Comparison of the Effect of Transpalatal Arch on Periodontal Stress and Displacement of Molars When Subjected to Orthodontic Forces. A Finite Element Analysis.

Introduction: The transpalatal arch has been used successfully for decades during routine orthodontic treatment for various purposes, including reinforcing anchorage. In the light of current scientific advancements with more precise knowledge of biology of tooth movement, it is prudent to study whether transpalatal arch is effective in preserving anchorage. Objectives: The aim of this finite element study was to evaluate and compare the effects of the transpalatal arch on periodontal stresses of molars and displacements when subjected to orthodontic forces. Methods: Stress patterns and displacements between models with and without a transpalatal arch were investigated by means of 3-dimensional finite element analysis. A finite element model of the maxillary first molars, periodontal ligament, alveolar bone, and transpalatal arch was created, that consisted of 1, 69,036 elements and 29,518 nodes. A simulated orthodontic retraction force of 2N was applied to the maxillary first molar in a mesial direction. Resultant von mises stresses were evaluated and compared in models with and without transpalatal arch, as well as displacement in models with and without transpalatal arch. Results: Results suggested that the presence of a transpalatal arch has no effect on molar tipping, decreases molar rotations, and reduces periodontal von mises stress magnitudes by less than 1%. Conclusions: The presence of the transpalatal arch induces only minor changes in the dental and periodontal stress distribution. Alternative methods can be used where absolute anchorage is required however transpalatal arch should not be considered an unnecessary tool in the treatment of orthodontic patients because of its various functions.

Pre-Surgical Nasolveolar Molding In Patients With Unilateral Clefts of Lip, Alveolus And Plate - A Case Report.

The case of a newborn male patient with unilateral cleft lip, alveolus and palate with a marked cleft nose deformity is presented. This may lead to an unsatisfactory aesthetic result after primary cheiloplasty and nasoplasty. Five months prior to surgery, the patient was treated with Naso-alveolar molding. The device consisted of an acrylic plate on the maxillary arch to which was attached a wire of 0.032 inch diameter which lifted the nasal dome. The alignment of the alveolar segments creates the foundation upon which excellent results of lip and primary nasal surgery are dependent in the repair of the cleft lip and palate patient. The purpose of this article is to highlight the effectiveness of naso alveolar molding appliance used to direct growth of the alveolar ridge, lips, and nose in the pre surgical treatment of cleft lip and palate. As a result of this appliance, the primary surgical repair of the nose and lip heals under minimal tension, thereby reducing scar formation and improving the esthetic result.