Objective: To test the hypothesis that there is no difference between the action of at-home and in-office vital bleaching on the shear bond strength of metallic brackets bonded with composite resin 24 hours after bleaching. Materials and Methods: Forty-five human upper premolars were randomly divided into three groups: (1) control, (2) 10% carbamide peroxide at-home bleached, and (3) 35% hydrogen peroxide in-office bleached. Twenty-four hours after bleaching the teeth were pumiced, bonded with metallic brackets, and stored in distilled water. One day after bonding the shear bond strength of the brackets was determined. Results: The mean shear bond strength of Group 1 (control) and Group 2 (carbamide peroxide bleached) were not statistically different. Group 3 (hydrogen peroxide bleached) had a significantly lower mean shear bond strength than Group 1 and Group 2. Conclusions: The hypothesis is rejected. Use of 10% carbamide peroxide bleaching does not significantly alter shear bond strength values. On the other hand, use of 35% hydrogen peroxide bleaching significantly reduces these values and diminishes the amount of resin remnant on the tooth surface after bracket debonding. (Angle Orthod. 2009;79:122-126.)

INTRODUCTION: Despite discussion on the merit of various cephalometric superimposition methods, there remains a need to assess which one can be used in daily practice with reasonably accuracy and less working time. OBJECTIVE: The aim of this study was to investigate four methods of cephalometric superimposition by means of assessing the longitudinal changes in craniofacial morphology caused by growth and response of adolescents with Class I malocclusion to orthodontic treatment involving first premolar extraction. METHODS: Pretreatment (T1) and post-treatment (T2) standardized lateral cephalometric radiographs of 31 adolescents (20 females and 11 males), with Angle Class I malocclusion and indication of premolar extraction, participated in this study. Radiographs were digitized, traced and had structures identified by means of a cephalometric software. Four superimposition methods were used: Björk structural method, Steiner/Tweed SN line, Ricketts N-Ba line at N-point and Ricketts N-Ba line at CC-point. Positional changes were quantified by horizontal and vertical linear changes in the following cephalometric landmarks: anterior/posterior nasal spine (ANS and PNS), gnathion (Gn), Gonion (Go), Pogonion (Pog), A-point and B-point. Differences between T1 and T2 in horizontal and vertical positional changes for all superimposition methods were assessed by one-way analysis of variance (ANOVA) and Bonferroni correction (p < 0.05). RESULTS: There were no statistically significant differences among the cephalometric superimposition methods or when patients' sex was considered. CONCLUSION: Björk structural method, Steiner/Tweed SN line, Ricketts N-Ba line at N-point and Ricketts N-Ba line at CC-point methods were reliable and presented similar precision when the overall facial changes due to active growth and/or orthodontic treatment were examined.

To assess frequency of pain referred to the teeth in occipital neuralgia, migraine and tension-type headache. Material and methods:153 patients presenting with bruxing behavior and craniomandibular disorders (CMDs). Clinical examination, questionnaires, palpation, criteria for CMDs, bruxing behavior (BB), occipital neuralgia (ON), migraine (MIG), tension-type headache (TTH) and pain referred to the teeth. Results: Mean ages in the ON, MIG and TTH patients and controls were about 38.0, 37.0, 33.0 and 36.6 years, respectively (p = 0.17). The frequencies of dental pains in the subgroups ON and MIG were 37.1% and 25% (p = 0.52), ON and TTH, 37.1% and 18.6% (p = 0.03), ON and Controls 37.1% and 6.7% (p = 0.006), MIG and TTH 25% and 18.6% (p = 0.51), MIG and Controls 25% and 6.6% (p = 0.16) and TTH and controls 18.6% and 6.7% (p = 0.15). The frequencies of pain referred to the teeth decreased from the ON to the MIG, and then to the TTH and Control groups (x-square for independence p < 0.002, x-square for trends p < 0.001). Conclusion:The ON subgroup demonstrated the highest frequency of dental pain referred to the teeth. This frequency increased with the severity of pain. Neurophysiological mechanisms may explain higher frequency of referred pain associated with the severity of headache.