Objectives: Oral health problems can have potential effects beyond the oral cavity. The aim of this study was to evaluate the oral health-related quality of life in heart transplant recipients, compare the results with systemically healthy individuals, and investigate the effects of periodontal clinical parameters and periodontal and oral status on oral health-related quality of life.
Materials and Methods: For this retrospective study, we included heart transplant recipients who had previously undergone periodontal evaluation and age- and sex-matched systemically healthy individuals. Oral health-related quality of life was measured using the Oral Health Impact Profile-14. Periodontal status and oral health status were assessed using the following parameters: plaque index, bleeding on probing, probing depth, clinical attachment loss, gingival recession, and decayed, missing, and filled teeth index. We used the Mann-Whitney U test, χ2 test, and logistic regression analyses for statistical analyses.
Results: No significant differences were observed in total Oral Health Impact Profile-14 scores between heart transplant recipients and healthy individuals (P > .⁰⁵). However, mean probing depth, gingival recession, clinical attachment loss, and plaque index scores were significantly higher among heart transplant recipients than among healthy individuals. The number of missing teeth were also significantly higher (P < .⁰⁵) in the transplant group. Logistic regression analysis did not identify any variable with a significant impact on oral health-related quality of life.
Conclusions: Although periodontal disease parameters appeared more pronounced in heart transplant recipients, this was not reflected in oral health-related quality of life scores. The asymptomatic nature of periodontal deterioration and pretransplant dental procedures may contribute to this outcome. Our results underscored the importance of preventive, structured, and interdisciplinary oral care in this medically vulnerable population.

Key words : Immunosuppression, Oral health, Periodontal diseases, Solid-organ transplantation

Introduction
Heart transplantation (HTx) is the final treatment option for patients with end-stage heart failure,¹ offering substantial improvements in survival and overall quality of life due to advancements in surgical procedures and immunosuppressive therapies.² Despite substantial advancements in patient survival and postoperative outcomes, lifelong immunosuppression remains essential to prevent graft rejection; however, immunosuppression can lead to increased susceptibility to systemic and opportunistic infections.^3,4 The oral cavity harbors more than 500 bacterial species, therefore representing a major potential source of infection in immunocompromised individuals.^5,6 Oral health problems, like dental caries and periodontal diseases, are important because of their potential effects beyond the oral cavity. Periodontitis is a chronic inflammatory condition that can lead to bacteremia and contribute to systemic inflammation. Periodontitis has been associated with several systemic diseases, including cardiovascular disease, respiratory infections, and diabetes mellitus.^7,8 In diabetes, periodontal inflammation may worsen glycemic control, and poor metabolic control can further aggravate periodontal disease, showing a close interaction between oral and systemic health.⁹ Studies on different solid-organ transplant recipients have indicated that periodontal disease may represent a relevant and often underestimated risk factor for posttransplant infections. Poor periodontal status and the lack of adequate dental evaluation and treatment pretransplant have been associated with an increased risk of posttransplant infectious complications in liver, kidney, heart, and lung transplant recipients, including sepsis, fever-related hospitalizations, pneumonia, and infective endocarditis.^6,10-13 For example, a systematic review reported higher rates of pneumonia among lung transplant recipients with increased oral bacterial load and periodontitis.⁶ Accordingly, comprehensive dental and periodontal management before and after transplant is considered important for reducing oral infectious foci and potentially related complications. Oral health–related quality of life (OHRQoL) is a multidimensional concept that reflects the functional, psychological, and social effects of oral conditions on daily life.¹⁴ In the general population, conditions such as periodontal disease and tooth loss are clearly associated with reduced OHRQoL.¹⁵ Despite the clinical relevance of oral health in this population, data on OHRQoL, specifically in HTx recipients are scarce. Existing studies have focused primarily on clinical findings such as periodontal status or oral symptoms, without examining how patients subjectively perceive their oral health or how these perceptions compare with those of healthy individuals.^16-21 Clarifying how patients experience oral health subjectively and how oral health relates to overall health in HTx recipients is important. Moreover, to date, no study has directly compared OHRQoL in HTx recipients versus age- and sex-matched systemically healthy controls. Therefore, in the present study, we (1) evaluated OHRQoL in HTx recipients using the Oral Health Impact Profile-14 (OHIP-14) questionnaire, (2) compared their scores with those of age- and sex-matched healthy individuals, and (3) investigated the effects of periodontal parameters, oral health status, immunosuppressive therapy, and posttransplant duration on OHRQoL.

Materials and Methods

Study design and population
In this retrospective study, we included HTx recipients who were previously enrolled in the project D-KA18/28 and had undergone a comprehensive periodontal evaluation. All patients had received HTx at Başkent University Hospital, Department of Cardiovascular Surgery (Ankara, Türkiye), between 2003 and 2017. The control group consisted of systemically healthy individuals who received periodontal treatment at Başkent University Faculty of Dentistry, Department of Periodontology, between 2016 and 2019; health individuals were matched to the HTx group by age and sex. Because all oral, periodontal, and OHRQoL data had been collected and recorded before the study, no additional patient recruitment was performed. This study was approved by Başkent University Institutional Review Board (project D-KA25/22) and supported by the Başkent University Research Fund. The study was performed in accordance with the Helsinki Declaration of 1975, as revised in 2000. Eligibility criteria for HTx recipients included being clinically stable and at least 1 year posttransplant. Recipients were excluded if they had undergone periodontal treatment within the previous year, used antibiotics during the preceding 6 months, or exhibited clinical instability. Each HTx recipient was matched with a systemically healthy control individual of the same age and sex, as confirmed by medical records indicating the absence of systemic disease. Participants in the control group were also required to have no history of periodontal treatment within the past year and no antibiotic use in the preceding 4 months. The flowchart in Figure 1 summarizes the study design.

Dental and periodontal assessments
Dental status was evaluated using the DMF-T index, which records the number of decayed (D), missing (M), and filled (F) teeth. Periodontal health was assessed using previously documented clinical parameters, including plaque index (PI), gingival index, probing depth, clinical attachment loss (CAL), gingival recession (GR). All measurements were obtained from standardized periodontal charts recorded during routine clinical examinations before the study period.

Oral health-related quality of life assessment
The OHRQoL was evaluated in study participants by using previously collected scores from the Turkish version of the OHIP-14 questionnaire.²²

Statistical analyses
We used SPSS version 25 software for data analyses. We presented descriptive statistics for quantitative variables as mean ± SD and median (minimum to maximum [range]). We evaluated differences between the categories of a qualitative variable with 2 categories with the Mann-Whitney U test when normality assumptions were not met. We examined relationships between 2 qualitative variables with the χ2 test. We analyzed risk factors affecting the quantitative dependent variable with logistic regression analysis. P < .⁰⁵ was considered statistically significant.

Results

Participant characteristics
Among 72 participants included in the study, 36 were in the transplant group and 36 were in the control group, which were matched for age and sex. Smoking habits did not differ significantly between groups (P > .⁰⁵).

Dental findings
The DMF-T scores were similar between the 2 groups; however, the number of missing teeth was significantly higher in the transplant group (P < .⁰⁵) (Table 1).

Periodontal findings
Heart transplant recipients exhibited significantly higher PI, CAL, and GR values compared with healthy controls (P < .⁰⁵). Other periodontal parameters did not differ significantly between the groups (Table 1).

OHIP-14 scores
No significant differences in total OHIP-14 scores were shown between the HTx and control groups (P > .⁰⁵). Similarly, none of the 7 OHIP-14 subdomains, including functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap, showed significant differences between groups (P > .⁰⁵) (Table 2). Age, sex, transplant survival, rejection status, periodontal diagnosis, smoking habits, DMF-T, and CAL were included in a logistic regression model as potential predictors of OHIP-14 scores. However, none of these variables showed a significant association with OHIP-14 (P > .⁰⁵) (Table 3).

Discussion
The present study evaluated OHRQoL and periodontal status in HTx recipients and compared these findings with age- and sex-matched systemically healthy individuals. The findings of our study showed that HTx recipients had more pronounced periodontal disease parameters (mean GR, CAL, and PI) and a higher number of missing teeth compared with systemically healthy individuals. However, no significant difference was found in total OHIP-14 scores between the HTx and healthy control groups (P > .⁰⁵). This indicates that the OHRQoL perceptions of HTx recipients were not affected despite having clinically poorer oral health conditions. Regression analysis also revealed that none of the examined variables had a significant effect on OHRQoL. To the authors’ best knowledge, this is the first study to compare OHRQoL in HTx recipients with age- and sex-matched systemically healthy individuals. The higher periodontal disease parameters and missing teeth observed in HTx recipients in our study were consistent with general trends in the literature on oral health in solid-organ transplant recipients.^16,21,23-27 Previous studies in lung transplant recipients have shown significantly higher moderate or severe periodontal disease prevalence and high DMF-T scores and edentulism rates compared with the general population.²³ Similarly, both heart failure patients and HTx recipients have been shown to present with substantial periodontal treatment needs.¹⁷ Compared with the general population, HTx recipients also exhibited an increased need for periodontal treatment.²⁰ The detrimental effects of periodontal disease on OHRQoL among systemically healthy individuals have been well documented.^15,28 Evidence has consistently shown that periodontal parameters, such as CAL and GR, are associated with worse OHRQoL scores.^29-31 Despite research showing objectively poorer periodontal and oral health in kidney, liver, and lung transplant recipients, OHRQoL often remains comparable to that of healthy individuals or is only slightly impaired.^{17,23,24,26,27} The inconsistency between objective clinical conditions and subjective perceptions may be explained by the tendency of patients to view oral health problems as secondary to their overall health burden. After transplant, risks such as infection and graft rejection, along with psychosocial challenges, raise the threshold for patients to perceive oral health problems. This phenomenon is described by the response shift theory.³² In this setting, chronic oral conditions may exert limited influence on perceived functional well-being, as broader systemic priorities dominate the patient’s health experience. Results of our study showed that, although clinical periodontal parameters (CAL, GR, PI) were poorer in HTx recipients, this was not reflected in their OHRQoL scores. Another factor that may contribute to this observation is the implementation of pretransplant dental protocols. During this period, symptomatic infected or severely compromised teeth are often extracted to reduce the risk of infection. The removal of problematic teeth may decrease pain and discomfort and lead to an improvement in perceived oral well-being, even if periodontal conditions worsen over time. In the present study, the lack of significant differences in probing depth and periodontal diagnoses between groups, despite higher CAL and GR values in HTx recipients, may partly reflect the preventive effect of these pretransplant dental interventions. The largely asymptomatic nature of chronic periodontitis may also be an important factor. Because periodontal disease often progresses without noticeable pain or functional problems, patients may not perceive periodontal disease as a serious condition. This may lead to reduced attention to dental follow up and oral hygiene regimens, which is concerning given the potential systemic consequences of periodontal infections. Daily activities such as chewing and tooth-brushing can induce transient bacteremia, and, in immunocompromised transplant recipients, this presents a plausible risk for severe systemic infections and even graft-related complications.^10,13,33 Together, the findings of this study reveal a clear disconnect between clinical periodontal need and patient-perceived effects. Although HTx recipients demonstrated measurable periodontal deterioration, these objective changes were not reflected in their subjective assessments of OHRQoL. This gap emphasizes the importance of proactive, structured, and interdisciplinary oral care for transplant recipients, including regular periodontal monitoring, reinforced oral hygiene instruction, and individualized maintenance programs aimed at preventing disease progression and minimizing systemic risk. However, several limitations should be considered when interpreting these results. The retrospective design precluded causal inference, and reliance on previously documented clinical data introduced the possibility of variability in measurement or record accuracy. The sample size, although comparable to similar studies in transplant dentistry, limited the ability to perform detailed subgroup analyses. In conclusion, HTx recipients exhibited significantly worse periodontal health, including greater attachment loss, GR, and tooth loss, while their OHRQoL remained comparable to healthy controls. This discrepancy likely reflects the diminished perceived relevance of oral conditions in the context of substantial systemic and psychosocial burdens associated with transplant, as well as the asymptomatic progression of periodontal disease. The presence of notable periodontal deterioration in a relatively young cohort underscores the potential for rapid disease progression under immunosuppression and highlights the importance of controlling periodontal inflammation due to its possible systemic implications. These findings reinforce the need for preventive, structured oral care and close collaboration between transplant teams and dental professionals to ensure early detection, effective maintenance, and improved long-term outcomes for HTx recipients.