivity 0.86, specificity 0.98, and positive and negative predictive values were 0.95 and 0.94. When the predictive model was applied on IG, all five unsuccessful cases were predicted correctly, while only 1 out of 23 successful patients was predicted incorrectly. Conclusion CondAx-ML was identified as a reliable predictor for long-term stability of early Class III treatment with RME and FM.

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