Electrocardiographic Alterations During Endosseous Implant Placement Performed with Local Anesthetic Agents

Purpose: The purpose of this study was to analyze electrocardiographic alterations during dental implant surgeries when local anesthetic agents were used. Materials and Methods: Twenty implants were placed in 18 healthy patients. An electrocardiogram and Wincardio software were used to gather recordings from 12 static leads every 2 minutes, continuously record coronary artery (D2) derivations, and automatically measure the following electrocardiographic parameters: heart rate, duration and amplitude of the P wave, PR segment duration, ST segment deviation, QRS complex duration, and duration of the RR, QT, and corrected QT (QTc) intervals. Results: Analysis of variance of the values obtained at the different stages showed significant differences (P < .05) for the heart rate and for the duration of the RR and QT intervals. The heart rate increased during the anesthesia, incision, and bone drilling stages, reaching a peak during drilling. Duration of the RR and QT intervals decreased during the incision and drilling stages. Among the electrocardiographic parameters individually assessed, several altered values were found for the duration of the P wave, the QRS complex, and the QT and QTc intervals. Sinusal tachycardia and bradycardia, sinusal arrhythmia, supraventricular extrasystole, ventricular extrasystole, and T-wave inversion were detected. Conclusion: Dental implant placement surgery may induce electrocardiographic alterations. The most frequently found arrhythmias were extrasystole and sinusal tachycardia. The anesthesia, incision, and bone drilling stages exhibited the highest heart rate values and the shortest durations of the RR and QT intervals. INT J ORAL MAXILLOFAC IMPLANTS 2009;24:412-418

Influence of anesthetics on pharyngeal flap surgery: a 23-year study

This study assessed the influence of anesthetics on early complications after pharyngeal flap surgery. A 23-year retrospective chart review was carried out of all patients at the authors` institution who underwent superiorly based pharyngeal flap surgery. Variables analyzed were gender, age at the time of surgery, cleft type, anesthesia procedure used and complications in the early postoperative period. 2299 patients (50% male; 50% female) who underwent pharyngeal flap surgery between 1980 and 2003 were reviewed. The highest number of surgeries was performed in patients aged 11-20 years. There were 1042 patients with at least one type of complication. Of these, 39 required reoperation to control complications such as bleeding and airway obstruction. There were no records of death. Vomiting and pain were the most frequent postoperative complications (16% and 14% of patients, respectively). Lower complication rates were observed when anesthesia protocols included sevoflurane, propofol and opioids.

Influence of nicotine on healing process of autogenous bone block grafts in the mandible: A histomorphometric study in rats

Purpose: The aim of this study was to perform qualitative and quantitative analyses of the effect of nicotine on autogenous bone block grafts and to describe events in the initial healing phase and the differences in the repair processes between animals exposed to nicotine and controls. Materials and Methods: Forty-eight female Wistar rats were randomly divided into 2 groups, the nicotine group and the saline group. All animals received either nicotine (3 mg/kg) or saline 4 weeks before the surgical procedure and continued to receive nicotine from surgery to sacrifice at 7, 14, or 28 days. The autogenous bone block graft was harvested from the calvaria and stabilized on the external cortical area near the angle of the mandible. Results: The histologic analyses of the nicotine group depicted a delay in osteogenic activity at the bed-graft interface, as well as impairment of the organization of the granulation tissue that developed instead of blood clot. Nicotine-group specimens exhibited less bone neoformation, and the newly formed bone was poorly cellularized and vascularized. The histometric analysis revealed significantly less bone formation in the nicotine group at both 14 days (23.75% +/- 6.18% versus 51.31% +/- 8.31%) and 28 days (42.44% +/- 8.70% versus 73.00% +/- 4.99%). Conclusion: Nicotine did jeopardize the early healing process of autogenous bone block grafts in rats but did not prevent it.

Anesthetic efficacy of inferior alveolar nerve block plus buccal infiltration or periodontal ligament injections with articaine in patients with irreversible pulpitis in the mandibular first molar

Objective. We compared the anesthetic efficacy of inferior alveolar nerve block (IANB) plus buccal infiltration (BI) and IANB plus periodontal ligament (PDL) articaine injections in patients with irreversible pulpitis in the mandibular first molar. Study design. Fifty-seven volunteers, patients with irreversible pulpitis in the mandibular first molar admitted to the Department of Stomatology, Second Affiliated Hospital, Sun Yat-Sen University, randomly received conventional IANB, containing 1.7 mL 4% articaine/HCl with 1:100,000 epinephrine, plus either BI or PDL injections containing 0.4 mL articaine/HCl with 1: 100,000 epinephrine. The patients recorded the pain of the injections and endodontic access on a Heft-Parker visual analog scale (VAS). Results. According to the VAS scores, all patients experienced no or mild pain with BI and PDL injections after the application of IANB. Anesthetic success occurred in 81.48% for IANB plus BI (IANB/BI) compared with 83.33% for IANB plus PDL injection (IANB/PDL injection). None of the observed differences between the 2 groups was significant (P > .05). Conclusion. Both injection combinations resulted in high anesthetic success in patients with irreversible pulpitis in the mandibular first molar. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:e89-e93)

Evaluation of the buccal vestibule-palatal diffusion of 4% articaine hydrochloride in impacted maxillary third molar extractions

Aims: The aim of this study was to evaluate the vestibular-palatal diffusion of 4% articaine with epinephrine 1: 100,000 and 1: 200,000, in impacted maxillary third molar extractions, without palatal injection. Materials and Method: Two hundred teeth were selected from patients age 15 to 46. Patients were divided into 4 groups: 1A, were anesthetized with 4% articaine 1: 100,000 and the surgery was initiated 5 minutes following anesthesia. 1B, used 4% articaine 1: 100,000 but the surgery was started 10 minutes after anesthesia. 2A, used 4% articaine 1: 200,000 the surgery was started 5 minutes after. 2B, used 4% articaine 1: 200,000 but 10 minutes was allowed for anesthetic diffusion before the initiation of in groups (50 extractions each) only buccal vestibule anesthesia was initially administered (i.e. no palatal injections were used). Results: The rate of sufficient vestibule-palatal diffusion, as determined by the lack of necessity of supplemental palatal anesthesia, was: 1A(84%), 1B(98%), 2A(78%), 2B(82%). Chi-square (X2) and residual analyses showed that a higher vestibule-palatal diffusion was obtained using 4% articaine 1: 100,000 with a period of 10 minutes (p<0.05). Conclusions: Most of the extractions could be performed only with vestibule anesthesia. However, vasoconstrictor concentration and the time interval between administration of the anesthetic and initiation of surgery did influence buccal vestibule-palatal diffusion of 4% articaine in the extraction models used.

A comparison of the clinical anesthetic efficacy of 4% articaine and 0.5% bupivacaine (both with 1 : 200,000 epinephrine) for lower third molar removal

Objective: This study compared the clinical efficacy of 4% articaine (A200) and 0.5% bupivacaine (B200), both with 1: 200,000 epinephrine, for lower third molar removal. Study design: Fifty patients underwent removal of symmetrically positioned lower third molars, in 2 separate appointments, under local anesthesia either with A200 or B200, in a double-blind, randomized, and crossover manner. Time to onset, duration of postoperative analgesia, duration of anesthetic action on soft tissues, intraoperative bleeding, and hemodynamic parameters were evaluated. Results: A statistically significant difference between the time to onset of A200 (1.66 +/- 0.13 minutes) and B200 (2.51 +/- 0.21 minutes) was found (P < .05). There was no statistically significant difference in the duration of analgesia, whether the patient was subjected to osteotomy or not, regardless of the local anesthetic used (3 to 4 hours; P < .05). However, when patients received B200 they experienced a statistically significant longer period of anesthesia on the soft tissues as compared with when they had received A200 (around 5 hours and 4 hours, respectively, P < .05). The surgeon`s rating of intraoperative bleeding was considered very close to minimal for both anesthetics. In the surgeries with osteotomy, the comparison between A200 and B200 showed statistically significant differences in the diastolic (64 mm Hg and 68 mm Hg, respectively, P = .001) and mean arterial pressure (86 mm Hg and 89 mm Hg, respectively, P = .031) when data from all the surgical phases were pooled. Additionally, the mouth opening at the suture removal was statistically different for A200 and B200 solutions (91.90% +/- 3.00% and 88.57% +/- 2.38% of the preoperative measure, respectively) when surgeries required bone removal (P < .05). Conclusions: In comparison with 0.5% bupivacaine, 4% articaine (both with 1: 200,000 epinephrine) provided a shorter time to onset and comparable hemostasis and postoperative pain control with a shorter duration of soft tissue anesthesia in lower third molar removal.

Modulatory role of locus coeruleus and estradiol on the stress response of female rats

The activity of the hypothalamic-pituitary-adrenal axis is modulated by the norepinephrinergic system and, in females, also by the ovarian hormones. We investigated the role of ovarian steroids and the locus coeruleus (LC) on stress-induced corticosterone secretion in female rats. Ovariectomized rats without hormonal replacement (OVX) or treated with estradiol (OVE) or estradiol plus progesterone (OVEP) were subjected to jugular cannulation. Immediately after that, each hormonal treatment group was subjected to LC lesion or sham surgery or no brain surgery. After 24 h, blood samples of all 9 groups were collected before and after ether inhalation. Other four groups (OVX control, sham and lesioned, and OVE) were perfused for glucocorticoid receptor (GR) immunocytochemistry in hippocampal CA1 neurons and paraventricular nucleus (PVN). Estradiol replacement decreased while LC lesions increased stress-induced corticosterone secretion. The effect of LC lesion was potentiated with the removal of ovarian steroids. Since GR expression of lesioned animals decreased in the hippocampus, but not in PVN, we suggest that the effect of LC lesion on corticosterone secretion could be due to a reduction in the efficiency of the negative feedback system in the CA1 neurons. However, this mechanism is not involved in the estradiol modulation on corticosteroid secretion, as no change in GR expression was observed in estradiol-treated animals.

Treatment of Zygomatic Arch Fracture With Lag Screws

Zygomatic arch fractures often occur as part of a zygoma fracture or Le Fort type III fractures of the maxillary. Isolated fractures of the zygomatic arch comprise around 10% of all zygoma fractures. The main etiologic factors are traffic accidents, falls, assaults, and sport accidents. Treatment may involve minimally invasive surgical procedures for slightly dislocated fractures or surgery with more extensive access for large dislocations of bone segments. This article reports the case of a 41-year-old male victim of physical aggression to the face with a steel sickle with an exposed, unstable fracture of the zygomatic arch. The patient underwent general anesthesia, and after the reduction of the fractures, the bone segments were fixed with 2.0-mm screws.

Serum oxytocin concentrations in elective caesarean delivery: a randomized comparison of three infusion regimens

Background: The aim of this study was to determine serum oxytocin concentrations following different regimens of prophylactic oxytocin administration in women undergoing elective caesarean delivery. Methods: Thirty healthy pregnant patients were randomized, after clamping of the umbilical cord, to receive intravenous oxytocin in one of the following groups: G1 (n = 9), 10 IU of oxytocin infused over 30 min (0.33 IU/min); G2 (n = 11), 10 IU of oxytocin infused over 3 min and 45 s (2.67 IU/min); and G3 (n = 10), 80 IU of oxytocin infused over 30 min (2.67 IU/min). Both patient and surgeon were blinded to allocation. Uterine tone was assessed by surgical palpation. Serum oxytocin concentration was determined by enzyme immunoassay before anaesthesia (T0) and at 5 (T5), 30 (T30) and 60 (T60) min after the start of oxytocin infusion. Results: Serum oxytocin concentrations (mean standard error, ng/mL) were not significantly different in the groups at T0 (0.06 +/- 0.02, 0.04 +/- 0.02 and 0.07 +/- 0.04, respectively, P = 0.76), and T60 (0.65 +/- 0.26, 0.36 +/- 0.26 and 0.69 +/- 0.26, respectively, P = 0.58). G3 showed higher concentrations than G1 at 15 (3.65 +/- 0.74 versus 0.71 +/- 0.27, P = 0.01) and at T30 (6.19 +/- 1.19 versus 1.17 +/- 0.37, P < 0.01), and were higher than G2 at T30 (6.19 +/- 1.19 versus 0.41 +/- 0.2, P < 0.01). Haemodynamic data and uterine tone were considered satisfactory and similar in all groups. No additional uterotonic agents were needed. Conclusion: Serum oxytocin measurements made using enzyme immunoassay in healthy pregnant women undergoing elective caesarean delivery showed that administration of 80 IU oxytocin over 30 min resulted in higher serum oxytocin levels after 5 and 30 min than the two other regimens. The concentrations did not differ between groups at 60 min. (C) 2011 Elsevier Ltd. All rights reserved.

Isolation, Characterization, and Differentiation Potential of Canine Adipose-Derived Stem Cells

Adipose tissue may represent a potential source of adult stem cells for tissue engineering applications in veterinary medicine. It can be obtained in large quantities, under local anesthesia, and with minimal discomfort. In this study, canine adipose tissue was obtained by biopsy from subcutaneous adipose tissue or by suction-assisted lipectomy (i.e., liposuction). Adipose tissue was processed to obtain a fibroblast-like population of cells similar to human adipose-derived stem cells (hASCs). These canine adipose-derived stem cells (cASCs) can be maintained in vitro for extended periods with stable population doubling and low levels of senescence. Immunofluorescence and flow cytometry show that the majority of cASCs are of mesodermal or mesenchymal origin. cASCs are able to differentiate in vitro into adipogenic, chondrogenic, myogenic, and osteogenic cells in the presence of lineage-specific induction factors. In conclusion, like human lipoaspirate, canine adipose tissue may also contain multipotent cells and represent an important stem cell source both for veterinary cell therapy as well as preclinical studies.

A light and scanning electron microscopy study of bone healing following inferior alveolar nerve lateralization: An experimental study in rabbits

Purpose: The purpose of this study was to evaluate the bone healing kinetics around commercially pure titanium implants following inferior alveolar nerve (IAN) lateralization in a rabbit model. Materials and Methods: Inferior alveolar nerve lateralization was performed in 16 adult female rabbits (Oryctolagus cuniculus). During the nerve lateralization procedure, 1 implant was placed through the mandibular canal, and the IAN was replaced in direct contact with the implant. During the 8-week healing period, various bone labels were administered for fluorescent microscopy analysis. The animals were euthanized by anesthesia overdose, and the mandibular blocks were exposed by sharp dissection. Nondecalcified samples were prepared for optical light and scanning electron microscopy (SEM) evaluation. Results: SEM evaluation showed bone modeling/remodeling between the IAN and implant surface. Fluorochrome area fraction labeling at different times during the healing period showed that bone apposition mainly occurred during the first 2 weeks after implantation. Conclusions: The results obtained showed that bone healing/deposition occurred between the alveolar nerves in contact with a commercially pure titanium implant. No interaction between the nerve and the implant was detected after the 8-week healing period. Appositional bone healing occurred around the nerve bundle structure, restoring the mandibular canal integrity and morphology.

Anesthetic Activation of Central Respiratory Chemoreceptor Neurons Involves Inhibition of a THIK-1-Like Background K(+) Current

At surgical depths of anesthesia, inhalational anesthetics cause a loss of motor response to painful stimuli (i.e., immobilization) that is characterized by profound inhibition of spinal motor circuits. Yet, although clearly depressed, the respiratory motor system continues to provide adequate ventilation under these same conditions. Here, we show that isoflurane causes robust activation of CO(2)/pH-sensitive, Phox2b-expressing neurons located in the retrotrapezoid nucleus (RTN) of the rodent brainstem, in vitro and in vivo. In brainstem slices from Phox2b-eGFP mice, the firing of pH-sensitive RTN neurons was strongly increased by isoflurane, independent of prevailing pH conditions. At least two ionic mechanisms contributed to anesthetic activation of RTN neurons: activation of an Na(+)-dependent cationic current and inhibition of a background K(+) current. Single-cell reverse transcription-PCR analysis of dissociated green fluorescent protein-labeled RTN neurons revealed expression of THIK-1 (TWIK-related halothane-inhibited K(+) channel, K(2P)13.1), a channel that shares key properties with the native RTN current (i.e., suppression by inhalational anesthetics, weak rectification, inhibition by extracellular Na(+), and pH-insensitivity). Isoflurane also increased firing rate of RTN chemosensitive neurons in urethane-anesthetized rats, again independent of CO(2) levels. In these animals, isoflurane transiently enhanced activity of the respiratory system, an effect that was most prominent at low levels of respiratory drive and mediated primarily by an increase in respiratory frequency. These data indicate that inhalational anesthetics cause activation of RTN neurons, which serve an important integrative role in respiratory control; the increased drive provided by enhanced RTN neuronal activity may contribute, in part, to maintaining respiratory motor activity under immobilizing anesthetic conditions.

Opposite effects of fasting on TGF-beta 3 and T beta RI distribution in the gastric mucosa of suckling and early weanling rats

Objective: Our aim was to evaluate the effects of a dietary regimen (suckling or early weaning) and feeding status (fed or fasted) on the distribution of transforming growth factor-beta 3 (TGF-beta 3) and TGF receptor-I (T beta RI) in the gastric epithelium of pups Methods: Wistar rats were used At 15 d, half of the pups were separated from dams and fed with hydrated powered chow On day 17, suckling and early weanling rats were subjected to fasting (17 h). Four different conditions were established. suckling fed and fasted and early weanling fed and fasted At 18 d stomachs were collected under anesthesia and were fixed in 4% formaldehyde for immunohistochemistry The number of immunostained epithelial cells per microscopic field was determined for TGF-beta 3 and T beta RI in longitudinal sections from the gastric mucosa Results: We found that during suckling, fasting reduced the number of immunolabeled cells per field of both molecules when compared with the fed group (P < 0.05), whereas in early weaning, food restriction increased TGF-beta 3 and T beta RI distributions (P < 0.05) We also observed that TGF-beta 3 and T beta RI were more concentrated in parietal cells in the upper gland in suckling pups, whereas after early weaning these were displaced to parietal and chief cells at the bottom of the gland Conclusion: Suckling and early weaning directly influence TGF-beta 3 and T beta RI distributions in the gastric epithelium in response to fasting, such that early weaning anticipates the effects observed in adult rats. Furthermore, the differential concentrations of TGF-beta 3 and T beta RI indicate that they might be important for cell proliferation events in growth control (C) 2010 Elsevier Inc. All rights reserved

In vivo hydroquinone exposure alters circulating neutrophil activities and impairs LPS-induced lung inflammation in mice

Hydroquinone (HQ) is an environmental contaminant which causes immune toxicity. In this study, the effects of exposure to low doses of HQ on neutrophil mobilization into the LPS-inflamed lung were investigated. Male Swiss mice were exposed to aerosolized vehicle (control) or 12.5, 25 or 50 ppm HQ (1 h/day for 5 days). One hour later, oxidative burst, cell cycle. DNA fragmentation and adhesion molecules expressions in circulating neutrophils were determined by flow cytometry, and plasma malondialdehyde (MDA) levels were measured by HPLC. Also, 1 h later the last exposures, inflammation was induced by LPS inhalation (0.1 mg/ml/10 min) and 3 h later, the numbers of leukocytes in peripheral blood and in the bronchoalveolar lavage fluid (BALF) were determined using a Neubauer chamber and stained smears; adhesion molecules expressed on lung microvessel endothelial cells were quantified by immunohistochemistry; myeloperoxidase (MPO) activity was measured in the lung tissue by colorimetric assay; and cytokines in the BALF were determined by ELISA. In vivo HQ exposure augmented plasma MDA levels and oxidative activity of neutrophils, but did not cause alterations in cell cycle and DNA fragmentation. Under these conditions, the number of circulating leukocytes was not altered, but HQ exposure reduced LPS-induced neutrophil migration into the alveolar space, as these cells remained in the lung tissue. The impaired neutrophil migration into BALF may not be dependent on reduced cytokines secretions in the BALF and lung endothelial adhesion molecules expressions. However, HQ exposure increased the expression of beta(2) and beta(3) integrins and platelet-endothelial cell adhesion molecule-1 (PECAM-1) in neutrophils, which were not further enhanced by fMLP in vitro stimulation, indicating that HQ exposure activates circulating neutrophils, impairing further stimulatory responses. Therefore, it has been shown, for the first time, that neutrophils are target of lower levels of in vivo HQ exposure, which may be considered in host defense in infectious diseases. (C) 2011 Elsevier Ireland Ltd. All rights reserved.