ABSTRACT
@#Benign condylar hyperplasia is one of the causes of mandibular lateral deformity, it is easily to be misdiagnosed clinically and leads to the treatment failure. This article will elaborate the etiology and clinical features of benign condylar hyperplasia, as well as the diagnostic points and treatment progress, based on the literature and the clinical experience of our research group, to provide evidence-based medical evidence for the standardized clinical treatment of benign condylar hyperplasia. The etiology of benign condylar hypertrophy includes neurotrophic disorders, local circulatory disorders, traumatic injuries (especially condylar injuries that occur in childhood), unilateral mastication, temporomandibular arthritis, endocrine disorders, condylar osteoma, and heredity. Benign condylar hypertrophy is insidious, and occurs most frequently in individuals 10-30 years old, and the course of disease can last for many years. Its clinical characteristics are slow progressive facial asymmetry. Radionuclide bone scans have become the basis for the diagnosis and differential diagnosis of and treatment planning for benign condylar hypertrophy. Different treatment plans for active and inactive periods need to be developed, including close observation, proportional condylar resection and orthognathic surgery.
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Introduction: Patients presenting Temporomandibular Disorders (TMD) are common in our daily clinical practice. One of the possible conditions that lead to TMD is the habitual chewing side syndrome. Methods: In this case report a clinical approach is presented to manage the TMD related to unilateral vicious mastication. A 42 years old woman presented reporting headaches, difficulty to open mouth, presence of sensitivity in the left ear and TMJ region, soreness on the left side temporal region and sensitivity in the anterior inferior teeth. It was noted that the patient habitually clenched and ground teeth. Patient mentioned chew more on the left side. Results: After confirming the unilateral mastication, a modified therapy based on the Neuro occlusal Rehabilitation was applied through the use of a splint. After 60 days the patient described absence of the previous symptoms and pain relief. Conclusion: The evaluation of the masticatory pattern is often neglected; however, it is of great importance since it can lead to several conditions such as condyle wear, pain, alteration of the occlusal plane, deviation of the medial line, deviation of the mandible at mouth opening, bone alterations, Temporomandibular joint(TMJ) hypofunction, headache, among others.
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Objective To apply chaos characteristics to prediction of the unilateral mastication.Methods The paper calculated the Largest Lyapunov Exponent of the masseter muscle of some males and females with a method from small data sets,which then was processed by reusable two-factor analysis of variance.Results The results shows that the signal of the masseter muscle has chaos characteristics,the male's Largest Lyapunov Exponent is higher that the female's,and the chaos degree of the masseter muscle on both sides is consistent nearly.Conclusion The Largest Lyapunov Exponent can be used to characterize the signal of the masseter muscle.Comparative Analysis of the Largest Lyapunov Exponent on both sides can be used as reference when to predict and diagnose the unilateral mastication.
ABSTRACT
There are several variations in normal mastication. In them, unilateral mastication is chewing, predominantly on a preferred side of the dentition and hardly on the non-preferred side. Continual unilateral mastication may alter the coordination of masticatory muscles. Although they studied about these EMG of masticatory muscles, there were no information about characteristics of masticatory muscle activity in unilateral mastication. Therefore, In this study, we investigated the activity of the masseter and anterior temporal muscles during rest, clenching in maximum intercuspation and gum chewing in habitually unilateral mastication group com-pared with normal group and tried to know effects of continual unilateral mastication on activity of masticatory muscles. The results of this study were as follows 1. In electromyographic activity during rest, in bilateral mastication group pattern of muscle activity of right and left side was symmetrical. But, in unilateral mastication group, records of anterior part of temporal muscle was higher than that of bilateral mastication group (p<.01) and patterns of muscle activity of right and left side in both muscle were asymmetrical.(p<.05). 2. In electromyographic activity during clenching in maximum intercuspation, records of superficial part of masseter muscle were higher than anterior part of temporal muscle in both group. Muscle activity of temporal muscle in unilateral mastication group was a little higher than bilateral mastication group and asymmetry of activity pattern in temporal and masseter muscle was shown but these differences were not statistically significant. (p< .05). 3. In electromyographic activity during gum chewing, temporal muscle was activated earlier than masseter muscle and .aximum bite force is derived from masseter muscle in both group. In unilateral mastication group, electromyographic activity of masseter and temporal muscle of preferred chewing side, regardless of right or left side chewing, was higher than that of bilateral mastication group and especially, difference in masseter muscle was statistically significant. (p< .01) Based on the above results, our study suggested that recording of masticatory muscle activity will be helpful in the effective diagnosis and treatment of some types of the parafunctional habits.