|Year : 2019 | Volume
| Issue : 1 | Page : 58-65
Factors influencing the impact of temporomandibular disorders on oral health-related quality of life among school children aged 12–15 years in Mangalore: An observational study
Swapna Sarit, Gururaghavendran Rajesh, BH Mithun Pai, Ramya Shenoy
Department of Public Health Dentistry, Manipal College of Dental Sciences, Manipal Academy of Higher Education, Mangalore, Karnataka, India
|Date of Submission||03-Sep-2018|
|Date of Acceptance||25-Jan-2019|
|Date of Web Publication||15-Mar-2019|
Dr. Swapna Sarit
Department of Public Health Dentistry, S.C.B. Dental College and Hospital, Cuttack, Odisha
Source of Support: None, Conflict of Interest: None
Background: Temporomandibular disorders (TMDs) have been recognized as common orofacial conditions which cause considerable pain. Apart from dental caries and periodontal diseases, TMDs are becoming significant ailment affecting individuals due to their magnitude and impact on individuals. Few studies have examined the impact of TMDs on oral health-related quality of life (OHRQoL) in adolescents, especially in the Indian context. Aim: To assess the factors affecting the impact of TMDs on OHRQoL among 12 to 15-year-old schoolchildren in Mangalore. Materials and Methods: A cross-sectional study was carried out among 12 to 15-year-old schoolchildren in Mangalore. Signs and symptoms of TMDs and parafunctional habits were analyzed using a screening questionnaire recommended by the American Academy of Orofacial Pain. OHRQoL was measured by the 16-item version of Children Perception Questionnaire (CPQ11-14). Malocclusion was also assessed using Dental Aesthetic Index (DAI). Data were analyzed using Statistical Package for the Social Sciences (SPSS) software, version 14 (SPSS Inc., Chicago, IL, USA). Chi-square test and step-wise multiple logistic regression test were employed. P < 0.05 was considered statistically significant. Results: TMDs showed statistically significant association with OHRQoL among the schoolchildren (P < 0.05). Parafunctional habits and malocclusion were also significantly associated with both TMDs and OHRQoL among the study participants. Multivariate analysis found few parafunctional habits and malocclusion to be the significant predictors for both TMDs and OHRQoL (P < 0.05). Conclusion: Parafunctional habits, malocclusion, and TMDs had statistically significant association with OHRQoL. Parafunctional habits and malocclusion were found to be significant predictors for both TMDs and OHRQoL. TMDs and the associated factors have an impact on the psychosocial functioning of the children. This study emphasizes the importance of OHRQoL assessment for evaluating TMD patients because it can have a substantial impact on functional, emotional and psychologic aspects, thus negatively affecting the OHRQoL of children.
Keywords: Adolescent, habits, malocclusion, quality of life, temporomandibular disorders
|How to cite this article:|
Sarit S, Rajesh G, Mithun Pai B H, Shenoy R. Factors influencing the impact of temporomandibular disorders on oral health-related quality of life among school children aged 12–15 years in Mangalore: An observational study. J Indian Assoc Public Health Dent 2019;17:58-65
|How to cite this URL:|
Sarit S, Rajesh G, Mithun Pai B H, Shenoy R. Factors influencing the impact of temporomandibular disorders on oral health-related quality of life among school children aged 12–15 years in Mangalore: An observational study. J Indian Assoc Public Health Dent [serial online] 2019 [cited 2022 Aug 12];17:58-65. Available from: https://www.jiaphd.org/text.asp?2019/17/1/58/254324
| Introduction|| |
Temporomandibular disorders (TMDs) have been known to be a common orofacial condition which causes substantial pain. The American Dental Association in 1983 has suggested the term “temporomandibular disorders” (TMDs), “which refers to a group of disorders characterized by pain in the temporomandibular joint (TMJ), the periauricular area, or the muscles of mastication; TMJ noises (sounds) during mandibular function; and deviations or restriction in mandibular range of motion.” The primary symptom includes localized pain in the orofacial region, which is defined by the International Association for the Study of Pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” In addition to pain, other symptoms such as joint sounds (clicking and crepitus), which can be related to alterations or limitations in mandibular dynamics, might also be presented by patients suffering from TMDs.
Results from other previous studies suggest that there should be a clear-cut difference between patients who suffer from the most common painful spasm in the muscles of mastication (often labeled myofascial pain dysfunction or myogenic facial pain) and those suffering from internal derangement of the TMJ. There is a third, and smaller group, called atypical facial pain, whose complaints range from vague and wandering pain in the jaw region. Internal derangement or osteoarthritis of the TMJ leading to TMD complaints showed relatively low levels of pain and psychological distress. Based on the available literature, physical and systemic conditions as well as psychological factors have been detrimental causal factors for TMDs. Stress, depression, and anxiety lead to a lower pain threshold through alteration of nociceptive impulses and release of neurotransmitters from the central nervous system.
These psychological alterations increase the frequency, intensity, and duration of parafunctional habits, such as tooth clenching and grinding, which cause hyperactivity of masticatory muscles, TMDs, and higher patient morbidity.
Such patients as a result of these TMDs often suffer from different psychological and physical conditions, especially from long-standing orofacial pain. Every patient suffering from TMDs expresses his/her symptoms in a unique way. Hence, there is a need for standardized assessment of self-perceived disorders of the stomatognathic system that should be focused in clinical studies. TMD patients suffer from a variety of psychosocial distress as a consequence of their condition. Furthermore, psychosocial distress is identified as a possible risk factor for TMDs, with the extent of psychosocial distress considered a major prognostic factor for treatment response.
The interaction between TMDs and mental state is particularly clear in patients suffering from complaints involving the limitation of the basic functions of the masticatory motor system, both biological (chewing) and interpersonal (speech and emotional expression). One of the predominant symptoms, and at the same time the main cause of the patients reporting for treatment due to TMDs, is the pain of the orofacial muscles, mainly muscles associated with mastication.
Hence, today, there is a preference for a bio-psycho-social integrated approach. Oral Health Related Quality of Life (OHRQoL) measurement is a well-accepted way of characterizing the impact of a disease on the individual's perceived oral health. Using OHRQoL measurements, it is possible to compare the impact of different conditions. The short form of Children's Perception Questionnaire (CPQ11-14) is one of the most specifically used OHRQoL instruments for the concerned age group. OHRQoL measures provide essential information while assessing the treatment needs of individuals and populations; making clinical decisions; and evaluating interventions, services, and programs. Child Oral Health Quality of Life (COHQoL) questionnaire and the Child-Oral Impacts on Daily Performances are the most common measures that are employed for children and preadolescents. The COHQoL is a set of multidimensional measure assessing the negative impact of oral diseases and disorders on the well-being of 6 to 14-year olds and their families. Child Perceptions Questionnaire for children aged 11 to 14 years (CPQ11–14) is one of them. As a comprehensive instrument, it is potentially well suited to characterize patients suffering from TMD, as pain, functional limitations, discomfort, disability, and handicap affect a substantial part of this population. Oral diseases alter various aspects of life, thus leading to impairment in the quality of life of an individual.,
OHRQoL assessments are essentially important for patients suffering from TMDs because of the high negative impact of psychosocial factors on orofacial pain. TMDs have generally been thought to be a condition affecting only adults or the geriatric population; however, previous studies in literature have reported signs and symptoms in children and adolescents to be as frequent as in adults or the older population and its prevalence.
Although literature linking TMD to OHRQoL continues to grow, few studies have examined its impact on adolescents, especially in the Indian context. Keeping this in mind, this study was conceptualized to determine and assess the factors having an impact of TMDs on OHRQoL among schoolchildren aged 12–15 years in Mangalore.
| Materials and Methods|| |
The present study employed a cross-sectional design. It was conducted among schoolchildren aged 12–15 years in Mangalore, Karnataka. List of all the schools in Mangalore was obtained from the block education officer, and stratified random sampling technique was employed to select the schools for the present study. The schools were stratified as government, private-aided, and private schools. Ethical clearance was obtained from the Institutional Ethics Committee (IEC) of Manipal College of Dental Sciences, Mangalore (protocol ref no. 15127).
A pilot survey was conducted among 35 schoolchildren aged 12–15 years in Mangalore, prior to the main study. Sample size of a minimum of 90 study participants was calculated according to the findings of the pilot study using G Power software (version 3.1.2, Denmark) with effect size of 0.5, 95% confidence interval (CI), and at 80% power of the study. A total of 314 participants were screened for the present study, and data collection was stopped on reaching the required number of 90 cases with TMDs.
Inclusion criterion for the present study was schoolchildren aged 12–15 years. Participants not willing to give parents' written informed consent and their own assent and children suffering from any systemic diseases constituted the exclusion criteria. Data collection was completed over a period of 6 months.
The questionnaire was translated to the local language (Kannada) by the first translator and back translated to English language by a second translator. The final version of the questionnaire in Kannada was then finalized by the investigators and the two translators. Before the commencement of the main study, the questionnaires were administered to the study participants which were not included in the final study. The questionnaire was validated with 35 children before administration after obtaining approval from the IEC. The questionnaire was given to five subject experts who assessed the comprehensibility, relevance, and appropriateness of the questionnaire. Reliability of the questionnaire was assessed by employing Cronbach's alpha. Calibration of the examiner was done to establish interexaminer reliability, which was assessed by employing the Kappa statistic. Based on the pilot study, Kappa statistic was found to be 0.9, which suggests good agreement.
Demographic details, medical history, and the dental attendance pattern of the study children were obtained from their parents by using questionnaire method. Signs and symptoms of TMD and parafunctional habits were analyzed by using a screening questionnaire recommended by the American Academy of Orofacial Pain. This questionnaire consisted of ten questions with yes/no response along with patient history and detailed clinical examination. Participants having both the signs and symptoms were considered to have TMDs.,,
OHRQoL was measured by the 16-item version of CPQ11-14. Moreover, median scores were employed to differentiate the population having good or poor quality of life for the four subscales as well as the overall scores from the CPQ11-14.
Clinical examination of TMJ and malocclusion status of the schoolchildren was done in natural lighting conditions in the school settings with the child sitting on a chair with a head rest.
Data were analyzed using the Statistical Package for the Social Sciences (SPSS), version 14 (SPSS Inc., Chicago, IL, USA). Chi-square test was used to assess the relationship between TMDs and OHRQoL among high schoolchildren in Mangalore. Step-wise multiple logistic regression was performed to assess the predictors of TMDs and OHRQoL among the participants. Using this method, variables which showed a statistically significant difference at the 95% level (P < 0.05) were selected.
| Results|| |
A total of 314 schoolchildren from five different schools participated in this cross-sectional survey. There were 98 participants in government schools, 124 participants in private-aided schools, and 92 participants in private schools. The mean age of the study population was 13.84 ± 0.9 years. The mean age was 13.84 ± 0.96, 13.75 ± 0.88, and 13.87 ± 0.85 years in government, private-aided, and private schools, respectively. Males formed 61.1% (192) and females formed 38.9% (122) of the study population. Sociodemographic characteristic distribution has been presented [Table 1].
Chi-square test was undertaken to find the association between TMDs and OHRQoL. Moreover, it was found that TMDs were significantly associated with the following domains: oral symptoms (odds ratio [OR] = 0.7, CI = 0.57–0.86, P = 0.001), emotional well-being (OR = 0.69, CI = 0.54–0.79, P < 0.001), and social well-being (OR = 0.71, CI = 0.58–0.87, P = 0.003). It was also found that TMDs were also significantly associated with the overall scores of OHRQoL (OR = 0.78, CI = 0.62–0.97, P = 0.035) [Table 2]. It was found that all the following habits: nail biting (OR = 2.18, CI = 1.72–2.74, P < 0.001), tooth clenching (OR = 1.26, CI = 1.12–1.41, P < 0.001), tooth grinding (OR = 1.1, CI = 1.02–1.19, P < 0.001), and lip biting (OR = 1.42, CI = 1.24–1.63, P < 0.001) were significantly associated with TMDs [Table 3]. It was also found that malocclusion (OR = 0.71, CI = 0.61–0.81, P < 0.001) was significantly associated with TMDs [Table 4]. It was also found that nail biting (OR = 0.7, CI = 0.7–0.8, P < 0.001) and gum chewing habits (OR = 0.2, CI 0.15–0.31, P < 0.001) were significantly associated and negatively impact the OHRQoL of the study participants [Table 5]. It was found that malocclusion was significantly associated and negatively impacts all the four domains, namely oral symptoms (OR = 0.15, CI = 0.1–0.22. P < 0.001), functional limitation (OR = 0.14, CI = 0.006–0.032), emotional well-being (OR = 0.12, CI = 0.08–0.19, P < 0.001), and social well-being (OR = 0.18, CI = 0.13–0.26, P < 0.001) as well as the overall scores of OHRQoL (OR = 0.2, CI = 0.14–0.27, P < 0.001) [Table 6]. Step-wise multiple regression analysis was used to evaluate the OHRQoL among the schoolchildren in relation to age, gender, religion, socioeconomic status, previous dental visits, various habits, malocclusion, and TMDs. The analysis revealed that previous dental visit is a significant predictor for poor OHRQoL. In addition, it was found that lip biting and gum chewing habits as well as malocclusion were significant predictors for poor OHRQoL [Table 7]. Step-wise multiple regression analysis was also used to evaluate TMDs among the schoolchildren in relation to age, gender, religion, socioeconomic status, previous dental visits, various habits, malocclusion, and OHRQoL. The analysis revealed that gender and religion are significant predictors for poor TMDs. Furthermore, it was found that nail biting, tooth clenching, and tooth-grinding habits as well as malocclusion were significant predictors for TMDs [Table 8].
|Table 2: Association of temporomandibular disorders with oral health-related quality of life among the study participants|
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|Table 3: Association of various habits with temporomandibular disorder among the study participants|
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|Table 4: Association of malocclusion with temporomandibular disorders among the study participants|
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|Table 5: Association of various habits with oral health-related quality of life among the study participants|
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|Table 6: Association of malocclusion with oral health-related quality of life among the study participants|
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|Table 7: Multivariate analysis (step wise) with oral health-related quality of life as the dependent variable|
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|Table 8: Multivariate analysis (step wise) with temporomandibular disorders as the dependent variable|
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| Discussion|| |
The present study was an attempt to determine the factors affecting the impact of TMDs on OHRQoL among schoolchildren aged 12–15 years in Mangalore. The esthetic appearance of a person determines his/her self-perception, which negatively impacts his/her quality of life. This may be particularly true for children and adolescents with poor teeth or unattractive occlusal traits, who often end up being the targets for teasing, name-calling, and harassment from other children. Our results showed that TMD patients exhibited significantly lower scores in oral symptoms, emotional well-being, and social well-being domains of OHRQoL. Multiplicity of signs and symptoms was also associated with impaired OHRQoL. These findings also correlate and strengthen the current perception that TMDs are complex disorders and not a localized orofacial pain condition. It can be clearly viewed under a bio-psycho-social model of illness. Our findings are in corroboration with those of previous studies by Rener-Sitar et al., John et al., Dahlström and Carlsson, and Rusanen et al. However, our findings showed no association between TMDs and the functional limitation domain of OHRQoL, which might be due to the fact that children already having sought treatment for the limiting conditions.
It is believed that TMDs are often associated with deleterious habits as they lead to a traumatic dental occlusion which may affect the teeth and muscles of mastication and TMJs. This can hamper the functional balance of the entire stomatognathic system.,, The results of the present study revealed similar findings as the habits such as nail biting, tooth clenching, tooth grinding, and lip biting had a significant association with TMDs. A possible explanation could be that the persistence of these deleterious oral habits can be the etiological factor of malocclusion, and it has been believed that malocclusion has a negative impact on OHRQoL. As all these habits may be induced by some form of emotional disorder and/or stress, these oral functions can adversely affect the TMJ. However, gum-chewing habit was not found to be associated with TMDs in the present study. Further studies are needed to further explore the potential role of habits in the etiology of TMDs.
Malocclusion has an important role to play in the development of TMDs. The arrangement of the teeth determines the end position of jaw closure during chewing and swallowing. Hence, people suffering from TMDs have a high possibility that they might be having some form of malocclusion.,, Our findings found a statistically significant association between malocclusion and TMDs.
The results presented in this study show a significant contribution of the impact of parafunctional habits on OHRQoL, highlighting the need to further explore their role in health-related quality of life research. The results of the present study indicate that there was a statistically significant association between nail-biting and gum-chewing habits and OHRQoL. One of the possible causes for this observation might be the relationship of these habits with stress. As the study participants in the present study belonged to the adolescent age group, hormonal or emotional changes in them might lead to the presence of nail-biting and gum-chewing habits. There might be academic pressure that could also contribute toward the habit among the study participants. However, the present study found no association of OHRQoL with tooth clenching, tooth grinding, and lip biting. The findings of the present study are in corroboration with those reported by Alamoudi.
Adolescence is a period of change where emotional reorganization involves various internal and external changes taking place simultaneously. As a result of such factors, there has been a peak in the interest in the impact of malocclusion on the adolescent's psychosocial well-being. Malocclusion was evaluated by focusing on dental appearance using the Dental Aesthetic Index (DAI), and it was found that it had a negative impact on the adolescent's OHRQoL. In fact, there was an association between all domains such as oral symptoms, functional limitations, emotional well-being, and social well-being as well as the overall scores of OHRQoL and malocclusion among the study participants.
Onychophagia, commonly known as nail biting, is a habit that is difficult to quit and reflects how extreme nervousness or inability to handle stressful conditions can lead to anxiety and depression. This abnormal habit may cause various malocclusions associated with dento-alveolar segment of the oral cavity. Crowding and rotations of incisors are common with this habit. The findings of the present study indicate the same, as malocclusion was significantly associated with nail-biting habit.
The results of step-wise multiple binary logistic regression indicate that previous visits to the dentist, lip-biting and gum-chewing habits, and malocclusion were predictors of poor OHRQoL. Habits and malocclusion might have a direct or indirect impact on OHRQoL. The frequency of dental visits can also influence the quality of life among the study participants. Results also indicated that gender, religion, malocclusion, and habits such as nail biting, tooth clenching, and tooth grinding were significant predictors for TMDs. Food and other oral habits are mostly influenced by gender and religion which might play a role in the development of the TMDs.
The present study has to be viewed in light of its limitations. Since the present study employed a cross-sectional design, further studies are needed to fully understand the relationship between TMDs and OHRQoL. The present study among TMD patients adds information that is comparable with the widely available literature reports from other populations. Further studies are needed to conclude whether or not these instruments differentiated between children and adolescents with various conditions that may have a clinical significance. Studies measuring factors that may account for the variation in OHRQoL observed in TMD patients, as well as for other oral conditions, should also be taken into consideration. Finally, there is a need for longitudinal studies to check the responsiveness of OHRQoL measures to change prior to using it in a context where change is expected, desired, or possible.,
| Conclusions|| |
The present study has shown that TMDs have a negative impact on the OHRQoL of the schoolchildren aged 12–15 years. Malocclusion was found to be one of the major factors causing TMDs, which in turn negatively affects the OHRQoL of the children. Habits can be the causative factors for malocclusion and TMDs, which might negatively affect OHRQoL of the schoolchildren. Policymakers should plan health policies integrating oral health interventions and mental interventions specifically in adolescents. This will aid in obtaining better outcomes in relation to their oral as well as general health, thus reducing the financial burden as well.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Casanova-Rosado JF, Medina-Solís CE, Vallejos-Sánchez AA, Casanova-Rosado AJ, Hernández-Prado B, Avila-Burgos L, et al.
Prevalence and associated factors for temporomandibular disorders in a group of Mexican adolescents and youth adults. Clin Oral Investig 2006;10:42-9.
Blanco-Aguilera A, Blanco-Hungría A, Biedma-Velázquez L, Serrano-Del-Rosal R, González-López L, Blanco-Aguilera E, et al.
Application of an oral health-related quality of life questionnaire in primary care patients with orofacial pain and temporomandibular disorders. Med Oral Patol Oral Cir Bucal 2014;19:e127-35.
Rollman GB, Gillespie JM. The role of psychosocial factors in temporomandibular disorders. Curr Rev Pain 2000;4:71-81.
Bertoli E, de Leeuw R, Schmidt JE, Okeson JP, Carlson CR. Prevalence and impact of post-traumatic stress disorder symptoms in patients with masticatory muscle or temporomandibular joint pain: Differences and similarities. J Orofac Pain 2007;21:107-19.
Resende CM, Alves AC, Coelho LT, Alchieri JC, Roncalli AG, Barbosa GA, et al.
Quality of life and general health in patients with temporomandibular disorders. Braz Oral Res 2013;27:116-21.
Rener-Sitar K, Celebić A, Mehulić K, Petricević N. Factors related to oral health related quality of life in TMD patients. Coll Antropol 2013;37:407-13.
Reissmann DR, John MT, Schierz O, Wassell RW. Functional and psychosocial impact related to specific temporomandibular disorder diagnoses. J Dent 2007;35:643-50.
Berger M, Oleszek-Listopad J, Marczak M, Szymanska J. Psychological aspects of temporomandibular disorders – Literature review. Curr Issues Pharm Med Sci 2015;28:55-9.
Jokovic A, Locker D, Guyatt G. Short forms of the Child Perceptions Questionnaire for 11-14-year-old children (CPQ11-14): Development and initial evaluation. Health Qual Life Outcomes 2006;4:4.
John MT, Reissmann DR, Schierz O, Wassell RW. Oral health-related quality of life in patients with temporomandibular disorders. J Orofac Pain 2007;21:46-54.
Dahlström L, Carlsson GE. Temporomandibular disorders and oral health-related quality of life. A systematic review. Acta Odontol Scand 2010;68:80-5.
Murray H, Locker D, Mock D, Tenenbaum HC. Pain and the quality of life in patients referred to a craniofacial pain unit. J Orofac Pain 1996;10:316-23.
Rusanen J, Silvola AS, Tolvanen M, Pirttiniemi P, Lahti S, Sipilä K, et al.
Pathways between temporomandibular disorders, occlusal characteristics, facial pain, and oral health-related quality of life among patients with severe malocclusion. Eur J Orthod 2012;34:512-7.
Health measurement scales: A practical guide to their development and use (5th
edition). Aust N Z J Public Health 2016;40:294-5.
Motghare V, Kumar J, Kamate S, Kushwaha S, Anand R, Gupta N, et al.
Association between harmful oral habits and sign and symptoms of temporomandibular joint disorders among adolescents. J Clin Diagn Res 2015;9:ZC45-8.
Motta LJ, Guedes CC, De Santis TO, Fernandes KP, Mesquita-Ferrari RA, Bussadori SK, et al.
Association between parafunctional habits and signs and symptoms of temporomandibular dysfunction among adolescents. Oral Health Prev Dent 2013;11:3-7.
Franco-Micheloni AL, Fernandes G, Gonçalves DA, Camparis CM. Temporomandibular disorders among Brazilian adolescents: Reliability and validity of a screening questionnaire. J Appl Oral Sci 2014;22:314-22.
Almoznino G, Zini A, Zakuto A, Sharav Y, Haviv Y, Hadad A, et al
. A oral health-related quality of life in patients with temporomandibular disorders. J Oral Facial Pain Headache 2015;29:231-41.
Melchior M, Mazzetto M, Felicio C. Temporomandibular disorders and parafunctional oral habits: An anamnestic study. Dent Press J Orthod 2012;17:83-90.
Rener-Sitar K, Celebić A, Stipetić J, Marion L, Petricević N, Zaletel-Kragelj L, et al.
Oral health related quality of life in Slovenian patients with craniomandibular disorders. Coll Antropol 2008;32:513-7.
Miettinen O, Lahti S, Sipilä K. Psychosocial aspects of temporomandibular disorders and oral health-related quality-of-life. Acta Odontol Scand 2012;70:331-6.
Tecco S, Crincoli V, Di Bisceglie B, Saccucci M, Macrĺ M, Polimeni A, et al.
Signs and symptoms of temporomandibular joint disorders in Caucasian children and adolescents. Cranio 2011;29:71-9.
Alamoudi N. Correlation between oral parafunction and temporomandibular disorders and emotional status among Saudi children. J Clin Pediatr Dent 2001;26:71-80.
Silva LF, Thomaz EB, Freitas HV, Pereira AL, Ribeiro CC, Alves CM, et al.
Impact of malocclusion on the quality of life of Brazilian adolescents: A Population-based study. PLoS One 2016;11:e0162715.
Sachan A, Chaturvedi TP. Onychophagia (Nail biting), anxiety, and malocclusion. Indian J Dent Res 2012;23:680-2.
] [Full text]
Barbosa TS, Leme MS, Castelo PM, Gavião MB. Evaluating oral health-related quality of life measure for children and preadolescents with temporomandibular disorder. Health Qual Life Outcomes 2011;9:32.
Li S, Malkinson S, Veronneau J, Allison PJ. Testing responsiveness to change for the early childhood oral health impact scale (ECOHIS). Community Dent Oral Epidemiol 2008;36:542-8.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8]