OBJECTIVE: To compare dentoalveolar and skeletal changes produced by the pendulum appliance (PA) and the distal screw appliance (DS) in Class II patients. METHODS: Forty-three patients (19 men, 24 women) with Class II malocclusion were retrospectively selected for the study. Twenty-four patients (mean age, 12.2 +/- 1.5 years) were treated with the PA, and 19 patients (mean age, 11.3 +/- 1.9 years) were treated with the DS. The mean distalization time was 7 months for the PA group and 9 months for the DS group. Lateral cephalograms were obtained at T1, before treatment, and at T2, the end of distalization. A Mann-Whitney U test was used for statistical comparisons of the two groups between T1 and T2. RESULTS: PA and DS were equally effective in distalizing maxillary molars (4.7 mm and 4.2 mm, respectively) between T1 and T2; however, the maxillary first molars showed less distal tipping in the DS group than in the PA group (3.2degrees vs. 9.0degrees, respectively). Moreover, significant premolar anchorage loss (2.7 mm) and incisor proclination (5.0degrees) were noted in the PA group, whereas premolar distal movement (1.9 mm) and no significant changes at the incisor (0.1degrees) were observed in the DS group. No significant sagittal or vertical skeletal changes were detected between the two groups during the distalization phase. CONCLUSIONS: PA and DS seem to be equally effective in distalizing maxillary molars; however, greater distal molar tipping and premolar anchorage loss can be expected using PA.
Bicuspid ; Humans ; Incisor ; Male ; Malocclusion ; Molar* ; Retrospective Studies ; Statistics, Nonparametric

The renewed interest in dimeric salicylates as broad-spectrum anti-inflammatory and anti-diabetic agents provided a rationale to investigate the dimerization of the substituted salicylate -tetrahydrocannabinolic acid (THCA-A, ) as a strategy to solve its instability to decarboxylation and to generate analogues and/or pro-drugs of this native pre-cannabinoid. Activation of the carboxylic group with the DCC-HOBt-DMAP protocol afforded a high yield of the OBt ester , that was next converted into the highly crystalline di-depsidic dimer upon treatment with DMAP. The mono-depsidic dimer was also formed when the reaction was carried out with partially decarboxylated THCA-A samples. The structure of the depsidic dimers was established by spectroscopic methods and by aminolysis of into the pre-cannabinoid amide . Both dimers showed excellent shelf stability and did not generate significant amounts of -THC upon heating. However, only the didepsidic dimer activated PPAR-, the major target of pre-cannabinoids, but strong binding to serum proteins abolished this activity, also shielding it from the action of esterases.