A randomized clinical trial to compare the Goshgarian and Nance palatal arch.
ABSTRACT The aim of this trial was to evaluate whether a Nance or Goshgarian palatal arch was most effective for prevention of mesial drift, distal tipping, prevention of mesio-palatal rotation of the upper first permanent molars, and patient comfort and ease of removal. Patients were recruited from a district general hospital and a specialist orthodontic practice and randomly allocated to a Goshgarian (n = 29) or a Nance (n = 28) group. Pre-treatment study models (T1) were taken followed by the placement of the palatal arch, premolar extractions, and upper and lower fixed appliances. The clinical end point was 6 months (T2), at which time, an impression for an upper study model was taken. The amount of upper first permanent molar mesial movement, distal tipping, and mesio-palatal rotation was measured by scanning T1 and T2 study models and then using a software program to calculate molar changes. In addition, the patients recorded their discomfort scores using a seven-point Likert scale at each recall visit. Forty-nine patients (86 per cent) completed the trial. t-tests were used to compare molar movements between the Goshgarian and Nance palatal arch groups. There were no statistically significant differences between the palatal arches in terms of prevention of mesial drift or distal tipping (P > 0.05). There was a statistically significant difference in the amount of molar rotation between the arch types, with both exhibiting some disto-palatal rotation even though they were not activated for this movement. The Goshgarian palatal arch produced marginally more disto-palatal rotation than the Nance arch (P = 0.02), although this may not be considered clinically significant. A Mann-Whitney test revealed that there was also a statistically significant difference in pain scores between the Goshgarian and the Nance arch, with the latter being associated with more discomfort (P = 0.001). This trial did not support any preference in the use of the Goshgarian or Nance palatal arch, unless the slightly reduced patient discomfort with the Goshgarian arch is considered significant.
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ABSTRACT: The purpose of this study was to measure tongue pressure exerted on the loop of the transpalatal arch (TPA) during deglutition and to consider the influence of the distance of the loop of the TPA from the palatal mucosa and the anteroposterior position of the loop. Tongue pressures of 4 subjects with normal occlusion were measured with subminiature pressure sensors fixed on the TPA. The distances from the palatal mucosa to the surface of the pressure sensor were set at 2, 4, and 6 mm. The loop of the TPA was placed at the level of the middle of the maxillary second premolars (P), first molars (M1), or second molars (M2). Nine types of TPA devices were measured for each subject. The maximum recorded tongue pressure was taken from each act of deglutition. The minimum pressure value was exerted at position P when the distance from the palatal mucosa to the surface of the pressure sensor was 2 mm. The maximum value was obtained at position M2 and a distance of 6 mm from the palatal mucosa. When distances of 2, 4, and 6 mm were compared, significant differences between 2 and 4 mm, and between 2 and 6 mm were found. Significant differences were observed in comparisons between the positions P and M1, M1 and M2, and P and M2.American Journal of Orthodontics and Dentofacial Orthopedics 02/2003; 123(1):29-34. · 1.46 Impact Factor
- British journal of orthodontics 11/1978; 5(4):201-3.
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ABSTRACT: The correction of a unilateral first molar crossbite with a Goshgarian type of transpalatal arch was evaluated in 35 children from 6 years, 8 months to 15 years, 11 months old. Fifteen of the children were treated with an arch activated for expansion only and 20 children with an arch activated in a similar way but with the inclusion of buccal root torque of the anchorage tooth. With both types of activation, the arches worked in a statically determinate system, i.e., the tooth in crossbite was allowed to tip buccally. The movements of the first molars as a result of the treatment were monitored by measurements on dental casts and frontal cephalometric roentgenograms. In addition, the width of the midpalatal suture was measured on occlusal roentgenograms of the maxilla. In the children treated with an arch activated only for expansion, the molars on both sides of the dental arch moved buccally during the treatment. In the children treated by torque activation, on the other hand, there was a considerable buccal movement of the molar on the side of the crossbite without any significant buccal movement of the anchorage tooth. In individual cases, the molar on the noncrossbite side moved and tipped palatally and in some cases buccally but to a minor degree. With both types of activation, there was only a slight change in inclination of the transverse occlusal plane through the first molars; the plane opened up slightly toward the side of the crossbite. For both types of activation, there was a slight widening of the palatal suture during the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)American Journal of Orthodontics and Dentofacial Orthopedics 05/1995; 107(4):418-25. · 1.46 Impact Factor