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The subfascial temporalis dissection and reconstruction of the temporalis muscle for pterional craniotomy are described. These procedures preserve the frontotemporal branch of the facial nerve and increase exposure along the sphenoid ridge. A good cosmetic appearance and good temporalis muscle function are achieved postoperatively.
The present study was carried out to examine if the jaw-tongue reflex (JTR) could be elicited in man and if afferent fibers from the jaw-closing muscles were involved in this reflex. Electromyographic (EMG) activities were simultaneously recorded from the genioglossus (GG), the tongue retruding (TR) muscles, and the anterior temporal (TA), the posterior temporal (TP), the masseteric (Mass) and the digastric (Dig) muscles under various conditions. The results were as follows: 1. EMG activities of the GG and the TR muscles were increased during clenching, voluntary and passive jaw-opening, and chin-tapping. 2. Electrical stimulation of the deep temporal and masseteric nerves evoked H-reflex in the TA and the Mass muscles. EMG activities in the GG and the TR muscles were detected as the intensity of the electrical stimulation were increased. 3. The tonic vibration reflex (TVR) was induced in the jaw-closing muscles by applying vibratory stimulation to the bellies of the TA and the Mass muscles. EMG activities of the GG and the TR muscles were increased as the TA muscle activity was increased. It is concluded that the JTR is elicited in man and suggested that low threshold afferent fibers from the jaw-closing muscles, mainly the temporal muscle, were involved in eliciting the JTR in man.
OBJECTIVE: To study the modulation of jaw-stretch and blink reflexes by experimental posterior temporalis muscle pain. METHODS: Thirty healthy volunteers (15 males, 25.5+/-0.6 years and 15 females, 27.4 +/- 1.2 years) were included. Short-latency stretch reflex responses were evoked in the masseter and temporalis muscles by fast stretches (1 mm displacement, 10 ms ramp time) and the blink reflexes were evoked by painful electrical pulses (0.5 ms duration), delivered by a concentric electrode placed on the left lower forehead close to the supraorbital foramen before, during and 15 min after a period with experimentally induced muscle pain. RESULTS: The normalized peak-to-peak amplitude of the stretch reflex in the painful temporalis was significantly higher during pain in both males and females compared with pre- and post-pain conditions (P < 0.004). The R2 root mean square (RMS) of the blink reflex decreased significantly during muscle pain as compared to the pre-pain (P < 0.03) in both males and females. CONCLUSIONS: The present results indicated that experimental posterior temporalis muscle pain facilitates the jaw-stretch reflex, whereas the nociceptive specific blink reflex is inhibited. SIGNIFICANCE: Present study suggested that these reflexes are suitable models for probing pontine and medullary pain processing.
The possible influences of the direction of occlusal loading delivered to the incisors in the sagittal direction during chewing on jaw movement and jaw closing muscle activity were investigated. Ten healthy children with crossbite of one or two incisors on the right side were selected. Each subject chewed a piece of chewing gum on the right side, and jaw displacements and electromyographic signals from the posterior temporalis and superficial masseter muscles on the ipsilateral side were sampled simultaneously. After orthodontic correction of the incisor crossbite relationship, identical records were taken. The inclinations of the gliding contacts for each posterior tooth in the lateral jaw excursion position were consistent before and after the treatment. The posttreatment records showed broader jaw movement patterns in the frontal view and faster jaw movement velocity in the lateral direction at a level close to the habitual maximum intercuspation position, when compared with the pretreatment records (P < 0.05). The duration of the muscle activity and the incidence of the silent periods of the masseter muscle during chewing significantly decreased after the treatment (P < 0.05). The current results give a neurophysiologic rationale for explaining the significance of orthodontic treatment in improving lowered masticatory efficiency in the way that the change in direction of the occlusal load achieved by tooth movement influences on the periodontal sensory input, which, in turn, modifies the trigeminal motor output and thus, eventually, jaw muscle activities.
The effects of the progressive activation of the Herbst appliance on the activity of the masseter and temporalis elevator muscles of the mandible were monitored in a group of 14 consecutively treated 10-15-year-old subjects with an Angle Class II, division I malocclusion. A cast silver splint Herbst appliance was activated in multiple stages at a rate of 2 mm/2 mo. The functionality of the superficial masseter and anterior portion of the temporalis muscles was monitored at maximum bite force using surface electromyography (EMG). The EMG recordings were taken at an incisal edge-to-edge position and a retruded mandibular position, both at a vertical interincisal separation of 3 mm using an acrylic bite plate. Measurements of maximum voluntary isometric clenches were taken during adaptive functional changes at pretreatment (baseline) and during the first 6 months of Herbst appliance therapy. Results showed great individual and inter- and intrasessional differences in electromyographic activity of the muscles before and during treatment. At the retruded position, the masseteric activity increased by the sixth month while temporalis activity remained at the same level. Following treatment, the masseteric imbalance was reduced, but the temporalis imbalance was unchanged. At the edge-to-edge position, masseteric activity increased by the sixth month, while temporalis activity remained unchanged. The masseteric imbalance was reduced by the sixth month, while the temporalis imbalance was reduced from the fourth month into treatment. The results imply a favorable muscular response to a progressive regime of Herbst appliance activation.
This research evaluated the relationship between balancing side molar contacts and chewing patterns measured with a jaw movement analyser and multi-channel electromyography (EMG) of the masticatory muscles. Nine healthy subjects with relatively normal occlusions participated in the experiment and were divided into those with balancing side molar contacts and those without. The block gum chewing task was performed on each side of the mouth for 10 s. The results showed more asymmetrical levels of jaw closing muscle activity during unilateral chewing in the group with balancing side molar contacts when compared with the group without these contacts.
One way to look at nocturnal oral parafunction such as bruxism, is using polysomnography. Although in recent years several studies have been carried out, it is almost impossible to compare the respective results because of the lack of standardization in the methodology used. The nocturnal muscular activity of m. Masseter and m. Temporalis Anterior has been registered in 21 patients suffering from bruxism, prior and after treatment with a bite-plane made according to Jeanmonod. A group of five persons without any dental or muscular parafunction has been included as a control. A computer program based on the biomechanical principles of muscle contraction has been developed and was used to analyse the raw electromyography (EMG) signal. The data shows a significant decrease (P = 0.008) in nocturnal parafunctional muscle activity with the bite-plane in situ. The present study shows that by analysing the raw signal obtained via EMG using a specially designed computer program, it becomes possible to isolate the occurrence of parafunctional events in the EMG signal and to study the influence of a given therapy on this EMG signal.
The purpose of this study was to investigate the relationship between the presence of temporomandibular joint (TMJ) pain and the magnetic resonance (MR) imaging findings of osteoarthrosis (OA), and effusion. The study comprised 112 consecutive TMJ pain patients. Criteria for including a patient were report of unilateral pain near the TMJ, with the presence of unilateral TMJ pain during palpation, function, and/or unassisted or assisted mandibular opening. Bilateral sagittal and coronal MR images were obtained to establish the presence or absence of TMJ OA, and/or effusion. Comparison of the TMJ side-related data showed a significant relationship between the clinical finding of TMJ pain and the MR imaging diagnoses of TMJ OA (P=0.000), and TMJ effusion (P=0.000). Further, there was a significant relationship between the MR imaging diagnosis of TMJ OA and TMJ effusion (P=0.000). Use of the Kappa statistical test indicated poor diagnostic agreement between the presence of TMJ pain and the MR imaging diagnosis of TMJ OA (K=0.22), TMJ effusion (K=0.29), and TMJ 'OA and effusion' (K=0.30). The study's findings suggest that while clinical pain is correlated to TMJ-related MR imaging findings, clinical pain in and of itself, is not reliable for predicting the presence of TMJ OA and/or effusion. Validation of MR imaging diagnoses would involve the investigation of cross-sectional and longitudinal evidence to assess decisive differences in terms of prognosis and/or treatment outcome.
This article summarizes our current face lift technique and its evolution over the last 20 years. Our goal has been to provide excellent results with as little risk as possible. Changes in technique have been motivated primarily by improved understanding of facial anatomy. In this article we discuss the anatomic concepts we have found most useful in developing a safe, precise procedure, and we present our current preferred techniques.
The maximum bite force (MBF) appears to be different when measured at different jaw openings (e.g., Manns et al., 1979; Mackenna and Turker, 1983; Lindauer et al., 1993). However, the change could be related to a change in the bite direction. We have measured the MBF on incisors and its direction in three dimensions for different jaw openings in ten subjects. Surface electromyography (EMG) of anterior temporalis and masseter muscles on both sides was recorded simultaneously. The results showed that: (1) the average %MBF increased as the jaw was opened, reached a plateau between 14 and 28 mm of incisal separation, and then decreased at wider jaw openings; (2) the initial forward bite direction with respect to the mandibular occlusal plane shifted backwards during jaw opening; and (3) the activity of the masseter muscles declined and that of the temporalis muscles was largely unchanged, resulting in an increase of the ratio between the activity in temporalis and masseter muscles (T/M). There was a significant correlation between bite direction and jaw opening (r = 0.51, p < 0.001) and between T/M ratio and jaw opening (r = 0.56, p < 0.001). Based on comparative data, we have calculated sarcomere lengths while the jaw is opened and hypothesize that the average %MBF reaches its maximum when the sarcomeres in the masseter muscle achieve their optimum length. A plateau continues during further jaw opening, until those of temporalis reach their optimum length while those of masseter lengthen beyond their optimum length. The change in bite direction was attributed to either a change in the relation between upper and lower bite points as the jaw was opened or the gradual decline of masseter activity at larger openings.
The aim of this study was to investigate the reliability between different examiners when using the axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The hypothesis was that the standardized RDC/TMD examination protocol enables calibrated examiners to evaluate all examination items reliably. After calibration training by the RDC/TMD calibration team including the calibration of palpation pressure and the performance of the standardized examination protocol, four examiners, blinded to the patients' medical histories examined 24 subjects in a randomized sequence. One experienced examiner was the standard (hierarchical calibration). The recorded measurements strictly followed the RDC/TMD. Intraclass correlation coefficients (ICC), bias and precision were calculated to estimate interrater reliability. Acceptable (0.75 > or = CC > 0.4) to excellent (ICC > 0.75) reliability was found for 20 of the 23 (87%) examinations. Only sub-retromandibular muscle palpation and joint sound vibration recordings on lateral excursion showed poor-results (ICC < or = 0.4). The RDC/TMD examination protocol enables calibrated examiners to perform most (87%) examination items with satisfactory reliability. Therefore multi-site studies based on the RDC/TMD examination protocol may become feasible, keeping in mind the unsatisfactory reliability of 13% of the items (clicking during laterotrusion to the ipsilateral side, palpation of the posterior and submandibular region).
OBJECTIVE: The aim of this study was to investigate the mandibular functions of patients with cleft lip and palate (CLP) by means of modified Rakosi Functional Analysis and to test whether there was a risk of tendency to temporomandibular joint disorder when compared with Angle Class I non-CLP patients. DESIGN: Fifteen patients with unilateral CLP with a mean age of 12.2 +/- 1.91 years and randomly selected 15 Angle Class I orthodontic patients with a mean age of 10.5 +/- 2.01 years as a control group. None of the subjects had complaint of symptoms of temporomandibular joint disorder in their histories. All subjects were evaluated using modified Rakosi Functional Analysis method in accordance with a scoring system of the findings. MAIN OUTCOME MEASURES: Intra- and extracapsular clinical functional surveys were taken. A Mann-Whitney U test was used to evaluate the differences between the CLP and non-CLP groups. RESULTS AND CONCLUSION: There was a significant difference (p <.01) between the distributions of the total scores of the two groups. A significant difference (p <.05) in right lateral movement was also observed between the two groups. However, there were no significant but borderline differences in clicking, crepitus, and maximum mouth opening findings between the two groups. Because these results do not explain the reason for the aforementioned differences, further studies seem essential.
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The aim of the thesis was to compare the short- and long-term effects of acupuncture and occlusal splint therapy in patients with craniomandibular disorders (CMD). One hundred and ten patients, 23 males and 87 females, participated in the study. All patients exhibited moderate or severe signs and symptoms of CMD and had had pain for more than six months. The participants were randomly assigned to three groups: acupuncture, occlusal splint therapy or control. Ten different subjective and/or clinical assessment variables were used in the evaluation of the treatment effect. Immediately after treatment, acupuncture and occlusal splint therapy had reduced the symptoms as compared with the control group which remained essentially unchanged. Acupuncture gave better subjective results than occlusal splint in the short-term. In the 12-month long-term follow-up, 57% of the patients who received acupuncture and 68% of the patients who received occlusal splints benefitted subjectively and clinically from the treatment. There were no statistically significant differences between the two groups in any of the assessment variables. Those patients who received various additional therapies following acupuncture and/or occlusal splints rarely responded favorably to additional treatment. No serious adverse events or complications were observed in the study. Acupuncture seems to have adverse events of a more general nature whereas adverse events of the occlusal splint seem to be more related to the orofacial region. The majority of the patients responded positively to the comfort of both treatment modes. In order to measure tenderness (pressure pain threshold, PPT) more objectively, the usefulness of an algometer was evaluated. A good reliability and validity was found for the algometer in recording the PPT in the masticatory muscles. The reliability was further improved by connection of a stopwatch to the algometer so that the pressure rate could be kept within acceptable limits. A moderate but statistically significant correlation was found between PPT and clinical and subjective variables. The algometer was sensitive enough to detect pre- and post-treatment changes. A statistically significant reduction in tenderness was found immediately after and at the 6-month follow-up for both treatment modes. This series of studies showed that acupuncture gave positive results similar to those of occlusal splint therapy in patients with primarily myogenic CMD symptoms over a 1-year period.
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Integrated electromyographic (IEMG) activity was recorded in 15 children with Class II, Division 1 malocclusion undergoing treatment with an activator. EMG activity was recorded with surface electrodes from anterior temporal and masseter muscles, with and without the activator in the postural mandibular position, during saliva swallowing and maximal voluntary clenching. Similar IEMG activity in the postural mandibular position and during maximal voluntary clenching, with and without activator, was observed. During saliva swallowing, the activity in both muscles was significantly higher with the activator. This supports the rationale for diurnal wear of the activator. Simple linear regression analysis showed a significant negative correlation between the change of masseter muscular activity during saliva swallowing and age of the children (r = -0.51), suggesting that treatment with the activator should be started at an early age.
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