Transpalatal Arch (TPA) clinical trials

Comparing Clinical Application of Innovatedly Made Transpalatal Arch (TPA) From 3D Reconstructed Model and Conventionally Made TPA

Trans-palatal Arch or TPA is an intra oral device that is occasionally used in conjunction of orthodontic fixed appliance treatment. It has two main types, the fixed or removable TPA. The purpose of this appliance is to maintain upper jaw's arch width and preventing upper molar teeth from moving forward. It holds the upper molar teeth in their original position so that if any upper teeth are extracted to make room for the others to straighten, the upper molars will not move into the extraction spaces. It comprises of a stainless steel wire with a central semi loop that fits comfortably across but not touching the palate. On each side, it is attached with metal bands around each of the two upper molar teeth. The construction of TPA requires at least three appointments that take up one to three weeks time. Firstly, an elastic "doughnut" like rubbery separators will be placed between the upper molar teeth using a special tool. Slight tightness is usually felt when the separators are inserted. The whole procedure takes less than a couple of minutes. Patients will be sent away for up to 14 days with the separators in place. For the second appointment, the separators will be removed with dental probe. The correct size metal bands are then selected for the upper molar teeth. Once a correctly fitting band has been chosen, an impression (mould) of the upper teeth with the bands in place will be taken. The impression, together with the bands will be sent to the laboratory for construction of the TPA. Separators will be placed again until patients come back to have TPA fitted. If the mould of the teeth is scanned and printed out using three dimensions (3D) technology, the number of appointments could be reduced. The second appointment which requires molar bands selection, impression and replacement of separators of upper teeth could be skipped. Molar bands selection can be carried out outside the mouth and straight away sent to the laboratory for TPA construction. All parties involved, patients, clinicians and dental technologists will benefit the innovation by reduction of time spent for TPA related procedure. However, the study that compares innovated TPA from 3D reconstructed models and conventional method has never been done and related similar studies are very scarce.