| Class Ⅱ malocclusion is one of the most common orthodontic problems,and it occurs in about one third of the all malocclusions. The most consistentdiagnostic finding in Class II malocclusion is mandibular skeletal retrusion. Atherapy able to enhance mandibular growth is indicated in these patients. Awide range of functional appliances aimed to stimulate mandibular growth byforward posturing of the mandible is available to correct this type of skeletal andocclusal disharmony.Although many studies in young adults have demonstratedthat skeletal mandibular changes can be produced by posturing the mandibleforward, the effects on humans are more equivocal and controversial. class IImalocclusions in adults are usually treated by either orthognathic surgery orcamouflage treatment, depending on the severity of the skeletal discrepancy.However, recently, some articles have been published on Forsus appliancetreatment in adult patients. This method has been shown to be most effective in Class Ⅱ treatment in both early and late adulthood. The aim of this study was tocompare the dentoskeletal changes and alterations of mandibular condyle-disc-fossa relationships in subjects at the peak and the end of the pubertal growthperiod treated with the Forsus device.Objective:1. The aim of this study was to compare the alterations of mandibularcondyle-disc-fossa relationships in subjects at the peak and the end of thepubertal growth period treated with the Forsus device.2. The aim of this study was to compare the dentoskeletal changes and insubjects at the peak and the end of the pubertal growth period treated with theForsus device.Methods: The sample consisted of35subjects with Class II malocclusions whowere classified according to their hand-wrist radiographs. Twenty-three patientswere at or just before the peak phase of pubertal growth (peak pubertalgroup:MP3-E,MP3-G. range,11.5-15.5years). Twelve patients were near the endof the pubertal growth period (late pubertal group: R-IJ R-J. range,18.6-22.8years). The study was conducted by using lateral cephalometricradiographs and magnetic resonance images obtained at the beginning and at theend of the application of the Forsus fatigue resistant device. The treatmentperiod was7.6months.Results:1.Before treatment and after treatment, analysis of the magnetic resonanceimages showed no positional changes of the mandibular condyle in relation tothe glenoid fossa in either group (P>0.05). For young adult, the left hyperplasiaof condyle is0.53±0.15mm. the right hyperplasis of condyle is0.49±0.27mm.For adolescents, the left hyperplasia of condyle is0.83±0.21mm. the right hyperplasia of condyle is0.81±0.32mm.2. Although the articular disc was positioned more anteriorly in the peakpubertal group compared with its pretreatment position (P<0.05), the position ofthe disc was still within the physiologic range. No significant intergroupdifference was observed for disc-condyle relationship (P>0.05).3.The Wilcoxon signed rank test was used to evaluate differences withingroups. The changes observed in both groups were compared by using theMann-Whitney U test. In both groups, the mandible was positioned anteriorly(B-FHp, Pg-FHp, and SNB increased) with a consequent decrease in the ANBangle(P<0.05). In the peak pubertal group, increases in mandibular length(Co-Gn) and ramus height (Co-Go)were found to be statistically significant;significant differences were observed between the two groups concerning thesemeasurements (P<0.05). In the peak pubertal group, the SNGoGn angleremained unchanged during treatment with the Forsus device(P>0.05), whereasit showed a significant decrease in the late pubertal group (P<0.05). However,the difference between the two groups was nonsignificant(P>0.05).4. Dental parameters showed similar alterations in both groups, with theexception of the distance from the mandibular molars to the mandibular plane,which was significantly greater in the peak pubertal group (P<0.05). For bothgroups, palatal tipping and extrusion of the maxillary incisors, protrusion andintrusion with labial tipping of mandibular incisors, distal tipping of maxillarymolars, and mesial movement and mesial tipping of the mandibular molars wereobserved at the end of the Forsus device treatment.Conclusions:The increase in mandibular prognathism accomplished by Forsus therapy inadolescents seems, in particular, to be a result of condylar and glenoid fossa remodeling. For adolescents patients, the height and length of mandible areincreased. However, For young adults patients, palatal tipping and extrusion ofthe maxillary incisors, protrusion and intrusion with labial tipping of mandiularincisors, distal tipping of maxillary molar and mesial movement and mesialtipping of the mandibular molars were observed at the end of Forsus treatment.Because the Forsus appliance is most successful in Class II patients also at theend of the growth period, the treatment method could be an alternative toorthognathic surgery in borderline skeletal Class II cases. Magnetic resonanceimaging renders an excellent opportunity to visualize the temporomandibularjoint remodeling growth processes. |
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