Muscle Response during Treatment of Class II Division 1 Malocclusion with Forsus Fatigue Resistant Device

Abstract

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.

A comparison of the treatment effects of the Forsus Fatigue Resistance Device and the Twin Block appliance in patients with class II malocclusions

“…In contrast, the amount of change in the FRD group was not significantly different from in the controls, which parallels the findings of the late puberty FRD group in a previous study18 but is in disagreement with another 16. The differences between previous reports may not be easily explained because they could be associated with the treatment protocol and duration, wires, and slot dimension; fixed appliance torque differences;16 the age factor;18,20 and possible different neuromuscular responses 24. There was a highly significant increase in the corpus length of all three groups (Student’s t- test P <0.001) but no significant difference between them (ANOVA P =0.70), which suggests it was only a result of the growth effect.…”

Three-dimensional assessment of the temporomandibular joint and mandibular dimensions after early correction of the maxillary arch form in patients with Class II division 1 or division 2 malocclusion

“…This minimum time interval was accepted to rule out the changes related to physiological growth; furthermore, a minimum 6-month period is necessary for the adaptation of the masticatory muscles to the changing functional demands. 26 , 27 , 28 , 29 …”

Aparatos de avance mandibular: ¿mito o realidad?

“…El forsus debe actuar por lo menos 6 meses para permitir una adecuada adaptación neuromuscular y permitir un resultado estable a largo plazo [66].…”