Assessment of the dental status of drug-addicted patients with parafunction of the dental-jaw apparatus

The number of drug addicts in the world is growing every year. The aim of the study was to assess the dental status of drug-addicted patients with parafunction of the dental-jaw apparatus. We used clinical, analytical, functional and histological research methods. 119 drug-addicted and 110 non-drug-dependent patients aged 18 to 54 were examined. In order to confirm the presence of parafunctions of the dental-jaw apparatus in patients, we conducted an occludogram study, as well as an assessment of the index of parafunctions of the masticatory muscles and the degree of their severity. The structure of tooth tissues was examined by histological method. Examination of drug-addicted patients revealed the presence of numerous carious cavities, secondary adentia, enamel erosion, pathological abrasion, signs of gingivitis and periodontitis, tooth chipping. The prevalence of parafunction of the dental-jaw apparatus, in particular bruxism, in drug-addicted patients is 1.56 times higher than this figure among non-drug addicts. The results of the occludogram and the index of parafunctions of the masticatory muscles differ significantly between the study groups. The mean value of the masticatory muscle parafunction index among drug-addicted patients is 2.06 times significantly higher than the value among non-drug-addicted men and 2.03 times higher among women. Histological examination of the tooth tissues of drug-addicted patients indicates a disorder of the mineralization of both enamel and dentin. Thinning of the peripheral zone of the pulp, which is normally represented by a layer of odontoblasts, which provide regeneration and nutrition of dentin, is more common in persons under 25 years of age. Drug use adversely affects the dental status of patients and the condition of the hard tissues of the tooth.

На умовах ліцензії CC BY 4.0 parafunctions of the masticatory muscles and the degree of their severity. The structure of tooth tissues was examined by histological method. Examination of drug-addicted patients revealed the presence of numerous carious cavities, secondary adentia, enamel erosion, pathological abrasion, signs of gingivitis and periodontitis, tooth chipping. The prevalence of parafunction of the dental-jaw apparatus, in particular bruxism, in drug-addicted patients is 1.56 times higher than this figure among non-drug addicts. The results of the occludogram and the index of parafunctions of the masticatory muscles differ significantly between the study groups. The mean value of the masticatory muscle parafunction index among drug-addicted patients is 2.06 times significantly higher than the value among non-drugaddicted men and 2.03 times higher among women. Histological examination of the tooth tissues of drug-addicted patients indicates a disorder of the mineralization of both enamel and dentin. Thinning of the peripheral zone of the pulp, which is normally represented by a layer of odontoblasts, which provide regeneration and nutrition of dentin, is more common in persons under 25 years of age. Drug use adversely affects the dental status of patients and the condition of the hard tissues of the tooth.
The number of drug addicts in the world is growing every year [3,6]. Drugs adversely affect the human body, including the condition of the oral cavity and hard tissues of the teeth [2,5]. This in turn leads to the development of parafunctions of the dental-jaw apparatus, in particular to bruxism. The connection between the occurrence and nature of oral diseases with drug use today is not in doubt [4,6]. Correction of the method of treatment depending on the progression of pathology or specific changes that occur in the process of specialized treatment will ensure the implementation of the most complete and predictable treatment algorithm for patients of this profile. The literature describes the most characteristic disorders of the dental-jaw apparatus, which occur in the process of drug dependence on cocaine [8,11,12], cannabioids, opiates, hallucinogens, heroin and methadone, which plays an important role in the possibility of suspicion of drug addiction of patients during dental treatment [9,10].
The combination of permanent prosthetics with the use of orthodontic appliances, splints, spleens and deprogrammers will stabilize the existing changes in the dental status of drug-addicted patients with parafunctions, this will help to implement a comprehensive algorithm for rehabilitation of drug users. Taking into account the peculiarities of the manifestations of parafunctions in drug addicts and patients of drug treatment facilities play an important role in choosing an adequate method of treatment.
Thus, the purpose of the research is to assess the dental status of drug-addicted patients with parafunction of the dental-jaw apparatus.

MATERIALS AND METHODS OF RESEARCH
We used clinical, analytical, functional and histological research methods [1,7,14]. 119 patients of the communal non-profit enterprise "Transcarpathian Regional Medical Center for Mental Health and Addiction Medicine" of the Transcarpathian Regional Council in Uzhhorod were examined with their prior consent and with observance of data anonymity (main group). Patients, in the anamnesis of which there are no data on drug use (110 patients), with their consent were selected to the study group (comparison group). Age of patients was from 18 to 54 years. 21/ Том XXVI / 1 Clinical and instrumental examination of patients was performed according to the generally accepted algorithm of the World Health Organization. According to the Commission on Biomedical Ethics (Protocol N 5 of 10.03.2020), the experimental studies were carried out in compliance with the basic provisions of the GCP (1996), the Council of Europe Convention on Human Rights and Biomedicine (1997), the Helsinki Declaration of the World Medical Association on Ethical Principles conducting scientific and medical research with human participation  and Order N 66 of the Ministry of Health of Ukraine of February 13, 2006.
In order to confirm the presence of parafunctions of the dental-jaw apparatus in our patients, we conducted an occludogram study, as well as an assessment of the index of parafunctions of the masticatory muscles and the degree of their severity according to the methods described by Flejsher G. [7].
In order to assess the presence of occlusal contacts, occludograms were used, with their imaging on a wax plate. After conducting this study, it was found that 100% of subjects have supercontacts on the oclusal surfaces of premolar and molar of both jaws. To determine the occlusal contacts, a double-sided two-color articulation paper from Bausch with a thickness of 40 μm was used. Occlusal contacts were determined on both jaws [7]. With the mouth wide open, a piece of paper was placed on the lower jaw and the patient was asked to forcefully close the mouth several times until the teeth were in full contact. At the same time on one jaw occlusal contacts were represented in blue, on the oppositein red. Intraoral photography of the upper and lower jaws was performed. The percentage of occlusal contacts of the teeth was calculated using the «Stepanizer» and «ImageJ» programs.
Mathematical analysis of data and verification of the results, in particular the calculation of arithmetic mean and standard errors were performed on the basis of software "Statistica 6.0" and "Microsoft Excel 2010". Statistical analysis of the results was performed using standard statistical programs "Statistica 6.0" and "SPSS 14" (Stat Soft Inc.). Statistical data processing was performed by methods of variation statistics with the calculation of arithmetic mean values (M), standard deviation (t), standard error of the mean (m). As well as the share of the studied feature in the general population (P), standard deviation (t), standard error of the mean (m). Student's t-test for independents was used variables. The critical level of statistical significance of the null hypothesis was taken at p<0.05 [1].
The study compared the clinical status with the data of histological examination of the hard tissues of the teeth.
According to the indications, in some patients 14 teeth were extracted (10 in drug addicts and 4 in non-drug addicts). Vital teeth (5 premolar and 9 molar) were extracted due to periodontal disease and grade 3 mobility. Subsequent fixation was performed in 10% formalin solution, and decalcification -in trichloroacetic acid solution. The sections were performed using a diamond burr up to 20 μm thick, after which the study of hard tissue changes was performed in direct and reflected light. The sections were stained with hematoxylin and eosin according to conventional methods [14].

RESULTS AND DISCUSSION
Among 119 examined patients with anamnestic data on drug use, 98 people (main group) showed signs of parafunction of the dental-jaw apparatus, such as pathological abrasion of the teeth, which makes up 82.35% of all examined. Among the 110 examined non-drug-dependent patients, signs of parafunction of the dental-jaw apparatus were found in 58 patients (comparison group), which is 52.73%. Thus, the prevalence of bruxism in drug-addicted patients is 1.56 times higher than in the comparison group.
The highest number of drug addicts with bruxism was observed among patients with a history of use of various drugs. This group comprises 38.78% (38 people). Patients who used or use morphine derivatives make up 25.51% (25 people) and amphetamine or cocaine -22.45% (22 people). The smallest number -patients with anamnestic data on use of cannabis, LAD (Lysergic acid diethylamide) or marijuana and their proportion is 13.26% (13 people).
The distribution of patients with bruxism by gender and age was also carried out. Men significantly predominate in the main group (83 people) and make up by 69.4% more than the number of women (15 people). However, this is due to the predominance of men among drug addicts in general. In the comparison group, the number of women (30 people) exceeds the number of men (28 people) by 3.4%. In the main group, both in men and women, the largest number of patients with bruxism is observed at the age of 25-34 years, that is 42.2% (35 men) and 40.0% (6 women), respectively. In the comparison group, both in men and women, the largest number of patients with bruxism is observed at the age of 35-44 years, that hich is 42.9% (12 men) and 36.7% (11 women), respectively. These results indicate that drugs affect the structure of tooth tissues, as "rejuvenation" of this pathological process occurs.

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Examination of drug-addicted patients revealed the presence of numerous carious cavities, secondary adentia, enamel erosion, pathological abrasion, signs of gingivitis and periodontitis, tooth chipping.
We conducted an occludogram study, according to which all patients in the main and the comparison group had values less than 100%. This is regarded as an uneven distribution on the elements of the masticatory apparatus, the presence of supracontacts (Table 1). Occludogram indices are worse in women than in men in both groups. In main group the value of 50-60% dominates, which is 46.99% among men and 46.67% among women. This is 1.64 and 1.56 times higher than this index in non-drug-addicted patients. The value of the occludogram of 60-70% is observed in 34.94% of men and 40.0% women. 70-80% occur in 15.66% of drug-addicted male patients and 13.33% of women.
In the comparison group value of 60-70%, dominates which is 39.29% among men and 46.67% among women. The value of the occludogram of 50-60% is observed in 28.57% of men and 30.0% of women. 70-80% occur in 21.43% of men-drug addicts and in 6.66% of women.
Thus, the results of the occludogram differ significantly between the study groups, which confirms the negative impact of drugs on the dental status of patients.
The mean value of the masticatory muscle parafunction index for drug-addicted men is 12.03±0.64, and for women is 12.58±0.71 (Table 2). Both in males and females severe masticatory muscle parafunctions dominate, accounting for 48.19% of surveyed males drug addicts and 53.34% of females. In second place in terms of the share of parafunction of the masticatory muscles of the middle degree, the share of which is 40.97% and 33.33%, respectively. The smallest proportion falls on parafunctions of masticatory muscles of mild degree, namely 10.84 and 13.33%. The parafunction index of masticatory muscles is slightly worse in women. There was no significant difference by sex between the indices of masticatory muscles parafunction in patients of the main group (p˃0.05). The mean value of the masticatory muscle parafunction index for non-drugdependent men is 5.83±0.23, and for women is 6.17±0.41, which is significantly (p <0.05) different from the value in the main group. Histological examination of tooth tissues of drugaddicted patients showed thinning of the enamel, Hunter-Schreger bands are less pronounced, the wrong radial direction, lines of Retzius are not traced everywhere. Enamel contains low-mineralized areas, namely enamel spindles, plates and bundles. Enamel spindles are areas of enamel where the processes of odontoblasts penetrate, forming a thickening. Enamel bundles are located on the border of the transition of enamel to dentin, enamel plates penetrate the entire thickness of the enamel. All of them indicate a disorder of mineralization and are a substrate for the occurrence of carious changes in the tooth. Areas of disturbed mineralization are also observed at the boundary of dentin and cementum (Fig. 1, 2). In some areas dentin is exposed, this creates the conditions for various chemicals to enter the dentinal tubule. Dentine tubules are clearly visible but there are areas with loss of direction. 21/ Том XXVI / 1 T a b l e 2 There are single areas of dead pathways and sclerosed dentin, which are formed as a result of odontoblast death and remain empty (dead pathways) or filled with a matrix (sclerosed dentin) (Fig. 3, 4). The existing spaces of the interglobular dentin of the crown and the granular layer of Thoms, which located on the border of the mantle and peripulpar dentin and are little or non-mineralized areas and are regarded as a substrate for caries. The contour lines of Owen in dentin were noted in persons under 25 years of age, which indicate periods of impaired mineralization of this tissue. Also in this age group of patients thinning of the peripheral zone of the pulp is more often found, which is normally represented by a layer of odontoblasts, the processes of which are located in the dentinal tubules. These cells are responsible for the regeneration and nutrition of dentin. No changes were detected in the cement. In the periodontium, the perforating fibers (Sharpey's fibers) are thinned, which may explain the increased mobility of some teeth in the examined drug-addicted patients.

Index of parafunctions of masticatory muscles of patients of the main group (M±m)
Among the surveyed drug addicts Bojchenko O.M. et al. most often observed periodontal disease, unsatisfactory state of oral hygiene, and rapid progression of pathological changes in the periodontium in persons who regularly took narcotics. The predominance of ulcerative-necrotic changes in people who used hypnotics was revealed. The dental status of these patients requires an individual approach to oral hygiene, treatment of pathological processes and their prevention. Treatment tactics should be differentiated, tailored to the specific patient and the characteristics of the drug that provoked this process, taking into account the duration of use, the presence or absence of concomitant pathology [2]. Klima M. et al. noted the importance of the study of hard dental tissues for postmortem toxicological examination of persons suspected of drug addiction [13]. In the study of endodontically treated teeth, the concentration of narcotic substances was higher in the crown than in the root of the tooth, which is apparently due to the absence of the vascular network as the system of drug transport in the structure of such elements. Bahdila D. et al. confirmed the connection between periodontal disease and dental caries with cocaine use [11]. The chances of periodontitis were highest among cocaine users who used ≥3 of other substances. In addition, cigarette smoking increased the likelihood of severe periodontitis and dental caries among cocaine users, whereas those who used both cocaine and methamphetamine showed only an increase in the amount of tooth decay. As a result of the examination of drug addicts, Evstratenko V.V. et al. concluded that in patients taking heroin and methadone a deterioration in dental status is noted [5]. The main manifestations of drugs are the development of carious process, inflammatory diseases of the oral cavity, salivation disorders, the formation and spread of chronic odontogenic infection. The negative effect of methadone is more pronounced in comparison with heroin due to the contact of the tablet form of the drug with the oral mucosa.
Control over changes in the structure of the dental-jaw apparatus will allow timely correction of orthopedic prosthetics in the context of systemic therapy of drug addicts in order to improve their quality of life and achieve the most effective and predictable indicators of rehabilitation.

CONCLUSIONS
1. Drug use negatively affects the dental status of patients. The prevalence of parafunction of the dental-jaw apparatus, in particular bruxism, in drugaddicted patients is 1.56 times higher than this figure among non-drug addicts.
2. The results of the occludogram and the index of parafunctions of the masticatory muscles differ significantly between the study groups. The mean value of the masticatory muscle parafunction index among drug-addicted patients is 2.06 times significantly higher than the value among non-drugaddicted men and 2.03 times higher among women.
3. Histological examination of the tooth tissues of drug-addicted patients indicates a disorder of the mineralization of both enamel and dentin, revealed thinning of the enamel. Thinning of the peripheral zone of the pulp, which is normally represented by a layer of odontoblasts, which provide regeneration and nutrition of dentin, is more common in persons under 25 years of age.
Conflict of interest. The authors declare no conflict of interest.
Prospects for further research are to establish the relationship between changes in the dentalmaxillary apparatus caused by drug use and the parameters of the active substance and the duration of dependence.