Fazal Ghani*, Munir Khan**
How to CITE:
J Pak Dent Assoc 2010;19(1): 5 - 14
To explore, in local subjects, the effect, on oral-health-impact-profile (OHIP) scores, of missing teeth, edentulous areas and some socio-demographic factors.
During the period from June to November 2007, a cross-sectional study involving 243 partially dentate subjects was conducted at Khyber College of Dentistry, Peshawar (Pakistan). With the method of interviewing and clinical examination and using a 33-OHIP-statements sheet, OHIP scores for subjects were determined. Socio-demographic as well as data for the number of missing teeth and edentulous areas were also recorded.
OHIP scores were positively correlated with the number of missing teeth (r = 0.29) and the number of edentulous spaces (r = 0.37). Subject’s age and socio-economic status were more important co-variables influencing OHIP scores as compared to gender and educational level. Generally, higher OHIP scores were recorded for subjects who had anterior edentulous spaces, distal extension spaces or multiple and larger bounded spaces. Also much higher scores were recorded in those having bounded and distal extension spaces in addition to anterior spaces. OHIP-statements with high scores as an indication of adversely affecting QoL were those related to the function of chewing and esthetics. Some OHIP-statements that had been tested in other countries were found un-important for determining oral-health-related-quality-of-life (OHRQoL) in the present subjects.
With their varying influence, missing teeth, edentulous spaces, age and socio-economic status proved important variables influencing both the OHIP scores and OHRQoL.
Oral health-related quality of life, Oral health impact profile scores, Impaired oral health, Missing teeth, Edentulous areas.
An increased life-expectancy or the addition of few years to a subject life achieved through advancement in therapeutic medicine would not be a significant achievement without the addition of quality to those added years. The same will be the case with a given treatment that will not bring a significant improvement in the functional, psycho-social well-being and hence in the quality of life (QoL) of a patient. Thus both the extension of people’s life spans and treatment provision must reflect the evidence of improving their QoL 1, 2. QoL measures have the potential benefit in clinical decision making situations and as diagnostic and outcome-measuring tools for comparing treatments 3. To further highlight the importance of QoL studies, the modern day agenda for general health-care throughout the world now emphasizes on the social confidence and well-being of the community. It stresses upon the increased health status awareness and maintenance of QoL of the population 4.
To measure both negative and positive changes in oral-health status, dental researchers have been called upon to broaden their focus on the pathophysiological assessment of clinical disease by incorporating psycho-social assessments of QoL 5 – 6. Furthermore, at a health policy level, health care researchers are being urged to demonstrate “what works” in improving an individual’s functional and psycho-social well-being. Thus a broadened research focus, on both the negative consequences of disease and the positive dimensions of health, is implicit within the “US Healthy People 2000 Initiative” which aims to improve both the life- span and the QoL 1. The assessments of QoL encompass social, psychological as well as functional aspects 7 Evidence suggests oral- health as multi-dimensional 8. Oral health-related quality of life (OHRQoL) characterizes a patient’s perception of oral-health. Using various measures and multi-item scales, the QoL assessment exercise has enabled the measurement of patient’s perceived benefits of prosthodontic treatment 9. The OHRQoL is assessed by reading the score through statements describing oral health impact profile (OHIP). Generally, a number of self-reported measurements of the adverse impacts of oral conditions on daily living are recorded 10. The important qualities of OHIP questionnaires have been considered as their ability of extracting latent, sub-conscious and un-expressed needs and of making patients aware of their own QoL preferences and wishes 11. QoL measures provide a broader basis for assessing oral-health at individual and population levels 12. The English language OHIP questionnaire, originally developed in Australia by Slade and Spencer, is an intensively used instrument 13. It consists of 49- statements grouped into seven domains based on a conceptual model of oral- health. It uses the framework of WHO International Classification of Impairments, Disabilities and Handicaps 14. The questionnaire while having well – documented psychometric properties has proved as a sensitive screening tool for identifying people with high levels of self- perceived impacts due to oral conditions 15 16. The number of teeth as well as the type of prosthesis (fixed or removable and partial or complete) and its status have been all considered key and influencing factors having impact on oral health status and thus on the patient QoL 9,16, 17. Diminished OHRQoL has been linked to tooth loss, untreated dental decay, extensive periodontal disease, pathologies and abnormalities within the stomatognathic system and limited access to dental care 18, 19. The loss of teeth and poor dentition is known to influence the mastication of foods and nutritional status 20 – 23. The adequate rehabilitation of edentulous state with dentures has a beneficial effect on mastication and diet 24 – 27. The loss of many teeth is known to adversely affect occlusal force, chewing efficiency, swallowing, food selection, nutritional status and physical ability especially in subject not wearing dentures 28 31. A case-control study also suggested the loss of teeth as a risk factor for Alzheimer’s disease 32. In fact, it has been determined that edentulous subjects without dentures had a significant risk for death independent of physical mental health status at baseline 33 –35. Facial attractiveness has been found to affect social attitudes and actions and is important in employment situations 36 – 38. In one study, it was recognized that missing and decayed teeth drastically affected the appearance of some participants. This resulted in a negative impression on prospective employers and poor self esteem for the individuals 36. Additionally, adverse oral health conditions have been found to affect systemic health, QoL and economic productivity 37. The patient’s point of view regarding dental treatment satisfaction and OHRQoL is increasingly recognized as an important outcome of dental care 38 – 40.
In dentistry, especially in prosthodontics, several methods have been introduced to measure the impact of different oral conditions on the patient’s life 3. Partial edentulism with or without wearing of removable partial dental prostheses (RPDPs) has been the subject of many studies and the patient acceptance of a reduced dentition as well as the satisfaction with RPDPs is documented for different groups 41 – 42. It would, from the results of these studies, be reasonable to expect RPDP wearers as dissatisfied with their oral conditions. On the other hand, the motivation for RPD use may be of a social meaning to such an extent that they are considered as an important body part 43. Partial edentulism and the wearing of RPDPs will form a good basis for studying a new method for establishing patient preferences and QoL aspects in prosthodontic decision-making 44. In prosthodontics, the diagnosis is based more on function and aesthetics than other disciplines of dentistry. Therefore the patient-centered approach in treatment planning is important 44. The results of one study about the wearing of RPDPs or not and partial edentulism seem to support earlier results that the aesthetic aspect of anterior dental arches is a major subjective factor and that aesthetics is one of the most important domains in patient needs and wishes 44, 46. In case of local patients, it has been found that for better functional restoration, fixed dental prostheses (FDPs) were preferred for the restoration of posterior edentulous spaces.47. Results from a population-based survey in Germany demonstrated that subjects were more satisfied with FDPs as compared to those wearing RPDPs 9. similarly, other studies, also showed that subjects with complete dentures consistently had poorer OHRQoL than those with implant 40, 48.
A large national population -based survey conducted in Germany about OHRQoL covering a wide age range of adults confirmed denture status as the strongest predictor of impaired OHRQoL compared to socio-demographic factors. Age and socioeconomic status were not important predictors after adjusting for denture status. The authors suggested that it should routinely be used as a stratifying factor in comparative studies 19. Other studies exploring the influence of denture status on OHRQoL have shown a strong association between OHRQoL and denture status 49 – 51. A population- based cross- sectional Canadian study showed more impairment for edentulous subjects when compared to dentate subjects for all seven OHIP-E dimensions 51.With each additional missing tooth, the OHIP score increased by 0.3 when other important variables were controlled 52
In fact research effort of the kind has proved highly valuable for identifying ways to increase oral health promotion activities and provision of cost-effective dental restorative services to targeted individuals 53 – 55. With the already established association between oral health and QoL, our understanding on the subject has considerably enlarged. However, mostly information has been based on research done abroad. This information thus may not be applicable to our local situation. At the same time, no such studies regarding the relationship between clinical oral health and QoL issues have ever been done in this country. Thus examining such associations will clarify how oral-health condition with the number of missing teeth and edentulous areas of subjects of diverse socio-demographic status would affect the psycho-social well-being, functions and QoL in subject of the local populace
During the period of June to November 2007, a cross-sectional study with a convenience sampling technique and involving 243 partially dentate subjects was conducted at Khyber College of Dentistry, Peshawar (Pakistan). The selection criteria are given in Table I. Using a 33-OHIP statements sheet, OHIP scores were determined for each subjects . Their socio-demographic as well as data for the number of missing teeth and edentulous areas were also recorded. Patients were clinically examined, personally interviewed and self-reported data were documented on a questionnaire the purposes, procedure, benefits of the study were explained to patients and their informed consent was obtained.
Clinical intra-oral examination were mainly focused on recording the total number of missing teeth and the total number of edentulous areas present in both jaws of each patient. The patient educational level was recorded as I = None, II = Up-to Secondary School, III = Graduate and IV = Postgraduate Education. Similarly, the patient socio-economic status was categorized on the basis of annual income in Pakistani Rupees as low (< 100,000 or 1-Lakh), medium (>100, 0000 to 200,000) and high, (>200.000). For each OHIP item/statement (Table VII) the subject was asked how frequently he / she had experienced its impact on his / her QoL. Subjects were also asked to rate their experience of dental problems due to missing teeth so as to capture measures of the seven dimensions of functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability and handicap of the OHIP. Responses were made on a Likert-type scale (never = 0, hardly ever = 1, occasionally = 2, fairly often = 3 and very often = 4). In this scale, no effect of a statement (never = 0) was considered as the minimum effect and no further exploration of the degree of this “no” effect was investigated. The 33-items / statements taken from the original 49-item / statement English-language OHIP Form.13. These were translated into local language in consultation with the senior teaching faculty at the ‘PUSHTO ACADEMY’ University of Peshawar. The sum of the level of frequency of all 33 items as were recorded produced an overall OHIP score. The higher scores indicated a poorer OHRQoL as the OHIP index measured the severity of problems.
The data were computed, tabulated and analyzed by SPSS version 10.0. These were presented as frequency distributions, percentages, mean values and corresponding standard deviations (SD). For quantitative variables (age) ranges and means SD were given. For qualitative variables (gender, socioeconomic status and educational level) frequencies were calculated as percentages. The distributions of responses to the OHIP items were examined, and frequencies / percentages were given for each of the response to the OHIP statement. For testing the association of OHIP scores of patients with factor of age, gender, socioeconomic status and educational level, Chi-Square(x2) test was applied. To see the correlation of oral health impact profile scores with the number of missing teeth and the number of edentulous areas, correlation coefficient was used
The partially dentate patients (N = 243) had their ages ranging between 30 and 50 years with a mean age of 39.3± 6.04 . Male patients were 135 (55.6%) as compared to 108 (44.4%) females with a male to female ratio of 1:0.8. Proportions of missing teeth and OHIP scores in the various age-groups is depicted in Table II. The association of OHIP scores with age of the patients was found statistically significant (x2 = 7.82, P = 0.05). OHIP scores had significant association with the patients gender (x2 = 0.19, P = 0.05). Distribution of patients by their socio-economic status is given in Table III. The percentages of
patients in each of the low, medium and high socio-economic categories are shown in this table. The number of male patients having high socio-economic status was 28 (20.8%) and females 10 (9.2%). Likewise, the number of male patients in the category ‘medium’ were 99 (73.3%) and female patients 83 (76.9%). In the low category, the number of males were 8 (5.9%) with females 15 (13.9%). The level of association between the OHIP scores and the patients socio-economic status was significant (x2 = 15.5, P = 0.05).
Distribution of the patients according to their respective education levels is given in Table IV. Their distribution on this basis was 157 (64.6%) in level-I, 28 (11.5%) in level-II, 37 (15.2%) in level-III and 21 (8.7%) in level-IV. Furthermore, male patients having level-I education were 71(52.6%) and female patients 86 (79.6%). Similarly, those with level-II education were 19 (14.1%) males and 9 (8.3%) females. Males with level-III education were 26 (19.3%) as compared to 11 (10.2%) females. Likewise, males having level-IV education were 19 (14.0%) as compared to only 2 (1.9%) females. The association between OHIP scores and educational level was found significant (x2 = 4.28 P > 0.05). Data for the proportions of patients and their corresponding OHIP scores for the various categories of the numbers of missing teeth are given in Table V.
The value of the co-efficient of correlation of 0.29 showed a positive correlation between the number of missing teeth and the corresponding OHIP scores indicating a link of the number of missing teeth to a poorer OHRQoL as the OHIP index measured the severity of problems. Table VI gives details of the proportions of patients and their corresponding OHIP scores for the various categories of the numbers of edentulous spaces The value of the co-efficient of correlation of 0.37 clearly shows that there is a positive correlation between the number of edentulous areas and the OHIP scores. Inspection of the data in Table V shows that some more than 40% subjects were those
who had six or more missing teeth. In these patients, the average OHIP scores ranged from 20.5 to 52.6. In comparison, the average OHIP scores ranged from 8.8 to 19.0 for those who had 15 missing teeth in their mouth. Similarly inspection of the data in Table VI shows that some 59% subject who had three or more edentulous spaces, their OHIP scores ranged from 22.0 to 86.5 as compared to average OHIP scores ranging from 13.3 to 20.0 for those who had one or 2 edentulous spaces respectively
Generally, higher OHIP scores were recorded for subjects who had anterior edentulous spaces, distal extension spaces, multiple bounded spaces and extensive and larger edentulous spaces. Even much higher scores were recorded in those who had, in addition to anterior spaces, bounded and distal extension spaces. This clearly tells that the number of missing teeth, their distribution and the type and location of the edentulous spaces would affect the OHRQoL of patients as measured by the higher OHIP scores. Another interesting trend in the data was that a great proportion of the subjects had Missing anterior spaces, multiple bounded spaces as compared to distal extension spaces. The distributions of responses to each of the 33-items in OHIP sheet are presented in Table VII. These show that irrespective of the levels of problems, the most important OHIP items which impacted the OHRQoL of a great majority of the partially dentate subjects were the problems in chewing, eating, general concerns of the feeling of teeth missing, remaining upset with the loss of teeth. In a great majority of patients, a very severe impact on QoL was seen for only a few OHIP items. Inspection of the data in Table VII, clearly show that many OHIP-items / statements (not shown in bold in this table) were minimally or negligibly affected by missing teeth and edentulous areas present.
This study confirmed that both the number of missing teeth and edentulous spaces as well as the two socio-demographic co-factors of age and socio-economic status were by far the strongest predictors for impaired OHRQoL associated with partial edentulism. It however, such a greater effect of the gender and educational level of the patients was not seen.
The number of missing teeth was found a strong predictor for impaired OHRQoL as measured by recording the scores for the 33-items determining the OHIP 13, 56, 51, 57. However, our results about the missing teeth and OHR QoL correlation suggest that all lost teeth might not be equally important in their influence on OHRQoL. For example, out of 243 patients, our results showed that for one missing tooth the average OHIP score was 16.4 and for two missing teeth the average score was 10.6 and for three missing teeth the average score was 8.8. The reason for this variation in scores may be due to the likely pronounced impact of the aesthetic aspect of anterior dental arches which is one of the most important domains in patient needs and wishes. The patients who had one missing anterior tooth reported high scores for the OHIP-33 items compared to patients who had two or three missing teeth in the posterior dental arches. This may be an indication that persons with missing anterior teeth are so influenced by such a dominant factor that the concern of posterior natural teeth is reduced. The results from a study on partially dentate subjects and removable partial dentures seem to support ours as well as earlier results that the aesthetic aspect of anterior dental arches is a major subjective indicator influencing OHRQoL of patients 44.
The positive correlation between OHRQoL and missing teeth in our study supports the recommendations of a previous study highlighting that the data of missing teeth should routinely be used as a stratifying factor in comparative studies 19. Another study showed that the number of missing teeth had the strongest relation (r = 0.33) among six clinical measures investigated 58. This is in accordance with our findings where the value of r is 0.29. Other multi-variate- analyses, including demographic factors and clinical variables, found the number of missing teeth a statistically significant predictor for perceived oral health and OHRQoL as measured by means of the dental impact of daily living (DIDL) instrument 59 – 60. Many cross-sectional studies confirmed hypothesized relationships between clinical, socio-demographic or dental care factors and OHRQoL. For example, tooth loss and lower socio-economic status typically were correlated with poorer QoL.50, 58 – 61. Another study proved that approximately 70% of patients reported that they had changed their food choices because of missing teeth and that financial cost was a barrier to dental
treatment 62. These studies support the present findings that missing teeth and socioeconomic status were closely related to impaired OHRQoL. There was also a strong relationship between age and OHRQoL. Because age may be influential both on its own and even more so through its relationship to missing teeth, which is a strong predictor for OHRQoL. The findings of the present study are supported by the English and German studies 16, 51, 57, 63 – 65. However, differences would be expected in the results of those studies compared with present one even if cross-cultural equivalence can be assumed for the OHIP 66. The reason for this difference may be that the age range of our patients was 30-50 years compared to the German population where it was 16 – 79 years and the English study by including much older adults 16.The effect of gender and educational level on the OHRQoL was not so strong among the patients of this study. Education level as a co-variable was only weakly associated with OHRQoL for the age range 16-60 years in the German population 16. This seems to support the present findings. As in this study, gender differences were not associated with OHRQoL but age differences were. The present results are supported again by this study conducted in Germany. The number of teeth was considered a key factor influencing the impact oral health status had on QoL in the OHRQoL-UK study whereas in Germany denture status (a related measure) was found influential 16.
As expected the site and the number of remaining natural teeth played a central role as a determinant of subjective oral health. The current data demonstrate that missing teeth and edentulous spaces were associated with a reduction in OHRQoL However, as noted by others 10, 19, 67 the relationship between increasing tooth loss and more severe impacts on oral health was not a simple, monotonic one. For example, for one missing tooth, the impact was relatively more severe in terms of higher score as compared to three missing teeth. This was due to the site of that one single missing tooth and more probably the specific individual characteristics of patients in that subset. The impact scores increased if a single tooth was missing in the anterior dental arches. Similarly, a study comparing two national samples of UK and Australia showed that in the UK, mean OHIP scores were worst for people with 16 or fewer teeth, which is supportive of the present results that showed higher scores if 16 or more missing teeth were present 10. The findings from this latter mentioned study 10 indicate that adverse impacts of oral health would increase rapidly for people with fewer than 25 teeth which are supportive of the present results that showed that the OHIP score increased rapidly for more than seven missing teeth.
Striking finding of our study is that the key factor accounting for high OHIP scores is the position of the teeth lost which is supported by a study on adult patients 68. This study demonstrated that age had a fundamental influence on OHRQoL and that loss of teeth was associated with a reduction in OHRQoL independent from the effect of age although age and tooth loss were closely associated but the relationship between loss of teeth and QoL appeared to work on a more complex basis. Our findings are supported by studies from UK and Australian national samples10. We found that those aged 45-50 years showed the worst (highest) scores and those aged 30-35 years showed better (low) scores.
In fact, it has very recently been confirmed that fulfilling prosthetic needs was not only about recovering oral masticatory function, but this also improved both physical and mental health-related quality of life69. Based on the results of our study, we believed that tooth loss, edentulous spaces, age and socio-economic position were principal determinants of variation in oral health impact. Our findings are supported by oral health surveys of adults in the UK and Australian populations 10, 37. However, as observed in the 2nd International Collaborative Study, we also agree to their statement that pointed out that the relative contribution of various determinants and the magnitude of their effects would vary between populations and / or cultural sub-groups within populations 67. We found that gender and educational level did not adversely influence OHRQoL. Many studies have not found statistically significant OHRQoL differences for gender or educational level 10, 16, 19. However, we found that age and socio-economic status were related to OHRQoL. A possible explanation for the observed relationship was the accepted belief and observation that tooth loss and its extent is a sequel of increased age and poorersocio – economic status . The OHIP items/statements that we removed from the original 49-items questionnaire were; dentures not fitting, breath stale, taste worse, tooth doesn’t look right, tooth ache, painful aching, painful gums, headaches, sensitive teeth, uncomfortable dentures, others misunderstood, unable to brush teeth, less flavor in food, sleep interrupted, less tolerant of family and irritable with others. We used a shortened questionnaire i.e. OHIP-33 partly to reduce participant burden and partly due to the close relationships among the concepts of all OHIP items/statements which m a k e differentiation among various OHIP items/statements somewhat difficult 8. In addition, this study aimed to report impacts associated with tooth loss and edentulous spaces on OHRQoL, whereas, some of the OHIP items like dentures not fitting, uncomfortable dentures, tooth-ache, tooth doesn’t look right, headaches, unable to brush teeth etc were irrelevant. Further, the large number of items within the OHIP might create relatively consistent results and might lead to incorrect measurement of the perception of oral health status of an individual 12. Moreover, Locker and Allen 70 reported that a long measure may need to be shortened because it takes long time to complete, increases the cost of administration and data management and increases respondent burden. Furthermore, item non response was higher with long questionnaires. This may lead to a loss of a substantial portion of cases or problems arising from the necessity to impute missing data. Therefore, a short form of OHIP was developed to test its performance in a cross sectional study of local subjects.
There are findings from other countries that show that a locally relevant questionnaire would be more appropriate for assessing the OHIP on QoL of subjects in that region locally 4, 71 – 72. The 14-item Malaysian short form of the OHIP was developed and selection of the items was based on an assumption that items were important when they were frequently reported by the patients 1.
This study ensured the validity, internal consistency and reliability of the short version in terms of coverage
Likewise, a short form of OHIP was developed for the K o r e a n p o p u l a t i o n c o n s i s t i n g o f 1 4 – O H I P items/statements 70. The OHIP-K showed excellent reliability and validity and was rendered a better choice for the evaluation of OHRQoL among the Koreans. Similarly, a short form of OHIP was used for the South Australian population i.e. OHIP-14 to evaluate the health and QoL outcomes 72. Therefore, we developed our own OHIP-33 in this survey which we considered appropriate.
Not withstanding the observed complexities regarding the associations or the lack of these between the impact of various individual OHIP items or their total scores, of the condition of oral and dental health status and of the socio-demographic variables of patients, as well as the evidence for support or the lack of it for the present findings from studies done abroad, this study has given some very useful information regarding the design of local studies of the kind. For examples, we noted many OHIP items / statements that were little or not affected by the condition of missing teeth or edentulous areas and hence their negligible effect on the OHRQoL of local subjects. However, before large scale local studies are done to see the precise impact on these items on the QoL of local patients, their reliability and validity would remain uncertain. Some locally relevant items that were clearly and obviously impacted by the studied oral conditions were identified
These were related to functional impairment in terms of efficiency and comfort during eating and diet restriction, feeling of having missing teeth, esthetic consciousness and related concerns. Thus several social domains which were otherwise important in inhabitants of developed countries were mostly found less important. This emphasizes the need for a relevant and shorter OHIP questionnaire for future such local studies
CONCLUSIONS AND RECOMMENDATIONS
- Higher OHIP scores were recorded for subjects who had missing teeth leading anterior edentulous spaces, distal extension spaces, multiple bounded spaces and extensive and larger edentulous spaces. Similarly, much higher scores were recorded in those having bounded and distal extension spaces in addition to anterior spaces.
- Chewing and aesthetics problems seem to be the two most important domains in patient needs and wishes.
- The likely effect of various prosthodontic treatments will be a reduced OHIP score in those partially dentate patients who never had an experience of wearing any oral prostheses. Thus maintaining teeth or using dental prostheses after losing teeth are important for the oral health and improved QoL.
- The development of a locally relevant and shorter version of the original OHIP questionnaire with relevant items is considered important
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