The Assessment of Prolonged Inferior Alveolar Nerve Blockade for Postoperative Analgesia in Mandibular Third Molar Surgery by a Perineural Addition of Dexamethasone to 0.5% Ropivacaine: A Randomized Comparison Study.

Background: Perineurally adding dexamethasone to local anesthetics could enable postoperative analgesia. Our aim was to investigate the efficacy of 4 mg dexamethasone and 0.5% ropivacaine on the prolonged duration of mandibular anesthesia for postoperative analgesia during third molar surgery. Materials and method: The patients of both sexes, and in the age range of 17 to 50 yrs of age, received the Gow-Gates anesthesia. Group I received 4 mL of plain 0.5% ropivacaine, with perineurally added 1 mL/4 mg of dexamethasone; group II received 4 mL of plain 0.5% ropivacaine with perineurally added 1 mL of 0.9% saline; group III received 4 mL of plain 0.5 bupivacaine with perineurally added 1 mL of 0.9% saline. The prime anesthesia outcome was the duration of conduction anesthesia (DCA); the secondary outcome was the duration of analgesia (DAN) and analgesia before analgesic intake. Results: In 45 randomly selected subjects (mean age 27.06 ± 8.20), DCA was statistically longest in group I (n = 15) (592.50 ± 161.75 min, p = 0.001), collated with groups II (n = 15) and III (n = 15) (307.40 ± 84.71 and 367.07 ± 170.52 min, respectively). DAN was significantly the longest in group I (mean: 654.9 ± 198.4 min, p = 0.001), compared with group II (345.4 ± 88.0 min) and group III (413.7 ± 152.3 min), with insignificant adverse reactions. One-third of the operated patients absented from the use of analgesics. Conclusion: A amount 0.5% ropivacaine with dexamethasone usefully served as an analgesic with a success rate of 93.4% of the given anesthesia.

The Use of Cone Beam CT(CBCT) in Differentiation of True from Mimicking Eagle's Syndrome.

Differentiation of true from mimicking Eagle's syndrome based on conventional radiography is difficult; however, cone beam computed tomography (CBCT) images can contribute to proper diagnosis of mimicking Eagle's syndrome. The aim was to study radiological images of a 37-year old female patient (patient #1), with chronic cervicofacial pain who underwent radiological diagnosis with a conventional panoramic machine; another 75-year old male patient (patient #2), with chronic oropharyngeal pain, underwent a radiological diagnosis with the CBCT machine, with a field of a view of 16 × 12 cm. Exposure factors were 120 kVp, 7 mA, with a 20 s exposure time of acquisition. The results show a panoramic image (patient #1) with a pathologically elongated styloid process 46 mm of length, which was surgically removed, releasing the patient from further pain episodes. CBCT acquisition (patient #2) showed an impacted left maxillary canine in the edentulous maxilla and a peculiar elongation of both stylohyoid complexes as impressive, "collar-like", bilateral, elongated, multiple segmented, calcified stylohyoid complexes, without pressure on the vital neurovascular neck structures, mimicking true Eagle's syndrome. The impacted maxillary canine was surgically extracted with a subsequent resolution of pain episodes and the cessation of neurological complaints. The conclusions suggest that the use of CBCT images can contribute to differentiating mimicking from true Eagle's syndrome, which has been rarely reported in the literature.

Assessment of conduction anesthesia effectiveness using the angulated needle approach for the inferior alveolar nerve block.

BACKGROUND: Ambulatory painless surgery is dependent on local anesthesia effectiveness. AIM: Evaluating the anesthetic efficacy of the angulated needle approach (ANA) for the inferior alveolar nerve block (IANB). MATERIAL AND METHOD: Group I received direct IANB; group II received indirect IANB; group III received the IANB with ANA. The quality of anesthesia score (QAS), numerical pain intensity score (NRS), onset time of full anesthesia (OT), and perianesthetic complications were measured. RESULTS: Ninety patients (mean age: 37.47 ± 18.90, p = 0.027) of both sexes were split into three equal groups. Group III had the lowest QAS value with the success rate of 93.3%, compared to the statistically significantly worse QAS values of group II, with the success rate of 80% (p = 0.016). Group II had the statistically significant highest NRS values relative to group I (p = 0.002) and group III (p = 0.000001). The shortest OT occurred in group I, when compared to group II (p = 0.000484) and group III (p = 0.000498). The transient syncope and positive aspiration occurred in single cases. CONCLUSION: The ANA for the IANB could successfully serve as a "first choice", or as an "addendum technique" in the cases of multiple failed attempts for direct and indirect IANB techniques.

A randomized anesthethic potency comparison between ropivacaine and bupivacaine on the perioperative regional anesthesia in lower third molar surgery.

BACKGROUND: Perioperative pain control by means of local anesthesia is an intrinsic part of surgical practice. AIM: To evaluate the anesthetic potencies between ropivacaine and bupivacaine in the surgery of mandibular horizontally impacted teeth. MATERIAL AND METHOD: Outpatients of both sexes, in the age range from 18 to 70 yrs. of age (mean age: 26.48 ± 3.66), participated in this clinical study. After mandibular conduction anesthesia of 0.75% ropivacaine in group I, 0.5% bupivacaine in group II, and 2% lidocaine with 1:100000 epinephrine in group III, the following anesthetics variables were measured: quality of anesthesia score (QAS), success rate of local anesthesia (SLA), onset time of anesthesia (OT), duration of anesthesia (DA), intensity of intraoperative pain (IIP) (VAS scale in mm). Blood pressure, and pulse were measured. RESULTS: Ninety patients, divided into three equal groups, were enrolled for the study. Ropivacaine gained statistically significant (p < 0.05) variables: QAS of 1.77 ± 0.68 and IIP was 18.90 ± 6.11 mm (p < 0.05). The SLA of the achieved local anesthesia was 96.6%, 93.3% and, 86.6% for ropivacaine, lidocaine with epinephrine 1:100000, and bupivacaine groups, respectively. OT was 151.50 ± 80.93, 168.27 ± 79.73, and 89.80 ± 27.91 sec, for groups I, II and III, respectively. The DA for ropivacaine was 412.17 ± 110.04 min, while the one for bupivacaine and lidocaine with epinephrine 1:100000 was 376.30 ± 98.51 min., and 216.13 ± 47.69 min., respectively. Hemodynamic parameters were insignificant to cause side effects. CONCLUSION: 0.75% ropivacaine provided successful local anesthesia in 96.6% of the patients, better quality and onset of anesthesia with the duration of anesthesia of 412.17 ± 110.04 min and lower intraoperative pain than in the case of 0.5% bupivacaine and 2% lidocaine with epinephrine.

Activation process in excitable systems with multiple noise sources: One and two interacting units.

We consider the coaction of two distinct noise sources on the activation process of a single excitable unit and two interacting excitable units, which are mathematically described by the Fitzhugh-Nagumo equations. We determine the most probable activation paths around which the corresponding stochastic trajectories are clustered. The key point lies in introducing appropriate boundary conditions that are relevant for a class II excitable unit, which can be immediately generalized also to scenarios involving two coupled units. We analyze the effects of the two noise sources on the statistical features of the activation process, in particular demonstrating how these are modified due to the linear or nonlinear form of interactions. Universal properties of the activation process are qualitatively discussed in the light of a stochastic bifurcation that underlies the transition from a stochastically stable fixed point to continuous oscillations.

Activation process in excitable systems with multiple noise sources: Large number of units.

We study the activation process in large assemblies of type II excitable units whose dynamics is influenced by two independent noise terms. The mean-field approach is applied to explicitly demonstrate that the assembly of excitable units can itself exhibit macroscopic excitable behavior. In order to facilitate the comparison between the excitable dynamics of a single unit and an assembly, we introduce three distinct formulations of the assembly activation event. Each formulation treats different aspects of the relevant phenomena, including the thresholdlike behavior and the role of coherence of individual spikes. Statistical properties of the assembly activation process, such as the mean time-to-first pulse and the associated coefficient of variation, are found to be qualitatively analogous for all three formulations, as well as to resemble the results for a single unit. These analogies are shown to derive from the fact that global variables undergo a stochastic bifurcation from the stochastically stable fixed point to continuous oscillations. Local activation processes are analyzed in the light of the competition between the noise-led and the relaxation-driven dynamics. We also briefly report on a system-size antiresonant effect displayed by the mean time-to-first pulse.

Persistence and failure of mean-field approximations adapted to a class of systems of delay-coupled excitable units.

We consider the approximations behind the typical mean-field model derived for a class of systems made up of type II excitable units influenced by noise and coupling delays. The formulation of the two approximations, referred to as the Gaussian and the quasi-independence approximation, as well as the fashion in which their validity is verified, are adapted to reflect the essential properties of the underlying system. It is demonstrated that the failure of the mean-field model associated with the breakdown of the quasi-independence approximation can be predicted by the noise-induced bistability in the dynamics of the mean-field system. As for the Gaussian approximation, its violation is related to the increase of noise intensity, but the actual condition for failure can be cast in qualitative, rather than quantitative terms. We also discuss how the fulfillment of the mean-field approximations affects the statistics of the first return times for the local and global variables, further exploring the link between the fulfillment of the quasi-independence approximation and certain forms of synchronization between the individual units.

Use of N-butyl cyanoacrylate with metacryloxisulfolane (glubran 2) surgical glue for flapless closure of oroantral communication.

AIM: To present first experience of the use N-butyl cyanoacrylate with metacryloxisulfolane (Glubran 2) synthetic surgical glue, in the nonsurgical closure of oroantral communication (OAC). MATERIAL AND METHODS: Two OACs, created after the exodontia of tooth 27 in 2 female patients, were sealed and closed with Glubran 2 surgical glue and monitored OACs, until the epithelization of the sockets was ended successfully. Two months postclosure of OACs, the sealed OACs were evaluated on the panoramic image and Water's view radiography. RESULTS: The extraction wounds with OACs were monitored until 23rd and 25th postinterventional days, when epithelization of socket ended successfully. On the panoramic image and Water's view radiography, there were no radiological signs of maxillary sinus pathoses. CONCLUSION: Glubran 2 can be successfully applied in the closure of OAC from 3 to 5 mm in diameter.

Mean-field approximation of two coupled populations of excitable units.

The analysis on stability and bifurcations in the macroscopic dynamics exhibited by the system of two coupled large populations composed of N stochastic excitable units each is performed by studying an approximate system, obtained by replacing each population with the corresponding mean-field model. In the exact system, one has the units within an ensemble communicating via the time-delayed linear couplings, whereas the interensemble terms involve the nonlinear time-delayed interaction mediated by the appropriate global variables. The aim is to demonstrate that the bifurcations affecting the stability of the stationary state of the original system, governed by a set of 4N stochastic delay-differential equations for the microscopic dynamics, can accurately be reproduced by a flow containing just four deterministic delay-differential equations which describe the evolution of the mean-field based variables. In particular, the considered issues include determining the parameter domains where the stationary state is stable, the scenarios for the onset, and the time-delay induced suppression of the collective mode, as well as the parameter domains admitting bistability between the equilibrium and the oscillatory state. We show how analytically tractable bifurcations occurring in the approximate model can be used to identify the characteristic mechanisms by which the stationary state is destabilized under different system configurations, like those with symmetrical or asymmetrical interpopulation couplings.

Endosteal (central) osteochondroma of the mandibular body.

Cartilaginous pathology of the jaws is relatively uncommon, owing the fact that the osteochondroma of the mandibular body are extremely rare. This paper elaborates on the rare case of endosteal (central) osteochondroma created 6 months after exodontia in the left body of the mandibula in tooth region #36. After obtaining a histologic diagnosis of an osteochondroma, a tumor was locally resected. One year later, panoramic radiographs showed bone regeneration at the site of the previously resected osteochondroma. However, extreme caution should be maintained, because an osteochondroma could be the first feature of osteosarcoma or chondrosarcoma. Therefore, regular clinical examinations and radiographic evaluations are mandatory every 6 and 12 months, respectively.

Usefulness of cone-beam CT for presurgical assessment of keratoma (cholesteatoma) of the maxillary sinus.

BACKGROUND: Evaluating the presurgical usefulness of cone-beam CT (CBCT) in the diagnosis and subsequent surgery of keratoma (cholesteatoma) of the maxillary sinus. METHODS: CBCT scans were obtained by using 3-dimensional CT (3DCT) apparatus. The exposure factors had a field of view of 16 × 12 cm, 120 kVp, 7 mA, and an exposure time of 20 seconds. The acquired image data consisted of a 14-bit sensor that delivers 16,384 shades of gray with a standard isotropic cubic voxel size of 0.3 mm. RESULTS: The CBCT scans clearly demonstrated a 22- × 16.82- × 17.62-mm expansile lesion in the left maxillary sinus area, with thin cortical plates, and a focal perforation of the medial cortical plate at the level of the apices. CONCLUSION: All CBCT visual data provide impressive, full 3D images of maxillary sinus keratoma, and help us to perform successful surgery.

Cluster synchronization of spiking induced by noise and interaction delays in homogenous neuronal ensembles.

Properties of spontaneously formed clusters of synchronous dynamics in a structureless network of noisy excitable neurons connected via delayed diffusive couplings are studied in detail. Several tools have been applied to characterize the synchronization clusters and to study their dependence on the neuronal and the synaptic parameters. Qualitative explanation of the cluster formation is discussed. The interplay between the noise, the interaction time-delay and the excitable character of the neuronal dynamics is shown to be necessary and sufficient for the occurrence of the synchronization clusters. We have found the two-cluster partitions where neurons are firmly bound to their subsets, as well as the three-cluster ones, which are dynamical by nature. The former turn out to be stable under small disparity of the intrinsic neuronal parameters and the heterogeneity in the synaptic connectivity patterns.

[Assessment of ropivacaine postoperative analgesic effect after periapical maxillary incisors surgery].

BACKGROUND/AIM: Ropivacaine is a relatively new long-acting local anesthetic. The aim of this study was to compare the postoperative analgesic effect of topical anesthetics ropivacaine 0.75% and lidocaine 2% with adrenaline in the postoperative treatment of periapical lesions in the maxilla. METHODS: The study was conducted on 60 subjects, divided into two groups. The study-group received 0.75% ropivacaine without a vasoconstrictor, while the control group was treated with 2% lidocaine with adrenaline (1 : 80.000). Block anesthesia for n. infraorbitalis was used and local anesthetics were applied also on the palatine side for the end branches of n. nasopalatinus. The following parameters were observed: time elapsed from the application of an anesthetic until the first occurrence of pain after the surgery and first intake of an analgesic, the intensity of initial pain, pain intensity 6 h after the application of anesthetics and the total number of analgesics taken within 24 h after the completion of surgery. RESULTS: The pain appeared statistically significantly earlier in the patients who had been given lidocaine with adrenaline (p < 0.001), while statistically significantly higher mean values of initial postoperative pain (p < 0.05) and pain intensity 6 h after the intervention (p < 0.01) were also registered in the same group of patients. In the period of 24 h upon the intervention, the study-group patients were taking less analgesics as compared to the control-group subjects (46.6% vs 73.3%), who were given analgesics earlier, although no statistically significant differences were observed related to the number of analgesic doses taken. CONCLUSION: The results of our study indicate a better postoperative analgesic effect of ropivacaine as compared to lidocaine with adrenaline.

Spontaneous formation of synchronization clusters in homogenous neuronal ensembles induced by noise and interaction delays.

The spontaneous formation of clusters of synchronized spiking in a structureless ensemble of equal stochastically perturbed excitable neurons with delayed coupling is demonstrated for the first time. The effect is a consequence of a subtle interplay between interaction delays, noise, and the excitable character of a single neuron. The dependence of the cluster properties on the time lag, noise intensity, and the synaptic strength is investigated.

The use of absorbable polyglactin/polydioxanon implant (Ethisorb(®)) in non-surgical closure of oro-antral communication.

Oro-antral communications (OAC) greater than 4-5 mm in diameter can seldom be counted on to heal spontaneously without the necessity for surgical closure. The initial experience in applying an absorbable polyglactin/polydioxanon implant (Ethisorb(®)), in non-surgical closure of OAC ranging from 5 to 7 mm in diameter, is presented. Twelve patients of varying ages with OAC up to 72 h in duration, have been treated with Ethisorb(®). Failures were not demonstrated in the form of the creation of an oro-antral fistula (OAF), and in all patients, OAC-s were closed with the epithelization of post-extraction wounds up to 21 days after implantation of Ethisorb(®). Based on these initial encouraging results, we propose that an Ethisorb(®) biopolymeric absorbable implant can be used in selected clinical cases for non-surgical closure of OAC.

Stability, bifurcations, and dynamics of global variables of a system of bursting neurons.

An approximate mean field model of an ensemble of delayed coupled stochastic Hindmarsh-Rose bursting neurons is constructed and analyzed. Bifurcation analysis of the approximate system is performed using numerical continuation. It is demonstrated that the stability domains in the parameter space of the large exact systems are correctly estimated using the much simpler approximate model.

Use of 2-Octyl-Cyanoacrylate in surgical closing of Postparotidectomy salivary fistulas.

A salivary fistula is one of possible postoperative complications in the surgery of parotid gland tumors. We present three cases of postparotidectomy salivary fistulas, successfully treated by surgical access using 2-octyl-cyanoacrylate while closing the skin layer. The previous treatment of these cases by other therapeutic options did not give satisfactory results. In a 5-year follow-up period there were no signs of fistulas relapses. The surgical access with use of 2-octyl cyanoacrylate can be one of therapeutic options for the closing of postparotidectomy salivary fistulas, especially in cases where other therapeutic accesses are not successful.

[Macroglossia and Beckwith-Wiedemann syndrome].

INTRODUCTION: In 1963 Beckwith presented a report on the first patient with extreme cytomegaly of adrenal cortex, hyperplasia of kidneys and pancreas and Leydig cell hyperplasia. Wiedemann completed description of the new syndrome by adding umbilical hernia and macroglossia. The diagnosis is made based on the clinical signs of omphalocele or some other umbilical deformity, macroglossia, congenital asymmetry, visceromegaly (liver, pancreas, and kidneys). CASE OUTLINE: A 16-month-old male child was admitted for examination because of macroglossia. He underwent examination on several occasions by an endocrinologist due to recurrent hypoglycaemic crisis. The patient was observed by a paediatric neurophysicatrist for disorders of mental development. Hypoglycaemia, muscular hypotonia of the anterior abdominal wall with umbilical hernia and macroglossia were observed by clinical examination. Inratraoral examination revealed macroglossia with microstomia, suckling and swallowing difficulties, hypotonia of the perioral muscles with increased salivation. It was therefore decided to perform surgical reduction of the prominent tongue and develop good condition for nutrition, speech function and the development of orofacial system. CONCLUSION: The diagnosis of macroglossia is based on subjective clinical criteria such as the morphology and amount of protrusion of the tongue, difficulty in articulating sounds, breathing, and hypersalivation. Some authors have suggested that the tongue size may be analyzed radiographically with a cephalogram. Treatment of macroglossia is controversial because of the absence of objective clinical criteria.

[Evaluation of anesthetic effect of ropivacaine in surgery of chronic periapical lessions].

INTRODUCTION: Ropivacaine is used in orthopedcs, gyneacology, surgery, ophtamology, whereas experience about its usage in dentistry is still limited. The aim of this research was to compare the anesthetic effect between local anesthetics ropivacaine and bupivacaine, in surgical disposals of chronical periapical lessions in maxilla. MATERIAL AND METHODS: The study included the patients that had indications for surgical removal of chronical periapical lessions at one of the frontal teeth of upper jaw. The total total number of examinees was 60, and they were devided in two groups. Ropivacaine chloride (0.75%) was used as a local anesthetic in one group (Naropin 0.75%; Astra Zeneca), and in the other one bupivacaine chloride (0.5%) (Vexelit 0.5%; Zdravlje). The authors applied 1.8 ml of block anesthesia for the n. infraorbitalis (intra-oral approach) as well as 0.2 ml of the local anesthetic from the palatine side for the final branches of N. nasopalatinus in order to observe the following anesthetic parameters. (I) Beginning of anesthesia was followed by the appearence of upper lip numbness. (II) Pain rating scale according to Sisk was used for the objective measurement of the anesthesia quality. (III) The pain intensity during the intervention was measured by visual analogous scale, on which the patient denoted the intensity of pain he had felt during the intervention. (IV) Duration of anesthetic effect--it is followed by soft tissues numbness. RESULTS AND DISCUSSION: After the ropivacaine application anesthesia effect started in 1.57 min. and after the usage of bupivacaine in 1.67 min. The mean duration of soft tissue numbness after the application of ropivacaine was 321 minutes. Bupivacaine had a shorter anesthetic effect--296.5 minutes. The quality of anesthesia after the usage of ropivacaine was assessed by the surgeons with average mark--1.76. Interventions in which this anesthetic was used were performed with minimal pain and without additional anesthesia. The quality of anesthesia after the usage of bupivacaine (3.03) was statistically much worse (p < 0.01) in comparison to ropivacaine. In visual analogous scale where patients denoted the intensity of pain during the intervention with ropivacaine the marked average value was 30.1 mm while the average value with usage of bupivacaine was 41.7 mm. The patients from the control group, where bupivacaine was used, had much stronger pain, statistically significant (p < 0.05) in comparison to the group where ropivacaine was used. Our results show that the quality of anesthesia that was attained with 0.5% bupivacaine was much worse than the quality of anesthesia after the application of 0.75% ropivacaine. CONCLUSION: Ropivacaine has a potential to replace bupivacaine completely in cases when there is the indication for its usage in oral surgery (longlasting intervention, interventions followed by intensive postoperational pain, nerve blockade).

[Stimulation of mucoperiostal slice epithelization by small power laser after the primary plastic of oroantral communication].

INTRODUCTION: The oroantral communication is a pathologic communication between the oral cavity and maxillary sinus. It originates with extraction of the upper lateral teeth. Primary plastics communication, which is more extensive than 5 mm has been unsuccessful in 16%. Small power lasers have positive reaction on wounds healing. The aim of this work was to determine the lasers effects on slice epithelization after the plastics more extensive than 5 mm. MATERIAL AND METHODS: The experimental research was done on dogs with extraction of the upper second premolars on both sides, and formed oroantral communication having diameter of 10 mm. After the plastics of sinus, the left side slices were exposed to radiation for 7 days, and the opposite slices healed spontaneously. Eight points (8x1J) were treated for 100s by GaAlAs laser, power 10 mW and wavelength 670 nm. Biopses of the slices connections were taken on the 14th day to be laboratory treated and examined microscopially. The study included 36 examinees with communication diameter of 10 mm and performed plastics of sinuses. In half of the examinees wounds were exposed to radiation for 7 days, and in other examinees they healed spontaneously. The results were analyzed on the fourteenth day according to the scale: (1) complete healing, without dehiscention; (2) incomplete healing, with minimal dehiscention; (3) communication did not heal, with partial dehiscention; (4) open communication, with significant dehiscention. RESULTS AND DISCUSSION: The microscopic analysis shows that no wounds exposed to radiation were overcast with mucous membrane which had smooth sub epithelia chronic inflammation and inflammable infiltrate, and strong fibroplasias and granulations. Wounds exposed to radiation had mucous membrane without any signals of inflammation. Laser radiation causes anti-inflammatory reaction, i.e., it provokes reduction of exudation, alteration and proliferation, it blocks cyclo- and lipo-oxygenation by delaying the synthesis of prostaglandin, stimulates neutrophyll, macrophage and lissome activity and it activates the function of immune complex T and B lymphocytes, so this difference could be primary referred to the action of laser. Our clinical study shows that complete healing of oroantral communication was recorded in 88.8% of the examinees who were exposed to radiation in relation to 50%, of those who did not receive radiation therapy which is statistically much higher percentage (chi2 test < 0.05). The surgery was repeated in 5.6% of those who had received radiation therapy and in 16.7% of those who had not been exposed to radiation. Laser radiation stimulates changing of ADP in ATP and it accelerates cells metabolism, it increases microcirculation and accelerates substance exchange of cells, it increases DNK and RNK synthesis and stimulates cells division, which cause quicker regeneration of epithelia, i.e., it accelerates the process of wound healing. CONCLUSION: It can be concluded that small power laser can be used successfully as additional method of treatment, after closing of oroantral communication surgically.