The effect of orthodontic tooth movement on the sensitivity of dental pulp: A systematic review and meta-analysis.

Objectives: Orthodontic tooth movement (OTM) is a process that's initiated by orthodontic forces. As a consequence, the forces could restrict pulpal blood supply, possibly affecting dental pulp. The study aimed to review the available evidence on the short and long-term effects of orthodontic tooth movement on dental pulp sensitivity and to identify clinically relevant risk factors. Sources: PubMed, Embase, Scopus, and Web of Science were searched for papers from 1990 to the end of December 2021. Study selection: The studies that evaluated dental pulp sensitivity of teeth undergoing OTM were included in the systematic review. Randomized, nonrandomized and case-controlled studies were included in the analysis. Risk of bias in each study was assessed using the ROBINS-I tool. Data: The systematic search yielded an initial sample of 1110 studies, 17 were included in qualitative analysis. Most studies were classified as moderate risk of bias, however only limited long-term evidence with a higher risk of bias exists. Electric pulp test (EPT) sensitivity threshold during active OTM was increased by 4.25 SD (P < 0.001) and the relative risk (RR) of pulpal non-sensitivity was 13.27 (P < 0.001) higher compared to pre-orthodontic baseline status. Significant differences were between subgroups associated with the type of OTM. A positive relationship between pulpal non-sensitivity and mean patient age was discovered (P = 0.041). After OTM the risk of pulpal non-sensitivity remained 5.76 times higher (P < 0.001) in the long term. Conclusions: Evidence showed that OTM could affect dental pulp sensitivity. The type of OTM and patients' age were identified as clinically relevant risk factors. Clinical significance: Orthodontic tooth movement negatively impacts the sensitivity of dental pulp during active treatment and to a lesser degree in the long term. Pulpal sensitivity tests during active OTM should therefore be interpreted with caution. Data indicates younger patients have a lower risk of negative pulpal sensitivity during orthodontic treatment.

Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesis.

Globe artichoke (Cynara cardunculus var. scolymus) belongs to the Asteraceae family, in which one of the most biologically significant class of secondary metabolites are sesquiterpene lactones (STLs). In globe artichoke the principal STL is the cynaropicrin, which contributes to approximately 80% of its characteristic bitter taste. Cynaropicrin content was assessed in globe artichoke tissues and was observed to accumulate in leaves of different developmental stages. In the receptacle, a progressive decrease was observed during inflorescence development, while the STL could not be detected in the inflorescence bracts. Almost undetectable amounts were found in the roots and inflorescence stems at the commercial stage. Cynaropicrin content was found to correlate with expression of genes encoding CcGAS, CcGAO and CcCOS, which are involved in the STL biosynthesis. A more detailed study of leaf material revealed that cynaropicrin predominantly accumulates in the trichomes, and not in the apoplastic cavity fluids. Analysis of the promoter regions of CcGAO and CcCOS revealed the presence of L1-box motifs, which confers trichome-specific expression in Arabidopsis, suggesting that cynaropicrin is not only stored but also synthesized in trichomes. A transient expression of GFP fusion proteins was performed in Nicotiana benthamiana plants: the CcGAS fluorescence signal was located in the cytoplasm while the CcGAO and CcCOS localized to the endoplasmatic reticulum.

The effect of hyperbaric oxygenation on postradiation xerostomia and saliva in patients with head and neck tumours.

The study was designed to evaluate the influence of hyperbaric oxygenation (HBO) therapy on salivary gland function and the growth of salivary Streptococcus mutans, Lactobacillus and Candida albicans in patients with head and neck tumours who had undergone radiation therapy. Sixteen patients were included, with radiation doses from 58 to 70 Gy. The first examination was performed at baseline before the first HBO therapy (33.7 ± 9 months after radiation therapy), and the second after 20 daily HBO therapies in a hyperbaric chamber at 2.5 ATA (absolute atmospheres), where patients breathed 100% oxygen for 90 min each day. Measurements of salivary flow, buffer capacity, saliva pH and colony density of S. mutans, Lactobacillus and C. albicans in stimulated saliva were conducted, and xerostomia grade was assessed. Salivary flow increased from 0.20 ± 0.1 to 0.39 ± 0.2 ml/min at the end of HBO therapy (p < 0.001). Salivary pH also increased from 6.0 ± 0.2 to 6.5 ± 0.1 (p < 0.05). The colony density decreased from the time at baseline to the end of HBO therapy for S. mutans (p < 0.001), Lactobacillus (p < 0.05) and the fungus C. albicans (p < 0.05). The xerostomia grade decreased from 2.63 ± 0.2 to 1.94 ± 0.2 after HBO (p < 0.001). There was no significant change in buffer capacity. The increased salivary secretion rate and salivary pH, and decreased S. mutans and Lactobacillus colony density that were observed after HBO therapy may reduce caries progression in those patients.

Autonomic dysfunction in presymptomatic and early symptomatic Huntington's disease.

OBJECTIVES: Although autonomic dysfunction was found in advanced Huntington's disease (HD) patients it is not clear whether there is autonomic dysfunction in presymptomatic and early symptomatic HD. MATERIAL & METHODS: Different cardiovascular autonomic tests were performed in 14 presymptomatic HD mutation carriers (PHD), 11 early symptomatic HD patients (EHD) and in 25 sex and age matched controls. RESULTS: We found attenuated response to simple mental arithmetic test (relative heart rate in PHD and EHD was 10% lower than in controls; diastolic pressure was 10.6% lower in EHD than in controls; P < 0.05) and exaggerated response to the late phase of cold pressor test (relative heart rate was 10% higher in PHD and 7% higher in EHD than in controls; P < 0.05). The rest of the cardiovascular autonomic tests did not reveal significant differences between patients and controls. CONCLUSIONS: Our results suggest that subtle autonomic dysfunction occurs even in PHD and EHD.

The role of alpha1- and alpha2-adrenoceptors in gender differences in cutaneous LD flux response to local cooling.

The present study was designed to assess the hypothesis that alpha2-adrenergic response plays a predominant role in sex differences in cutaneous microvascular response to cold. For this purpose, we studied the effect of the selective alpha1-antagonist prazosin (1 microl of 1.2 mM solution) and the alpha2-antagonist yohimbine (1 microl of 12 mM solution) microinjected into the skin area where the laser-Doppler (LD) flux response to local cooling was measured in healthy male and female subjects. Multiple regression analysis showed correlation between LD flux response at the site of local cooling (direct response) and gender (P = 0.039). The LD flux decrease was smaller in males. The application of the yohimbine significantly diminished the LD flux response at the site of local cooling in females but not in males (P < 0.05). In contrast, the injection of prazosin did not significantly affect the response. These findings strongly support the suggestion of a decisive role of alpha2-adrenoceptors in cold-induced gender difference at the level of cutaneous microvasculature at the site of local cooling. Multiple regression analysis of LD flux response to cold exposure at the site distant to cooling (indirect response) also confirmed correlation between LD flux response and gender (P = 0.022). The LD flux decrease was smaller in males. The alpha1-antagonist abolished the LD flux response to cold exposure (P = 0.000). These results corroborate the importance of alpha1-adrenoceptors in skin microcirculatory response to indirect local cooling mediated by the sympathetic vascular reflex.

Role of alpha-adrenoceptors in the cutaneous postocclusive reactive hyperaemia.

Laser-Doppler (LD) flow measurements reveal typical flow oscillations in the descending part of the cutaneous postocclusive reactive hyperaemia (PRH). The origin of these oscillations is still poorly understood. We tested the hypothesis that the high frequency (HF) components within the frequency band 0.06-0.2 Hz are due to the local myogenic mechanism, whereas the low frequency (LF) components within frequency band 0.01-0.05 Hz reflect sympathetic vasomotor activity. LD flow was monitored on fingertips of 11 healthy volunteers before and after an 8-minute occlusion of digital arteries. We studied the effect of intradermal microinjection (1 microl) of alpha-antagonists (prazosine, yohimbine) and alpha-agonists (phenilephrine, clonidine) on PRH oscillations. We analysed the magnitude of peak flow and its duration and performed spectral power analysis to obtain fundamental HF and LF frequencies (defined as components with the highest amplitude in the part of the respective frequency band). The results (mean +/- SE) for each substance were compared to the control values obtained after microinjection (1 microl) of 0.9% NaCl. The fundamental HF significantly decreased from 0.11 +/- 0.008 Hz after an injection of saline solution to 0.08 +/- 0.006 Hz after an application of antagonists (p<0.05). The local application of alpha-antagonists did not abolished HF oscillations what suggests that activity of local sympathetic nervous system is not essential in generation of these oscillations. However, the significant decrease of fundamental frequency in HF band after application of alpha-antagonists supports the hypothesis of their local origin and could be explained by the effect on pacemaker myogenic mechanism.

Gender differences in cutaneous laser doppler flow response to local direct and contralateral cooling.

To investigate the role of sympathetic neurovascular reactivity in the gender differences of cutaneous, cold-induced vasomotor response, we compared direct (at the site of cooling) and indirect (at a site remote from the cooling site) response measured by laser Doppler (LD) flowmetry in 12 healthy males and 12 healthy females. The females underwent testing twice, once in the follicular and once in the luteal phase of the menstrual cycle. We measured LD flow before and during local cooling of one hand at 15 degrees C. We found that local cooling evokes a significantly greater decrease in cutaneous LD flow in females than in males in direct as well as in indirect response conditions (p < 0.05). Comparing the response in females in the different phases of menstrual cycle, we obtained a significantly greater direct response to local cooling in the luteal phase than in the follicular phase (p < 0.05). In contrast, there was no menstrual-cycle-dependent difference in the indirect response to cold. The results of our study strongly indicate that sympathetic neural reactivity, as assessed by way of an indirect response to a cold stimulus, significantly contributes to gender differences in the response to local cooling. In contrast, the variation in microvascular responsiveness to cold exposure due to the menstrual cycle is most probably caused by local vascular mechanisms rather than by variation in sympathetic neural reactivity to local cooling.

Microvascular skin response to local cooling and body tilt early after digital replantation.

To elucidate the alteration in cutaneous microvascular reactivity early after replantation (14-21 days), laser Doppler (LD) flow changes evoked by direct and indirect local cooling and head-up body tilt were studied in the replanted digits (n = 10) and compared with those evoked in the healthy contralateral digits of the same patients (n = 10). During the first 3 minutes of direct cooling of the injured hand, LD flow increased significantly compared with the LD flow before cooling, which confirms that moderate vasodilation is the dominant component of the response to local cooling in skin microcirculation in the early period after replantation. During body tilt, LD flow in the healthy contralateral digit decreased significantly in only the first minute, while LD flow in the replanted digit started to decrease in the second minute after tilting; the decrease was significant from the third to the sixth minute. These results are consistent with the hypothesis that increased human skin alpha-adrenergic receptor sensitivity may be present as early as 2 to 3 weeks after replantation.