Journal of Conservative Dentistry
Home About us Editorial Board Instructions Submission Subscribe Advertise Contact e-Alerts Login 
Users Online: 357
Print this page  Email this page Bookmark this page Small font sizeDefault font sizeIncrease font size
 


 
Table of Contents   
ORIGINAL ARTICLE  
Year : 2011  |  Volume : 14  |  Issue : 2  |  Page : 120-127
"Electromyographic pattern of masticatory muscles in altered dentition" Part II


1 Department of Conservative Dentistry and Endodontics, Dr. R. Ahmed Dental College and Hospital, Kolkata, India
2 Department of endodontics, Santosh Dental College, Gaziabad, Uttar Pradesh, India
3 Department of Physiology, I M S B H U, Varanasi, Uttar Pradesh, India

Click here for correspondence address and email

Date of Submission12-May-2010
Date of Decision11-Sep-2010
Date of Acceptance21-Dec-2010
Date of Web Publication7-Jul-2011
 

   Abstract 

Aim : The aim of this study is to show that a change in occlusal contacting pattern of tooth has definite influence over the behavior of orofacial musculature, resulting deleterious effect on it. Keeping this in view, the electromyographic (EMG) activity of temporalis and masseter muscles in rest position of mandible, maximum clenching and chewing, was studied in total 24 subjects--14 subjects with normal occlusion and rest 10 with normal occlusion and one tooth carious which was prepared to receive an inlay with high point. This high point or occlusal interference was introduced intentionally to have a change in occlusion or "altered dentition". The subjects were all male medical volunteers with average age group of 20 years. A particular variety of chewing substance - chewing gum was used in this study. No EMG activity was detected in the rest position of mandible. In maximum clenching, balanced type of activity was seen bilaterally in normal occlusion.Whereas in changed occlusion, an unbalanced type of muscle activity was seen in temporalis muscle during maximum clenching. There was an overall decrease in activity in both the muscles during maximum clenching and during chewing. This decrease in activity was statistically significant in most of the times. A non-specific pattern of muscle activity resembling spasm in skeletal muscle -- a state of "hyperactivity" was also found during chewing in presence of occlusal interference. This spasm-like activity may cause pain in the muscles of masticatory apparatus. All these abnormal types of behavior of muscle were abolished after removal of high point and establishing the previous normal occlusion. It is therefore, for the clinicians to understand the importance of establishing occlusal equilibrium in day to day practice.

Keywords: Altered dentition, EMG pattern, masticatory

How to cite this article:
Adhikari H D, Kapoor A K, Prakash U, Srivastava A B. "Electromyographic pattern of masticatory muscles in altered dentition" Part II. J Conserv Dent 2011;14:120-7

How to cite this URL:
Adhikari H D, Kapoor A K, Prakash U, Srivastava A B. "Electromyographic pattern of masticatory muscles in altered dentition" Part II. J Conserv Dent [serial online] 2011 [cited 2019 Jun 24];14:120-7. Available from: http://www.jcd.org.in/text.asp?2011/14/2/120/82607

   Introduction Top


Tooth contact is a part of the reflex mechanism controlling the mandibular movements and muscular contraction [1],[2] Occlusal relationship and forces exerted by the orofacial musculature are in a state of dynamic equilibrium. Any change in occlusion has a definite influence over muscle contraction, [3],[4],[5] and may cause various disturbances of different parts of stomatognathic system including development of TMJ dysfunction syndrome in long run . [6] Keeping this in view, the present investigation was designed to study the activity of masticatory muscles with the help of electromyography (EMG) both in the subjects with normal occlusion and intentionally produced functional malocclusion or "altered dentition."


   Materials and Methods Top


The present study was conducted with total 24 subjects.They were all male medical volunteers (average age 20 years) with complete dentition (third molar excluded) and normal occlusion (as per criteria stated by Gravers). Fourteen subjects were included in the control group and the rest were in experimental group. Five subjects in experimental group were having left lower first molar carious and the rest five were having right lower first molar carious.

While selecting the subjects, those with the history of myofacial pain dysfunction syndrome and orthodontic treatment, lip incompetence, tenderness in any muscle of mastication and previous restoration in tooth were excluded.

The carious tooth was prepared for inlay. Wax pattern was made and checked. A 2-3 mm of sprue wax of 12-gauge diameter (nearly 2.1 mm.) was added over the occlusal aspect of the wax pattern, so that an occlusal interference was produced in centric occlusion position. Then the inlay was casted. It was then finished, polished and checked for proper fitting. The intentionally produced interference was trimmed to reduce its size to roughly about 1mm and checked for required occlusal interference. Idea to introduce the occlusal interference in the inlay was to develop functional malocclusion or "altered dentition" in the subjects of experimental group. Depending on the side of interference, the subjects in the experimental group were divided into two sub groups:

Experimental-Left-sided interference (E-L)

and Experimental-Right-sided interference (E-R).

Anterior belly of masseter and anterior belly of temporalis of both sides (which are for convenience mentioned here as masseter and temporalis, respectively) were studied. Bipolar surface electrodes were used. Electrodes were placed according to the method of Moss J.P, [7] Ahlgren J et al, [8] and Kawazoa Y et al. [9] The EMG recording of these muscles was done in both groups (1) at most comfortable position of jaw i.e., at rest position, (2) during maximum clenching at maximum intercuspal position and (3) during chewing a chewing gum from both the sides.

In experimental group, during the activity of maximum clenching and chewing, recording was done three times - i) preoperatively i.e., before the tooth was prepared for inlay restoration, ii) postoperatively, after the inlay with measured high point or occlusal interference was fitted in the tooth and iii)again postoperatively, after establishing occlusal equilibrium by thorough grinding the high point and proper finishing and polishing the inlay.

Before recording, volunteers were seated comfortably on a dental chair. Position of the head was kept vertical and no movement was allowed as jaw muscles respond to change in head position. They were trained how to keep mandible in most comfortable centric relation position of jaws and to close it in maximum intercuspal position and clench maximally for a particular period of time. For the purpose of chewing, specific brand of chewing gum was used. The volunteers were instructed to crush the gum first and to make it a bolus of even consistency and then was asked to keep it over posterior teeth of one side and chew it only once-- constituting one chewing cycle and to take rest for a while and to start again when commanded. Consecutive three such cycles constituted one session. The same procedure was repeated on other side.

Muscle activity was recorded by means of "Polyrite" - a 2-channel EMG machine with integrator and pen writing recorder. The calibration of the EMG machine - 50 μv = 10 mm was fixed for the whole experimental procedure, meaning 10 mm of pen deflection was resulted from 50 μv of electrical energy and the paper speed was fixed at 25 mm per second of time. Following were the combinations of muscle pair (after the method of Green field et al) [10] taken in this study for simultaneous EMG recording --



The simultaneous recordings thus obtained from the predetermined muscle pairs from control and experimental groups were studied and analysed statistically.

Observations

No EMG activity was detected at rest position of mandible in all the subjects included in the present study.

The muscle activity recorded during various sessions in control and experimental groups were tabulated as follows:

During chewing the gum

Chewing from the left side

As is seen from the table, the activity of the left temporalis muscle was 50 ± 10.44 μv and that of right temporalis was 44.85 ± 13.9 μv. The activity of the left temporalis muscle was 11.48% higher (P>0.1) than the right temporalis.

The activity of left masseter muscle was seen 69.21 ± 11.47 μv and that of the right masseter 60.42 ± 10.26 μv. The left masseter activity was 14.54% higher (statistically significant P<0.05) than that of the right side.

So it was observed that during left side chewing left-side activity was higher than right-side activity and the activity of masseter was higher than that of temporalis.

Chewing from the right side

The activity of the right temporalis muscle was 56.78 ± 8.4 μv and that of left temporalis was 44.00 ± 10.25 μv. The activity of the right temporalis muscle was 29.04% higher (statistically highly significant, P<0.001) than the left temporalis.

The activity of the right masseter muscle was recorded 68.07 ± 11.49 μv and the activity of the left masseter 56.64 ± 12.68 μv. Now the activity of former was seen to be 20.18% higher (statistically significant, P<0.02) than that of later.

That means during chewing from right side, the right-side activity was higher than the left side and the activity of masseter was higher than that of temporalis.

Therefore from the results obtained from left and right-side chewing, it was apparent that the chewing side activity was higher than non-chewing side activity and the activity of masseter was greater than that of corresponding temporalis.

During maximum clenching

During clenching the jaw maximally in centric occlusion position, the activity of left temporalis muscle,(54.07 ± 14.34 μv) was more or less equal to that of right temporalis muscle (53.35 ± 11.53 μv). Left side activity was 1.34% higher (statistically insignificant, P>0.10) than that of right side.

Similarly the activities of left and right masseter muscles were also more or less same. The right masseter activity (66.35 ± 12.16 μv) was only 2.20% higher (statistically insignificant, P>0.10) than that of left side (64.92 ± 10.08 μv).

This means during clenching the jaw maximally in centric occlusion-position the activity of the similar muscles of both sides were more or less balanced and the activity of masseter was greater than that of temporalis.

During maximum clenching

Control group v\s Experimental group

Left temporalis

As compared to the activity of the left temporalis in control group of subjects (54. 07 ± 14.37 μv) the activity of the same muscle in group E-L (41.0 ± 11.59 μv) and E-R (34.6 ± 9.81 μv) was seen to be decreased by 24.17% (P>0.05) and 36% (statistically significant, P<0.01), respectively.

Right temporalis

In relation to the activity of the right temporalis muscle in control group (53.35 ±11.53 μv), the activities of the same muscle in group E-L (45.8 ± 10.89 μv) and E-R (36.4 ± 11.28 μv) was observed to be decreased by 14.15% (P>0.1) and 31.77% (statistically significant, P<0.02), respectively.

Left masseter

In comparison to the activity of left masseter muscle in control group (64.92 ± 10.08 μv) the activity of the same muscle in E-L (49.0 ± 8.94 μv) and E-R (52.4 ± 11.78 μv) was decreased by 24.52% (statistically significant, P<0.01) and 19.28% (P> 0.05), respectively.

Right masseter

The contractile activity of right masseter of E-L (49.4 ± 9.71 μv) and E-R (53.4 ± 11.19 μv) were seen to be decreased by 25.54% (statistically significant, P<0.01) and 19.5% (P>0.05), respectively as compared to that in control group (66.35 ± 12.16 μv).

Therefore it is concluded that in the experimental group of subjects due to presence of occlusal interferences, there was overall decrease of contractile activity of the masticatory muscles under study and the decrease of activity was statistically significant in most of the time.

Experimental group: Left-sided interference (E-L)

Unlike in control group, a difference was observed between the activities of left and right temporalis muscles. The activity of right temporalis (45.8±10.89 μv) was 11.7% higher (P>0.1) than that of left temporalis (41.00±11.59 μv).

But the activities of left and right masseter muscles were nearly same. The activity of right masseter (49.4±9.71 μv) and was only 0.8% higher (P>0.1) than that of left side (49.0±8.94 μv).

Experimental group: Right-sided interference (E-R)

The activity of right temporalis (36.4±11.28 μv) was found 5.2% higher (P>0.1) than that of left temporalis (34.6 ±9.81 μv).

The activity of right masseter (53.4 ±11.19 μv) was only 1.9% higher (P>0.1) than that of left masseter (52.4 ±11.78 μv)

Therefore in maximum clenching, the activity of temporalis in two sides was found unbalanced or asymmetrical (difference in activity in group E-L 11.7% and E-R 5.2%) whereas masseteric activity was seen to be more or less balanced bilaterally.

Chewing gum from left side

C, control group; E-L, experimental group with left-side interference; E-R, experimental group with right-side interference

During chewing from left side

Control group v\s Experimental group

Left temporalis

In comparison with the activity of left temporalis muscle in control group (50.0 ± 10.44 μv), the activity of left temporalis of group E-L (38.8 ± 12.85 μv) and E-R (36.8 ± 4.38 μv) was seen to be decreased by 22.4% (P>0.10) and 26.4% (statistically significant, P<0.01), respectively.

Right temporalis

Similarly, as compared to the activity of right temporalis (44.85 ± 13.9 μv) in control group, the activity of the same muscle in E-L (25.8 ± 12.98 μv) and E-R (28.40 ± 10.62 μv) was seen to be decreased by 42.47% (statistically significant, P<0.02) and 36.67% (statistically significant, P<0.02), respectively.

Left masseter

In relation to the activity of left masseter in control group (69.21 ± 11.47 μv), the activity of the same muscle in the subjects in group E-L (47.8 ± 10.94 μv) and E-R (48.0 ± 11.51 μv)was seen to be decreased by 30.93% (statistically significant, P<0.01) and 30.64% (statistically significant, P<0.01), respectively.

Right masseter

As compared to the activity of right masseter muscle in control group (60.42 ± 10.26 μv), the activity of same muscle in group E-L (32.8 ± 11.6 μv) and E-R (35.1 ± 11.48 μv) was observed to be decreased by 45.71% (statistically highly significant, P<0.001) and 41.74% (statistically highly significant, P<0.001), respectively.

Experimental group: Left-sided interference (E-L)

The activity of left temporalis was seen to be 38.8 ±12.85 μv and that of right temporalis was 25.8 ±12.98 μv. The left temporalis activity was 50.38% higher (P>0.1) than that of right temporalis.

The activity of left masseter was seen to be 47.8 ±10.94 μv whereas that of right masseter was 32.9 ±11.6 μv. The left masseteric activity was 45.73% higher (P>0.05) than that of right masseteric activity.

Experimental group: Right-sided interference (E-R)

The activity of left temporalis was seen to be 36.8 ±4.38 μv and that of right temporalis was 28.0 ±10.62 μv. The left temporalis activity was 29.57% higher (P>0.1) than that of right temporalis.

Similarly the activity of left masseter was seen to be 48.0 ±11.51 μv whereas that of right masseter was 35.1 ±11.48 μv. The left masseteric activity was 36.36% higher (P>0.1) than that of right masseteric activity.

So it was observed that during chewing from left side, the activity of left side was higher than that of right side and the activity of masseter was higher than that of temporalis.

Chewing gum from right side

C, control group; E-L, experimental group with left-side interference; E-R, experimental group with right-side interference

During chewing from right side

Control group v\s Experimental group

Left temporalis

In relation to the activity of left temporalis muscle in control group (44.0 ± 12.5 μv), the activity of the same muscle in group E-L (20.0 ± 8.63 μv) and E-R (27.0 ± 12.52 μv) was seen to be decreased by 54.54% (statistically highly significant, P<0.001) and 38.68% (statistically significant, P<0.01), respectively.

Right temporalis

In comparison with the activity of the right temporalis muscle (56.78 ± 8.4 μv) in control group, the activity of the same muscle in group E-L (41.8 ± 11.47 μv) and E-R (30.2 ± 9.57 μv) was decreased by 26.38% (statistically significant, P<0.05) and 41.8% (statistically highly significant, P<0.001), respectively.

Left masseter

As compared to the activity of the left masseter muscle in control group (56.64 ± 12.68 μv), the activity of the same muscle in group E-L (29.4 ± 5.12 μv) and in E-R (32.0 ± 11.81 μv) was decreased by 48.09% (statistically highly significant, P<0.001) and 43.5% (statistically significant, P<0.01), respectively.

Right masseter

In relation to the activity of the right masseter muscles in control group (68.07 ± 11.49 μv), the activity of the same muscle in group E-L (37.4 ± 12.79 μv) and E-R (43.4 ± 11.19 μv) was seen to be decreased by 45.05% (statistically highly significant, P<0.001) and 36.24% (statistically highly significant, P<0.001), respectively.

Experimental group: Left-sided interference (E-L)

The contractile activity of right temporalis muscle was recorded to be 41.8 ±11.47 μv and that of left temporalis muscle was 20.0 ±8.63 μv. The activity of right temporalis muscle was 109% higher (statistically significant, P<0.01) than that of left temporalis.

Similarly, the contractile activity of right masseter muscle was seen to be 37.4 ±12.79 μv and that of left masseter was 29.4 ±5.12 μv. The right masseteric activity was 27.21% higher (P>0.1) than that of left masseter.

Experimental group: Right-sided interference (E-R)

The contractile activity of right temporalis muscle was recorded to be 30.2 ±9.57 μv and that of left temporalis muscle was 27.0 ±12.52 μv. The activity of right temporalis muscle was 11.85% higher (P>0.1) than that of left temporalis.

Similarly, the contractile activity of right masseter muscle was seen to be 43.4 ±11.19 μv and that of left masseter was 32.0 ±11.81 μv. The right masseteric activity was 35.62% higher (P>0.1) than that of left masseter.

The result of right side chewing was consistent with that of left side chewing. In other words, during chewing the activity was more in ipsilateral side and less in contralateral side.

In essence analyzing the observation of the tables it appeared that -

In control group during maximum clenching, activity of similar muscles of both sides was seen more or less balanced and during chewing, the chewing side activity was higher than non-chewing side [Table 1]. In experimental group, pre-operative EMG recording and the recording in post-operative phase after removal of high point and establishing occlusal equilibrium, are identical and consistent with that of control group.
Table 1: Average contractile activity of bilateral masseter and temporalis muscles in control group during chewing gum and maximum clenching


Click here to view


EMG recording in postoperative phase with high point inlay, the result was different in maximum clenching. In contrast to control group there was an overall decrease of activity of both the muscles and the decrease in activity was statistically significant [Table 2] in most of the time. The activity of temporalis was consistently observed reduced in magnitude on the side of interference. However, the result of masseter muscle was found more or less consistent all the time. [Table 2]
Table 2: Average contractile activity of temporalis and masseter muscles of both the sides in control and experimental groups in presence of high point inlay or occlusal interference during maximum clenching


Click here to view


Activity of the muscles on the chewing side was observed always higher than that of non-chewing side and [Table 1], [Table 3] and [Table 4]. Throughout the study, masseter muscle activity was seen higher than the corresponding temporalis [Table 1], [Table 2], [Table 3] and [Table 4] and it is the masseter which contracts first, then temporalis in chewing. In comparison to the result of control group, there was an overall decrease of muscle activity in experimental group when inlay with high point was fitted in tooth and this decrease in activity was statistically significant in most of the time [Table 2], [Table 3] and [Table 4].
Table 3: Average contractile activity of temporalis and masseter muscles of both the sides in control and experimental groups in presence of high point inlay or occlusal interference during chewing gum from left side


Click here to view
Table 4: Average contractile activity of temporalis and masseter muscles of both the sides in control and experimental group in presence of high point inlay or occlusal interference during chewing gum from right side


Click here to view


During chewing, some type of EMG activity was detected at the time of rest condition of jaw in the period between consecutive chewing cycles and sometimes at the end of last chewing cycles when the subjects in experimental group chewed the gum post operatively in presence of occlusal interference. This type of activity was abolished after removal of high point and establishing occlusal equilibrium --- the EMG pattern returned back similar to that recorded preoperatively. No EMG activity was found during the similar period of time in case of control group or experimental group in preoperative phase.

This EMG activity at rest condition of mandible was resembling spasm in skeletal muscles and was having following characteristics [6]

  1. Amplitude (mean activity): Low voltage discharges varying from 10 to 20 μv in contrast to that in chewing cycles which ranged from 30 to 53 μv.
  2. Frequency: Low frequency of 15-20 cycles per second in comparison with the frequency of EMG activity in chewing cycles which varied from 25 to 30 c. p. s.
  3. Duration: Varied from 200 to 600 msec and this spasm-like activity was exhibited in unexpected period of time when the muscles were supposed to show no electrical activity. It was inharmonious and not properly timed. No relationship between this activity and any preferred muscle or side of interference or side of chewing could be established in this study.



   Discussion Top


The observation of this study at rest position of jaw is consistent with that of Vitti M et al. [11],[12] However, Latif A, [13] Moyer R.E. [14] and Carlsoo S. [15] found activity in temporalis muscles and believed that temporalis have a role in maintaining rest position of mandible.

The unbalanced type of muscle activity as found during maximum clenching in experimental group postoperatively with high point inlay, is consistent with the study of Porritt E.J.; [16] Franks AST; [17] Bakke. M et al. [18] Similar pattern of EMG activity was also observed by Funakoshi. M. et al,[4] in response to the change in head position in the subjects with occlusal interference. Moss J.P, [7] proved that muscle activity in centric occlusion position is the best for discrimination between normal occlusion and malocclusion. As balance in activity of the muscles of left and right sides is a salient feature in normal occlusion, the unbalanced type of activity definitely reflects the effect of functional malocclusion. Only temporalis is affected, may be because it participates in myriad of complex activities of mandible and thus more sensitive than masseter to the sensory impulses particularly of short duration as in the study.

The pattern of EMG varies with chewing different types of food. So a particular variety of chewing substance - the chewing gum of a particular brand was supplied to all the volunteers. Consistency of the gum remains more or less same even after repeated chewing. Similar to the study of Mohamed S.E. et al, [19] chewing side activity was observed higher than non-chewing side. This is attributed to the greater excitatory firing of the pressoreceptors of periodontal ligament of chewing side. [18],[19] That the receptors of periodontal ligament excite the elevators of mandible was revealed by the anaesthetizing effect of these receptors in the study of Lund J.P et al. [20]

The overall decrease in muscle activity in the subjects of experimental group in presence of high point inlay in comparison with control group, is in consistence with the finding of Franks A.S.T. [17] and Bakke M. et al. [18] The possible mechanism of the decrease in contractile activity is due to unilateral premature contact or occlusal interference was believed to be operated via the receptors of periodontal ligament. [5],[17],[18] Each tooth contact by stimulating periodontal receptors generate impulses in the sensory neuron of trigeminal nerve and appropriate initiation, maintenance and cessation of mandibular activity i.e., co-ordinated jaw movements take place. [1],[2],[21],[22],[23] So stimulation of the receptors has a definite role on the masticatory muscles. Therefore, the reduction of activity in elevating muscles may be due to reduced number of receptors being active as a result of occlusal interference. Similar view was expressed by Bakke M. et al[18] whereas other workers [2],[18],[24],[25] believed that upon tooth contact, inhibition of mandibular elevators or "attenuating influence on efferent motor activity" is resulted by an afferent impulse from the receptors of periodontal ligament. This activity of the ligament abolishes when it is anesthetized. During mastication, the principle of reciprocal enervation between opening and closing muscles of mandible does not seen operative and the jaw opening muscles have also fewer muscle spindles. The receptors of periodontal ligament thus serve as a source of feed back for jaw opening reflex. Stimulation of those receptors by tooth contact inhibit jaw closing muscle and then jaw opening muscles contract to open it. This inhibition of the elevators on tooth contact also prevents over loading of the tooth and protects from mechanical damage.

Therefore, it may be suggested that the activity of the elevators in subjects with functional malocclusion was attenuated or inhibited due to afferent inhibitory influence of the proprioceptors of the tooth periodontal ligament. This was also expressed by Franks A.S.T. [17] in his study with bilateral onlays with interference.

The abnormal type of muscle activity found during chewing in presence of occlusal interference, was described as state of "Hyper-activity" by Jarabak J.R. [3] and "partial contraction of Muscle" by Kloprogge M.J.G.M. [23] Any relationship between this activity and any preferred muscle or side of interference or side of chewing, was not much observed in this study. Since the inlay with occlusal interference was placed for a short period of time, so definite pattern of altered muscle activity was not detected.

It is known that coordinated muscle activity for the multi-directional jaw movements is influenced by the stimulation of periodontal ligament receptors. The stimulation pattern of periodontal ligament receptors is scheduled by the pattern of occlusal contacts. Due to the presence of occlusal interference, this pattern was altered which possibly developed a pattern of activity - a "Sponteneous hyper-activity or spasmodic activity" to steer the mandible around the point of occlusal interference. [3],[23] Funakoshi M. et al, [4] described that "occlusal interference may always cause an excess excitation of mechanoreceptors of periodontal ligaments and afferent impulses from the receptors continuously stimulate the motoneurone which may cause an increase in "Jaw muscle tonus".

In the state of sustained contraction or spasm of muscle, excretory products accumulate more than they are eliminated. This results in painful stimuli. This pain may be referred to other neighboring muscles and joint and cause further spasm reflexl and may thus produce temporomandibular (TMJ) pain dysfunction syndrome (characterized by pain in muscles, joint, limitation of opening, clicking, etc.)

It has also been observed that most of the patients with TMJ dysfunction are associated with occlusal interference. [3],[23] The symptoms of these patients are abolished or atleast improved by occlusal therapy. [3],[4] Therefore, it may be said that occlusal interference is one of the causes of TMJ dysfunction syndrome.


   Conclusions Top


In various field of practising dentistry, there always remains a possibility of change in contacting pattern of lower tooth with the upper, which may or may not be in the knowledge of the clinician. With the change in contacting pattern of teeth, there will be a change in muscle contraction pattern. Stomatognathic system, within certain limit may adopt with this change. Beyond this limit it may produce various deleterious effects on the organs of the system e.g. muscle, joints,etc. Therefore the clinician has to be careful to follow properly the procedure of reproducing occlusal pattern of tooth such that the functional pattern of masticatory muscles remains unaltered.

 
   References Top

1.Graf H. Occlusal tooth contact pattern in relation to electromyographic activity during function. Am J Orthod 1964;50:701.  Back to cited text no. 1
    
2.Schaerer P, Stallard RE, Zander HA. Occlusal interference and mastication: An electromyographic study. J Prosthet Dent 1967;17:438-49.  Back to cited text no. 2
[PUBMED]    
3.Jarabak JR. An electromyographic analysis of muscular and temporo-mandibular joint disturbances due to imbalance in occlusion. Angle Orthod 1956;26:170.  Back to cited text no. 3
    
4.Funakoshi M, Fujita N, Takehana S. Relation between occlusal interference and jaw muscle activities in response to changes in head position. J Dent Res 1976;55:684-90.  Back to cited text no. 4
[PUBMED]  [FULLTEXT]  
5.Ingerval B, Calsson GE. Masticatory muscle activity before and after elimination of balancing side occlusal interference. J Oral Rehabil 1982;9:183-92. Quoted from: Mohamed SE, Christensen LV, Harrison JD. Tooth contact pattern and contractile activity of elevator jaw muscles during mastication of two different types of food. J Oral Rehabil 1983;10:87-95.  Back to cited text no. 5
    
6.Adhikari HD, Kapoor AK, Udai Prakash, Srivastava AB. EMG Pattern of Masticatory muscle in altered dentition. J Conserv Dent 2006;9:14-20.  Back to cited text no. 6
  Medknow Journal  
7.Moss JP. An electromyographic investigation of certain muscle activities associated with malocclusion of the teeth. Ph. D. Thesis, University of London ,1971. Function-fact or fiction? Am J Orthod 1975;67:625-46.  Back to cited text no. 7
    
8.Ahlgren J, Ingerval BP, Thilander BL. Muscle activity in normal and post normal occlusion. Am J Orthod 1973;64:445-56.  Back to cited text no. 8
    
9.Kawazoa Y, Kotani H, Hamade T. Relation between integrated electromyographic activity and biting force during voluntary isometric contraction in human masticatory muscles. J Dent Res 1979;58:1440-9.   Back to cited text no. 9
    
10.Greenfield, Wyke. Electromyographic observations on some of the muscles of mastication. J Anat 1955;89:578.  Back to cited text no. 10
    
11.Vitti M, Basmajian JV. Muscles of mastication in small children: An electromyographic analysis. Am J Orthod 1975;68:412-9.  Back to cited text no. 11
[PUBMED]    
12.Vitti M, Basmajian JV. Integrated actions of masticatory muscles: Simultaneous EMG from eight intramuscular electrodes. Anat Rec 1977;187:173-89.  Back to cited text no. 12
    
13.Latif A. An electromyographic study of temporalis muscle in normal persons during selected positions and movements of the mandible. Am J Orthod 1957;43:577-91.  Back to cited text no. 13
    
14.Moyer RE. Electromyographic analysis of certain muscles involved in T.M. movement. Am J Orthod 1960;36:481-515.  Back to cited text no. 14
    
15.Carlsoo S. Nervous co-ordination and mechanical function of the mandibular elevator; and electromyographic study of the activity, and an anatomic analysis of mechanics of the muscles. Acta Odontol Scand Suppl 1952;10:1-132.  Back to cited text no. 15
[PUBMED]    
16.Porritt EJ. An electromyographic study involving occlusal interference. Am J Orthod 1960;46:57-8.  Back to cited text no. 16
    
17.Franks AS. Influence of occlusal onlay on the electrical output of the masseters. Br Dent J 1961;3:214-6.  Back to cited text no. 17
    
18.Bakke M, Moller E. Distortion of maximal elevator activity by unilateral premature tooth contact. Scand J Dent Res 1980;88:67-75.  Back to cited text no. 18
    
19.Mohamed SE, Christensen LV, Harriso JD. Tooth contact patterns and contractile activity of the elevator jaw muscles during mastication of two different types food. J Oral Rehabil 1983;10:87-95.  Back to cited text no. 19
    
20.Lund JP, Lamarre Y. The importance of positive feed back from periodontal presso-receptors during voluntary isometric contraction of jaw closing muscle. J Biol Buccale 1973;1:345-51.  Back to cited text no. 20
[PUBMED]    
21.Perry HT, Harris SC. Role of neuro muscular system in functional activity of the mandible. J Am Dent Assoc 1954;48: 665-73.  Back to cited text no. 21
[PUBMED]    
22.Perry HT, Lammse GA. Occlusion in a stress situation. J Am Dent Assoc 1960;60:626-33.  Back to cited text no. 22
    
23.Kloprogge MJ, van Griethuysen AM. Disturbance in the contraction and co-ordination pattern of the masticatory muscles due to dental restoration. An electromyographic study. J Oral Rehabil 1976;3:207-16.  Back to cited text no. 23
[PUBMED]    
24.Brenman HS, Black MA, Coslet JG. Interrelationship between the electromyographic silent period and dental occlusion. J Den Res 1968;47:502.  Back to cited text no. 24
    
25.Ahlgren J. The silent period in the EMG of the jaw muscles during mastication and its relationship to tooth contact. Acta Odontol Scand 1969;27:219-27.  Back to cited text no. 25
[PUBMED]    

Top
Correspondence Address:
H D Adhikari
Flat-B 4/3 Purba Abasan DF-Block 1582/1 Rajdanga Main Rd, Kolkata-700107
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0972-0707.82607

Rights and Permissions



 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]

This article has been cited by
1 All on Four® Fixed Implant Support Rehabilitation: A Masticatory Function Study
Moara De Rossi,Carla Moreto Santos,Reginaldo Migliorança,Simone Cecílio Hallak Regalo
Clinical Implant Dentistry and Related Research. 2013; : n/a
[Pubmed] | [DOI]



 

Top
 
 
 
  Search
 
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  
 


    Abstract
   Introduction
    Materials and Me...
   Discussion
   Conclusions
    References
    Article Tables

 Article Access Statistics
    Viewed1960    
    Printed150    
    Emailed1    
    PDF Downloaded131    
    Comments [Add]    
    Cited by others 1    

Recommend this journal