|Year : 2020 | Volume
| Issue : 9 | Page : 1207-1214
Fixed orthodontic appliance impact on oral health-related quality of life during initial stages of treatment
Laila Fawzi Baidas, Norah AlJunaydil, Mawadh Demyati, Rawan Abu Sheryei
Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
|Date of Submission||18-Dec-2019|
|Date of Acceptance||01-Apr-2020|
|Date of Web Publication||10-Sep-2020|
Dr. Laila Fawzi Baidas
Associate Professor and Consultant, Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, P.O. Box 5967, 11432 Riyadh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Aims: Our study aimed to assess the oral health-related quality of life (OHRQoL) changes during the initial stage of fixed orthodontic appliance therapy and determined the impact of various orthodontic therapy needs on the OHRQoL of Saudi patients seeking orthodontic treatment. Materials and Methods: Forty-two patients aged 14–24 years (69% females) were recruited from the orthodontic clinics. OHRQoL was quantified by a self-administered short version of oral health impact profile (OHIP-14) questionnaire used before treatment (T0) and following bonding of fixed appliance on days 1 (T1), 7 (T2), 14 (T3), and 30 (T4). The higher the OHIP-14 score, the poorer the OHRQoL. The dental health component (DHC) of the index of orthodontic treatment needs (IOTN) was used to assess malocclusion severity. The missing, overjet, crossbite, displacement, overbite (MOCDO) hierarchical scale was used to categorize the most severe feature in each patient and determine the grade of orthodontic treatment need. Changes of OHRQoL over time were compared using the Friedman test. Result: Overall OHIP-14 score significantly increased following orthodontic appliance bonding at T1 and T2 compared to T0 (P < 0.001). The functional limitation domains in OHIP-14 pain and discomfort, physical disability, psychological disability, and psychological discomfort were affected at T1 compared to T0 (P < 0.05). Grade 4 IOTN-DHC (definite treatment needs) significantly influenced most OHIP-14 domains compared to other grades.
Conclusion: With the growing therapeutic and cosmetic demands of orthodontic treatment and the focus on OHRQoL, the study findings can be used to enhance patients' cooperation, expectation, and adherence to orthodontic treatment.
Keywords: Fixed appliances, IOTN-DHC, OHIP-14, OHRQoL, orthodontic treatment
|How to cite this article:|
Baidas LF, AlJunaydil N, Demyati M, Sheryei RA. Fixed orthodontic appliance impact on oral health-related quality of life during initial stages of treatment. Niger J Clin Pract 2020;23:1207-14
|How to cite this URL:|
Baidas LF, AlJunaydil N, Demyati M, Sheryei RA. Fixed orthodontic appliance impact on oral health-related quality of life during initial stages of treatment. Niger J Clin Pract [serial online] 2020 [cited 2020 Sep 26];23:1207-14. Available from: http://www.njcponline.com/text.asp?2020/23/9/1207/294690
| Introduction|| |
Oral health-related quality of life (OHRQoL) aids clinicians in identifying patient sufferings throughout the treatment and conforming to these factors within the recommended treatment options.,, These measures provide realistic expectations to patients and may improve their adherence to treatment. The oral health impact profile (OHIP) is a socio-dental questionnaire which was introduced, applied, and modified to detect the relation between social effect and treatment needs.,,, The OHIP questionnaire was used to assess the influence of malocclusion or fixed orthodontic treatment on OHRQoL. It is available in many languages and easily adaptable to different cultures.,,,,,,
Despite the clinical relevance and value of fixed orthodontic treatment impact on OHRQol, previous studies reported controversial results.,, These controversies could be explained by the malocclusion impact on OHRQoL.,,,,, Pain and discomfort, psychological disability, and low self-confidence are the major restraining factors to orthodontic treatment since they reduce patient cooperation and cause treatment discontinuation or missed appointments. Despite substantial clinical value, these areas are vague in the literature. Especially, there is a paucity of studies that analyze OHRQoL and malocclusion severity during the first stage of treatment. A good understanding of the treatment impact on OHRQoL can enhance patients' awareness, cooperation, and expectation of orthodontic treatment, which, in turn, can improve treatment outcomes, patient satisfaction and quality of oral health.
In the light of the importance of orthodontic treatment and severity of malocclusion impact on oral health, this study aimed to (1) compare OHRQoL before (T0) and following bonding of fixed appliance, at days 1 (T1); 7 (T2); 14 (T3); and 30 (T4), (2) determine OHRQoL changes by gender, age, socioeconomic status, and educational level, and (3) assess the effect of index of orthodontic treatment need-dental health component (IOTN-DHC) grades on OHRQoL.
| Materials and Methods|| |
Approval for this study was obtained from the institutional review board of the research center (E-19-4306, CDRC No. IR 0204).
Forty-two patients seeking orthodontic care at the orthodontic clinic of the (College of Dentistry, King Saud University in Riyadh, Saudi Arabia) in Saudi Arabia were selected. Random sampling was used based on the inclusion and exclusion criteria. The inclusion criteria were patients aged 14–24 years evaluated as having a need for comprehensive orthodontic treatment with no previous interventional therapy and orthodontic treatment with fixed appliances. Patients with cognitive disorders, any medical conditions, craniofacial syndromes, untreated dental caries, periodontal disease, or previous orthodontic treatment were excluded.
A sample size calculation was carried out using G* Power Software (220.127.116.11 ed.) based on prior studies., A sample size of 42 patients was required to show a significant change in OHRQoL. It is determined at α = 0.05 with effect size (ES = 0.4) and power of 90%.
Data collection and instruments for measurement
Each participant received a thorough explanation of the nature of the study and their role. Written informed consent was obtained. For patients below 18 years, their parents' consent was obtained. The informed consent forms included a description of the purpose, benefits, and drawbacks of the study. All participants were reminded to answer the questionnaire at the intentional time (set time determined for the study to remind the patient) through phone calls or messages.
OHIP-14 questionnaire. The questionnaire involved 14 items (two items per domain) covering seven domains: functional limitation, pain and discomfort, psychological discomfort, physical disability, psychological disability, social disability, and handicap. Likert scale was used to measure the responses to each item as never (0), hardly-ever (1), occasionally (2), fairly often (3), and very often (4). Each patient was asked to rate how frequently they experienced oral health. Sum of OHIP-14 scores can range from 0 to 56, and domain scores can range from 0 to 8. Patients with higher OHIP-14 scores experienced a greater negative impact on OHRQoL.
The Arabic short version of the OHIP-14 questionnaire, validated for the Saudi population, was used to measure OHRQoL after including the demographic data questions. The back-translation method was implemented to produce the Arabic version as recommended by the WHO guidelines., The scales were translated into Arabic by experts in both Arabic and English languages and checked, then back-translated into English to confirm the consistency of Arabic and English versions. Additionally, the Arabic version of the OHIP-14 was carefully revised by eight orthodontists to ensure proper translation, and more than 90% of them agreed that the questionnaire was clear. A pilot study on 10 patients determined its clarity, wording, ease of use, and understanding of the questionnaire. Based on their responses, relevant changes were made to some questions. Cronbach's alpha indicated reasonable internal consistency (>0.95) for OHIP-14 and acceptable reliability (0.793).
The questionnaire could be answered within the 10-min duration. The subjects answered the first questionnaire at T0. After bonding of the bracket and initial wire, a strategy was in place to monitor and collect the subjects' data from the questionnaire filled on T1, T2, T3, and T4.
Index of Orthodontic Treatment Need-dental health component (IOTN-DHC) The need for orthodontic treatment was assessed with IOTN-DHC. The cast of each patient was studied and measured on the missing, overjet, crossbite, displacement, overbite (MOCDO) hierarchical scale to identify the most severe features; M: missing teeth (including aplasia, displaced, and impacted teeth), O: overjet (including reverse sagittal overjet), C: crossbite, D: displacement of contact points, and O: overbite (including open bite).
A grade was assigned based on the single most severe feature of malocclusion as grade 1 = no treatment needed, grade 2 = minimal treatment needed, grade 3 = borderline treatment needed, and grade 4 and 5 = definite treatment needed. Three examiners determined the grades. The inter-examiner and intra-examiner (repeated after one week) reliability of 10 orthodontic study models was at Kappa = 0.85. The IOTN calibration exercises were done at the orthodontic clinic of the (Institution name masked for blind review), by an expert orthodontist.
The statistical package for social science software (IBM-SPSS), version 24.0 was used, and the statistical significance was set at P < 0.05. Data were represented as mean, median, and standard deviation. Friedman test was used for nonparametric, repeated measures of OHIP-14 data to assess the change in total score, domain, and item score during initial treatment at each time point, and also to compare IOTN-DHC grades with the OHIP-14 total and domain scores. Mann-Whitney U test was used to compare gender and age groups, and the Kruskal-Wallis test was used to compare education levels and socioeconomic status with the overall OHIP-14 scores.
| Results|| |
All the patients (n = 42) answered all the questionnaires with a response rate of 100%. Thirteen (31%) participants were males, and 29 (69%) were females. Twenty-nine (69%, mean age = 15 years) were adolescents, and 13 (31%, mean age = 22 years) were young adults. One (2%) patient was in elementary school, 14 (33%) in middle school, 16 (38%) in high school, and 11 (26%) patients were in college. The majority of the patients (70%) belonged to the middle socioeconomic status.
A significant change in overall OHIP-14 score at the five intervals (T0 to T4) was observed following the bonding of fixed orthodontic appliances (P < 0.001). The total OHIP-14 score increased from T0 to T1 (7.38 vs. 12.48; P < 0.001), gradually decreased at T2 and T3, with an unexpected marginal increase at T4 [Figure 1].
|Figure 1: Mean overall oral health impact profile (OHIP-14) score (n = 42) at T0, T1, T2, T3, and T4 of the fixed orthodontic appliance bonding T0 = Baseline, days 1 (T1), 7 (T2), 14 (T3), and 30 (T4) after orthodontic appliance bonding|
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Significant changes were observed in most of the OHIP-14 domains at T0 vs. T1; functional limitation (P < 0.03), physical disability (P < 0.001), pain, and discomfort (P < 0.001), psychological disability (P = 0.007), and psychological discomfort (P < 0.001). [Table 1] provides comparisons of the mean score of each OHIP-14 domain at the five-time points.
|Table 1: Mean score for each oral health impact profile (OHIP-14) domain (n=42) at T0, T1, T2, T3, and T4 of the fixed orthodontic appliance bonding|
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Almost most of the items on OHIP-14 were significantly affected following orthodontic appliance bonding except pronunciation difficulties, irritability toward others, struggle with routine jobs, less satisfaction with life, and inability to do their own job. The domain scores for pain and discomfort, psychological discomfort, physical disability, and psychological disability, and the second item in the functional limitation (altered taste sensation) contributed significantly to the patients' overall scores. Unsatisfactory diet(P < 0.001), meal interruptions(P < 0.001), toothache(P < 0.001), discomfort while eating (P < 0.001), worsening of taste sensation (P = 0.046), and difficulty with relaxation (P = 0.006) were affected during T1 and T2 compared to T0. Self-consciousness(P = 0.001) and tense feeling (P = 0.022) were highest at T1 compared to any other time. Moreover, the self-esteem scores indicating embarrassment were also highest at T0 and T1 (P < 0.001) compared to other time points [Table 2].
|Table 2: Mean score of each OHIP-14 item (n=42) at T0, T1, T2, T3, and T4 of fixed orthodontic appliance bonding|
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Females reported a more negative impact on OHRQoL than males with the highest mean at T1 (14.07 vs. 8.92, respectively). However, using the Mann-Whitney U test, this statistical significance disappeared. Younger adults reported a higher impact on OHRQoL following fixed orthodontic appliance bonding at T1 (P = 0.006), T2 (P = 0.002), T3 (P = 0.007), and T4 (P = 0.037) compared to adolescents [Table 3].
|Table 3: Gender and age effects on the mean OHIP-14 score (n=42) at T0, T1, T2, T3, and T4 of fixed orthodontic appliance bonding|
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The socioeconomic status (low, middle, high) and the educational level (middle school, high school, and college) had no significant effect on the overall OHIP-14 score, although the middle socioeconomic status group had a higher mean difference. [Table 4].
|Table 4: Education and socioeconomic effects on the mean OHIP-14 score (n=42) at T0, T1, T2, T3, and T4 of fixed orthodontic appliance bonding|
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[Figure 2] demonstrates the distribution of the study sample, according to IOTN-DHC. Most of the patients had a definite need for orthodontic treatment (grade 4, 74%, and grade 5, 14%). About 12% were grade 3 with a borderline need for orthodontic treatment.
|Figure 2: Frequency distribution of the study sample (n = 42) according to the index of orthodontic treatment need-dental health component (IOTN-DHC)|
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The OHIP-14 scores for IOTN-DHC grades at different time points (T0 to T4) are demonstrated in [Figure 3]. At T1, the overall OHIP-14 score was highest for all IOTN-DHC grades, mainly grade 4. The OHIP-14 score reduced after T1 to reach the lowest score at T3 in patients with IOTN-DHC grades 4 and 5 and then increased slightly at T4. However, the OHIP-14 score continuously decreased in patients with IOTN-DHC grade 3 to reach the lowest at T4. The differences in the mean OHIP-14 score between T0 to T4 were significant in IOTN-DHC grade 3 (P = 0.020) and grade 4 patients (P = 0.001). IOTN-DHC grade 5 patients had no significant differences in the OHIP-14 mean scores.
|Figure 3: The overall OHIP-14 score at T0, T1, T2, T3, and T4 following bonding of orthodontic appliances for each IOTN-DHC (n = 42) T0 = Baseline, days 1 (T1), 7 (T2), 14 (T3) and 30 (T4) after orthodontic appliance bonding|
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The mean scores of the OHIP-14 domains were compared between the five-time points (T0 to T4) based on IOTN-DHC grades. In grade 3 (borderline need for treatment), psychological discomfort (P = 0.031), and psychological disability (P = 0.013) domains were significantly affected between T0 to T2. In grade 4, physical disability (P < 0.001), as well as pain and discomfort (P < 0.001), had the highest mean OHIP-14 score at T1 compared to T0. Functional limitation was high at T0 and reduced at T3, T4 (P = 0.031). Psychological discomfort was also affected in grade 4 (P = 0.16) at T1 compared to T2, T3, and T4. In contrast, grade 5, a definite need for orthodontic treatment, showed a significant difference only in the pain and discomfort domain (P = 0.025) between T0 and T1 [Table 5].
|Table 5: Comparison between the mean scores of each OHIP-14 domain at T0, T1, T2, T3, and T4 following bonding of orthodontic appliances based on index of orthodontic treatment need-dental health component (IOTN-DHC) grade (n=42)|
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| Discussion|| |
Physical and psychological consequences of fixed orthodontic appliance therapy have been the scope of many cross-sectional or longitudinal studies in different populations, yet there is conflicting evidence about the extent of these effects.,,,, This study evaluated the OHRQoL in patients undergoing orthodontic therapy using a questionnaire at different time points during the 1st month following appliance bonding, in combination with the orthodontic treatment needs. Any questionnaire instrument requires an accurate translation and validation process before its use in a new cultural group or population. The translated Arabic version of OHIP demonstrated good validity, reliability, and high internal consistency in the Saudi population.,
The baseline or pretreatment OHIP-14 score was low in our patients, signifying that the perception of malocclusion on OHRQoL was low in Saudi patients compared to other populations.,, The OHRQoL decreased drastically (high OHIO-14 scores) on the 1st day following fixed orthodontic appliance bonding. In general, for patients undergoing orthodontic treatment, the OHRQoL reduces during the 1st week with gradual improvements seen after week 1 of bonding the fixed orthodontic appliance. This shows that the initial stage following fixed appliance bonding will have an impact on the patient's daily activity.
The OHIP-14 domains that were significantly affected by the bonding of the fixed orthodontic appliances were pain and discomfort, physical disability, psychological disability, and discomfort. These findings are comparable to the report by Mansour et al. on the impact of orthodontic treatment after 24 h of bonding, and the findings of Chen et al. that physical pain, psychological discomfort, and physical disability were significantly impacted during the 1st week after appliance fixation. Our results also support the finding that orthodontic treatment affects the patient's life during the 1st day and 1st week., The improvement seen after the 1st week could be due to adaptation or learned experience of treatment. The social disability and handicap domains were not affected and can be attributed to personality characteristics and the performance of general daily activities despite the oral condition.
On the 1st day of orthodontic treatment, patients experienced aching in the mouth (86.8%), meal interruptions (78.9%), discomfort while eating (76.3%), unsatisfactory diet (63.2%), difficulty with relaxation (47.4%), embarrassment and a tense feeling (42.1%), and were self-conscious (36.8%). The negative experience of our patients in the domain items physical pain, physical disability, psychological disability, and psychological discomfort, it was similar to other studies., Previous studies report that pain and discomfort could start within a few hours after appliance bonding, peak at 24 h, and usually decreases after 72 h. The pain from orthodontic treatments has a definite influence on the daily life and activities of patients. Behavioral changes with diet and eating can be an adaptation to the pain from orthodontic treatment., Additionally, our patients reported embarrassment and lack of self-confidence on the 1st (T1) and 7th day (T2) following bonding of fixed orthodontic appliances, most likely since the face is the center of attention during communication. Furthermore, our patients felt tenser and had difficulty with relaxation after appliance bonding similar to other studies, which report that sleep quality is affected following the bonding of orthodontic appliances.,
In this study, gender did not influence the scores following appliance bonding agreeing with some studies, while differing from others., The methodology differences among the studies and the small sample size could contribute to these differences. OHIP is the most valid tool for evaluation in all age groups,,,, since it was initially developed for older adults, and subsequently adapted and validated for use in adolescents. Our result that the younger age group tended to experience more negative impact compared to the older age group was similar to a few studies., This difference was not significant probably due to the small sample size. Scott et al. reported that age does not have any effect on the level of treatment discomfort. Also, the patients' educational level or socioeconomic status did not influence the OHRQoL following bonding of fixed orthodontic appliances, as seen by the absence of influence by social variables.
The percentage of patients who required definite orthodontic treatment was 84%, and higher compared to other studies.,,, This definite treatment need (malocclusion grade 4) had a negative impact on OHRQoL especially after the 1st and 7th days following bonding of fixed orthodontic appliance. Malocclusion does significantly affect the OHRQoL as reported in the systematic review of the literature by Liu et al. Hassan and Amin assessed the effect of different orthodontic treatment needs of 366 Saudi Arabian young adults. Johal et al. prospectively assessed the impact of fixed orthodontic treatment on the self-esteem of 52 subjects with different treatment needs. All the abovementioned studies used larger samples and assessed wider variations of malocclusion. Remarkably, a similar result was obtained in our study despite the different backgrounds and sample size.
QoL is a relative and non-absolute measure; hence, the results are stated as a comparison of the impact on daily activities between orthodontic treatment needs. Subjects with severe malocclusion may not report a negative impact on the QoL, whereas others with minor irregularity report high negative impacts. Our results showed that definite orthodontic treatment need (grade 4) significantly increases physical disability, pain and discomfort, psychological disability, and psychological discomfort. However, the borderline treatment need (grade 3) significantly influences physical disability, pain, and discomfort. These results coincided with Hassan and Amin's study of young Saudi adults whose definite orthodontic treatment needs significantly affected mouth ache, self-consciousness, tension, embarrassment, irritability, life satisfaction, taste, and relaxation. In addition, Johal et al. found that the overall OHRQoL was affected in subjects with severe malocclusion during the first 3 months of orthodontic treatment.
The present study is based on a clinical sample collected from one clinical setting—the orthodontic clinic at the (College of Dentistry, King Saud University in Riyadh, Saudi Arabia) which cannot be generalized to all patients selected for orthodontic treatment. The relatively small sample size is another limitation. Therefore, further multicentered large samples and more extended duration studies are recommended to confirm our findings.
| Conclusion|| |
OHRQoL is affected during the initial stage of orthodontic treatment, especially after the 1st and 7th days following the bonding of fixed orthodontic. Age, gender, educational level, and socioeconomic status had no effect on the OHRQoL. This study highlights the impact of orthodontic treatment needs as related to the DHC on OHRQoL. The definite treatment need (grade 4) had a marked negative effect on the OHRQoL. The results stress the importance of active patient-based evaluation of OHRQoL and treatment need to provide more realistic treatment expectations before obtaining their informed consent and pursuing treatment.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Cunningham SJ, O'Brien C. Quality of life and orthodontics. Semin Orthod 2007;13:96-103.
Feu D, Quintao CCA, Miguel JAM. Quality of life instruments and their role in orthodontics. Dental Press J Orthod 2010;15:61-70.
Hagg U, McGrath C, Zhang M. Quality of life and orthodontic treatment need related to occlusal indices. The Hong Kong Medical Diary [serial on the internet www.fmshk.org]. 2007;12:8-11. Available from: http://www.fmshk.org/database/hkmd/hkmd200710.pdf
Zhou Y, Wang Y, Wang X, Voliere G, Hu R. The impact of orthodontic treatment on the quality of life a systematic review. BMC Oral Health 2014;10:14-66.
Slade GD, Spencer AJ. Development and evaluation of the Oral Health Impact Profile. Community Dent Health 1994;11:3-11.
Locker D. Measuring oral health: A conceptional framework. Community Dent Health 1988;5:3-18.
Slade GD. Derivation and validation of a short-form oral health impact profile. Community Dent Oral Epidemiol 1997;25:284-90.
Locker D. Oral health and quality of life. Oral Health Prev Dent 2004;2:247-53.
Andiappan M, Gao W, Bernabe E, Kandala, N-B, Donaldson AN. Malocclusion, orthodontic treatment, and the Oral Health Impact Profile (OHIP-14): Systematic review and meta-analysis. Angle Orthod 2014;85:493-500.
Chen M, Wang DW, Wu LP. Fixed orthodontic appliance therapy and its impact on oral health-related quality of life in Chinese patients. Angle Orthod 2010;80:49-53.
Mansor N, Saub R, Othman SA. Changes in the oral health-related quality of life 24 h following bonding of fixed orthodontic appliances. J Orthod Sci 2012;1:98-102.
Nagarajappa R, Ramesh G, Sandesh N, Lingesha RT, Hussain MA. Impact of fixed orthodontic appliances on quality of life among adolescents' in India. J Clin Exp Dent 2014;6:e389-94.
Costa AA, Serra-Negra JM, Bendo CB, Pordeus IA, Paiva SM. Impact of wearing fixed orthodontic appliances on quality of life among adolescents: Case-control study. Angle Orthod 2015;86:121-6.
Wang J, Tang X, Shen Y, Shang G, Fang L, Wang R, et al.
The correlations between health-related quality of life changes and pain and anxiety in orthodontic patients in the initial stage of treatment. Biomed Res Int 2015; ID725913, 7 pages. Available from: http://dx.doi.org/10.1155/2015/725913
Johal A, Alyaqoobi I, Patel R, Cox S. The impact of orthodontic treatment on quality of life and self-esteem in adult patients. Eur J Orthod 2015;37:233-7.
Zhang M, McGrath C, Hagg U. The impact of malocclusion and its treatment on quality of life: A literature review. Int J Paediatr Dent 2006;16:381-7.
Liu Z, McGrath C, Hagg U. The impact of malocclusion/orthodontic treatment need on the quality of life. A systematic review. Angle Orthod 2009;79:585-91.
Hassan A, Amin H. Association of orthodontic treatment needs and oral health-related quality of life in young adults. Am J Orthod Dentofacial Orthop 2010;137:42-7.
Hassan A, Hassan M, Lenajwi A. Association of orthodontic treatment needs and oral health-related quality of life in Saudi children seeking orthodontic treatment. Patient Prefer Adherence 2014;8:1571-79.
de Oliveira C, Sheiham A. Orthodontic treatment and its impact on oral health-related quality of life in Brazilian adolescents. J Orthod 2004;31:20-7.
El mahgoub FA, Abuaffan AH. The impact of orthodontics treatment needs related to dental health on the oral health-related quality of life of dental students. Clin Res Trials 2015;1:70-4.
Al-Jundi MA, Szentpetery A, John MT. An Arabic version of the oral health impact profile: Translation and psychometric properties. Int Dent J 2007;57:84-92.
Guillemin F, Bombardier C, Beaton D. Cross-cultural adaptation of health related quality of life measures: Literature review and proposed guidelines. J Clin Epidemiol 1993;46:1417-32.
Brook PH, Shaw WC. The development of an index of orthodontic treatment priority. Eur J Orthod 1989;11:309-20.
Arrow P, Brennan D, Spencer AJ. Quality of life and psychosocial outcomes after fixed orthodontic treatment: A 17-year observational cohort study. Community Dent Oral Epidemiol 2011;39:505-14.
Palomares NB, Celeste RK, Oliveira BH, Miguel JA. How does orthodontic treatment affect young adults' oral health-related quality of life&? Am J Orthod Dentofacial Orthop 2012;141:751-8.
Erdinc AM, Dincer B. Perception of pain during orthodontic treatment with fixed appliances. Eur J Orthod 2004;26:79-85.
Sergl HG, Klages U, Zentner A. Pain and discomfort during orthodontic treatment: Causative factors and effects on compliance. Am J Orthod Dentofacial Orthop 1998;114:684-91.
Brown DF, Moerenhout RG. The pain experience and psychological adjustments to orthodontic treatment of preadolescents, adolescents and adults. Am J Orthod Dentofacial Orthop 1991;100:34956.
Mandall NA, Vine S, Hulland R, Worthington HV. The impact of fixed orthodontic appliances on daily life. Community Dent Health 2006;23:69-74.
Scheurer PA, Firestone AR, Burgin WB. Perception of pain as a result of orthodontic treatment with fixed appliances. Eur J Orthod 1996;18:34957.
Jokovic A, Locker D, Stephens M, Kenny D, Tompson B, Guyatt G. Validity and reliability of a questionnaire for measuring child oral-health-related quality of life. J Dent Res 2002;81:459-63.
Scott P, Sherriff M, Dibiase AT, Cobourne MT. Perception of discomfort during initial orthodontic tooth alignment using a self-ligating or conventional bracket system: A randomized clinical trial. Eur J Orthod 2008;30:22732.
McGrath C, Bedi R. Population based norming of the UK oral health related quality of life measure (OHQoL-UK). Br Dent J 2002;193:521-4.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]