Estudo comportamental das aferências do núcleo ventral do corpo trapezóide ao primeiro núcleo do circuito neural do reflexo auditivo de sobressalto: núcleo da raiz coclear

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Simplificação no tratamento da fratura de ângulo mandibular por meio do acesso intrabucal

Mandibular fractures are the injury most commonly found in the facial bones. They have varied etiology, such as automobile, motorcycle and cycling accidents, physical abuse and falls. The choice of treatment of mandibular fractures most often employed is the reduction and fixation of bone fragments. Regarding fractures involving the mandibular angle, access headgear is the most widely used, in view of the action of masticatory muscles causing greater displacement of fractured stumps. Therefore, the proposal to introduce a conservative approach and facilitated for the treatment of fractures of the mandibular angle, as well as to demystify the contraindication to intraoral approach cases unfavorable fracture displacement, this work is to report a clinical casesurgical mandibular angle fracture, treated by intraoral approach. The fracture was fixed with two plates, one following the external oblique line system (1.5 mm) and a lower system (2.0 mm), with the help of percutaneous trocar. This approach is very promising for these cases, in order to ease the technical as well as by reducing the technical complications of extraoral approach.

Variação da temperatura superficial dos músculos masseter e temporal anterior durante o apertamento dental voluntário com placas interoclusais maxilares de duas diferentes espessuras

Muscle activity has been studied indirectly through analyses of temperature variation in skin surface temperature on the masticatory muscles. These procedure may be an important tool for clinical evaluation and assessment of the evolution of temporomandibular disorders, as well as monitoring the adopted protocol. Thus, its utilization for identified pathological alterations on blood circulation and/or on metabolic activity in subcutaneous tissues, such as the masticatory muscles, is justified. The aim of this study was to investigate the effect of occlusal splints’ thickness on the variation of surface temperature of the anterior temporal and masseter muscles during rest and clenching. It were analyzed 20 symptomatic subjects (10 males and 10 females) selected through the Research Diagnostic Criteria (RDC) questionnaire. Temperature expressed in degrees Celsius (ºC) was measured on the surface of both muscles measured with the aid of a digital thermometer with an infrared radiation reading system. The surface temperature of the anterior temporal and masseter muscles presented significant reduction during teeth clenching in relation to the mandibular rest position. However, there were no significant differences between conditions with and without occlusal splint or between the different thicknesses of splints analyzed. Masticatory muscles showed a considerable similar behavior for both sides, and no significant distinctions were observed between male and female patients.

Temporomandibular disorders in females: acupuncture compared to occlusal splint

To compare the effect of acupuncture and occlusal splint in the treatment of temporomandibular disorders (TMD) in female patients.Method: Forty-eight female patients (mean age of 39.3±6.8 years) with diagnosed pain in muscles or joint according to RDC/TMD criteria were attended at UNESP - Aracatuba Dental School. Including criteria were reported pain in the chewing muscles and/or in the temporomandibular joint measured by a visual analogue scale (range from 0 to 10) and a reported reduction of the maximum mouth opening. Excluding factors were major occlusal problems, systemic diseases, pregnancy and age below 18 years. After randomization, the first group was treated with acupuncture performed by instructed dentist. The second group was treated with occlusal splint. The outcome variables were assessed at baseline (prior to the first treatment session) and after 1, 3 and 6 months. Primary criteria of success were improvement of mouth opening and pain reduction.Result: Acupuncture group exhibited chewing pain decrease from 5 (at baseline) to 1, 2 and 1 after 1, 3 and 6 months, respectively. In the splint group, chewing pain decreased from 4 to 2, 1 and 2 after 1, 3 and 6 months, respectively. The mouth opening (in mm) increased from 28 (at baseline) to 42, 44 and 46 after 1, 3 and 6 months, respectively in the acupuncture group. In the splint group, mouth opening improved from 29 to 40 after 1 month, and to 43 and 42 after 3 and 6 months. A significant pain reduction was noted for both groups when compared to the baseline (p<.001; Wilcoxon test). Acupuncture group had a significant clinical improvement of opening mouth (Mann-Whitney). Conclusion: The present outcomes suggest a positive association among acupuncture and occlusal splint on the reduction of chewing pain. Acupuncture was more effective in the mouth opening increase.

Parafunção severa: reabilitação oral com prótese total mandibular x overlay maxilar: relato de caso

In many oral rehabilitation professionals seeking venture renew people smile. However, these procedures have functional implications and aesthetic criteria which must be satisfied so that the final result is predictable. The restoration of relations intermaxillary, phonetics, masticatory function, esthetics and patient comfort are the goals to be achieved. An effective way to achieve these goals when immediate reconstruction with permanent dentures is not possible, make use of a type of partial denture called overlay. Bruxism is a manifestation of biopsychological imbalance that affects the stomatognathic system, characterized by clenching and / or attrition of teeth together so centric or eccentric, can be manifestation of nocturnal or diurnal. Its effects can manifest themselves in different parts of the stomatognathic system, varying the severity of the damage as the resistance of the structures affected, the time of existence, its regularity and the general state of the wearer. The description of the steps followed in solving this case, in which the patient edentulous mandibular arch while the maxillary arch showed absence of teeth 16 and 26 and, except for the teeth 17 and 27, all other teeth showed wear very sharp in the sense denoting incisal cervical, severe impairment of the vertical dimension, the quality of masticatory function and a marked impairment phonetic, this case report aims to guide the beginning of a rehabilitation, as well as the transitional phase of treatment for recovery of functional and aesthetic relationships intermaxillary .

Influência do formato do rebordo alveolar sagital em reabilitações com associação de prótese parcial removível de extremidade livre e implante ósseo integrado

The association of mandibular distal extension removable partial dentures with an osteointegrated implant is a treatment option at hasn't been fully explored by modern rehabilitation dentistry yet. The objective of this study is to evaluate, by means of the bidimensional method of finite elements, the distribution of tension on the structures supporting the distal extension removable partial denture (DERPD), associated to a 10.0 x 3.75 mm osteointegrated implant with an ERA retention system, in alveolar ridges of different shapes. Eight models were created, representing, from a sagittal perspective: Model A (MA) – a half arch with a horizontal ridge without posterior support, with the presence of the lower left canine, and a conventional DERPD, with metallic support in the incisal aspect of this canine, as replacement for the first and second pre-molars and the first and second molars of the lower left half arch; Model B (MB) – similar to MA, but different because of the presence of a 3.75 x 10.00 mm implant with an associated ERA retention system in the posterior region of the DERPD base; Model C (MC) - similar to MA, however with a distally ascending ridge format; Model D (MD) – similar to MC, but different because there is an implant associated to a retention system; Model E (ME) - similar to MA, however with a distally descending ridge format; Model F (MF) – similar to ME, but ditfferent in the sense that there is an implant with an associated ERA retention system; Model G (MG) – similar to MA, however with a distally descending-ascending ridge format; Model H (MH) – similar to MG, but different in the sense that there is an implant with an associated ERA retention system. The finite element program ANSYS 9.0 was used to load the models with vertical forces of 50 N, on each cuspid tip. The format of distal descending edge (ME and MF) was that presented worse results, so in the models with conventional RPD as in the models with RPD associated to the implant and ERA system of retention, for the structures gingival mucosa and tooth support. 1) the distally descending ridge presented the most significant stress in the model with the conventional RPD (ME) or with a prosthesis associated to an implant (MF) and 2) the horizontal ridge (MB) provided more relief to the support structures, such as the tooth and the spongy bone, when there was an implant associated to an ERA retention system. The incorporation of the implants with the ERA system retention, in the posterior area of the toothless edge, it promotes larger stability and retention to PPREL, improving the patient's masticatory acting and, consequently, its comfort and function.

Pistas diretas para o tratamento de mordida cruzada posterior

The malocclusions are one focus of discussions in public health, due to which it is necessary to incorporate correction procedures that are inexpensive, easy to perform and which can be made in health services. Planas Direct Tracks meet such characteristics which make them advantageous for the crossbite correction. The aim of this study was to present a case in which correction of unilateral crossbite was performed with the resources available in a public clinic. This is a 6 year-old patient who presented functional unilateral crossbite in canines and posterior teeth. A cross decreased maxillary arch leading to a condition of unilateral posterior crossbite was detected. Occlusal adjustments were performed in canine and posterior teeth; however it was not enough to restore the occlusal balance. It was decided to prepare Planas Direct Tracks in canines, allowing functional balance, which prevented masticatory movement alteration during the growth phase and malocclusion correction. Controls were performed every six months to evaluate the patient's progress and whether or not new occlusal adjustments were necessary. Monitoring and treatment were conducted for 5 years, until stabilization of the permanent dentition ensuring treatment. It is concluded that Planas Direct Tracks were effective for the correction of unilateral posterior crossbite. So, it is essential to note that this procedure can be performed in public services.

Oclusão em prótese sobre implante - parte I

Osseointegrated implants have specific nature distinguish them from natural teeth making them more susceptible to the efforts generated by mastication. The absence of periodontal ligament, which absorbs the masticatory forces and allows the movement of the teeth interfere with the reception of occlusal loads and therefore the predictability of implants. In the boneimplant interface did not occur the phenomena of dissipation of impact, even the movement induced. Thus, during planning and installation of implant prosthesis, the type and characteristics of occlusal pattern adopted should be established with criteria to be no grounds for future failures. In this regard we highlight the occlusal overload generated by several reasons like the presence of premature contacts, interference during motion excursive, deleterious habits and inappropriate extensions on cantilevers. Thus, the objective is to provide a review of the literature regarding the importance of occlusion in oral rehabilitation with implants. Factors to be considered in establishing a favorable occlusion, consistent with prostheses on implants will be described

Efeitos neuroprotetor e regenerativo do selante de fibrina derivado da peçonha de serpente combinado com células tronco mononucleares após reparo do nervo isquiático de ratos neonatos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Time series analysis of jaw muscle contraction and tissue deformation during mastication in miniature pigs

Masticatory muscle contraction causes both jaw movement and tissue deformation during function. Natural chewing data from 25 adult miniature pigs were studied by means of time series analysis. The data set included simultaneous recordings of electromyography (EMG) from bilateral masseter (MA), zygomaticomandibularis (ZM) and lateral pterygoid muscles, bone surface strains from the left squamosal bone (SQ), condylar neck (CD) and mandibular corpus (MD), and linear deformation of the capsule of the jaw joint measured bilaterally using differential variable reluctance transducers. Pairwise comparisons were examined by calculating the cross-correlation functions. Jaw-adductor muscle activity of MA and ZM was found to be highly cross-correlated with CD and SQ strains and weakly with MD strain. No muscle’s activity was strongly linked to capsular deformation of the jaw joint, nor were bone strains and capsular deformation tightly linked. Homologous muscle pairs showed the greatest synchronization of signals, but the signals themselves were not significantly more correlated than those of non-homologous muscle pairs. These results suggested that bone strains and capsular deformation are driven by different mechanical regimes. Muscle contraction and ensuing reaction forces are probably responsible for bone strains, whereas capsular deformation is more likely a product of movement.

Temporomandibular disorders in headache patients

Objective: To identify the frequency of signs and symptoms of temporomandibular disorder (TMD) and its severity in individuals with headache. Study Design: 60 adults divided into three groups of 20 individuals: chronic daily headache (CDH), episodic headache (EH) and a control group without headache (WH). Headache diagnosis was performed according to the criteria of International Headache Society and the signs and symptoms of TMD were achieved by using a clinical exam and an anamnestic questionnaire. The severity of TMD was defined by the temporomandibular index (TMI). Results: The TMD signs and symptoms were always more frequent in individuals with headache, especially report of pain in TMJ area (CDH, n=16; EH, n=12; WH, n=6), pain to palpation on masseter (CDH, n=19; EH, n=16; WH, n=11) which are significantly more frequent in episodic and chronic daily headache. The mean values of temporomandibular and articular index (CDH patients) and muscular index (CDH and EH patients) were statistically higher than in patients of the control group, notably the articular (CDH=0.38; EH=0.25; WH=0.19) and muscular (CDH=0.46; EH=0.51; WH=0.26) indices. Conclusions: These findings allow us to speculate that masticatory and TMJ pain are more common in headache subjects. Besides, it seems that the TMD is more severe in headache patients.

Electromyographic Study in Patients With Surgically Treated Facial Fractures

This study, using surface electromyography, analyzed the activity of the masseter muscles of 30 patients with facial bone fractures that were surgically treated. Evaluations were made before surgery and in the 7th, 30th, and 60th days after surgery. The value of each measure and the average of 3 maximum voluntary isometric contractions lasting 5 seconds each were registered, and statistical analyses were performed. Patients had a mean age of 31 years and an average of 1.33 fractures. They were grouped according to the type of fracture as follows: mandibular (50%), zygomatic complex (33%), maxilla (10%), and associated fractures (6.7%). There was a lower masseter activity in the preoperative period, when compared with normal values in all groups of fractures. There was a sharp drop in the masseter activity in the postoperative period of 7 days, and all groups showed recovery of activity in 60 days but still below the normal value referenced in the literature. The mean values of the masseter activity, in descending order, were from the zygomatic complex, mandibular, maxillary, and associated fractures. The unilateral mandibular fractures showed higher values than the bilateral fractures in most of the evaluations. There was a highly significant difference in the comparison of the evolution of the masseter activity on both sides, for mandibular and zygomatic complex fractures, and the pairwise comparison showed significant difference between most groups. It was concluded that facial fractures and surgical procedures had negative effects in the muscle activity as observed using electromyography.

High prevalence of orofacial complaints in patients with fibromyalgia: a case-control study

Objective. The aim of this study was to investigate the orofacial complaints and characteristics of patients with fibromyalgia syndrome (FS) compared with controls. Study Design. We evaluated 25 patients diagnosed with FS compared with 25 gender-and age-matched controls by using a detailed clinical protocol for orofacial pain diagnosis and dental examination. Results. FS patients had a higher frequency of temporomandibular disorders (TMD), masticatory complaints, pain with mandibular movements, and pain upon palpation of the head and neck area. There were no significant differences related to the dental exam. Conclusions. Orofacial complaints including TMD may be present either as symptoms of FS or as a comorbidity associated with this condition. A comprehensive evaluation of patients with FS is necessary to identify the need for specific treatments for orofacial complaints. Future studies, especially those with longitudinal design, should clarify whether a cause-effect relationship exists between orofacial complaints and fibromyalgia. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:e29-e34)

The effect of a Lucia jig for 30 minutes on neuromuscular re-programming, in normal subjects

The Lucia jig is a technique that promotes neuromuscular reprogramming of the masticatory system and allows the stabilization of the mandible without the interference of dental contacts, maintaining the mandible position in harmonic condition with the musculature in normal subjects or in patients with temporomandibular dysfunction (TMD). This study aimed to electromyographically analyze the activity (RMS) of the masseter and temporal muscles in normal subjects (control group) during the use of an anterior programming device, the Lucia jig, in place for 0, 5, 10, 20 and 30 minutes to demonstrate its effect on the stomatognathic system. Forty-two healthy dentate individuals (aged 21 to 40 years) with normal occlusion and without parafunctional habits or ternporomandibular dysfunction (RDC/TMD) were evaluated on the basis of the electromyographic activity of the masseter and temporal muscles before placement of a neuromuscular re-programming device, the Lucia jig, on the upper central incisors. There were no statistically significant differences (p < 0.05) in the electromyographic activity of the masticatory muscles in the different time periods. The Lucia jig changed the electromyographic activity by promoting a neuromuscular reprogramming. In most of the time periods, it decreased the activation of the masticatory muscles, showing that this device has wide applicability in dentistry. The use of a Lucia jig over 0, 5, 10, 15, 20 and 30 minutes did not promote any statistically significant increase in muscle activity despite differences in the data, thus showing that this intra-oral device can be used in dentistry.

Changes in FDB and soleus muscle activity after a train of stimuli during upright stance

Background: Evidence of self-sustained muscle activation following a brief electrical stimulation has been reported in the literature for certain muscles. Objectives: This report shows that the foot muscle (Flexor Digitorum Brevis - FDB) shows a self-sustained increase in muscle activity during upright stance in some subjects following a train of stimuli to the tibial nerve. Methods: Healthy subjects were requested to stand upright and surface EMG electrodes were placed on the FDB, Soleus and Tibialis Anterior muscles. After background muscle activity (BGA) acquisition, a 50 Hz train of stimuli was applied to the tibial nerve at the popliteal fossa. The root mean square values (RMS) of the BGA and the post-stimulus muscle activation were computed. Results: There was a 13.8% average increase in the FDB muscle EMG amplitude with respect to BGA after the stimulation was turned off. The corresponding post-stimulus Soleus EMG activity decreased by an average of 9.2%. We hypothesize that the sustained contraction observed in the FDB following stimulus may be evidence of persistent inward currents (PIC) generated in FDB spinal motoneurons. The post-stimulus decrease in soleus activity may have occurred due to the action of inhibitory interneurons caused by the PICs, which were triggered by the stimulus train. Conclusions: These sustained post-stimulation changes in postural muscle activity, found in different levels in different subjects, may be part of a set of possible responses that contribute to overall postural control.