The association between denture self-satisfaction rates and OHRQoL - a follow-up study

Patient-report outcome (PROs) provide practice guides for clinical treatment. Despite declining edentulism and increasing implant treatment, the need for complete denture treatment will remain substantial in the future [1‐4]. For most edentulous patients in Taiwan, complete denture will be the first treatment option [5]. The growing elderly population worldwide and the extended edentulism status have increased the need for successful denture treatment. Denture treatment is a time-consuming process, the follow-up adjustment of denture fitting and tissue adaptation to get a satisfactory outcome is important. It has been found that psychological factors may play an important role in those patients who experience difficulty in adapting to new dentures [6‐8]. The function, social and psychological impact of edentulous status have been discussed in many previous studies [1, 4, 6, 9‐12]. PROs allow for the straight quantification in patients’ opinion of distinct aspects of denture intervention.

During clinical trials, patient-ratings in treatment satisfaction are often assessed along with quality of life [13‐15]. It has been suggested that self-ratings of satisfaction may be more sensitive to change than quality of life, particularly for comparisons of palliative treatment for chronic medical conditions [16]. Self-rating satisfaction will vary with an individual’s preferences, expectations and with the quality of the information given by the physician [14, 17].

Patient’s satisfaction [1, 15, 16, 18] and OHRQoL [19‐24] are the most common factors to consider in patient-centered analysis of prostheses treatment. The OHIP is a reliable and valid instrument suitable for assessment of OHRQoL in cross-sectional and longitudinal studies [1, 3, 4, 25‐27]. A number of studies have evidenced the correlation between patient satisfaction and quality of life. In Chen’s study, it was suggested that dentist-patient communication and denture quality are correlated with the patient’s satisfaction. Joselyn’s study also showed a positive association between dental satisfaction and OHRQoL. Kao’s paper [4] suggested that denture treatment is associated with responsiveness of OHRQoL With the complex correlation between various dimensions of satisfaction and OHRQoL, we need a more comprehensive assessment of satisfaction patterns [4, 5].

The correlation between expectation and satisfaction after complete denture treatment has been assessed in some previous studies [28‐30]. However, this satisfaction of treatment is multi-dimensional concept. There is a discordant conclusion about the relationship between denture satisfaction and OHRQoL [5, 7, 31‐33]. The objectives of this study were to try to identify the key dimension in satisfaction from the combination of satisfaction clusters, and its effect on the change of OHRQoL of elderly denture users.

In Table 1, a strong correlation (p value < 0.001 in all pairs) was found among the six different satisfaction dimensions. The five cluster solution is determined by cluster analysis. The means and standard deviation of six satisfaction dimensions across clusters demonstrated that the identified clusters had varied patterns of the six satisfaction dimensions in Fig. 1. The cluster “NAS” was the lowest satisfaction score at every dimension, and cluster “SDG” had a similar pattern, but a slightly higher satisfied score. A lower satisfaction pattern was found in the dimension of chewing ability, stability, doctor and general in cluster “MS”. And only dissatisfaction of chewing ability and stability was found in cluster “QS”. In cluster “HS”, a higher satisfaction score was found in six dimensions of denture use. The basic demographics and personal habits of the five clusters are shown in Table 2. A higher proportion of males was found in clusters “NAS”(51.81%), “SDG”(48.92%) and “MS”(55.68%), but the diversity did not reach a statistically significant difference. The education level, smoking cigarettes, areca quid chewing and alcohol drinking were similar in the five clusters. However, a lower economic status (11.56%) was found in cluster “HS”, which reached a statistically significant difference.

The responsiveness of seven conceptual dimensions in OHIP-7T was compared among the five satisfaction groups. The mean of OHIP-7T before treatment, 6 months after treatment and observed difference is shown in Table 3. It shows that there was almost no difference in OHIP-7T before and after treatment in cluster “NAS” (ES = 0.12), which means that only 12% improved in OHIP-7T after denture treatment. And an increasing impact improved level was found in cluster “SDG” to “HS” by ascending sequence.

The related factors affecting the responsiveness of overall OHIP-7T are presented in Table 4. Since there are some diversity existing among demographic variables, we will use statistical model to adjust these confounders. The satisfaction group is an important affecting factor after adjusting for demographic variables, personal habits, the experience of denture use, perceived oral and general health and pretreatment OHIP-7T score. To control the effect of confounding factors in improvement of OHRQoL, the statistical models were performed in Table 4 and Table 5. In Table 4, the regression coefficience in group “HS” was 7.31, which means that OHRQoL improvement in group of “HS” was 7.31 more than in in group of “NAS” after denture treatment. When controlling other confounders in model, the greatest improvement of OHRQoL after denture treatment was found in group “HS”(β = 7.31(95%CI: 6.26–8.36) compared to satisfaction group “NAS”, followed by group “QS” (β = 4.71(95%CI: 3.54–5.87)), group “MS”(β = 4.33(95%CI: 2.92–5.74)) and group “SDG”(β = 3.25(95%CI: 2.10–4.41)). A statistically significant increasing pattern was detected in satisfaction and OHRQoL from Table 4. The affected OHRQoL dimension levels of improvement between pre- and post-treatment at the five satisfaction cluster groups is presented in Table 5. The most improved OHIP dimension was observed at “psychological discomfort” in every cluster group. In group “NAS”, the other significantly improved OHIP dimensions were “handicapped”(OR = 2.18(95%CI: 1.06, 4.45)) and “function limitation” (OR=1.93(95%CI:1.01, 3.68)), which means that the subject with impact OHIP dimensions of “handicapped” and “function limitation” in pre-treatment are 2.18 and 1.93 times of the chance for having got improved after denture treatment separately. In group “HS”, with the exception of “psychological discomfort” (OR = 29.32(95%CI: 20.51, 43.56)), the dimension of “function limitation” (OR = 29.89(95%CI: 20.51.43.56)) is also an important improvement dimension.

The use of clinical measures only to assess the oral health of individuals has been criticized because they fail to consider functional and psychosocial aspects of health and do not adequately reflect the function, concerns and perceived needs of individuals [20‐23, 39]. There is little evidence supporting association between patient-reported QoL and satisfaction [40, 41]. But, the collinearity of distinct satisfaction dimensions would be more complex when evaluating the relation between self-rated satisfaction and OHRQoL.

The satisfaction group is an important affecting factor after adjusting for demographic variables, personal habits, the experience of denture use, perceived oral and general health and pretreatment OHIP-7T score. Our paper is the first study to evaluate the multi-dimension cluster satisfaction patterns related to the OHRQoL, which provide a concept to deal with the collinearity of distinct satisfaction dimensions. We modified the analyzing method in each dimension of satisfaction used in previous studious. It was found that the responsiveness of OHIP-7T is acceptable in our study. There are several important findings in this study. The first is that the major satisfaction dimensions affecting OHRQoL are the dimensions of doctor and general. Also the OHIP improved pattern is strongly associated with satisfaction groups and also show a dose-response relationship. The second finding is that “psychological discomfort” is the most improved dimension of OHIP in every satisfaction group, and “function limitation” also showed great improvement in the “HS” satisfaction group. The third important finding is that satisfaction associated with “chewing ability” and “stability” are the major parts affecting overall OHRQoL. One of the advantages of using patient satisfaction as a treatment outcome is its simplicity and comprehensibility in a clinical environment [5]. From edentureous subject’s opinions, it is expected that new denture fit and function should be equal to or even better than their natural teeth [5]. However, the status of resorbed ridges, collapsed muscles and other physical changes would be the important baseline considerations. It should be an important part of dentist-patient communication before denture treatment. During the process of denture treatment, satisfaction can provide an insight into complete denture wearers’ physiological and psychological capacities [33, 42]. In our study, approximately 33% of denture wearers was dissatisfied with their denture, which is similar to previous studies [31, 43, 44]. Among all the dissatisfied wearers, two thirds showed dissatisfaction to their doctor and general dimensions. Chen’s study [5] showed that more than 30% of elderly people have experienced difficulty in adapting to their prostheses. Dentist-patient communication might play a key role in patients satisfaction regarding denture-wearing episodes, after-care concerns, and instructions related to nutrition, speech, nocturnal wear and denture hygiene [1, 2, 8, 45]. General health, age, gender, personality traits, experience with previous dentures and patient expectations regarding medical care were factors relating to the satisfaction of denture [29, 45‐49]. The “psychological discomfort” is the most improved OHIP dimension, and this pattern is found in every satisfaction group. Although the improved impact in every satisfaction group varies. The dimension of “psychological discomfort” is the reflection of psychological capacities, which demonstrated the importance of dentist-patient relationship [5, 44, 50]. Denture wear not only comprised of good fabrication quality, but also denture-wearing episodes and after care concerns, individual follow-up schedules, and instructions related to daily wear. It is important to gain a deeper comprehension of patients’ psychosomatic phenomena, hence, more extensive, clinic and patient-based research should be carried out to gain more knowledge about patients’ expectations and final evaluation of complete denture treatment.

The function aspect of complete denture is also an important factor relating to OHRQoL. Michaud’s study found that a person’s perceived chewing ability and oral condition are the most important factors affecting OHRQoL [14]. The “chewing ability” and “stability” are related to eating and speaking capacity, which are the most important oral functions. The results of our study are in agreement with those of Awad and Feine [51], who demonstrated that the functional aspects (chewing and speaking ability) significantly affect the rating of satisfaction, and it also found this function aspect as having a critical impact on OHRQoL.

The items related to eating were the functions that most participants reported to be positively affected. This was an expected finding, as teeth are directly involved in chewing and biting, and thus enjoyment of eating. In this study, we found that both the satisfaction in function and psychosocial aspects of denture wearers significantly affect the OHRQoL. However, the dissatisfaction in doctor and general aspects had a higher impact on OHRQoL than in chewing capacity and stability of denture. Previous studies [51, 52] found that the ability of chewing is the most important factor in denture satisfaction. But in Tuker’s paper of 2009, the association between subjective reported satisfaction with the objective measure of denture quality such as retention and stability are often statistically insignificant [53]. In 2018, Luo’s study [54] realized that the denture wearers expected the attention and concern of their suffering from dentistry professional groups, including understanding their expectation of the denture treatment, their clarity of explanation about the treatment and follow-up adjustments. Further study is needed to examine the insight of the patient’s perception after denture treatment.

There are some limitations in our study. First, we did not encounter any discrepancies between outcome measures due to denture material, since the material and funding for complete sets of removable denture are standardized for all patients. Second, it is in terms of generalizability of these results. It is not known if similar findings would prove comparable if the OHRQoL tool was used with younger denture wearers. Third, our study proved that patient-based measures are associated with improvement of OHRQoL. But, the effect of expert-based measures on denture satisfaction and OHRQL improvement still needs further study in the future.

In this study, we found that the satisfaction of doctor and general is the main dimension affecting improvement of OHIQoL after denture treatment. And it is also found that the importance of psychological aspects have greater impact than physical aspects in OHIP. Among denture wearers in Taiwan elderly, psychological value is the greatest impacting dimension on OHRQoL. Additional efforts should be made to improve satisfaction of patients with their dentures through development of communication among dental professional teams, and to improve the OHRQoL, which is one of the most important factors with denture wearers. Also, we expect that the shorter OHIP-7T will be a useful alternative instrument when time and resources are limited.