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.

MSX1 Polymorphism in an Eastern Nepalese Non Syndromic cleft lip/palate patient population.

This study was carried out to evaluate the role of MSX1 799 G >T gene polymorphism with non Syndromic cleft lip/palate in Eastern Nepalese patient population. For the study, whole blood samples (2 ml) were obtained from 40 subjects and controls. Genomic DNA was extracted from the blood of the subjects by using ethanol, chloroform treatment. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method was used to check for the presence of polymorphism. The results indicated that a patient has MSX1 799 G>T variant. The patient was a male aged 24 years was a complete unilateral left sided cleft lip/palate involving alveolus, hard and soft palate. He had normal development and no associated anomaly. There was no family history of cleft lip/palate and no history of any teratogenic exposure during embryonic life as revealed by his mother. This may be a case of sporadic polymorphism. It may be concluded that ,although we detected the presence of a MSX1 799 G>T polymorphism in one patient, a further investigation with large sample size, including many SNP’s on families must be performed to get conclusive results.

Perceived Source of Stress Among Undergraduate Dental Students at BPKIHS, Nepal.

Stress is defined as the body's nonspecific response or reaction to demands made on it, or to disturbing events in the environment. The current study was undertaken to determine the prevalence of the sources of stress among the undergraduate dental students of, BPKIHS, Nepal. The descriptive cross sectional study was conducted using the Dental Environmental Stress Questionnaire (Westerman et al, 1993). The questionnaire was administered in the classroom. Data analysis was carried out using SPSS version 12.0.Based on the results obtained it was concluded that fear of failing, academic workload and requirements for completing the graduation were the most prevalent stressors. Clinical factors related to lack of time, patients unavailability and attitude of the faculty were considerately stressful. The living conditions and social factors were found to be the least of the stressful events. Factors related to marriage and children were deemed not related to creating any stress in the academic environment.This study highlights a need to review the current curriculum of the undergraduate students and to make suitable modifications to create a less stressful study environment for the future dentists of the country.