| Objective:To discuss the clinical effects of adolescent patients with severe skeletal class III openbite malocclusions who were treated with camouflaged orthodontic therapy.Methods: Two female adolescent patients with severe skeletal class III openbite malocclusions started orthodontic treatment in Shenyang Stomatological Hospital in 2011 were chosen. Both of them was 14 years old with early permanent teeth, after the peak of growth and development(Cvs4). Case one presented with severe high Angle, a concave facial profile, an ANB angle of- 5 °, completely mesial relationship in both sides of canine and molar teeth. There were 2mm of maxillary crowding and 6mm of mandibular crowding. The patient presented crossbite in all teeth, widely openbite with a 6mm interincisor distance and a 3 mm reverse overjet. The maxillary midline was in the center, the mandibular midline was deviated to left 2 mm. Case two presented with average angle, a concave facial profile, an ANB angle of- 4 °, completely mesial relationship in right side canine and molar teeth, neutral relationship in left side canine and molar teeth. There were 5mm of maxillary crowding and 0.5mm of mandibular crowding. The patient presented crossbite in all teeth, widely openbite in anterior teeth, with a 2.5mm interincisor distance. The maxillary and mandibular midline was deviated to right 2 mm and to left 4mm, respectively. The index of Tweed- Merrifield differential diagnostic analysis was 240.5 and 137.75, respectively, belong to severe degree. According to the measurement of cephalometry pre-therapy, the patients suggested to be orthognathic surgery indications, however, the patient refused surgical treatment. Finally, we made reasonable camouflaged orthodontic treatment plans for two patients, based on the analysis of pathogenesis with Shenshan analysis method. Treated with Straight Wire Appliance, case one with extraction of two mandibular first molars and the extraction spaces closed by sliding method, besides using maxillary occlusive pad when necessary, while case two coordinated with rapid maxillary expansion(RME). Elastic traction was used during the treatment of two cases. Pre-therapy and post-treatment cephalometric measurements were compared to observe the changes of hard and soft tissues.Results: After treatment, both of two patients’ upper and lower arches were aligned, relationships of bilateral canines and molars were neutralism, upper and lower median line were aligned. Facial profile and occlusal function were so improved that patients were satisfied with the results. Changes of cephalometric measurements before and after treatment:(1) in two cases, ANB Angle increased 2°and 2.5°respectively, Wits value added 3 mm and 4.5 mm respectively, showed that sagittal inharmony had been improved. What’s more, APDI reduced 4.5°and 6.5°respectively, showed lower skeletal class III tendency;(2) cant of occlusion plane(OP-FH) Angle decreased 9°and 2 ° respectively, prompted the occlusion plane counterclockwise rebuilt;(3) FCA increases 5 ° and 2.5 ° respectively, Z Angle decreased 5.5 °and 6 °respectively, showed that soft tissue was improved;(4) MP- FH increased 1.5 °and 2 ° respectively, MP- SN increase 1 ° and 1.5 ° respectively, showed slightly clockwise rotation of mandibular;(5) U1-NA、U1-SN angle increased and L1-NB、L1-MP angle decreased in case one because of camouflaged orthodontic treatment; U1-NA、U1-SN angle decreased in case two because of the apply of RME and L1-NB、L1-MP angle almost unchanged in case two;(6) Gn-Ar-L1 increased 4°, ANS-Ar-U1 increased 1.5 °, Go-Ar-M reduced 4 °, L1-MP reduced 1.4 mm in case one, suggested extrusion in upper and lower incisor,especially in lower, and intrusion in lower molars, while in case two, ANS-Ar-U1 increased 3°, Gn-Ar-L1 increased 1.5°, PNS-Ar-M increased 1°, Go-Ar-M increased 3°, suggested extrusion in bimaxillary incisor and mandibular molars.Conclusion: This paper presents two satisfactory cases of adolescent patients with severe skeletal class Ⅲ openbite that treated with camouflaged orthodontic treatment, although the coefficient degree of Tweed- Merrifield differential diagnostic analysis was severe and a number of cephalometric measurement suggested to be combination of orthognathic surgery and orthodontics indications. Pathogenesis analysis by Shenshan analysis method, personalized treatments plan formulation, grasping the characteristics of adolescents’ growth and development, consideration of patients’ non-surgical will contributed to these satisfactory treatment effects together. Taking advantages of adolescents’ growth potential after the growth peak, the ANB angle were both increased and gained effective skeletal improvement though cannot be completely corrected the same as orthognathic surgery. The slightly increase of mandibular plane angle suggest that we should speak highly of the clockwise rotation potential of mandibular and prevent extrusion of molar teeth. We can achieve perfect overbite, overjet and normal molar relationship by means of changing occlusion plane. Camouflaged orthodontic treatment for teenagers with skeletal class III openbite malocclusion is able to satisfy the patients’ strong will of taking non-surgical treatment, as well as improve facial profile and occlusal function obviously. |
PDF Full Text Request