Analysis of Class II patients, successfully treated with the straight-wire and Forsus appliances, based on cervical vertebral maturation status

Abstract

Following an initial worsening of the Class II molar relationship as a result of straight-wire appliance effects, Forsus appliance treatment initiated during cervical vertebral maturation status (CS) 3-4 elicits more effective and efficient correction of Class II molar relationships than when initiated during CS 5-6. Data support that these effects are due mainly to maxillary skeletal and dentoalveolar restraint during a period of more rapid mandibular growth.

Optimization of Class II Malocclusion Treatments Using the Forsus™ Fatigue Resistance Device and Its Post-Treatment Effect in Adult Patients: A Case Report

“…Based on this and supported by the literature, it was possible to consider and suggest some treatment options to the patient, such as a surgical-orthodontic treatment [20,38]; upper first molar extractions [39,40], the use of intermaxillary Class II elastics [24,41], which would need patient cooperation; and the use of fixed functional appliances-rigid [18,19,[21][22][23]25], semi-rigid [8,11,12,37], but, mainly, hybrid appliances as the Forsus™ Fatigue Resistant Device [3,7,11,[13][14][15]17,[32][33][34]35]. The chosen protocol was to use the Forsus™ Fatigue Resistant Device that has shown to be an effective device, providing greater comfort to patients [7,11,[14][15][16][17]33,34] and good resistance [10,13,15,35] when treating Class II malocclusions.…”

“…It is a comfortable device [7], as it does not completely limit the mandible movement and, in the current version, it shows a very low breakage rate [10,14,[32][33][34]. The Forsus appliance, when installed in the upper first molar tube in the lower leveling arch wire, at the distal of the cuspid bracket [3,11,15,17] or, at the distal of the lower first premolar [14], exerts a force of 220 g approximately in both jaws, in opposite directions [15,35]. And, the time it takes to completely correct a Class II malocclusion may vary from 5 -8 months on average [6,14,15,17].…”

“…The mandible may undergo anterior shift, improving the maxillomandibular relationship [1,3,5,6,11,13,15]. However, the effective growth of the mandible will rarely be considered an effect genuinely generated by the stimulus of the mandibular anterior growth [1,5,10,15,35,36], although there are authors that report some potential for effective growth in the mandibular body and ramus, when functional fixed devices are used in the pubertal growth peak stage [1,3,6,9,13].In the literature, it has been shown that dentoalveolar changes overcome the skeletal changes when any fixed functional device is used [4][5][6]21]. The mechanism of the dentoalveolar action of such devices over the upper anterior [2,[5][6][7][8][9][10][11]14,15,17,28,36,37] and posterior teeth [3,6,[8][9][10][11]13,35,36] and over the lower anterior …”

“…However, the effective growth of the mandible will rarely be considered an effect genuinely generated by the stimulus of the mandibular anterior growth [1,5,10,15,35,36], although there are authors that report some potential for effective growth in the mandibular body and ramus, when functional fixed devices are used in the pubertal growth peak stage [1,3,6,9,13].…”

“…The mechanism of the dentoalveolar action of such devices over the upper anterior [2,[5][6][7][8][9][10][11]14,15,17,28,36,37] and posterior teeth [3,6,[8][9][10][11]13,35,36] and over the lower anterior [5,6,8,[9][10][11][13][14][15]17,28,[35][36][37] and posterior teeth [3,8,[9][10][11]14,17] are often responsible for the clockwise shift of the occlusal [5,9,10,16,17,35] and palatal [2] planes, generating a clockwise resultant on the mandibular plane …”