Technique for soft tissue closure in surgeries for fixed implant-supported prostheses in the edentulous maxilla

A technique is presented that can be used as a straightforward, quick, and minimally invasive solution to improve soft tissue closure for surgeries involving bone reduction for fixed implant-supported prostheses in the edentulous maxilla.     

Precise Placement of Single‐Retainer Resin‐Bonded Fixed Dental Prostheses with an Innovative Splint Design

Single‐retainer resin‐bonded fixed dental prostheses (RBFDPs) are difficult to position due to the pressure of soft tissue at the pontic area and the single‐retainer design. This clinical report describes an innovative technique for the insertion of single‐retainer RBFDPs. An incisal inserting splint is used to position the RBFDPs reliably. With the help of grooves in the buccal and incisal area of the splint, the precise positioning of the splint on the adjacent teeth and the RBFDP can be controlled. Also, a hole in the retainer wing region of the splint gives access for pressure application on the wing during the bonding process. With the aid of this method, 25 single‐retainer FBFDPs were inserted in the correct position in a case series. The splint described here allows the precise insertion of single‐retainer RBFDPs and simplifies delivery.     

Vestibular paroxysmia in children: a treatable cause of short vertigo attacks

Vestibular paroxysmia due to neurovascular compression is a syndrome consisting of frequent short episodes of vertigo in adults that can be easily treated. Here we describe the initial presentation and follow‐up of three children (one female, 12y; two males, 8y and 9y) who experienced typical, brief, vertiginous attacks several times a day. Nystagmus was observed during the episodes. Cranial magnetic resonance imaging revealed arterial compression of the eighth cranial nerve. The attacks ceased after administration of low‐dose carbamazepine (2–4mg/kg daily). Vestibular paroxysmia must be considered in the differential diagnosis of children with brief vertiginous episodes.     

Sleep spindles and human cortical nociception: a surface and intracerebral electrophysiological study

Key points

• Sleep spindle are usually considered to play a major role in inhibiting sensory inputs.
• Using nociceptive stimuli in humans, we tested the effect of spindles on behavioural, autonomic and cortical responses in two experiments using surface and intracerebral electroencephalographic recordings.
• We found that sleep spindles do not prevent arousal reactions to nociceptive stimuli and that autonomic reactivity to nociceptive inputs is not modulated by spindle activity.
• Moreover, neither the surface sensory, nor the insular evoked responses were modulated by the spindle, as detected at the surface or within the thalamus.
• The present study comprises the first investigation of the effect of spindles on nociceptive information processing and the results obtained challenge the classical inhibitory effect of spindles.

Abstract

Responsiveness to environmental stimuli declines during sleep, and sleep spindles are often considered to play a major role in inhibiting sensory inputs. In the present study, we tested the effect of spindles on behavioural, autonomic and cortical responses to pain, in two experiments assessing surface and intracerebral responses to thermo‐nociceptive laser stimuli during the all‐night N2 sleep stage. The percentage of arousals remained unchanged as a result of the presence of spindles. Neither cortical nociceptive responses, nor autonomic cardiovascular reactivity were depressed when elicited within a spindle. These results could be replicated in human intracerebral recordings, where sleep spindle activity in the posterior thalamus failed to depress the thalamocortical nociceptive transmission, as measured by sensory responses within the posterior insula. Hence, the assumed inhibitory effect of spindles on sensory inputs may not apply to the nociceptive system, possibly as a result of the specificity of spinothalamic pathways and the crucial role of nociceptive information for homeostasis. Intriguingly, a late scalp response commonly considered to reflect high‐order stimulus processing (the ‘P3’ potential) was significantly enhanced during spindling, suggesting a possible spindle‐driven facilitation, rather than attenuation, of cortical nociception.

Abbreviations

AASM

American Academy of Sleep Medicine

EKG

electrocardiogram

EMG

electromyogram

EOG

electrooculogram

LEP

laser‐evoked potentials

MNI

Montreal Neurological Institute

MRI

magnetic resonance imaging

REM

rapid eye movement

SEEG

stereo‐electroencephalography

     

Melatonin in vivo prolongs cardiac allograft survival in rats

Melatonin, secreted by the pineal gland, is a multifunctional agent which (i) protects tissues from damage through free radical scavenging and attenuates ischemia/reperfusion injury in organ grafts; (ii) acts synergistically with cellular antioxidants; and (iii) displays complex, dose-dependent immunoenhancing and suppressing effects in vitro and in vivo. We analyzed the immunomodulatory effect of melatonin on acute allograft rejection. Cardiac grafts were transplanted from LBNF1 to LEW rats and anastomosed to the abdominal great vessels. The effect of low-dose (LD; 20 mg/kg/day) and high-dose (HD; 200 mg/kg/day) melatonin treatment in recipients compared with untreated controls was investigated. HD melatonin therapy abrogated acute rejection, significantly prolonging allograft survival (mean survival: 12.3 +/- 1 days S.D., n = 8, P < 0.0001) compared with untreated controls, which rapidly reject the transplant (6.3 +/- 1 days n = 12). LD therapy did not extend survival significantly (7.3 +/- 1.1 days, n = 12). Allospecific IgM showed a significant decrease in animals receiving HD therapy versus untreated recipients at days 10 and 14 post-transplantation (P < 0.01), whereas in the LD group at day 10, a significant increase in allospecific IgM (P < 0.01) over the HD cohort was demonstrated. HD treatment markedly reduced lymphocyte proliferative capacity compared with controls and the LD group. HD melatonin treatment abrogated acute allograft rejection and significantly prolonged graft survival. Our results suggest an involvement of melatonin in humoral and cellular immune pathways following perfused organ transplantation. These findings may indicate a novel therapeutic approach, based on modulation of the neuroendocrine/immune axis through melatonin as a possible future immunosuppressant in organ transplantation.