Can Orthodontic Treatment Be Stable 20 Years after the End of the Treatment Scheme? Treatment of a Class 2, Division 1 Malocclusion with Severe Skeletal Discrepancy and Its 20-Year Follow-Up

Abstract

Class II malocclusions, after class I malocclusions, are the most frequent in the juvenile Italian population. They are most often skeletal in origin and due to mandibular retrusion. Functional devices seem to have a beneficial effect on the growth of the jaw. Long-term maintenance of the achieved results is essential for therapeutic success in any orthodontic treatment; moreover, the retention phase should last as long as possible, especially in the lower anterior sector. A female patient aged 10 years and 3 months presented a visibly convex profile and a severe mandibular retrusion. The anamnesis brought to light the habit of oral breathing and lower-lip sucking. The cephalometric analysis showed a normodivergent skeletal class II. The first treatment phase involved the use of a Bass type for 12 months at the end of the functional treatment; the second phase of fixed therapy was carried out following the principles of bioprogressive techniques. The photos at the end of treatment show an important improvement in the profile; a full class I ratio of molar and canine teeth was achieved with an excellent interarch relationship and a correction of the V-shaped upper arch. The result is occlusally and profilometrically stable after 2, 4, 5, 10, 14, and 20 years. The maintenance of a stable orthodontic result over time is the result not only of a correct and physiological occlusion but also and above all of a correct diagnosis and correct identification of problems that can cause the malocclusion itself. Flawed habits such as interposition of the lower lip and oral breathing must be intercepted and corrected early in order to correct them and not affect the long-term result of orthodontic treatment. In this case, a functional device associated with an orthodontic fixed finishing and a correct retention phase were necessary to correctly treat a second-class mandibular retrusion whose result remained stable 20 years after the end of therapy.

Parafunctional habits: A literature review

“…Onychophagia develops alterations in the bite, resulting in the presence of a moderate overbite [34] , children present absence of the primate spaces which are intended to help the correct eruption of the permanent teeth [37] . Lip sucking has a high prevalence in the development of malocclusion and deep overbite [36] , due to alterations in the development of the maxilla, in the position of the mandible being in a lower position than normal [38] , the upper incisors are protruded and the lower incisors are retracted [39] . Onychophagia by early orthodontic treatment [34] , such as the use of a fixed intraoral appliance which is composed of twisted ligature wires placed along the incisal edges of the anterior-inferior teeth [40] .…”

“…Onychophagia by early orthodontic treatment [34] , such as the use of a fixed intraoral appliance which is composed of twisted ligature wires placed along the incisal edges of the anterior-inferior teeth [40] . In lip sucking, treatment options include myofunctional training to correct oral habits and establish muscle balance [41] , and the use of functional appliances [42] and fixed appliances such as the Bass that serves as a trainer [38] . Onychophagia is found with a greater predisposition between the ages of 12-16 years while lip sucking from the age of 6 years, both present the development of a moderate to deep overbite, should be treated by means of orthopedic appliances, in the case of lip sucking accompany it with myofunctional therapy.…”

The Use of TADs in the Mandibular Arch to Prevent Proclination of the Lower Incisors during the Use of the Mini Scope Herbst Appliance

“…However, there can be no doubt that a functional approach during the growth peak will lead to more rapid and predictable results since one is intervening in a phase during which the patient's own body is already predisposed towards important growth. As a result, when using a functional treatment, it is sufficient to direct the mandibular growth vector in order to obtain the best results and the greatest stability over time [8,[15][16][17][18]. The Herbst fixed functional appliance presents considerable advantages, chiefly due to the reduction in the collaboration required from the patient.…”