Influence of maxillary first molar rotation on the severity of dental class II malocclusion: A cross-sectional study.

AIM: The aim of the study was to evaluate and assess the influence of maxillary molar rotation on severity of dental class II malocclusion. MATERIALS AND METHODS: The study comprised of 4 different groups namely, 1/4th class II malocclusion, 2/4th class II malocclusion, 3/4th class II malocclusion and full class II malocclusion involving sample size of 20,15,16 and 12. The samples were subjected to digital evaluation of maxillary 1st permanent molar rotation using 4 parameters namely angle of Friel, Ricketts E-Line, angle of Henry and Premolar angle. RESULTS: The results were subjected to statistical analysis using one way ANOVA wherein group IV (Full class II malocclusion) exhibited a greater rotational value. On evaluation, angle of Friel exhibited a mean of 59.6±1.61 degrees, Ricketts E-Line was found to be 12.3±1.77mm while angle of Henry showed a mean of 19±3.19 degrees and premolar angle was 12.5±5.83 degrees. CONCLUSION: On evaluating molar rotation using angle of Friel, Ricketts E-Line, angle of Henry and premolar angle, full cusp class II malocclusion presented higher degree of mesiopalatal rotation maxillary molar rotation. With increasing mesiopalatal rotation, the severity of molar relation also increased from 1/4th to full class II. Hence the maxillary molar spatial position along the long axis majorly influences the molar relation wherein a full cusp class II molar relation exhibits higher degree of molar rotation.

Evaluation and comparison of surface characteristics of commercially available TMA wires using scanning electron microscopy and optical profilometer.

AIM: The aim of this study was to evaluate and compare the surface characteristics of colored titanium molybdenum alloy archwires (purple-coated TMA and honey dew-coated TMA) and the regular titanium molybdenum alloy archwires. MATERIALS AND METHODS: The experiment comprised three groups, Group I - regular TMA archwires, Group II - purple-coated TMA archwires, Group III - honey dew-coated TMA wires involving 21 samples each. The surface characteristics were assessed using scanning electron microscopy and optical profilometer. RESULTS: The results were statistically analyzed using analysis of variance wherein Group I regular TMA wires exhibited a root mean square value of 148.071 nm and a standard deviation of 9.0027 nm followed by group II (purple-coated TMA wires) which showed a root mean square value of 84.095 nm with a standard deviation of 2.6005 nm, while group III (honey dew-coated TMA wires) was found to have a root mean square value of 71.681 nm with a standard deviation of 1.4645 nm on subjecting to optical profilometry. CONCLUSION: The surface roughness is higher for regular TMA wire exhibiting superior characteristic of color-coated TMA wires, especially honey dew-coated TMA wires over the regular and purple-coated TMA wires. This property of the archwires details regarding its application in both sliding and frictionless mechanics in retraction phase of fixed orthodontic treatment.

Evaluation of kinetic friction between regular and colored titanium molybdenum alloy archwires.

AIM: The aim of this study was to evaluate the kinetic frictional properties of colored titanium molybdenum alloy (TMA) archwires (purple-coated TMA and honey dew-coated TMA) and the regular TMA archwires. MATERIALS AND METHODS: The experiment comprised of three groups, Group I - Regular TMA archwires, Group II - Purple-coated TMA archwires, Group III - Honey dew-coated TMA wires involving 21 samples each that were evaluated for their frictional properties using Instron Universal Testing Machine. RESULTS: The results were subjected to statistical analysis using analysis of variance wherein Group I Regular TMA wires revealed mean kinetic frictional value of 8.236 N and a standard deviation of 0.4038 N, while Group II (purple-coated TMA wires) showed a mean value of 5.297 N, standard deviation of 0.3128 N and Group III (honey dew-coated TMA wires) showed a mean value of 4.206 N and a standard deviation of 0.5353 N. CONCLUSION: The kinetic frictional values are higher for regular TMA wire exhibiting superior characteristic of color-coated TMA. Wires exhibiting superior characteristics are color-coated TMA wires, especially honey dew-coated TMA wires over the regular and purple-coated TMA wires. These superior properties of newly introduced wires can be considered for its application in both details friction and frictionless mechanics in retraction phase of fixed orthodontic treatment.