A new series of palatal and lingual appliances inserted in the lingual sheaths that attach to the molar bands are available. 2 The transforce sagittal expander is specifically designed for anteroposterior arch development in upper and lower arches and it can be used simultaneously in both upper and lower arches. 1, 8 The need of a sagittal and transverse arch developer becomes more important as mentioned by Defraia, et al 2006 who studied dental arch dimensions in the mixed dentitions of Italian children born in the 1950’s and 1990’s. They concluded that boys and girls born in the 1990s showed significantly smaller maxillary arches. 9 Trans-Force lingual appliances are designed to correct arch form in patients with constricted dental arches. Interceptive treatment with this new series of pre-activated lingual appliances offers new possibilities for arch development, in combination with fixed appli-ances. Palatal and lingual appliances insert in horizon-tal lingual sheaths in molar bands. No activation is required after the appliance is fitted, and this principle is extended to a series of appliances for sagittal and transverse arch development. Both sagittal and trans-verse appliances have additional components to achieve 3-way expansion where this is indicated. The invisible lingual appliances may be used in correction of all classes of malocclusion at any stage of develop-ment, from mixed dentition through permanent denti-tion, and this approach has wide indications in adult treatment.(William J Clark) 10 The purpose of this study was to evaluate the effi-ciency of using a Trans Force sagittal arch developer appliance in children with a constricted maxillary arch and a protracted lower arch together with a lower chin cap by using clinical and radiographic examination and model analysis. The patients were followed periodically every week in the dental clinic for any required correction or adjustment of the appliance. When by clinical exami-nation we noticed correction of the cross bite, we took another photograph, study models and lateral cephalo-metric x-ray and record the measures for assurance of correction. The following variables were measured: Photographs from profile view: position of upper lip relative to the lip chin to evaluate its advancement. Study models : 1)Arch length, Upper arch circumference, 2) Arch width in canine region. Lateral Cephalometric X-Ray SNA SNB ANB Wits U I to FH U I to Npg mm UI to pg Degree U I to NA mm U I to NA degree UL to E line All these measurements were recorded together with the time elapsed science fixation of the expander until complete correction of cross bite and final data analyzed. Measurement technique of the appliance According to the instructions of William J Clark, 2005, 10 the following procedures were followed for adjustment: The sagittal arch developer is provided in three sizes for the upper arch. The anterior contour is Adjusted accordingly. The mesio-distal length of the appliance varies by 2mm increments throughout the range. Materials and Methods A sample of 10 juvenile female patients in a mixed dentition stage with developing class III due to maxillary deficiency and mandibular excess, required upper arch developing as part of a first phase treatment were selected for the study. Those patients who had an anterior cross bite due to retro-clined upper incisors, and required face mask appli-cation were selected for the study. For each patient enrolled in the study the following was done as part of the full orthodontic diagnosis: Clinical examination ,Photographs frontal, profile-right and left , Study models , Panoramic X-ray film, and a Standardized lateral cephalometric X-ray. An upper sagittal arch developer was selected as part of the treatment plan for each patient and its force was calibrated according to the need of each case utilizing size 1 or 2 or 3 .The appliance was soldered to the molar bands palatally . The appliance was curved somewhat upward to touch the rouge area palatal to upper incisors. A concomitant application of a chin cap was used with the sagittal arch developer appliance for each patient. Measurement template A clear template is provided showing a scale model of the appliance in both compressed and fully extended forms. The template also illustrates the molar width in both positions. The arch length before treatment is measured with the help of the millimeter scale on the template.(Fig. 1) The arch length is measured for each side at the mesio-lingual gingival contour of the molar or alterna-tively the mesio-lingual cusp of the molar to the incisal point which is the mid-point of the gingival papilla between the central incisors. Fig. 1 Photograph of the template and forms of Transforce appliance. www.orthodontics.com November/December 2011 17
Journal of the American Orthodontic Society November-December 2011: Page 17
