tends to move forward [2]. 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 [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 [9][10][11][12]15] that can cause small increases on the facial height, especially in its lower anterior third [2,9,11,14].
Diagnosis and EtiologyA 21-year old patient looked for orthodontic treatment having as main complaint crowding of upper and lower teeth and a very
