Impact of Tooth Loss Position on Oral Health-Related Quality of Life in Adults Treated in the Community

Abstract

Background:

Tooth loss is known to have negative effects on both functional and psychological oral health-related quality of life (OHRQoL), but the impact of the position of the tooth loss (i.e. anterior or posterior) on the different psychosocial dimensions of OHRQoL has yet to be examined. Here, we examined how the position of lost teeth impacts the different dimensions of OHRQoL.

Methods:

This was a cross-sectional epidemiological study of adults aged 18 years and older attending routine examinations at primary care dental centers in Jeddah, Kingdom of Saudi Arabia. Demographic information was collected, and OHRQoL was assessed using the Oral Health Impact Profile-14 (OHIP-14) (Arabic form). Differences in total and subdomain OHIP-14 scores between individuals without tooth loss and those with ≥1 anterior or posterior missing teeth were assessed using Student's t-test, and analysis of covariance was used to assess the association between the presence and absence of missing teeth in each compartment and total and subdomain OHIP-14 scores after controlling for age, gender, and income.

Results:

The overall prevalence of tooth loss was 76%. In multivariate analysis controlling for age, gender, and income as covariates, anterior missing teeth were significantly associated with higher OHIP-14 total, physical pain, physical disability, psychological disability, and social disability scores, accounting for 6%–12% of the score variance. However, posterior missing teeth were only associated with total OHIP-14 and functional limitations domain scores, accounting for 6% and 7% of the variance, respectively.

Conclusions:

Here, we show for the first time the impact of the location of missing teeth on different OHRQoL dimensions. Anterior tooth loss has a wide-ranging impact on both physical and psychosocial functioning compared to posterior tooth loss, suggesting that anterior tooth restoration should be prioritized when treatment planning. The position of lost teeth must be considered in addition to the number of losses when examining the impact of tooth loss and its treatment on OHRQoL.

INTRODUCTION

Quality of life (QoL) is an important parameter to consider when assessing health status and treatment outcomes in dental patients. Oral health-related QoL (OHRQoL) describes the impact of orofacial conditions and dental interventions as perceived by the patient.[1] OHRQoL is a multidimensional concept that is influenced by physical health, psychology, social interactions, and the environment and as a consequence, standardized instruments have been designed to capture the different composite domains of OHRQoL.[1] One of the most widely used is the Oral Health Impact Profile-14 (OHIP-14), a short form self-reporting questionnaire comprising 14 items divided into seven dimensions of impact (functional limitation, pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap).[2] The OHIP-14 has been shown to be reliable,[2] sensitive to changes,[3,4] and have cross-cultural consistency[5] including in Arabic.[6]

Tooth loss remains a significant public health burden in Saudi Arabia, with a recent study reporting a 69% prevalence of tooth loss in a convenience sample of over 600 subjects in Riyadh, Saudi Arabia.[7] Since teeth are vital to mastication, speech, and facial esthetics, tooth loss can have a significant impact both on the individual and society. In meta-analyses and systematic reviews, tooth loss has been shown to have negative effects on both functional and psychological OHRQoL independent of the instrument used or the social context.[8,9,10,11] Furthermore, in our recent analysis of occlusal traits and OHRQoL, we found that tooth loss was the only independent predictor of high total OHIP-14 scores in a community sample of adults attending primary care clinics in Jeddah, Saudi Arabia, even when controlling for factors such as age, gender, and income.[12]

However, few studies have examined how the position of the tooth loss (i.e. anterior or posterior) affects OHRQoL or how different tooth loss locations affect the different functional and psychosocial dimensions of impact. Therefore, here, we examined how the position of lost teeth impacts the different dimensions of OHRQoL, hypothesizing that teeth lost from different areas of the mouth will have a differential impact on OHRQoL dimensions.

METHODS

Study design

This was a cross-sectional epidemiological study of adults aged 18 years and older attending routine examinations at primary care dental centers in Jeddah, Kingdom of Saudi Arabia. The local institution's ethical board review approved the study protocol, and all patients gave written informed consent after reading the study details.

Inclusion criteria, exclusion criteria, and sampling

The primary health-care centers were geographically located in five areas of the city (north, south, west, east, and center) according to the KSA Ministry of Health. The inclusion criteria were patients aged 18 years and above who were medically healthy and syndrome free. Subjects who had received previous orthodontic treatment were excluded.

Sampling and assessment metrics

A cluster sampling approach was employed to recruit twenty participants from each geographical area, resulting in a total sample of 100 participants. Collected data included demographic information and OHRQoL assessed using the OHIP-14 (Arabic form).[6] Age was subcategorized into three groups (18–40, 41–60, and >60), while income levels were categorized into six groups. Each OHIP question is answered on a five-point Likert scale (0–4), and total scores were obtained by summing the scores of each of the 14 questions. Mean domain scores were calculated by dividing the sum of the subdomain score by the number of questions in that subdomain. Higher OHIP-14 scores indicated worse OHRQoL.

The presence of missing teeth and their location, where the incisors and canines were regarded as anterior teeth and the premolars and molars were regarded as posterior teeth, were recorded during clinical examination by three calibrated examiners. Clinical examination was completed in the clinic's dental chair with an examination kit.

Statistical analysis

Each subject was assigned a unique identifier code, and data were deidentified. Data analysis was conducted using the Statistical Package for the Social Sciences program v. 22 (IBM SPSS Inc., Chicago, IL, USA). Differences in total and subdomain OHIP-14 scores between tooth loss groups (no missing teeth vs. ≥1 missing teeth) were assessed using Student's t-test. Analysis of covariance was conducted to assess the association between presence and absence of missing teeth in each compartment and total and subdomain OHIP-14 scores after controlling for age, gender, and income as confounding variables. Results were considered statistically significant if the P < 0.05.

RESULTS

All invited participants agreed to participate but, after exclusion of patients who had received previous orthodontic treatment and patients with missing data, 87 patients were available for final analysis. 54% were male and 46% were female [Table 1]. Participants were fairly evenly distributed across all income brackets (15%–20%) except for the lowest and highest income brackets, comprising 28.7 and 1.1% of participants, respectively [Table 1].

Table 1.

Clinical and demographic features of the study participants

Variable	n (%)	Prevalence of≥1 missing teeth (%)
Gender
Male	47 (54.0)	76.6
Female	40 (46.0)	75.0
Age (years)
18-40	31 (38.3)	90.3
41-60	38 (46.9)	71.1
>60	12 (14.8)	75.0
Income level
0	25 (28.7)	80.0
1	15 (17.2)	93.8
2	14 (16.1)	64.3
3	14 (16.1)	64.3
4	18 (20.7)	66.7
5	1 (1.1)	100

The overall prevalence of ≥1 missing teeth was high (76%). Although the prevalence of missing teeth was about equal according to gender, there was a particularly high prevalence of missing teeth in the 19–40-year age group (90.3% vs. approximately 70% in the older age groups) and in income level 0 and 1 groups (80% and 93.8%, respectively) compared to higher income levels groups (~65%).

Since we previously showed that missing teeth were the only occlusal trait associated with total OHIP-14 scores,[12] we next examined how the position of the missing teeth influenced OHRQoL according to both total OHIP-14 scores and subdomain scores. In univariate analysis [Table 2], one or more missing anterior teeth was significantly associated with higher (i.e. worse OHRQoL) total scores (17.2 vs. 25.1; P = 0.04) and physical pain (1.9 vs. 3.4; P = 0.02) and social disability (2.3 vs. 4.3; P = 0.008) domain scores. One or more missing posterior teeth were associated with higher functional limitation (2.1 vs. 3.9; P - 0.008) and psychological discomfort (2.9 vs. 4.2; P = 0.04) scores. Total and domain OHP-14 scores were not significantly different according to gender, age, or income, except for the psychological disability domain, which was significantly higher younger patients. In multivariate analysis controlling for age, gender, and income as covariates [Table 3], anterior missing teeth were significantly associated with higher OHIP-14 total, physical pain, physical disability, psychological disability, and social disability scores, accounting for 6%–12% of the variance in scores. However, posterior missing teeth were only associated with total OHIP-14 and functional limitations domain scores, accounting for 6% and 7% of the variance, respectively.

Table 2.

Univariate analysis of associations between missing tooth position and total and subdomain oral health impact profile-14 scores

	n	Mean	SD	P
Total score
Posterior
No missing	36	15.8889	15.48783	0.061
≥1 tooth	42	22.4524	14.98650
Anterior
No missing	56	17.1786	15.46622	0.041
≥1 tooth	22	25.1364	14.28051
Total
No missing	17	13.7647	16.34598	0.088
≥1 tooth	61	21.0000	14.98221
Functional limitation
Posterior
No missing	40	2.1000	2.52982	0.008
≥1 tooth	45	3.8889	3.43261
Anterior
No missing	61	2.9836	3.13311	0.769
≥1 tooth	24	3.2083	3.27014
Total
No missing	20	2.1000	2.24546	0.125
≥1 tooth	65	3.3385	3.34607
Physical pain
Posterior
No missing	39	2.1795	3.08538	0.648
≥1 tooth	44	2.4545	2.37677
Anterior
No missing	59	1.8814	2.57364	0.019
≥1 tooth	24	3.4167	2.81172
Total
No missing	19	1.8947	2.92299	0.435
≥1 tooth	64	2.4531	2.66625
Psychological discomfort
Posterior
No missing	38	2.9211	2.88876	0.036
≥1 tooth	44	4.2273	2.64895
Anterior
No missing	58	3.3448	2.76920	0.168
≥1 tooth	24	4.2917	2.89646
Total
No missing	19	3.0526	3.04546	0.319
≥1 tooth	63	3.7937	2.75423
Physical disability
Posterior
No missing	40	3.1250	3.40578	0.961
≥1 tooth	44	3.1591	2.89300
Anterior
No missing	60	2.7333	3.00207	0.057
≥1 tooth	24	4.1667	3.26599
Total
No missing	20	2.9000	3.44735	0.693
≥1 tooth	64	3.2188	3.04708
Psychological disability
Posterior
No missing	39	2.2051	3.01033	0.193
≥1 tooth	43	3.0930	3.10003
Anterior
No missing	59	2.4068	2.86548	0.215
≥1 tooth	23	3.3478	3.52406
Total
No missing	19	1.8421	2.79410	0.181
≥1 tooth	63	2.9206	3.12793
Social disability
Posterior
No missing	40	2.5500	2.53134	0.355
≥1 tooth	44	3.1591	3.36841
Anterior
No missing	61	2.3443	2.60055	0.008
≥1 tooth	23	4.2609	3.55755
Total
No missing	20	2.3500	2.51888	0.378
≥1 tooth	64	3.0313	3.13186
Handicap
Posterior
No missing	40	2.7250	3.49349	0.578
≥1 tooth	44	3.1364	3.26070
Anterior
No missing	60	2.7000	3.13699	0.302
≥1 tooth	24	3.5417	3.86713
Total
No missing	20	3.0000	3.85255	0.928
≥1 tooth	64	2.9219	3.22345

SD: Standard deviation

Table 3.

Analysis of covariance analysis of associations between missing tooth position and total and domain oral health impact profile-14 scores

	F statistic	P	ηp2
Total score
Anterior	8.0	0.006	0.11
Posterior	4.4	0.04	0.06
Functional limitation
Anterior	0.001	0.98	0.00
Posterior	6.0	0.02	0.07
Physical pain
Anterior	8.2	0.006	0.10
Posterior	4.2	0.61	0.008
Psychological discomfort
Anterior	1.96	0.17	0.03
Posterior	2.8	0.10	0.04
Physical disability
Anterior	4.0	0.05	0.05
Posterior	0.004	0.95	0.00
Psychological disability
Anterior	4.2	0.05	0.06
Posterior	3.1	0.08	0.04
Social disability
Anterior	9.5	0.003	0.12
Posterior	0.83	0.37	0.01
Handicap
Anterior	0.98	0.33	0.01
Posterior	0.13	0.72	0.002

DISCUSSION

Here, building on our previous study of the impact of occlusal traits on OHRQoL,[12] we provide granularity to the impact of missing teeth on the OHRQoL of adult patients in the primary care setting. While both anterior and posterior missing teeth had an impact the overall OHRQoL as measured by the OHIP-14 instrument, the position of the missing tooth had a differential impact on the patient. While posterior missing teeth only impacted function, anterior missing teeth had a much broader impact on patients, not only affecting them in terms of pain and physical disability but also in the psychosocial dimensions. Although the magnitude of the effect of missing teeth was small (<0.2 according to Cohen's guidelines[13]), these data nevertheless confirm our own and previous studies that unrestored missing teeth have a significant effect on patients' QoL[8,9,12,14] and suggest that restoration planning should prioritize anterior teeth to optimize QoL outcomes. The prevalence of missing teeth in our population (76%) was high and similar to previous studies reporting similarly high prevalence of missing teeth in other populations (Saudi Arabia and the UK) of between 62.5 and 94.4%.[7,15,16]

Missing teeth, and in particular the number of missing teeth, have generally been shown to have a negative impact on QoL, particularly in younger adults.[9] In their meta-analysis of similar studies using OHIP instruments to measure OHRQoL, Gerritsen et al.[8] reported that the impact on OHRQoL was proportional to the number of teeth lost, with a marked deterioration in OHRQoL in individuals with <17 teeth from three cross-sectional surveys representing over 13,000 individuals.[17,18] Similarly, in their recent study of 152 adults attending dental clinics in Riyadh, Saudi Arabia, Anbarserri et al.[14] reported that OHIP-14 scores were proportional to the number of teeth lost. Here, we compared complete dentition with tooth loss of one or more teeth, similar to Lawrence et al.,[19] who similarly found using the OHIP-14 that loss of one or more teeth was significantly associated with OHRQoL after adjusting for sex and “episodic” dental care.

However, fewer studies have examined the impact of the position of tooth loss on OHRQoL. Pallegedara and Ekanayake,[20] although examining elderly individuals with large numbers of missing teeth rather than our younger population with as few as only one missing tooth, found that individuals with anterior spaces were significantly more likely to have higher OHIP-14 scores. Using the OHIP-49, Walter et al.[21] similarly found that missing anterior teeth were independently and most strongly associated with impaired OHRQoL in adjusted analysis of adult patients attending dental outreach clinics. Similarly, Batista et al.[22] found that having one or more missing teeth including one in the anterior position had a greater impact on OHRQoL than fully dentate adult patients.

Our data now add to this growing body of evidence that the location of missing teeth impacts OHRQoL, with anterior tooth loss having a greater impact than posterior tooth loss (11% of the variation vs. 6% of the variation in adjusted analyses), not only on function but also psychosocial domains. It has been suggested that the greater impact of anterior missing teeth reflects the importance of esthetics and appearance in dictating the psychosocial morbidity associated with tooth loss.[22] Indeed, when examining the domains most affected by tooth loss location, we found that anterior loss affected psychological disability and social disability scores, while posterior loss did not, objectively supporting this hypothesis. Few studies have examined the specific domains affected by tooth loss. While Anbarserri et al.[14] found that tooth loss significantly affected the functional limitation and social disability domains, which we found were impacted most by posterior and anterior tooth loss, respectively, they did not examine tooth loss position in relation to OHIP-14 subdomains. Similarly, in their meta-analysis of twenty study samples with missing teeth, Schierz et al.[11] established that the impact of missing teeth on oral function, as measured by OHIP scores for the physical disability domain, was typically around 1.9 units, but these data were not separated by tooth position. Our data support that missing teeth impact both functional and psychosocial OHRQoL but that tooth position is a critical determinant of exactly how individuals are affected.

Our study has a number of limitations. This was relatively small sample from a single city, so the results may not be generalizable; however, we used a cluster sampling approach to attain a representative population. The OHIP-14 is a self-reported instrument, so may be subject to bias; however, the OHIP-14, despite being a short questionnaire, has been shown to be reliable,[2] sensitive to changes,[3,4] and have cross-cultural consistency.[5] Our study is strengthened by adjusting for the effect of gender, age, and income, which are known to impact OHRQoL.[23,24] Future studies should include other covariates such as educational level and caries experience to further establish the relative contributions of these factors in overall OHRQoL.

CONCLUSIONS

Here, we show for the first time the impact of the location of missing teeth on different dimensions of OHRQoL. Anterior tooth loss has a more wide-ranging impact on both physical and psychosocial functioning than posterior tooth loss, suggesting that anterior tooth restoration should be prioritized when treatment planning. The position of lost teeth must be considered in addition to the number of losses when examining the impact of tooth loss and its treatment on OHRQoL.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.