
==== Front
BMC Oral Health
BMC Oral Health
BMC Oral Health
1472-6831
BioMed Central London

39252017
4812
10.1186/s12903-024-04812-7
Research
Oral and dental health status in patients with chronic headache
http://orcid.org/0000-0002-4136-958X
Samami Mohammad 1
http://orcid.org/0000-0003-1913-559X
Najar-Karimi Fereshteh 2
http://orcid.org/0000-0002-6134-3440
Eghbali Babak Bakhshayesh 3
http://orcid.org/0009-0009-8384-8616
Sanati Aghil Hosseinpour 4
http://orcid.org/0000-0001-6980-8866
Rad Afagh Hassanzadeh afaghrad@gums.ac.ir

5
1 https://ror.org/04ptbrd12 grid.411874.f 0000 0004 0571 1549 Department of Oral and Maxillofacial Medicine, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran
2 https://ror.org/03hh69c20 0000 0004 4651 6731 Department of Oral and Maxillofacial Medicine, School of Dentistry, Alborz University of Medical Sciences, Karaj, Iran
3 https://ror.org/04ptbrd12 grid.411874.f 0000 0004 0571 1549 Department of Neurology, School of Medicine, Neuroscience Research Center, Poursina Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
4 General Dentist, Rasht, Iran
5 https://ror.org/04ptbrd12 grid.411874.f 0000 0004 0571 1549 Pediatric Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran
9 9 2024
9 9 2024
2024
24 105713 6 2024
26 8 2024
© The Author(s) 2024
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Introduction

Headache is an illness with high prevalence and adverse effects on quality of life. As oral or dental problems such as pain can trigger or aggravate it, we aimed to investigate and compare oral and dental health status in patients affected with chronic headaches and healthy individuals.

Methods

The present case-control study included 60 patients with chronic headaches (case) and 60 healthy individuals (control) in Rasht, Iran. The demographic characteristics and clinical examinations, including decayed/missing/filled teeth (DMF-T) and community periodontal index of treatment needs (CPITN) indices, as well as bruxism, frequency of tooth brushing and flossing, and maxillary and mandibular tooth wear were recorded in a checklist. Data analysis was performed using the IBM SPSS version 28 at a significance level of 0.05.

Results

The case group consisted of 25 men (41.7%) and 35 women (58.3%) with an average age of 32.55 ± 6.62 years, while the control group had 27 men (45%) and 33 women (55%) with an average age of 30.95 ± 6.33 years. The study groups were not significantly different in bruxism, frequency of tooth brushing and flossing, DMFT, CPTIN, and maxillary and mandibular tooth wear.

Conclusion

It seems that chronic headaches do not significantly affect the oral and dental health of the sufferers. Moreover, it appears that these patients are well aware of the role of oral and dental hygiene in triggering or aggravating the episodes of headaches.

Keywords

Oral Hygiene
Chronic headache
Toothache
issue-copyright-statement© BioMed Central Ltd., part of Springer Nature 2024
==== Body
pmcIntroduction

Headache is a common complaint of patients throughout the world. About 47% of headaches can be severe and even deliberating, leading to sleep disorders, disturbed daily activities, work problems, and mood changes, thereby causing considerable mental, economic, and social impacts in society [1]. Notably one of the largest cranial nerves, the trigeminal nerve, is the cause of almost all cases of headache and toothache [2]. Therefore, most toothaches can play a direct role in developing or exacerbating headaches of all types [3]. It has been reported that toothaches due to tooth decay, periodontal diseases, and temporomandibular disorders (TMD) may trigger migraine and other headaches [4–6]. Conversely, other disorders that occur in patients suffering from chronic headaches, such as anxiety and depression, can affect dental health, thereby triggering or exacerbating chronic headaches [7].

Oral and dental health can be influenced by several factors [8] and simultaneously can severely affect individuals in various ways, such as chewing ability and diet, which are influenced by the number of lost teeth, time of tooth loss, etc. [9]. Dental caries and periodontal diseases are important oral diseases with alarming global prevalence, especially in developing countries. Thus, decayed/missing/filled teeth (DMF-T) and community periodontal index of treatment needs (CPITN) are the most important indices for evaluating oral and dental health [9, 10].

Although the relationship between oral diseases and various systemic diseases, including diabetes, cardiovascular diseases, and hypertension has been assessed [11] and there have been limited comprehensive studies evaluating various oral health indices in patients with headaches of different types [4, 5, 9], the present study aimed to conduct an evaluation and comparison of oral and dental health status in healthy individuals and patients with chronic headaches. We hypothesized that maintaining a good oral and dental health status is crucial for patients with chronic headaches, as poor oral health can exacerbate headache symptoms through increased inflammation and potential infection. Regular dental care and good oral hygiene practices can help mitigate these risks, providing relief and improving overall quality of life. Additionally, addressing oral health issues may uncover underlying problems contributing to chronic headaches, facilitating more comprehensive treatment.

Methods

Patients and settings

The present case-control study was performed from Jan 2023 to Jan 2024 and included 120 participants in the case and control groups who were selected using the convenience sampling method. The case group included 60 patients referred to the Imam Reza clinic, Poursina Hospital, Rasht, Iran, with chronic headaches ( at least 15 days per month in the past three months [12]. Moreover, the control group included 60 patients referred to the specialized dental clinic of the Guilan University of Medical Sciences, International Branch, Anzali, Iran, who had no chronic headaches. The exclusion criteria were age younger than 12 (since younger children were not reliable for maintaining proper oral and dental health), those who developed chronic headaches following head trauma, pregnant women, smokers, alcohol users, and those who had any systemic or underlying disease [9, 13]. Groups were matched regarding age and sex. Considering a statistical power of 95%, α = 0.05, d = 2.5, and a Standard Deviation (SD) of 5.29 for the case group and 0 for the control group, the sample size was calculated as 58.16 for each group, which was considered 59.

Procedure

The patients with chronic headaches were examined by a single neurologist and their diagnosis was confirmed due to history taking, physical examination, laboratory workup, and magnetic resonance imaging. Afterward, they were referred to the dental clinic for dental examinations. Moreover, the 60 participants in the control group were selected from the patients presenting to the dental clinic. All participants were explained about the study’s goals and methodology and gave written informed consent for participation. Then, they underwent dental examinations by a single dental intern supervised by an oral and maxillofacial surgeon. Also, all participants were interviewed, and a checklist was filled out for each participant that included demographic characteristics (age, gender, and educational level) and items regarding dental hygiene, such as frequency of tooth brushing and flossing per day.

To describe the oral and dental condition, the DMF-T, Tooth Wear Index (TWI), and CPITN indices, which are approved by the World Health Organization (WHO), were used [14]. The DMF-T index was used for evaluating the dental condition. In this index, D represents the number of decayed teeth that need filling, M represents the number of missing teeth extracted due to severe decay, and F represents the number of filled teeth with permanent restorations. The final value of the DMF-T index was obtained by summing the three items and ranged from 0 to 32 (the third molar teeth were counted as well). Moreover, the impacted teeth, congenitally missed teeth, extra teeth, teeth extracted due to reasons other than decay, and remaining milk teeth are not counted in this index [15].

The severity of wear in natural teeth was evaluated using the TWI, and each jaw was scored 1–3 as follows:

1: No evidence of wear,

2: Superficial wear of several teeth at the enamel,

3: Severe wear with enamel destruction and visible dentin [16].

The CPITN index was used to evaluate the periodontal condition and treatment needs, such as the instructions on hygiene, brossage, dental scaling, and root planing. The first and second maxillary and mandibular molars and right central maxillary and mandibular incisors were probed at 6 mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual points with proper force (0.75 N equivalent to about 20–25 g) using a Williams periodontal probe and a disposable dental mirror. Moreover, the mesial tooth was examined in case of a missed index tooth. The probe was inserted into the gingival groove parallel to the longitudinal dental axis and walked around the tooth [17]. Then, the scoring was performed as follows:

Score 0: Healthy gums on probing,

Score 1: Bleeding on probing.

Score 2: Supragingival or subgingival plaque on probing,

Score 3: Presence of shallow pockets (4–5 mm),

Score 4: Presence of deep pockets (6 mm).

The highest number for each tooth was recorded in the checklist, and the mean score was considered the final CPITN score. All examinations were performed in the same way in the case and control groups.

Ethical considerations

The present study was approved by the Ethics Committee of the Vice-Chancellor of Research, Guilan University of Medical Sciences with the ethics code of IR.GUMS.REC.1401.437.

Statistical analysis

Data analysis was performed using IBM SPSS Statistics (Version 28). The qualitative data were described using the frequency and percentage (%), while the quantitative data were described using the mean and standard deviation (SD). Moreover, the normal distribution of the data was investigated using the Kolmogorov-Smirnov test, while Levene’s test was used to investigate the homogeneity of variances. In the case of the proved assumptions, the independent t-test and chi-square test were used for data comparisons. Otherwise, the Mann-Whitney test and Fisher’s exact test were used. Also, the logistic regression analysis was used for the simultaneous investigation of independent variables and adjusting the effect of confounding variables. The significance level was set at 0.05.

Results

The present study included a total of 120 participants, 60 patients in the case group and 60 individuals in the control group. The case group included 25 (41.7%) men and 35 (58.3%) women with the mean age of 32.55 ± 6.62 years, while the control group included 27 (45%) men and 33 (55%) women with the mean age of 30.95 ± 6.33 years. According to our findings, the case and control groups were not significantly different in age (p = 0.252), sex (p = 0.714), or educational level (p = 0.985) (Table 1).

Table 1 Intergroup comparison in terms of gender, age, and educational level

Variable	Case Group	Control Group	P-value*	
sex†

Number (%)

	Women	35 (58.3%)	33 (55%)	0.714††	
Men	25 (41.7%)	27 (45%)	
Educational Level†

Number (%)

	Illiterate	3 (5%)	3 (5%)	0.985††	
Without High School Diploma	11 (18.3%)	6 (10%)	
High School Diploma	18 (30%)	19 (31.7%)	
Academic Education	28 (46.7%)	32 (53.3%)	
Age‡ (year) mean ± SD	32.55 ± 6.62	30.95 ± 6.63	0.252‡‡	
† Data presented as frequency (%). ‡ Data presented as mean ± SD. ††P-value was calculated using the Chi-square test. ‡‡P-value was calculated using the Mann-Whitney test. * Significant difference (P < 0.05)

Table 2 shows no significant difference in the frequency of tooth brushing (p = 0.660) and flossing (p = 0.925), bruxism (p = 0.579), DMF-T (p = 0.085), CPITN scores (p = 0.849), and maxillary (p = 0.375) and mandibular tooth wears (p = 0.204).

Table 2 Intergroup comparison in terms of frequency of tooth brushing and flossing, bruxism, DMF-T and CPITN scores, and maxillary and mandibular tooth wears

Variable	Case Group	Control Group	P-value	
Frequency of Brushing†

Number (%)

	0	6 (10%)	14 (23.3%)	0.660††	
1	22 (36.7%)	14 (23.3%)	
2	20 (33.3%)	19 (31.7%)	
3	12 (20%)	13 (21.7%)	
Frequency of Flossing†

Number (%)

	0	8 (13.3%)	12 (20%)	0.925††	
1	20 (33.3%)	22 (36.7%)	
2	18 (30%)	15 (25%)	
3	14 (23.3%)	11 (18.3%)	
Bruxism†

Number (%)

	Absent	37 (61.7%)	23 (38.3%)	0.579††	
Present	34 (56.7%)	26 (43.3%)	
Maxillary Tooth Wear†

Number (%)

	Without Wear	16 (28.3%)	15 (25%)	0.375††	
Superficial Wear at the Enamel	18 (30%)	29 (48.3%)	
Severe Wear	25 (41.6%)	16 (26.7%)	
Mandibular Tooth Wear†

Number (%)

	Without Wear	17 (28.35%)	23 (38.3%)	0.204††	
Superficial Wear at the Enamel	23 (38.3%)	22 (36.7%)	
Severe Wear	20 (33.3%)	15 (25%)	
DMFT‡ mean ± SD	13.61 ± 6.54	11.76 ± 6.21	0.085‡‡	
CPITN‡ mean ± SD	1.16 ± 1.15	1.60 ± 1.18	0.849‡‡	
† Data presented as frequency (%). ‡ Data presented as mean ± SD. ††P-value was calculated using the Chi-square test. ‡‡P-value was calculated using the Mann-Whitney test. * Significant difference (P < 0.05)

Discussion

Poor oral hygiene and dental issues can exacerbate or even contribute to the persistence of diseases through mechanisms such as inflammation and infection. However, this study showed no significant difference in educational level, bruxism, frequency of tooth brushing and flossing, DMFT, CPTIN, and maxillary and mandibular tooth wear.

The present study reported a higher frequency of tooth brushing and flossing in the case group than in the control group. However, the difference was not significant, which was compatible with the study by Cempeskersoy et al. [18]. Moreover, the study by Maanifar et al. reported a significant intergroup difference in the frequency of flossing, while no significant difference was reported in the frequency of tooth brushing [19].

The present study reported no significant difference in bruxism between the case and control groups, which was compatible with the study by Porporatti et al. [20] and incompatible with the study by Das et al. [21]. Bruxism results from the hyperactivity of masticatory muscles and is characterized by grinding or clenching the teeth [22]. A study by Réus reported that awake bruxism is more associated with headaches compared to sleep bruxism. Moreover, sleep bruxism has no significant relationship with tension headaches, while its relationship with migraine was controversial [23]. On the other hand, a case report has revealed that the headache triggered by sleep bruxism is mostly a tension headache that occurs in the morning or during the day. Moreover, it is often episodic rather than chronic [21]. However, little evidence supports such a relationship [22]. A study by Wagner et al. reported a significant relationship between headaches and TMD disorders or anxiety. However, the relationship between headache and bruxism was not significant [6]. Thus, it seems that chronic headaches have a relationship with neuromuscular pressure caused by TMD or occlusion disorders aggravated by daily life stress. Furthermore, bruxism, especially awake bruxism, can develop as an associated symptom [22] and does not seem to be an independent variable in the development of headaches. However, there is a need for further studies on such a topic.

According to our findings, the study groups were not significantly different in DMF-T and CPTIN indices, which was compatible with the studies by Maanifar et al. and Torabi et al. [19, 24]. The mean DMF-T of patients with headaches in the study by Maanifar et al. (13.3 ± 5.29) was similar to our study (13.61 ± 6.54), while it was lower in the study by Torabi et al. (10.88 ± 6.47) [19, 24]. This consistency in DMF-T indices suggests a common pattern or baseline of oral health in patients with chronic headaches across different studies. However, a previous study reported a significantly higher DMF-T index in patients with migraine (13.95 ± 5.05) compared to the control group (4.08 ± 2.53), although the Simplified Oral Hygiene Index (OHI-S) was not different between the groups [25]. This could be attributed to variations in study populations, diagnostic criteria for headaches, or other underlying health conditions influencing oral health differently in migraine patients. This discrepancy highlights the need for further research to understand the factors contributing to these differences in oral health status among headache patients.

Considering the above results, it seems oral and dental health status is not affected by chronic headaches in these patients. In addition to maintaining oral hygiene by tooth brushing or flossing, the DMFT index and oral and dental condition depend on visits to the dentist for preventing or treating dental caries. Thus, the cultural aspects can also explain the controversy in the results of different studies. Moreover, Maanifar et al. reported more visits to the dentist in patients with chronic headaches compared to the control group [19]. It seems that more visits to the dentist and even better oral hygiene are an effort to reduce the frequency of headache episodes in patients with chronic headaches.

Besides, the present study did not show a significant difference in the TWI of maxillary and mandibular teeth between the study groups, which was compatible with the study by Maanifar et al. [19]. It is hypothesized that more visits to the dentist by the patients with chronic headaches may help in early diagnosis of TMD disorders and related predisposing factors, such as premature contacts. Subsequently, tooth wear is decreased in these patients due to the elimination of predisposing factors. Also, the role of nutritional habits and increased age on tooth wear cannot be ignored [26]. Therefore, differences in diet and age of the participants can also explain the controversial findings of different studies.

Strengths and limitations

This matched case-control study effectively utilized standardized indices (DMF-T, TWI, CPITN) for dental and periodontal assessments, conducted by a single assessor to ensure consistency. However, several limitations should be acknowledged. The use of convenience sampling may limit the generalizability of the findings, and potential unmeasured confounding variables could influence the results. Additionally, as a single-center study, the applicability of the findings to other regions with different socio-economic and cultural backgrounds is limited. Therefore, further multicenter studies that account for potential confounding variables are recommended to validate and expand upon these findings.

Conclusion

According to our results, chronic headaches do not significantly affect the oral and dental health status of the sufferers. Moreover, it appears that these patients are well aware of the role of oral and dental hygiene in triggering or aggravating the episodes of headaches. Further studies, particularly multicenter studies accounting for potential confounding variables, are necessary to validate these conclusions and explore underlying mechanisms in greater detail.

Acknowledgements

We acknowledge all participants and colleagues for their warm cooperation.

Author contributions

M S and F NK contributed to the study conception and design. Material preparation, data collection, and analysis were performed by all authors. The first draft of the manuscript was written by M S and A HR, and all authors critically revised the manuscript. All authors read and approved the final manuscript.

Funding

There was no funding or financial support in this study.

Data availability

All data generated or analyzed during this study are included in this published article.

Declarations

Ethics approval and consent to participate

A written informed consent letter was obtained from the participants. All experiments were performed in accordance with relevant guidelines and regulations of the Declaration of Helsinki. This study was approved by the Ethics Committee at Guilan University of Medical Sciences (Code: IR.GUMS.REC.1401.304).’’.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
==== Refs
References

1. Byun S-H Min C Yoo D-M Yang B-E Choi H-G Increased risk of migraine in patients with temporomandibular disorder: a longitudinal follow-up study using a national health screening cohort Diagnostics 2020 10 9 724 10.3390/diagnostics10090724 32962244
Byun S-H, Min C, Yoo D-M, Yang B-E, Choi H-G. Increased risk of migraine in patients with temporomandibular disorder: a longitudinal follow-up study using a national health screening cohort. Diagnostics. 2020;10(9):724.32962244 10.3390/diagnostics10090724
2. Edvinsson J Viganò A Alekseeva A Alieva E Arruda R De Luca C The fifth cranial nerve in headaches J Headache Pain 2020 21 1 17 10.1186/s10194-020-01134-1 31898478
Edvinsson J, Viganò A, Alekseeva A, Alieva E, Arruda R, De Luca C, et al. The fifth cranial nerve in headaches. J Headache Pain. 2020;21:1–17.31898478 10.1186/s10194-020-01134-1
3. Yakkaphan P Elias L-A Ravindranath PT Renton T Is painful temporomandibular disorder a real headache for many patients? Br Dent J 2024 236 6 475 82 10.1038/s41415-024-7178-1 38519684
Yakkaphan P, Elias L-A, Ravindranath PT, Renton T. Is painful temporomandibular disorder a real headache for many patients? Br Dent J. 2024;236(6):475–82.38519684 10.1038/s41415-024-7178-1
4. Chen YJ Hu KF Chan C Huang C Huang YH Wang YF Association of periodontal disease with migraine: a large-scale community‐based cross‐sectional study Headache: J Head Face Pain 2023 63 4 539 48 10.1111/head.14491
Chen YJ, Hu KF, Chan C, Huang C, Huang YH, Wang YF, et al. Association of periodontal disease with migraine: a large-scale community‐based cross‐sectional study. Headache: J Head Face Pain. 2023;63(4):539–48.10.1111/head.14491
5. Reyes AJ Ramcharan K Maharaj R Chronic migraine headache and multiple dental pathologies causing cranial pain for 35 years: the neurodental nexus BMJ Case Rep CP 2019 12 9 e230248 10.1136/bcr-2019-230248
Reyes AJ, Ramcharan K, Maharaj R. Chronic migraine headache and multiple dental pathologies causing cranial pain for 35 years: the neurodental nexus. BMJ Case Rep CP. 2019;12(9):e230248.10.1136/bcr-2019-230248
6. Wagner BA Moreira Filho PF Painful temporomandibular disorder, sleep bruxism, anxiety symptoms and subjective sleep quality among military firefighters with frequent episodic tension-type headache. A controlled study Arq Neuropsiquiatr 2018 76 387 92 10.1590/0004-282x20180043 29972421
Wagner BA, Moreira Filho PF. Painful temporomandibular disorder, sleep bruxism, anxiety symptoms and subjective sleep quality among military firefighters with frequent episodic tension-type headache. A controlled study. Arq Neuropsiquiatr. 2018;76:387–92.29972421 10.1590/0004-282x20180043
7. Minervini G Franco R Marrapodi MM Mehta V Fiorillo L Badnjević A The association between COVID-19 related anxiety, stress, depression, temporomandibular disorders, and headaches from childhood to adulthood: a systematic review Brain Sci 2023 13 3 481 10.3390/brainsci13030481 36979291
Minervini G, Franco R, Marrapodi MM, Mehta V, Fiorillo L, Badnjević A, et al. The association between COVID-19 related anxiety, stress, depression, temporomandibular disorders, and headaches from childhood to adulthood: a systematic review. Brain Sci. 2023;13(3):481.36979291 10.3390/brainsci13030481
8. Corridore D Saccucci M Zumbo G Fontana E Lamazza L Stamegna C Impact of stress on periodontal health: literature revision 2023 Healthcare MDPI
Corridore D, Saccucci M, Zumbo G, Fontana E, Lamazza L, Stamegna C, et al. editors. Impact of stress on periodontal health: literature revision. Healthcare: MDPI; 2023.
9. Sampson V Oral hygiene risk factor Br Dent J 2020 228 8 569 10.1038/s41415-020-1545-3 32332938
Sampson V. Oral hygiene risk factor. Br Dent J. 2020;228(8):569.32332938 10.1038/s41415-020-1545-3
10. Omara H Elamin A Oral health status and related risk factors among adolescents attending high schools in Khartoum, Sudan: a cross-sectional study Clin Epidemiol Global Health 2022 16 101080 10.1016/j.cegh.2022.101080
Omara H, Elamin A. Oral health status and related risk factors among adolescents attending high schools in Khartoum, Sudan: a cross-sectional study. Clin Epidemiol Global Health. 2022;16:101080.10.1016/j.cegh.2022.101080
11. Kapila YL Oral health’s inextricable connection to systemic health: special populations bring to bear multimodal relationships and factors connecting periodontal disease to systemic diseases and conditions Periodontol 2000 2021 87 1 11 6 10.1111/prd.12398 34463994
Kapila YL. Oral health’s inextricable connection to systemic health: special populations bring to bear multimodal relationships and factors connecting periodontal disease to systemic diseases and conditions. Periodontol 2000. 2021;87(1):11–6.34463994 10.1111/prd.12398
12. Murphy C Hameed S Chronic headaches 2023 StatPearls [Internet] StatPearls Publishing
Murphy C, Hameed S. Chronic headaches. StatPearls [Internet]: StatPearls Publishing; 2023.
13. Murphy C Hameed S Chronic headaches 2022 StatPearls [Internet] StatPearls Publishing
Murphy C, Hameed S. Chronic headaches. StatPearls [Internet]: StatPearls Publishing; 2022.
14. Jürgensen N Petersen P Promoting oral health of children through schools–results from a WHO global survey 2012 Community Dent Health 2013 30 4 204 18 24575523
Jürgensen N, Petersen P. Promoting oral health of children through schools–results from a WHO global survey 2012. Community Dent Health. 2013;30(4):204–18.24575523
15. Davari A, Daneshkazemi A, Abbasi S, Ziaei F. Relationship of decayed, missing, filled, Teeth and related indexes of glomerular filtration rate in various stages of chronic kidney disease in adults residing in Shahedieh City, Yazd Province. J Isfahan Dent School. 2022.
16. Tröltzsch M Cronin R Brodine A Frankenberger R Messlinger K Prevalence and association of headaches, temporomandibular joint disorders, and occlusal interferences J Prosthet Dent 2011 105 6 410 7 10.1016/S0022-3913(11)60084-X 21640243
Tröltzsch M, Cronin R, Brodine A, Frankenberger R, Messlinger K. Prevalence and association of headaches, temporomandibular joint disorders, and occlusal interferences. J Prosthet Dent. 2011;105(6):410–7.21640243 10.1016/S0022-3913(11)60084-X
17. Moeintaghavi A Akbari A Rezaeetalab F Association between periodontitis and periodontal indices in newly diagnosed bronchial asthma J Adv Periodontology Implant Dentistry 2022 14 2 97 10.34172/japid.2022.010
Moeintaghavi A, Akbari A, Rezaeetalab F. Association between periodontitis and periodontal indices in newly diagnosed bronchial asthma. J Adv Periodontology Implant Dentistry. 2022;14(2):97.10.34172/japid.2022.010
18. Peşkersoy C Peker Ş Kaya A Ünalp A Gökay N Evaluation of the relationship between migraine disorder andoral comorbidities: multicenter randomized clinical trial Turk J Med Sci 2016 46 3 712 8 10.3906/sag-1412-71 27513246
Peşkersoy C, Peker Ş, Kaya A, Ünalp A, Gökay N. Evaluation of the relationship between migraine disorder andoral comorbidities: multicenter randomized clinical trial. Turk J Med Sci. 2016;46(3):712–8.27513246 10.3906/sag-1412-71
19. Manifar S, Najafi S, Koopaie M, Tafakhori A, Farmanbordar D. Assessment of oral health status in chronic headache patients and its comparison with healthy control. J Craniomaxillofacial Res. 2021:22–8.
20. Porporatti AL Costa YM Conti PCR Bonjardim LR Calderon PS Primary headaches interfere with the efficacy of temporomandibular disorders management J Appl Oral Sci 2014 23 129 34 10.1590/1678-775720130557 25004051
Porporatti AL, Costa YM, Conti PCR, Bonjardim LR, Calderon PS. Primary headaches interfere with the efficacy of temporomandibular disorders management. J Appl Oral Sci. 2014;23:129–34.25004051 10.1590/1678-775720130557
21. Das S Gupta R Dhyani M Goel D Headache secondary to sleep-related bruxism: a case with polysomnographic findings J Neurosciences Rural Pract 2015 6 02 248 51 10.4103/0976-3147.150293
Das S, Gupta R, Dhyani M, Goel D. Headache secondary to sleep-related bruxism: a case with polysomnographic findings. J Neurosciences Rural Pract. 2015;6(02):248–51.10.4103/0976-3147.150293
22. Martynowicz H Smardz J Michalek-Zrabkowska M Gac P Poreba R Wojakowska A Evaluation of relationship between sleep bruxism and headache impact Test-6 (HIT-6) scores: a polysomnographic study Front Neurol 2019 10 487 10.3389/fneur.2019.00487 31139138
Martynowicz H, Smardz J, Michalek-Zrabkowska M, Gac P, Poreba R, Wojakowska A, et al. Evaluation of relationship between sleep bruxism and headache impact Test-6 (HIT-6) scores: a polysomnographic study. Front Neurol. 2019;10:487.31139138 10.3389/fneur.2019.00487
23. Reus JC Polmann H Mendes Souza BD Flores-Mir C Trevisol Bittencourt PC Winocur E Association between primary headache and bruxism: an updated systematic review J Oral Facial Pain Headache 2021 35 2 129 38 10.11607/ofph.2745 34129658
Reus JC, Polmann H, Mendes Souza BD, Flores-Mir C, Trevisol Bittencourt PC, Winocur E, et al. Association between primary headache and bruxism: an updated systematic review. J Oral Facial Pain Headache. 2021;35(2):129–38.34129658 10.11607/ofph.2745
24. Torabi M, Afshar SK, Sheikhzadeh S, Afshar MK. Assessment of oral health indices in Kerman adults aged 35–44 years. J Isfahan Dent School. 2009:94–8.
25. Nejad ZGKF Ghalyani P Ghorbani A Ghorbani F Evaluation of prevalence of dental caries among patients with migraine headache J Isfahan Dent School 2014 10 6 490 7
Nejad ZGKF, Ghalyani P, Ghorbani A, Ghorbani F. Evaluation of prevalence of dental caries among patients with migraine headache. J Isfahan Dent School. 2014;10(6):490–7.
26. Bartlett D O’Toole S Tooth wear: best evidence consensus statement J Prosthodont 2021 30 S1 20 5 10.1111/jopr.13312
Bartlett D, O’Toole S. Tooth wear: best evidence consensus statement. J Prosthodont. 2021;30(S1):20–5.10.1111/jopr.13312
