PRACA ORYGINALNA

ORIGINAL ARTICLE

Iryna M. Tkachenko, Yaroslav Y. Vodoriz, Iryna Y. Marchenko, Maryna A. Shundryk, Dmytro M. Korol, Olena V. Gurzhiy

Ukrainian medical stomatological academy, Poltava, Ukraine

ABSTRACT

Introduction: Abrasion of teeth significantly affects electromyography results. Analyzing electromyograms of patients who needs complex rehabilitation, it is necessary to note absence of dissociation of the structure, appearance of spontaneous activity in one of the muscles, presence of the prevailing chewing side, appearance of low-amplitude oscillations in biocurrents.

The aim: The purpose of this study was to determine the role of anterior teeth in the rehabilitation of patients with increased abrasion.

Material and methods: The experimental group involved patients (men and women) aged 20 to 59 years with increased abrasion of teeth I-III degrees. Patients were provided with all the necessary complexes of rehabilitation measures: direct restorations with composite materials using the adhesive system of the Vth generation (in case of light abrasion), indirect ceramic restorations (severe abrasion). All work was conducted in accordance with the Declaration of Helsinki (1964) and was approved by the Ethical Committee of the academy.

Results: Activity of the right masseter muscle was slightly higher than that of the left one (313.42 ± 97.96 ms. against 226.69 ± 35.39 ms. respectively). At the same time the resting time of the left and right masseter muscles slightly differs (300.57 ± 30.93 ms. and 307.96 ± 49.47 ms. respectively).

Conclusions: Rehabilitation of patients with increased abrasion using combined methods (direct composite restorations with the adhesive system of Vth generation and indirect ceramic restorations), give the possibility to restore the masticatory function (evidenced by an increase in the activity of right and leftmasseter muscle on 2%, a decrease in the rest phase on 20% almost and an increase in amplitude on 2.9%).

KEY WORDS: myography, tooth abrasion, dental restoration

Wiad Lek 2019, 72, 4, 553-557

INTRODUCTION

The idea of the qualified treatment of patients with increased abrasion of teeth and the rehabilitation of masticatory function can appear only on the basis of data on the nature of the movements of masticatory muscles, their tone and bioelectric activity. Undoubtedly, the main occlusal load is taken by posterior teeth (premolars, molars). However, the efficacy of rehabilitation cannot be reviewedconsidering only lateral teeth.

Abrasion of teeth significantly affects electromyography results [1-3]. Analyzing electromyograms of patients who needs complex rehabilitation, it is necessary to note absence of dissociation of the structure, appearance of spontaneous activity in one of the muscles, presence of the prevailing chewing side, appearance of low-amplitude oscillations inbiocurrents (Fig.1).

Treatment of patients with increased tooth abrasion requires a multidisciplinary and individual approach for each patient and demands the concerted efforts of several specialists. In order to succeed, rehabilitation measures cannot be carried out on isolated teeth, but should extend to dental arches, masticatory muscles, and temporomandibular joint. [4].

THE AIM

The purpose of this study was to determine the role of anterior teeth (central and lateral incisors, canines) in the rehabilitation of patients with increased abrasion. The data was represented by the electromyograms, which were recorded 6 months after the completion of the comprehensive treatment.

MATERIALS AND METHODS

The experimental group involved patients (men and women) aged 20 to 59 years with increased abrasion of teeth I-III degrees. Total number of participants was 25 people. Patients were provided with all the necessary complexes of rehabilitation measures: direct restorations with composite materials using the adhesive system of the Vth generation [5] (in case of light abrasion) (6), indirect ceramic restorations (severe abrasion) [7,8].

Clinically healthy individuals (men and women), without any sign of increased abrasion and periodontal disease, were included into the control group. Age of participants ranged from 20 to 59 years. Totally 25 peoplewere included.

An electromyography was recorded from every participant of the study before the beginning of rehabilitation. For the patients of the experimental group the procedure was repeated 6 months after the completion of rehabilitation. During the electromyographic study the patients were offered to take a functional test “arbitrary chewing” [2,3]. Using the masticatory efficacy table, the portion of anterior teeth was determined [9,10].

RESULTS AND DISCUSSION

CONTROL GROUP

Analyzing the digital data of the electromyograms of the control group, we drew attention to the fact that the time of activity and rest time of both the left and right masseter muscles almost did not differ.

The activity of the left masseter muscle was 148.06 ± 4.95 milliseconds, while the right one was 135.98 ± 3.59 ms. The resting time of the left chewing muscle was 152.37 ± 4.71 ms. and the right muscle was 155.02 ± 6.06 ms.

Notably that the coefficient of activity “K” for left and right masseter muscles is different and makes 0.98 ± 0.03 ms. and 0.91 ± 0.06 ms. respectively but this difference is not significant and indicates a lack of functional asymmetry. There is a significant difference in the indices of the amplitude of the left and right masseter muscles. The amplitude of the left masseter muscles is 207.58 ± 3.38 μV, while the right is only 288.41 ± 22.67 μV. This may indicate a more active movement of the right muscle compared to the left one.

EXPERIMENTAL GROUP BEFORE TREATMENT

Before conducting any treatment, the rates of electromyographic test are different from those results of the control group. In our opinion, this fact indicates a decrease in masticatory efficacy due to the pathology of hard tissues of teeth and the decrease occlusion height (Fig. 2).

The results of electromyograms analysis of experimental group patientsare presented in Table I.

It should be noted that the coefficient of chewing activity in the experimental group is much lower for the left muscle than for the right one (0.64 ± 0.063 and 0.74 ± 0.0660 respectively). The amplitude of the electromyogram amplitude of the left masseter muscle in the experimental group is 284.67 ± 34.21 μV, while the right one is 405.55 ± 27.36 μV.

Therefore, we suggest that the difference in electromyography rates of the experimental group is associated with a different degree of manifestation of increased tooth abrasion, as well as a violation of the masticatory function.

EXPERIMENTAL GROUP (6 MONTHS RECALL)

Six months after rehabilitation of patients a clearer structure of electromyograms can be determined (Fig. 3).

The activity of the left and right masseter muscles of patients slightly increased compared to the data obtained prior to treatment. The activity of the left masseter muscle in the experimental group is 326.47 ± 7.61 ms., the activity of the right one is 225.11 ± 19.15 ms. (Tab. I).

The rest time of the left and right muscles slightly decreased comparing to the results obtained before the treatment, but the difference between the scores was not significant.

It should be noted that the amplitude of the electromyogram of the left masseter muscle increased in comparison with the results obtained before the treatment (304.20 ± 30.46 μV) while the amplitude of the right muscle remained unchanged (405.55 ± 27.36 μV).

THE ROLE OF FRONTAL TEETH IN RESTORING THE MASTICATORY FUNCTION

According to Agapov`s table the following percents are assigned to the anterior teeth: central incisors – 2, lateral incisors – 1, and eagles – 3. [2,3] Total portion of anterior teeth on both jaws makes 24%.

Grace to the data obtained from the control group we can conclude that during the execution of chewing movements muscles are capable to perform an instantaneous active inclusion into action and to the same rapid transition to a state of rest. From the obtained data it is obvious that muscles do not play the equal role in the act of mastication. There is a difference in functional asymmetry.

The data gained from the patients of the experimental group demonstrates the difference between of the left and right sides. Thus, the activity of the right masseter muscle is slightly higher than that of the left one (313.42 ± 97.96 ms. against 226.69 ± 35.39 ms.respectively). At the same time the resting time of the left and right masseter muscles slightly differs (300.57 ± 30.93 ms. and 307.96 ± 49.47 ms. respectively).

According to the analyzed data the percentage part of anterior teeth in masticatory function rehabilitation makes 24%.

CONCLUSIONS

During the study, it was found that the rehabilitation of patients with increased abrasion using combined methods (direct composite restorations with the adhesive system of Vth generation and indirect ceramic restorations), give the possibility to achieve certain results, namely: not only to restore the shape of lost teeth, but also to restore the masticatory function (evidenced by an increase in the activity of right and leftmasseter muscleon 2%, a decrease in the rest phase on 20% almost and an increase in amplitude on 2.9%).

Masticatory pressure spread evenly over the whole tooth arch. Electromyography data confirms that a local approach or incomplete/partial restoration of dentition can negatively affect the effectiveness of masticatory function efficacy. Particularly, in the case of exclusion of anterior teeth from the treatment plan, the potential effectiveness of restoration of masticatory function decreases on 24%.

REFERENCES

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4. Tkachenko IM, Shlikova OA, Kaidashev IP. Vyznachennya polimorfizmu heniv kalekreyinu-4 ta matryksnoyi metoloproteinazy-20 u patsiyentiv z pidvyshchenoyu stertistyu zubiv [Determination of the polymorphism of genes of calrein-4 and matrix metoproteinase-20 in patients with increased tooth erosion]. Problems of ecology and medicine. 2012; 16 (5): 65-8. (Ua)

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6. Shilenko D, Gasanov R, Toncheva E [et al.]. Byomekhanycheskyy analyz faktorov vlyyayushchykh na dolhovechnost’ restavratsyy zhevatel’noy hruppy zubov[Biomechanical analysis of factors influencing durability of restorations of chewing group of teeth]. World of Medicine and Biology. 2009; 2 (2): 72-7. (Ru).

7. Vodoriz YY., Marchenko IY.,Shyndryk MA. [et al.] Review of treatment methods of patients with uncomplicated teeth fractures. Wiadomości Lek. 2018; 71 (7): 1360-4. Available from: https://www.ncbi.nlm.nih.gov/pubmed/30448811

8. Vodorіz Y.Y. Fizychni vlastyvosti restavratsiynykh materialiv pry rizniy hlybyni preparuvannya tverdykh tkanyn zubiv [Physical properties of restorative materials at different depth of preparation of tooth hard tissues]. News of problems in biology and medicine. 2018; 4 (1). 186–188.

9. Mitin N, Vasilieva T, Grishin M. Sovremennye metody otsenky zhevatel’noy éffektyvnosty na étapakh ortopedycheskoho lechenyya (obzor lyteratury).[Modern methods of evaluation of chewing efficacy during stages of orthopedic treatment (literature review)]. Vesner new medical technology. 2015; 9 (4): 43. (Ru).

10. Scubiy I, Korol D., Kindy D. [et al.] Sposib funktsionalnoho vyznachennya zhuvalnoyi efektyvnosti u patsiyentiv molodoho viku (eksperymentalna model)[A method of functional determination of chewing efficacy in young patients (experimental model)]. Bulletin of Biology and Medicine. 2015; 2 (119): 217-21. (Ua).

This investigation is a fragment of the research of the Ukrainian stomatological academy “Morpho functional characteristics of oral cavity tissues and their impact on therapeutic measures and the choice of treatment materials. Registration number 01145U001112. No external funding was received during for this investigation. There is no conflict of interests between authors and other organizations.

Authors’ contributions:

According to the order of the Authorship.

Conflict of interest:

The Authors declare no conflict of interest.

CORRESPONDING AUTHOR

Yaroslav Y. Vodoriz 

17 Zalizna Street, 36001 Poltava, Ukraine

tel:+380505420497

e-mail:yaroslavvodorez@gmail.com 

Received: 05.02.2019

Accepted: 29.03.2019

Figure 1. Fragment of an electromyogram of the left masseter muscle of the patient from the control group, 23 years old.

Figure 2. Fragment of an electromyogram of the left person’s own masticatory muscle 47 years before treatment.

Table I. Electromyography results

Group

Masseter muscles

Investigated parameters (M±m)

activity (ms.)

rest (ms.)

“К index

amplitude (μV)

Control

left

148,06

±٤,٩٥

152,37

±٤,٧١

0,98

±٠,٠٣

207,58

±٣,٣٨

right

135,98

±٣,٥٩

155,02

±٦,٠٦

0,91

±٠,٠٦

288,41

±٢٢,٦٧

Experimental

(before treatment)

left

226,69

±٣٥,٣٩

300,57

±٣٠,٩٣

0,64

±٠,٠٦٣

284,67

±٣٤,٢١

right

313,42

±٩٧,٩٦

307,96

±٤٩,٤٧

0,74

±٠,٠٦٠

405,55

±٢٧,٣٦

Experimental

(6m. after treatment)

left

326,47

±٧,٦١

276,66

±٢٦,٢٣

0,75

±٠,٠٣٤

304,20

±٣٠,٤٦

right

225,11

±١٩,١٥

230,73

29,19

0,74

±٠,٠٦٠

405,55

±٢٧,٣٦

Figure 3. Fragment of the electromyogram of the right masseter muscle of the patient, 48 years old, 6 months after treatment.