Quality of occlusal outcome following space closure in cases of lower second premolar aplasia using lingual orthodontic molar mesialization without maxillary counterbalancing extraction

Abstract

BackgroundControlled space closure in cases of isolated lower second premolar aplasia (ILSPA) without maxillary counterbalancing extraction is challenging. Anterior anchorage loss may occur during space closure resulting in compromised occlusal results in terms of an absence of proper canine guidance during laterotrusive mandible movements.In order to evaluate the effectiveness of Herbst telescope anchorage in combination with double-cable, pull mechanics and a completely customized lingual appliance for orthodontic space management in cases of ILSPA, we tested the null hypothesis that there is a significant deterioration in the sagittal canine relationship towards an Angle-Class-II occlusion expressed as a loss of anterior anchorage following space closure with molar mesialization.MethodsTwenty-five consecutively de-bonded subjects (female / male 17 / 8; aged at T0 (start of MB Tx) 12.3 to 20.6 years; mean age 15.0 / SD 1.7 years) were included in this retrospective analysis using the inclusion criteria of least of one lower second premolar aplasia; completed treatment with a totally customized lingual appliance (CCLA) in combination with Herbst telescopes. Exclusion criteria were the absence of counterbalancing maxillary extractions, as well as additional tooth aplasia other than lower second premolars. A total of 33 single, lower premolar aplasia space closures (right / left sided 17 / 16) were assessed using plaster casts and intra-oral photographs scaled to the plaster casts, at bonding (T0), Herbst insertion (T1), following gap closure (T2) and de-bonding (T3). Parallelism of roots was controlled by panoramic x-rays at T3.ResultsThe mean aplasia space at T0 was 7.5 mm (SD 2.6). Complete space closure was achieved in all 33 situations. The null hypothesis was rejected. There was a significant improvement in the initial canine relationships (mean 3.5 mm distal occlusion at T0) to a mean 0.1 mm at T3. When evaluated against the individual treatment plan, the following amounts of planned improvements were achieved: space closure 100%, canine relationship 97.5%, overjet 93.9%, overbite 96.4%, parallel roots in space closure site 93.9%.ConclusionHerbst telescope anchorage in combination with double-cable pull mechanics and a CCLA for orthodontic space closure can deliver predictable, high-quality treatment results.

Use of Mini-Implant Anchorage For Second Molar Mesialization: Comprehensive Approach For Treatment Efficiency Analysis

“…The integral indicator of the quality of treatment must take into account the timing of rehabilitation, since the use of the mini-implants as a promising method of orthodontic correction, can reduce the total time needed for iatrogenic interventions [5][6][7]. On the other hand, the terms of treatment, together with the parameters of functional and aesthetic restorations, affect the patient's satisfaction criterion due to the chosen appropriate rehabilitation algorithm.…”

“…Realization of such procedures without using any additional anchorage outlined by possible non-prognostic undesired effects. Previous results obtained during in vivo and in vitro studies suggested that after tooth movement in the form of mesialization there is a chance of periodontal support loss, but except that adverse effect of mesialization procedure could be associated with the rotation of mesialized tooth, its extrusion and non-preferable changes in occlusal force distribution [4][5][6][7][8][9].…”

“…Mesialization procedure of molars with the use of anterior dentition or premolars as an anchorage was found to be associated with the middle line deviations, posterior displacement of surrounding soft tissue, and changes of visual profile [6,8,9]. Because of these problems, researches proposed a variety of methods not only for the treatment of such complications but also for their prevention during controlled orthodontic tooth movement.…”

“…Because of these problems, researches proposed a variety of methods not only for the treatment of such complications but also for their prevention during controlled orthodontic tooth movement. That is why argued mesialization procedure due to the results of previous studies in some cases should be provided by the model of rectangular archwires, which helps to control changes of torque, inclination, and rotation of teeth [5][6][7].…”

Controlling incisor torque with completely customized lingual appliances

“…An edge-to-edge position of the respective mesial and distal sides of upper and lower first premolar was defined as a sagittal distal occlusion of ½ cusp. The true dimensions of the assessed premolar and malocclusion on the digital photographs were assessed using a calibration technique previously employed [13]: The intraoral photographs were scaled to the corresponding plaster casts by adjusting the dimensions of the upper first premolar to its corresponding dimensions taken from direct cast measurements, using a sliding caliper. In cases in which there were different extents of sagittal occlusion on either side, the side with greater Angle class II occlusion was chosen for assessment.…”