A randomized controlled trial of home tooth-whitening products

PURPOSE: To evaluate the effectiveness of two marketed home tooth-whitening products. METHODS: A randomized controlled clinical trial involving 87 adults who were randomly allocated into one of three groups: (1) 6% hydrogen peroxide whitening strips, (2) 18% carbamide peroxide whitening gel, and (3) a placebo (fluoride toothpaste) control group. Subjects were instructed individually and then used the given product daily for 2 consecutive weeks. Color was determined in brightness (L*), yellowness (b*) and redness (a*) [color space] at baseline and 8 weeks after dispensing the product by employing a high resolution digital camera (Fuji HC1000 CCD) to image the subject's anterior maxillary teeth under standard polarized lighting conditions. The subjects also completed a questionnaire on self-satisfaction with the treatment outcome. RESULTS: One-way ANOVA (Bonferroni test) demonstrated significant differences in color between the three groups with changes in brightness (L*, P< 0.001), yellowness (b*, P< 0.001) and redness (a*, P < 0.001). Changes in L* a* b* was greatest among those who used the 6% hydrogen peroxide whitening strips. Subjects in the whitening strip group also rated that product significantly (P < 0.01) more favorably than other groups with respect to the amount of whiteness improvement, as well as whitening satisfaction and overall impression while there is no significant difference between the whitening gel and the placebo groups.     

Objective discrimination between mandibular open/close excursion patterns: a clinical case report

The purpose of this clinical case report was to describe the kinematic variables of movement that best discriminated between asymmetrical and symmetrical mandibular excursion patterns in a patient with myogenic temporomandibular dysfunction. Two mandibular movements (deemed to be asymmetrical and symmetrical by both patient and physiotherapist) were each recorded six times on three occasions at six, twelve, and 15 weeks after commencement of an exercise programme. The mandibular movements were captured with a 12-camera Motion Analysis System (Motion Analysis Corp., Santa Rosa, CA) with kinematic variables expressed in six degrees-of-freedom. A two-way analysis of variance (ANOVA) for repeated measures was used to analyze the data. The asymmetrical pattern was characterized by increased axial rotation and decreased sagittal rotation but with no differences in translation values when compared to those of the symmetrical pattern. The results support the clinician's and patient's judgment regarding differences in quality of mandibular excursion patterns made over the course of time.     

Surveillance of drug abuse in Hong Kong by hair analysis using LC‐MS/MS

The aim of this study is to reveal the habits of drug abusers in hair samples from drug rehabilitation units in Hong Kong. With the application of liquid chromatography–tandem mass spectrometry (LC–MS/MS) technology, a total of 1771 hair samples were analyzed during the period of hair testing service (January 2012 to March 2016) provided to 14 drug rehabilitation units including non‐governmental organizations (NGOs), rehabilitation centers, and medical clinics. Hair samples were analyzed for abused drugs and their metabolites simultaneously, including ketamine, norketamine, cocaine, benzoylecgonine, cocaethylene, norcocaine, codeine, MDMA, MDA, MDEA, amphetamine, methamphetamine, morphine, 6‐acetylmorphine, phencyclidine, and methadone. The results showed that ketamine (77.2%), cocaine (21.3%), and methamphetamine (16.5%) were the frequently detected drugs among those drug abusers, which is consistent with the reported data. In addition, the usage of multiple drugs was also observed in the hair samples. About 29% of drug‐positive samples were detected with multiple drug use. Our studies prove that our locally developed hair drug‐testing method and service can be a valid tool to monitor the use of abused drugs, and which could facilitate rehabilitation program management.     

Are 1 or 2 dangerous? Clozapine and olanzapine exposure in toddlers

Clozapine (Clozaril) and olanzapine (Zyprexa) are two relatively new atypical antipsychotics that are structurally and pharmacologically related. There are currently no therapeutic indications for these pharmaceuticals in infants and toddlers.Presumably, as the usage of these medications in adults increases, the frequency of unintentional pediatric ingestions will increase. In 2001 the annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System included a separate subcategory for atypical antipsychotics under the heading of sedatives/hypnotics/antipsychotics. The toxidrome resulting from these drugs is predominately central nervous system depression and anticholinergic effects. Although the desirable lack of extrapyramidal symptoms in adults results in their greatest clinical utility, several reports of toxic ingestions in small children are noteworthy for having extrapyramidal manifestations. We review here the available reported clinical experience with toxic doses of these medications that in small children may amount to as little as a single tablet. Although such doses may be lethal, supportive care and gastrointestinal decontamination in this population will generally lead to a good outcome.     

ProDisc–C versus anterior cervical discectomy and fusion for the surgical treatment of symptomatic cervical disc disease: two-year outcomes of Asian prospective randomized controlled multicentre study

European Spine Journal - Our study aimed to evaluate non-inferiority of ProDisc-C to anterior cervical discectomy and fusion (ACDF) in terms of clinical outcomes and incidence of adjacent segment...     

Hemispheric roles in the perception of speech prosody

Speech prosody is processed in neither a single region nor a specific hemisphere, but engages multiple areas comprising a large-scale spatially distributed network in both hemispheres. It remains to be elucidated whether hemispheric lateralization is based on higher-level prosodic representations or lower-level encoding of acoustic cues, or both. A cross-language (Chinese; English) fMRI study was conducted to examine brain activity elicited by selective attention to Chinese intonation (I) and tone (T) presented in three-syllable (I3, T3) and one-syllable (I1, T1) utterance pairs in a speeded response, discrimination paradigm. The Chinese group exhibited greater activity than the English in a left inferior parietal region across tasks (I1, I3, T1, T3). Only the Chinese group exhibited a leftward asymmetry in inferior parietal and posterior superior temporal (I1, I3, T1, T3), anterior temporal (I1, I3, T1, T3), and frontopolar (I1, I3) regions. Both language groups shared a rightward asymmetry in the mid portions of the superior temporal sulcus and middle frontal gyrus irrespective of prosodic unit or temporal interval. Hemispheric laterality effects enable us to distinguish brain activity associated with higher-order prosodic representations in the Chinese group from that associated with lower-level acoustic/auditory processes that are shared among listeners regardless of language experience. Lateralization is influenced by language experience that shapes the internal prosodic representation of an external auditory signal. We propose that speech prosody perception is mediated primarily by the RH, but is left-lateralized to task-dependent regions when language processing is required beyond the auditory analysis of the complex sound.     

Coordination exercise and postural stability in elderly people: Effect of Tai Chi Chuan

OBJECTIVE: To evaluate the effects of coordination exercise on postural stability in older individuals by Chinese shadow boxing, Tai Chi Chuan (TCC). DESIGN: Cross-sectional study. SETTING: Research project in a hospital-based biomechanical laboratory. PARTICIPANTS: The TCC group (n = 25) had been practicing TCC regularly for 2 to 35 years. The control group (n = 14) included healthy and active older subjects. INTERVENTION: Static postural stability test: progressively harder sequential tests with 6 combinations of vision (eyes open, eyes closed, sway-referenced) and support (fixed, sway-referenced); and dynamic balance test: 3 tests of weight shifting (left to right, forward-backward, multidirectional) at 3 speeds. MAIN OUTCOME MEASURES: Static and dynamic balance of Sensory Organization Testing (SOT) of the Smart Balance Master System. RESULTS: In static postural control, the results showed no differences between the TCC or control group in the more simple conditions, but in the more complicated SOT (eyes closed with sway surface, sway vision with sway surface), the TCC group had significantly better results than the control group. The TCC group also had significantly better results in the rhythmic forward-backward weight-shifting test. Duration of practice did not seem to affect the stability of elder people. CONCLUSION: The elderly people who regularly practiced TCC showed better postural stability in the more challenged conditions than those who do not (eg, the condition with simultaneous disturbance of vision and proprioception). TCC as a coordination exercise may reduce the risk of a fall through maintaining the ability of posture control.