Treatment effects produced by preorthodontic trainer appliance in patients with class II division I malocclusion

Abstract

The aim of the present study was to evaluate cephalometrically the treatment effects of preorthodontic trainer on dentoskeletal components in individuals showing class II division I malocclusion. This study comprised of 50 class II div. I patients (20 test patients and 30 controls) in the age group of 8-12 years. The test group was treated with a preorthodontic trainer for a period of 15 months. Standardized lateral cephalograms of both groups were taken before and after the treatment period. The cephalograms were then evaluated to determine the skeletal and dental changes in the course of treatment and then compared with the normative growth data to eliminate the possible growth effects. The readings were tabulated and subjected to statistical analysis. The results of the study after excluding the changes due to growth showed reduction in ANB and OP-SN values, indicating a significant reduction in the skeletal class II relationship. An upward cant of the occlusal plane in the treatment group was noted, probably due to the forward rotation of mandible. A significant increase in the vertical dimensions of the face in general and the mandible in particular was observed with the use of preorthodontic trainer. A significant reduction in the overjet and an increase in the inclination of mandibular incisor (L1-NB deg) were noted in the treatment group when compared with control group. It can be concluded that class II corrections can be achieved with the preorthodontic trainer appliance, which appears to have mostly dentoalveolar effects with smaller but significant skeletal effects.

Myofunctional Trainer versus Twin Block in Developing Class II Division I Malocclusion: A Randomized Comparative Clinical Trial

“…However, the mandibular molars showed more mesial movement than maxillary molar favoring class I relation. These findings were in agreement with other studies, whether for the T4K [13,14] or twin block appliance [5,11]. The justification for molar relation improvement was based on the action of both appliances that share the same concept of forcing the patient to close in class I relation, resulting in mandibular forward movement with slight maxillary restriction.…”

“…The overjet reduction encountered by both appliances in this study was supported by many other studies in the literature, where Usumez et al [13], Dass and Reddy [14] reported a significant reduction in the overjet in children between 8-12 years over a mean period of 13 and 15 months, respectively, when using the T4K appliance compared to the untreated controls. Similar findings were reported for the twin block appliance [8,9,24].…”

“…Usumez et al, [13] demonstrated a significant overjet reduction, due to retroclination of the maxillary incisors and the significant proclination of the mandibular incisors, in their clinical study to evaluate the effects of early treatment with T4K on class II division I malocclusion on 20 children with an age range of 8.3-10.9 years old, compared to untreated controls with an age range of 9.6-11.0 years old. These findings were also supported by Dass and Reddy [14], who evaluated cephalometrically the treatment effects of the T4K on the dental and skeletal components in class II division I malocclusion on 20 patients of 8-12 years old for an observation period of 15 months. They noted a significant increase in the vertical dimension, as well as a reduction in the overjet, due to proclination of the mandibular incisors, and an increase in the mandibular incisor angle to the NB line in the treatment group over the untreated controls.…”

The Law of Minimum Vertical Dimension: Evidence for Improvement of Dental Occlusion

“…54 Correction of class II or III malocclusions achieved through use of functional orthodontic or orthopedic devices that aim to correct the OP inclination by seeking parallelism between it and Camper's plane and a bilaterally balanced VD and, as a consequence, bilaterally balanced PMFAs as well, has shown much more stable treatment results. 37,[65][66][67][68] Although the reference line that Coro at al 37 used in their report was the Frankfort's plane, they concluded that the POP shows significant correlation with jaw posture. The steeper the POP is, the more retrognathic and hyperdivergent the jaw posture is.…”

Treatment of Class II Division 1 Malocclusion with Myofunctional Trainer System in Early Mixed Dentition Period

“…22 Class II corrections can be achieved with the preorthodontic trainer appliance, which appears to have mostly dentoalveolar effects with smaller but significant skeletal effects. 23…”