The Intrusion of Anterior Teeth with iPanda: A Case Report and Finite Element Analysis

Aim: This case report proposed an alternative approach for correcting gummy smile. To demonstrate an anterior intrusion technique by using iPanda and intrusion arch in the Class II, deep bite malocclusion. To illustrate this approach on anterior and first molar teeth using finite element analysis (FEA). Material and method: A 38-year-old woman presented with maxillary anterior completed deep bite, gummy smile, maxillary and mandibular anterior teeth crowding, Class II canine, and missing four first premolars from previous orthodontic treatment. In order to improve the patient's smile, correct the deep bite and crowding, two titanium miniscrews (1.6x6mm) were placed at the midpalatal suture and iPanda was used as a maximum anchorage. The main archwire was used as a sectional for anterior and posterior teeth; also an intrusion arch (0.017x0.025 inches) was used to apply an intrusive force at the central incisors and canines on the main archwire. For FEA, under 20 gf of intrusive force on each anterior tooth, initial displacement of the individual anterior and first molar teeth in three directions was measured. Also, the von Mises stresses along the root were evaluated. Results: The results were the intrusion of 2.33 mm of the maxillary incisors. The interincisal relationship was improved. Significant reductions in overjet, maxillary incisor to palatal plane, and maxillary incisor to upper lip were observed after intrusion of the incisors. Her gummy smile, maxillary and mandibular anterior teeth crowding, and Class II canine were improved without altering the molar class I relationship. iPanda presented an effective anchorage to minimise the maxillary molar displacement. FEA illustrated that the maximum von Mises stress is evenly distributed across the central and lateral incisors and canines applied to the labial surface of the roots. Nevertheless, the first molars showed higher von Mises stress along the crown and root surface; it showed the least displacement due to iPanda anchorage. Conclusion: iPanda with intrusion arch is an alternative treatment approach to effectively intrude anterior teeth without the need of additional miniscrews. Moreover, this technique can reduce the risk of extrusion on maxillary first molars. Keywords: Anterior intrusion, finite element analysis, case report