Evaluación del trofismo del músculo temporal posquirúrgico en relación con el tiempo de manipulación y la infiltración transoperatoria de bupivacaína isobárica al 0.5% en pacientes sometidos a craneotomía pterional / Evaluation of temporal muscle trophism in relation to the manipulation time and infiltration of 0.5% isobaric bupivacaine through a pterional approach

Introducción: Existen diferentes técnicas para reconstrucción del músculo temporal (MT) en el abordaje pterional (AP) con el objetivo de evitar y disminuir la atrofia, hasta el momento ninguna ha logrado evitarla en su totalidad. La administración de bupivacaína genera regeneración de fibras musculares. Aún no existe en la literatura médica estudios que evalúen el tiempo de manipulación del MT y que den uso a la bupivacaína para el tratamiento de la atrofia después de un abordaje pterional, el presente estudio pretende describir los efectos de estas variables. Pacientes y métodos: Estudio longitudinal, incluyendo pacientes de 18-80 años y sometidos a abordaje pterional en los años 2016-2017. Evaluamos los efectos de la manipulación del MT y la administración de bupivacaína al 0,5% sobre el trofismo y la función del MT. Resultados: Veintinueve pacientes fueron sometidos a AP; 16(55,17%) contaron con criterios para infiltración con bupivacina al 0,5%. Se encontró una correlación negativa entre los tiempos de manipulación y el trofismo, no estadísticamente significativo (p>0,05). Se evalúo los índices de disfunción de Helkimo y Fonseca prequirúrgicos y posquirúrgicos encontrándose un incremento estadísticamente significativo en la disfunción (p<0,05). En pacientes infiltrados con bupivacaína al 0,5% se observó una diferencia media del espesor de MT de 0,275±1,18mm, en contraste con los no infiltrados de 2,39±1,30mm (t[27] = -5,118, p=0,0001). Conclusiones: La manipulación del MT durante el abordaje pterional, condiciona un impacto sobre la calidad de vida de acuerdo con los índices de disfunción, debido a la atrofia. Esta investigación presenta que la administración de bupivacaína al 0,5% durante la cirugía ofrece una disminución en la atrofia del MT

Introduction: There are different techniques for the reconstruction of the temporal muscle (TM) in the pterional approach (PA) in order to avoid and reduce atrophy, it has not been able to avoid it in its entirety. The administration of bupivacaine generates regeneration of muscle fibres. There are no studies in the medical literature that evaluate the time of TM manipulation and the use of bupivacaine for the treatment of atrophy after pterional approach, the present investigation aim is to describe the effects of these variables. Patient and methods: Longitudinal study, including patients from 18-80 years old with pterional approach at 2016-2017. We evaluated the effects of the TM manipulation times and the administration of 0.5% bupivacaine on the trophism and function of TM. Results: Twenty-nine patients underwent a PA; 16(55.17%) count with criteria for 0.5% bupivacain infiltration. We found a negative correlation between manipulation times and trophism, with no statistically significance (p>.05). We evaluated presurgical and postsurgical index of Helkimo and Fonseca's index, finding an increase of disfunction with statistically significance (p<.05). In patients who were infiltrated with 0.5% bupivacaine we observed a mean difference in the TM's trophism of 0.275±1.18mm, in contrast with no infiltrated which was 2.39±1.30mm (t[27] = -5.118, p=.0001). Conclusions: The manipulation of the TM during a pterional approach conditioned an impact on the quality of life according to the disfunction indexes, due to atrophy. This investigation exhibits that de administration of 0.5% bupivacaine during surgery offers a decrease in the TM atrophy

Evaluation of temporal muscle trophism in relation to the manipulation time and infiltration of 0.5% isobaric bupivacaine through a pterional approach. / Evaluación del trofismo del músculo temporal posquirúrgico en relación con el tiempo de manipulación y la infiltración transoperatoria de bupivacaína isobárica al 0,5% en pacientes sometidos a craneotomía pterional.

INTRODUCTION: There are different techniques for the reconstruction of the temporal muscle (TM) in the pterional approach (PA) in order to avoid and reduce atrophy, it has not been able to avoid it in its entirety. The administration of bupivacaine generates regeneration of muscle fibres. There are no studies in the medical literature that evaluate the time of TM manipulation and the use of bupivacaine for the treatment of atrophy after pterional approach, the present investigation aim is to describe the effects of these variables. PATIENT AND METHODS: Longitudinal study, including patients from 18-80 years old with pterional approach at 2016-2017. We evaluated the effects of the TM manipulation times and the administration of 0.5% bupivacaine on the trophism and function of TM. RESULTS: Twenty-nine patients underwent a PA; 16(55.17%) count with criteria for 0.5% bupivacain infiltration. We found a negative correlation between manipulation times and trophism, with no statistically significance (p>.05). We evaluated presurgical and postsurgical index of Helkimo and Fonseca's index, finding an increase of disfunction with statistically significance (p<.05). In patients who were infiltrated with 0.5% bupivacaine we observed a mean difference in the TM's trophism of 0.275±1.18mm, in contrast with no infiltrated which was 2.39±1.30mm (t[27] = -5.118, p=.0001). CONCLUSIONS: The manipulation of the TM during a pterional approach conditioned an impact on the quality of life according to the disfunction indexes, due to atrophy. This investigation exhibits that de administration of 0.5% bupivacaine during surgery offers a decrease in the TM atrophy.

Brain temperature effects of intravenous heroin: State dependency, environmental modulation, and the effects of dose.

Here we examined how intravenous heroin at a dose that maintains self-administration (0.1 mg/kg) affects brain temperature homeostasis in freely moving rats under conditions that seek to mimic some aspects of human drug use. When administered under standard laboratory conditions (quiet rest at 22 °C ambient temperature), heroin induced moderate temperature increases (1.0-1.5 °C) in the nucleus accumbens (NAc), a critical structure of the brain motivation-reinforcement circuit. By simultaneously recording temperatures in the temporal muscle and skin, we demonstrate that the hyperthermic effects of heroin results primarily from inhibition of heat loss due to strong and prolonged skin vasoconstriction. Heroin-induced brain temperature increases were enhanced during behavioral activation (i.e., social interaction) and in a moderately warm environment (29 °C). By calculating the "net" effects of the drug in these two conditions, we found that this enhancement results from the summation of the hyperthermic effects of heroin with similar effects induced by either social interaction or a warmer environment. When the dose of heroin was increased (to 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 mg/kg), brain temperature showed a biphasic down-up response. The initial temperature decrease was dose-dependent and resulted from a transient inhibition of intra-brain heat production coupled with increased heat loss via skin surfaces-the effects typically induced by general anesthetics. These initial inhibitory effects induced by large-dose heroin injections could be related to profound CNS depression-the most serious health complications typical of heroin overdose in humans.

Is there enough evidence to use botulinum toxin injections for bruxism management? A systematic literature review.

OBJECTIVE: The objective of the study was to conduct a systematic review of the literature assessing the effects of botulinum toxin (BoNT-A) injections in the management of bruxism. MATERIALS AND METHODS: Search for articles involved the PubMed, Scopus, Web of Science, Embase, Cochrane, Scielo and Lilacs databases. Specific terms were used and the search carried out from 1980 to March 2016 by three independent researchers. Randomized controlled studies (RCTs), prospective and before-after studies that applied BoNT-A at the masseter and/or temporalis muscles were included. RESULTS: Three RCTs and two uncontrolled before-after studies out of 904 identified citations were included in this review. All five articles dealt with sleep bruxism and featured a small sample size. None of them was about awake bruxism. Two randomized clinical trials were double-blinded, with a control group using saline solution. Two studies used polysomnography/electromyography for sleep bruxism diagnosis, whilst others were based on history taking and clinical examination. All studies using subjective evaluations for pain and jaw stiffness showed positive results for the BoNT-A treatment. In contrast, the two studies using objective evaluations did not demonstrate any reduction in bruxism episodes, but a decrease in the intensity of muscles contractions. CONCLUSION: Despite the paucity of works on the topic, BoNT-A seems to be a possible management option for sleep bruxism, minimizing symptoms and reducing the intensity of muscle contractions, although further studies are necessary especially as far as the treatment indications for bruxism itself is concerned. CLINICAL RELEVANCE: BoNT-A has been increasingly diffused in dentistry over recent years, being also used for pain management in patients with bruxism. Nonetheless, there is no consensus about its effects in this disorder.

Effectiveness of botulinum toxin type A for the treatment of chronic masticatory myofascial pain: A case series.

BACKGROUND: The aim of this study is to evaluate the effectiveness of botulinum toxin type A (BTX-A) for the treatment of chronic masticatory myofascial pain (MMP) over 12 months and to test a standardized protocol. METHODS: This is a prospective case series of consecutive adult patients with chronic MMP treated with injection of BTX-A into the bilateral temporalis and masseter muscles. The authors used the same anatomic landmarks and dosage and followed each patient for 12 months. The primary outcome variables were reduction in pain measured with visual analog scale (VAS) and Physician Global Assessment (PGA). Secondary outcome variables were change in maximum pain-free opening, change in palpatory pain points in the face and oral cavity, and change in results from a questionnaire measuring disability, dysfunction, and psychosocial effects of the disease. RESULTS: The authors included 15 women and 4 men (mean [standard deviation] age, 32.7 [6.9] years) in the study. Pain decreased significantly as measured with the VAS (P < .0001) and PGA (P < .0001). Maximum pain-free opening increased significantly (P = .010), but maximum voluntary opening did not change significantly (P = .837). The number of palpatory pain points (P < .0001) and the symptom questionnaire score decreased over time (P < .0001). CONCLUSIONS: The results of this case series suggest that injecting BTX-A into the bilateral temporalis and masseter muscles may be a safe and effective treatment for chronic MMP. PRACTICAL IMPLICATIONS: Controlled clinical trials are needed to confirm whether administration of BTX-A is effective in treating facial pain.

[Different types of injection in temporomandibular disorders (TMD) treatment]. / Les différents types d'injection pour traiter les dysfonctions de l'articulation temporomandibulaire.

INTRODUCTION: Intramuscular injections of botulinum toxin of type A (BoNTA) can release tension from masticatory and cervical muscles. Intra-articular injections relieve pain and sometimes diminish joint clicking and locking that occur during mouth opening. METHODS: Intramuscular injection of BoNTA is performed in our department since 2002. Injected muscles are masseter and temporal muscles. Later on, intra-articular injections of sodium hyaluronate were added, followed on a later stage by intra-articular injections of BoNTA for patients presenting with pain higher than 5/10 on an analogic visual scale. RESULTS: Eighty-five percent of the patients treated with intramuscular BoNTA injection improved. Total or partial pain relief was obtained in 95 % of the patients after intra-articular sodium hyaluronate injections. Seventy-six percent of the 56 patients treated by mean of intra-articular BoNTA injections improved, sometimes with a complete pain relief. DISCUSSION: These different techniques allow for good results, even if they do not represent a revolution in the treatment of temporomandibular disorders. In the hands of experienced practitioners, they have a low morbidity, are well accepted and are cost-effective.

Injecction of trigger points in the temporal muscles of patients with miofascial syndrome.

OBJECTIVE: The aim was to examine the effect of blocking trigger points in the temporal muscles of patients with masticatory myofascial pain syndrome, fibromyalgia and headache. METHOD: Seventy patients with one trigger point were randomly divided into 3 groups: injection with saline or anesthetic and non-injected (control). RESULTS: Pain was reduced in 87.71% patients injected with saline and 100% injected with anesthetic. Similar results were obtained for headache frequency. With regard to headache intensity, the injection groups differed from the control group, but not between themselves. CONCLUSION: Treatment with injection at trigger points decreased facial pain and frequency and intensity of headache. Considering the injected substance there was no difference.

Injecction of trigger points in the temporal muscles of patients with miofascial syndrome / Infiltrações de pontos-gatilho na musculatura temporal em pacientes com fibromialgia e cefaleia

Objective : The aim was to examine the effect of blocking trigger points in the temporal muscles of patients with masticatory myofascial pain syndrome, fibromyalgia and headache.Method : Seventy patients with one trigger point were randomly divided into 3 groups: injection with saline or anesthetic and non-injected (control).Results : Pain was reduced in 87.71% patients injected with saline and 100% injected with anesthetic. Similar results were obtained for headache frequency. With regard to headache intensity, the injection groups differed from the control group, but not between themselves.Conclusion : Treatment with injection at trigger points decreased facial pain and frequency and intensity of headache. Considering the injected substance there was no difference.

Objetivo : Comparar o efeito terapêutico do bloqueio de pontos-gatilho na musculatura temporal com soro fisiológico e anestésico em pacientes com síndrome da dor miofascial mastigatória, fibromialgia e cefaleia, entre sí e com controles não-infiltrados.Método : Setenta pacientes que apresentaram pelo menos um ponto-gatilho na musculatura temporal foram aleatoriamente divididas em 3 grupos: infiltração com soro fisiológico, infiltração com anestésico e controle (não-infiltradas).Resultados : Houve redução na intensidade de dor na face em 87,71% dos pacientes infiltrados com soro fisiológico e em 100% dos pacientes infiltrados com anestésico, mas não no grupo controle. Houve similaridade dos resultados considerando a frequência da cefaléia. Quanto à intensidade da cefaléia, tanto a infiltração com soro fisiológico, quanto com anestésico foram efetivos e sem diferença significativa entre sí, ao contrário do grupo controle.Conclusões : O tratamento com infiltração diminui a dor na face, bem com a frequência e a intensidade da cefaléia. Quando considerado a substância infiltrada não há diferenças no tratamento.

Sleep bruxism possibly triggered by multiple sclerosis attacks and treated successfully with botulinum toxin: Report of three cases.

Sleep bruxism refers to a nocturnal parafunctional activity including the clenching, grinding or gnashing of teeth. While most of the nocturnal bruxism cases seen in the general population are apparently idiopathic, it has been reported to be associated with a range of neurological diseases such as Huntington's disease, cranio-cervical dystonia and post-anoxic brain damage, but not multiple sclerosis (MS). We describe three cases of MS patients who have had moderate to severe complaints of bruxism in the two weeks following their relevant MS attacks. None of the three patients had a diagnosis of bruxism prior to her attack. The diagnosis was confirmed in one out of three by a polysomnography. One patient did not have any complaints related to bruxism previous to her attack, whereas two had mild and infrequent complaints. The symptoms of the relevant attacks were left hemihypesthesia in all and hemiparesis in two. None of the patients had spasticity that could result in severe teeth clenching. All three patients presented with morning headaches and jaw pain or tightness and were treated successfully with botulinum toxin (Btx) injections applied to their masseter and temporalis muscles. The cause of bruxism is controversial but lesions of the cortico-basalganglia-thalamo-cotrical loops are thought to be most likely. However, acute or chronic lesions in those pathways were not demonstrated in the 3 patients. It is feasible that they had normal appearing white matter interruptions in their cortico-basalganglia-thalamocortical loops along with their relevant attack.

Use of onabotulinumtoxinA in post-traumatic oromandibular dystonia.

PURPOSE: Post-traumatic oromandibular dystonia (PTOD) is a disorder whose symptoms can include bruxism, muscle pain, and involuntary muscle contraction, among others. The use of onabotulinumtoxinA (ObT-A) is helpful in controlling the symptoms of patients with PTOD. The aim of this study was to evaluate the use of ObT-A in the treatment of PTOD. MATERIALS AND METHODS: In this prospective case-series study, the population consisted exclusively of patients diagnosed with PTOD, without distinction by age or gender, from January 2007 to December 2010. The patients were diagnosed with PTOD and treated with ObT-A infiltration (primary predictor) at the Department of Maxillofacial Surgery at the Hospital Clínico Mutual de Seguridad (Santiago, Chile). The primary outcome variables were bruxism, muscle pain, and involuntary muscle contraction. The data were obtained through questionnaires registered in tables at each control. Systat 13.1 was used for statistical analysis. The statistical test used to compare patients' evolution over time was the test of signs. RESULTS: Thirty male patients 18 to 65 years old diagnosed with PTOD were treated with ObT-A infiltrations. The signs and symptoms associated with oromandibular dystonia (bruxism, muscle pain, and involuntary muscle contraction) were decreased in all patients after ObT-A infiltrations. CONCLUSIONS: The positive results and the absence of complications recommend the use of the infiltration protocol presented in this study for the treatment of PTOD.

Effects of botulinum toxin on jaw motor events during sleep in sleep bruxism patients: a polysomnographic evaluation.

STUDY OBJECTIVES: To investigate the effects of botulinum toxin type A (BoNT-A) injection on jaw motor episodes during sleep in patients with or without orofacial pain who did not respond to oral splint treatment. METHODS: Twenty subjects with a clinical diagnosis of SB completed this study. Ten subjects received bilateral BoNT-A injections (25 U per muscle) into the masseter muscles only (group A), and the other 10 received the injections into both the masseter and temporalis muscles (group B). Video-polysomnographic (vPSG) recordings were made before and at 4 weeks after injection. Rhythmic masticatory muscle activity (RMMA) and orofacial activity (OFA) were scored and analyzed for several parameters (e.g., frequency of episodes, bursts per episode, episode duration). The peak amplitude of electromyographic (EMG) activity in the two muscles was also measured. RESULTS: BoNT-A injection did not reduce the frequency, number of bursts, or duration for RMMA episodes in the two groups. The injection decreased the peak amplitude of EMG burst of RMMA episodes in the injected muscles (p < 0.001, repeated measure ANOVA) in both groups. At 4 weeks after injection, 9 subjects self-reported reduction of tooth grinding and 18 subjects self-reported reduction of morning jaw stiffness. CONCLUSIONS: A single BoNT-A injection is an effective strategy for controlling SB for at least a month. It reduces the intensity rather than the generation of the contraction in jaw-closing muscles. Future investigations on the efficacy and safety in larger samples over a longer follow-up period are needed before establishing management strategies for SB with BoNT-A. CITATION: Shim YJ; Lee MK; Kato T; Park HU; Heo K; Kim ST. Effects of botulinum toxin on jaw motor events during sleep in sleep bruxism patients: a polysomnographic evaluation.

Electromyographic analysis of masseter and temporal muscles, bite force, masticatory efficiency in medicated individuals with schizophrenia and mood disorders compared with healthy controls.

This study aimed to comparatively analyse the electromyographic activity of the masseter and temporal muscles at rest and during mandible postural clinical conditions (right and left laterality, protrusion and maximum voluntary contraction), right and left maximum molar bite forces and the masticatory efficiency of individuals with schizophrenia or mood disorders - all medicated (medicated groups) compared with control group (healthy volunteers) via electromyography. Individuals were distributed into three groups: Group I (Schizophrenia - 20 individuals), Group II (mood disorders - 20 individuals) and Group III (Control - 40 individuals). Basically, the results were only statistically significant for the clinical mandible conditions and bite force. The most unsatisfactory results were observed in the medicated groups in relation to the control group. The group with mood disorders obtained the most unsatisfactory results compared with the group with schizophrenia. It was suggested by these observations that the association of mood disorders and schizophrenia with medication has negatively affected the stomatognathic system in relation to controls when the electromyography and bite force were used for the analysis.

Changes in masticatory function after injection of botulinum toxin type A to masticatory muscles.

This study examined changes in masticatory function after botulinum toxin type A (BTX-A) injection using objective and subjective tests during 12 weeks. Also, we compared differences in masticatory function between group in which only masseter muscle (M group) was injected and group in which masseter and temporal muscle (M-T group) were injected. Forty subjects were assigned into two groups; M group (n = 20) and the M-T group (n = 20). The Meditoxin(®) was used as BTX-A injection. The mixing ability index (MAI) was used as the objective indicator, and visual analogue scale (VAS) and food intake ability (FIA) index were used as subjective indicators. Overall, the masticatory function drastically declined after 4 weeks and gradually recovered with time. Compared with the pre-injection state, the masticatory function decreased by 89·2% (MAI), 12·2% (FIA) and 32·2% (VAS) 4 weeks after the injection (P < 0·05). When the results between M group and M-T group were compared, scores of VAS and FIA were significantly different 4 weeks after the injection (P < 0·05), but the MAI score showed no significant difference between two groups. In conclusion, this study showed that masticatory function was significantly decreased after BTX-A injection into the masticatory muscle after 4 and 8 weeks from injection. However, masticatory efficiency measured using MAI could completely recover after 12 weeks. Furthermore, after 8 weeks from the injection, the masticatory function measured after injection into only the masseter muscle was similar to that measured after injection into both masseter and temporal muscle.

Botulinum injection for the management of myofascial pain in the masticatory muscles. A prospective outcome study.

We prospectively analysed the outcome after botulinum injection in patients who did not recover after conservative measures to manage masticatory myofascial pain, and who were not willing to take low dose tricyclic antidepressants as a muscle relaxant. We prospectively 62 patients were assessed with visual analogue scores (VAS) for pain on the affected side before, and 6 weeks after botulinum injection(s) (50 units Dysport in up to 3 sites), and measured mouth opening in mm. Of those treated 49 (79%) showed at least some improvement (pain reduced by more than 25%). Patients reported more than a 90% reduction in the VAS for 25 (30%) of the 84 sides of the face treated. Only 22 of the 62 patients had more than one course of treatment to the same side. Interincisal distance improved by a mean/median of 0.9 mm (p<0.03) after treatment. Side effects included 3 cases of temporary weakness of a facial muscle. Ranking the VAS pain scores using the Wilcoxon test before and after injection showed a significant reduction in pain (median change -29.5, interquartile range -53 to -16, p<0.0001). The treatment significantly improved patients' pain scores and the overall mean/median reduction in pain was 57%. Botulinum injection does not guarantee complete resolution of myofascial pain, but it usually has some beneficial effect in improving the symptoms, and should be considered as an alternate treatment for masticatory myofascial pain if conservative methods have failed.

Myofascial pain of the jaw muscles: comparison of short-term effectiveness of botulinum toxin injections and fascial manipulation technique.

A randomized controlled trial was performed to compare the short-term effectiveness of botulinum toxin injections and physiatric treatment provided by means of Fascial Manipulation techniques in the management of myofascial pain of jaw muscles. Thirty patients with a Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) diagnosis of myofascial pain were randomized to receive either single-session botulinum toxin injections (Group A) or multiple-session Fascial Manipulation (Group B). Maximum pain levels (VAS ratings) and jaw range of motion in millimeters (maximum mouth opening, protrusion, right and left laterotrusion) were assessed at baseline, at the end of treatment, and at a three-month follow-up. Both treatment protocols provided significant improvement over time for pain symptoms. The two treatments seem to be almost equally effective, Fascial Manipulation being slightly superior to reduce subjective pain perception, and botulinum toxin injections being slightly superior to increase jaw range of motion. Differences between the two treatment protocols as to changes in the outcome parameters at the three-months follow-up were not relevant clinically. Findings from the present investigation are in line with literature data supporting the effectiveness of a wide spectrum of conservative treatment approaches to myofascial pain of the jaw muscles. Future studies on larger samples over a longer follow-up span are needed on the way to identify tailored treatment strategies.

Comparison of glutamate-evoked pain between the temporalis and masseter muscles in men and women.

Pain in myofascial temporomandibular disorder (TMD) can affect both the masseter and temporalis muscles. Glutamate injection into the masseter muscle evokes pain that is greater in men than in women and this pain is attenuated by co-injection of the N-methyl-d-aspartate (NMDA) receptor antagonist ketamine (10 mmol/L) in men. Animal studies suggested that pain induced by peripheral NMDA receptor activation could differ between the temporalis and masseter muscles and between men and women. The study aims were to investigate differences in glutamate-evoked pain between these muscles and the effectiveness of ketamine to attenuate glutamate-evoked pain in both genders. Pain and mechanical sensitivity were induced in 2 sessions of an experiment in 14 women and 16 men by repeated injections of glutamate (0.5 mol/L) with and without ketamine (20 mmol/L) into the masseter and temporalis muscles. Two injections were applied into the same masseter muscle and 2 injections into the same anterior temporalis muscle at each session. Visual analogue scale (VAS) pain intensities and pain drawing areas were assessed. Glutamate-evoked pain and pain drawing area were significantly greater from the temporalis muscle than from the masseter muscle (P<.02) in both genders. Women reported significantly greater glutamate-evoked masseter muscle pain than men (P<.03). Co-injection of ketamine, at higher dose than previously used, was equally effective in attenuating glutamate-evoked pain from both muscles in both genders (P<.01). The current findings indicate that the characteristics of pain generated by intramuscular injection of glutamate vary for different masticatory muscles and may be partially generated through activation of peripheral NMDA receptors.

Masseter muscle fibre changes following reduction of masticatory function.

This study evaluated histological changes in masseter muscle fibres following reduced masticatory function by injection of botulinum toxin type A (BTX). Sixty 30-day-old Long-Evans male rats were randomly separated into four groups (15 per group): group I BTX masseter, 25U/ml (0.04ml each muscle) BTX was injected in bilateral masseter muscle whilst bilateral temporalis muscles received an equal amount of normal saline; group II BTX temporalis, 25U/ml (0.04ml each muscle) BTX was injected in bilateral temporalis muscle whilst bilateral masseter muscle received an equal amount of normal saline; group III BTX temporalis and masseter, bilateral temporalis and masseter were given 25U/ml (0.04ml each muscle) BTX; group IV normal saline (control), bilateral temporalis and masseter were given normal saline (0.04ml each muscle). After 45 days, the rats were killed, the muscles dissected and mean muscle mass recorded. The superficial masseter muscles were immunohistochemically analysed. Fibre sizes in group III were bigger than those in other groups. There was a small percentage of type IIa fibres in group III. Reduction in muscle fibre size and transition of muscle fibre subtypes from type IIa to IIx or IIb fibres may occur due to reduced masticatory function.

[Treatment of severe bruxism with botulinum toxin type A]. / Tratamiento del bruxismo grave con toxina botulínica tipo A.

INTRODUCTION: The possible usefulness of botulinum toxin type A in the treatment of bruxism has not been studied exhaustively, being limited to some isolated case reports, two short case-series and a double-blind study involving a small number or patients. This article report our long-term experience in the treatment of bruxism with botulinum toxin type A. PATIENTS AND METHODS: The outcome of 19 patients with severe bruxism who underwent periodical treatment with botulinum toxin A infiltrations in both temporal and masseter muscles, using initial doses of 25 IU per muscle, during a follow-up period ranging from 0.5 to 11 years, is described. Doses were adjusted in follow-up visits according the response degree. RESULTS: None of the patients reported side-effects. Final doses ranged from 25 to 40 IU per muscle (mean: 29.7 ± 4.9 UI), and duration of the effect from 13 to 26 weeks (mean: 16.7 ± 5.1 weeks). CONCLUSION: Botulinum toxin A infiltrations are a safe and useful treatment for patients with severe bruxism.

[The effect of treatment of temporalis muscle fascia grafts with formaldehyde on the success rates of tympanoplasty]. / Temporal kas fasya greftlerinin formaldehit ile islenmesinin timpanoplasti basari oranlarina etkisi.

OBJECTIVES: This study aims to investigate the effect of formaldehyde treatment of temporalis muscle fascia grafts used during tympanoplasty on the postoperative success rates. PATIENTS AND METHODS: Fifty-four patients who underwent tympanoplasty between January 2006 and January 2007 in the Department of Otolaryngology, Medicine Faculty of Uludag University and who were under regular follow-up were included in this prospectively planned study and divided into two groups: the study group (n=24) and the control group (n=30). Temporal muscle fascia grafts were used in all patients. The grafts were treated with formaldehyde in the study group. All the controls of the patients were performed by otomicroscopy. Audiometric tests were performed at the 6th month controls. RESULTS: It was found out that perforation was permanently repaired in 79.2% of the study group and in 73.3% of the control group (p>0.05). We obtained an evident improvement in the average airway bone gap in both groups. We could not detect any statistical significance in the comparison of the operation duration between the groups although the operation duration in the study group was shorter (the study group: 735 seconds, the control group: 775 seconds). CONCLUSION: The formaldehyde treatment of the temporalis muscle fascial graft used in tympanoplasty was not superior in closing perforation and operation length compared to its direct dry use. However, we concluded that the graft could be more easily manipulated during the operation.

Modulation of exteroceptive suppression periods in human jaw-closing muscles by subanaesthetic dose of propofol.

Exteroceptive suppression (ES) periods in human jaw-closing muscles can be conditioned by a wide range of somatosensory stimuli and cognitive states. The aim of this study was to examine the effects of subanaesthetic doses of midazolam, ketamine and propofol on the short latency (ES1) and long latency (ES2) reflex in the jaw-closing muscles. First, we tried to evaluate the various methodological criteria for ES recording. We then examined the effect of subanaesthetic doses of midazolam (0·035 mg kg(-1)), ketamine (0·30 mg kg(-1)) and propofol (0·35 mg kg(-1)) on these reflexes of recording left masseter and temporalis muscle. ES duration did not differ greatly in the present study, recorded with the correct adjustment of stimulating and recording conditions. None of the subanaesthetic doses of the agents influenced ES1, and no significant effects on ES2 were observed with midazolam and ketamine. However, significant inhibitory change was observed in ES2 with propofol. ES2 is thought to be mediated by afferents, which descend in the spinal trigeminal tract and connect with a polysynaptic chain of excitatory interneurones located in the lateral reticular formation. Our observations indicate that propofol is uniquely effective not only through involvement of the gamma-aminobutyric acid type A receptor, but also through a range of other effects.