Community Dent Oral Epidemiol 2015; 43; 33–46 All rights reserved
Ó 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Do people with shortened dental arches have worse oral healthrelated quality of life than those with more natural teeth? A population-based study
Haiping Tan, Karen G. Peres and Marco A. Peres Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, Adelaide, SA, Australia
Tan H, Peres KG, Peres MA. Do people with shortened dental arches have worse oral health-related quality of life than those with more natural teeth? A population-based study. Community Dent Oral Epidemiol 2015; 43: 33–46. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. Abstract – Objective: To test whether people with shortened dental arches (SDA) have impaired oral health-related quality of life than those with more natural teeth. Method: We analysed data from the 2004–2006 Australian National Survey of Adult Oral Health (including telephone interview, oral epidemiological examinations and mailed questionnaire). Participants aged ≥15 years and with intact anterior teeth were eligible in this study. We used multivariable negative binomial regression analyses to test the association of SDA, according to two alternative definition (1. having intact teeth and 3-5 natural occlusal units; 2. having intact anterior teeth and four natural occlusal units), with OHIP-14 severity and extent, adjusting for potential confounders, including demographic variables (age and sex), socioeconomic variables (income and education), behaviour characteristics (time since last visit, reason for the last dental visit, difficult in paying $100 dental bill and dental insurance possession), and dental outcomes (coronal and root caries, and periodontal disease). Result: We analysed on 2,750 dentate participants that were eligible for the study. When SDA was classified as intact anterior teeth, four occlusal units and no dental prosthesis, no statistical difference in OHIP-14 severity or extent was identified compared with those with intact anterior teeth, over four occlusal units and no dental prosthesis. Participants who presented intact anterior teeth, 3-5 occlusal units and no prosthesis showed 50% higher rates of OHIP-14 severity than those with intact anterior teeth, over five occlusal units and no prosthesis while their OHIP-14 extent was similar to that of the reference group. Conclusion: SDA is not associated with negative impacts on quality of life, according to both OHIP-14 severity and extent, when SDA is defined as four occlusal units and no dental prosthesis. When SDA is defined as 3-5 occlusal units and no dental prosthesis, it is only associated with OHIP-14 severity, but not OHIP-14 extent.
It has been recognized that tooth loss can affect oral health-related quality of life (OHRQoL) (1). The traditional approach to restorative dentistry stresdoi: 10.1111/cdoe.12124
Key words: dental health survey(s); dental public health; epidemiology; oral rehabilitation; quality of life Haiping Tan, Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, Level 1, 122 Frome Street, Adelaide, Adelaide, SA 5000, Australia Tel: +61 8 8313 4044 Fax: +61 8 8313 3070 e-mail: [email protected] Submitted 13 February 2014; accepted 28 July 2014
ses the use of idealized morphological criteria and mechanically oriented concepts. For example, one textbook in prosthodontics emphasizes that a full
33
Tan et al.
complement of teeth is a prerequisite for a healthy masticatory system and satisfactory oral function (2). Indeed, an important issue in prosthodontic treatment of broken-down dentitions is the decision on which, if any missing teeth, should be replaced to maintain OHRQoL. Literature to date has provided conflicting evidence with regard to the effect of dentures on OHRQoL (3–7). At present, the principle aim of dental care may be considered to be maintenance of a natural functional dentition throughout life, including all the social and biological functions, such as self-esteem, aesthetics, speech, chewing, taste and oral comfort (8). The current criteria for a healthy or physiological occlusion, as developed by Ramfjord and Ash (9), reflected this shift: (i) the absence of pathologic manifestations; (ii) satisfactory function (aesthetics, chewing, etc); (iii) variability in form and function; and (iv) adaptive capacity to changing situations. Variability in form and function means that the number of teeth may vary, and thus, the number may be less than 28. Keeping a certain number of teeth, depending on their position and condition, might give more satisfaction than having the missing teeth replaced with partial dentures (10). The concept of ‘shortened dental arches’ (SDA) was first used by Kayser for a dentition with intact anterior teeth and loss of posterior teeth (11). By November 2013, when a literature search on SDA and OHRQoL was conducted, we only found two studies and they had small samples. One study tested the relationship between patterns of missing OUs and OHRQoL among SDA patients in specialist prosthodontic clinics (12). The other study tested cost-effectiveness of functionally orientated treatment based on the SDA concept, compared with a partial removable dental prosthesis, with the treatment effect measured as OHRQoL (13). It is unknown whether at a population-level people with SDA have worse OHRQoL, compared with those with more natural OUs or those with fixed or removable prosthesis. A population-based study to investigate the association between OHRQoL and the presence of SDA may provide evidence for policy makers to better understand where resources should be allocated in terms of denture treatment to improve OHRQoL. This study aimed to compare the OHRQoL by dentition status among the Australian population aged ≥15, using two alternative definitions of dentition status. The null hypothesis to be tested is that individuals with SDA have no worse OHRQoL compared with those with more natural teeth.
34
Methods Data were from the 2004–2006 Australian National Survey of Adult Oral Health (NSAOH) (14). People aged ≥15 were selected randomly from the population from all six states and two territories by a stratified, clustered, random sampling procedure. Telephonic interviews of potential participants established eligibility and collected sociodemographic and dental care information. Dentate participants were invited to an oral epidemiological examination, after the completion of which they received a questionnaire by mail. The target sample size was calculated to address different survey aims, namely 80% power with 5% type-I error in detecting reductions of 10% in age group-specific mean DMFT since the 1987–1988 national survey. The survey was approved by the University of Adelaide’s Human Research Ethics Committee and Australian Institute of Health and Welfare, and participants gave written informed consent. This manuscript is structured to address STROBE guidelines (15).
Telephonic interview survey Participants were asked questions about their sex, age (15–24, 25–34, 35–44, 45–54 or ≥55), yearly household income ($80,000+, $40,000 4 natural occlusal units with prosthesis 4 occlusal units and no prosthesis (SDA) 0.20 in the unadjusted or adjusted analysis are not included in the multivariable model). Model 1: adjusted for demographic variables (age and sex). Model 2: adjusted for model 1+ socioeconomic variables (yearly household income and education). Model 3: adjusted for model 2+ behaviour characteristics (reason for last visit, difficulty in paying $100 dental bill, insured or not and smoking status). Model 4: adjusted for model 3+ dental outcomes (coronal caries and periodontal disease). a Count ratio reflects change in the ratio of OHIP-14 extent for a unit change in the corresponding ‘Dentition Status’ groups.
one in Australia. The response rates for telephonic interview and oral epidemiology examinations were about 50%, and it was unknown about the difference in the oral health status and selfreported information between the participants and nonrespondents. There are two definitions of SDA in the literature. By November 2013, by searching for the citations via ‘Web of Knowledge’ (apps.webofknowledge.com), we found that the original definition of SDA as having intact anterior teeth and 3–5 natural OUs (18) has been cited by 71 papers, while the recent definition of SDA as having intact anterior teeth and four natural OUs (19) has been cited by 56 papers. The latter one seemed to be more commonly adopted recently. We still conservatively adopted two definitions of SDA and found that people with four OUs have equivalent OHRQoL to those with more natural teeth, while the result was not consistent when 3–5 OUs were used as a cut-off point for SDA. Thus, we supported that a SDA with four OUs was the criteria for maintaining a good OHRQoL.
In the 2004–2006 Australian NSAOH, 14.9% of adult population wear dentures and there was a threefold relative difference in the frequency of denture wearing among people eligible for public dental care (30.1%) compared with ineligible people (10.4%), which might be attributed to the subsidy of denture treatments by the dental public health system (14). Considering the high impact of denture treatments on the health system, especially within the public sector, it is necessary to consider a threshold for indication towards denture treatment to fairly allocate resources and potentially improve OHRQoL for the population. The existing literature indicates that the prognosis of free-end saddle removable partial dentures may not be predictable and may even be problematic, and its contribution to oral functions in patients with SDA is considered to be dubious (22). The current population-based study finding has important implications for oral health care at a population level. Given the evidence that the OHRQoL among people with four OUs is not inferior to that of people with more natural teeth, the treat-
39
Tan et al.
ment goals should be changed from the preservation of complete dental arches towards the preservation of a reduced natural, functional dentition such as SDA. Accordingly, the complex treatment plan involving removable prosthodontic treatment should move towards preventive and restorative treatments concentrating on the functionally strategic and sustainable parts of the existing dentition to maintain a SDA. The latter also has the advantages of being less time-consuming and less expensive (18). Although there were only 2.5% of people with four OUs in this study, the sample size was big enough for comparison of OHIP-14 among different dentition groups. The study findings are applicable for, for example, around 434 092 people aged ≥15 [about 2.5% of the 17 363 689 Australian population aged ≥15 (23)], which indicates maintaining a SDA, with the adoption of the definition as four OUs and no prosthesis, should be considered as an important oral healthcare policy, especially in the public health system. To conclude, people with SDA (when it is defined as four OUs and no dental prosthesis) have no worse OHRQoL compared with those with more natural teeth, according to OHIP-14 severity and extent.
5.
6.
7.
8. 9. 10.
11. 12.
13.
14.
Acknowledgements The NSAOH was supported by the Australian Government Health Agencies, including NHMRC Grants #299060, #349514 and #349537. Colgate Oral Care provided gifts for participants. The authors gratefully acknowledge the chief investigators of the survey, ARCPOH staff and the dental team for data collection and express thanks to all participants. The authors declare no potential conflict of interest with respect to the authorship and/or publication of this article.
15.
16. 17.
Reference 1. Brennan DS, Spencer AJ, Roberts-Thomson KF. Tooth loss, chewing ability and quality of life. Qual Life Res 2008;17:227–35. 2. Carr AB, McGivney GP, Brown DT. McCracken’s removable partial prosthodontics, 11th edn. St. Louis, Missouri: Mosby Inc.; 2005: 5–6. 3. Gilbert GH, Meng X, Duncan RP, Shelton BJ. Incidence of tooth loss and prosthodontic dental care: effect on chewing difficulty onset, a component of oral health-related quality of life. J Am Geriatr Soc 2004;52:880–5. 4. John MT, Koepsell TD, Hujoel P, Miglioretti DL, LeResche L, Micheelis W. Demographic factors, den-
40
18.
19. 20.
21.
ture status and oral health-related quality of life. Community Dent Oral Epidemiol 2004;32:125–32. Tsakos G, Marcenes W, Sheiham A. The relationship between clinical dental status and oral impacts in an elderly population. Oral Health Prev Dent 2004;2: 211–20. Wong MC, McMillan AS. Tooth loss, denture wearing and oral health-related quality of life in elderly Chinese people. Community Dent Health 2005;22: 156–61. Pallegedara C, Ekanayake L. Effect of tooth loss and denture status on oral health-related quality of life of older individuals from Sri Lanka. Community Dent Health 2008;25:196–200. Sheiham A. Public health aspects of periodontal diseases in Europe. J Clin Periodontol 1991;18:362–9. Ramfjord SP, Ash MM. Occlusion, 4th edn. Philadelphia: WB Saunders, 1995; 83–5. Ellas AC, Sheiham A. The relationship between satisfaction with mouth and number, position and condition of teeth: studies in Brazilian adults. J Oral Rehabil 1999;26:53–71. Kayser AF. Shortened dental arches and oral function. J Oral Rehabil 1981;8:457–62. Baba K, Igarashi Y, Nishiyama A, John MT, Akagawa Y, Ikebe K et al. Patterns of missing occlusal units and oral health-related quality of life in SDA patients. J Oral Rehabil 2008;35:621–8. McKenna G, Allen F, Woods N, O’Mahony D, Cronin M, Damata C et al. Cost-effectiveness of tooth replacement strategies for partially dentate elderly: a randomized controlled clinical trial. Community Dent Oral Epidemiol. 2014;42:366–74. doi: 10.1111/ cdoe.12085. Slade GD, Spencer AJ, Roberts-Thomson KF. Australia’s dental generations: the National Survey of Adult Oral Health 2004–06. Canberra: Australian Institute of Health and Welfare, 2007; AIHW cat. no. DEN 165. von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Epidemiology 2007; 18:800–4. Page RC, Eke PI. Case definitions for use in population-based surveillance of periodontitis. J Periodontol 2007;78(7 Suppl.):1387–99. Slade GD. Derivation and validation of a short-form oral health impact profile. Community Dent Oral Epidemiol 1997;25:284–90. Witter DJ, van Palenstein Helderman WH, Creugers NH, K€ ayser AF. The shortened dental arch concept and its implications for oral health care. Community Dent Oral Epidemiol 1999;27:249–58. Kanno T, Carlsson GE. A review of the shortened dental arch concept focusing on the work by the K€ ayser/ Nijmegen group. J Oral Rehabil 2006;33:850–62. Slade GD, Nuttall N, Sanders AE, Steele JG, Allen PF, Lahti S. Impacts of oral disorders in the United Kingdom and Australia. Br Dent J 2005;198: 489–93. Sabbah W, Watt RG, Sheiham A, Tsakos G. The role of cognitive ability in socio-economic inequalities in oral health. J Dent Res 2009;88:351–5.
Shortened dental arches and quality of life 22. Nassani MZ, Tarakji B, Baroudi K, Sakka S. Reappraisal of the removable partial denture as a treatment option for the shortened dental arch. Eur J Dent 2013;7:251–6.
23. Australian Bureau Statistics Census, 2011; www.abs. gov.au.
Appendices Table A1. Association between OHIP-14 severity and dentition status 1 by negative binomial multivariable analyses Unadjusted count ratioa (95% CI) Dentition status 1 >5 occlusal units Ref. and no prosthesis >5 natural occlusal 0.84 (0.60–1.17) units with prosthesis 3–5 occlusal units and 1.39 (1.12–1.73) no prosthesis (SDA)
Ó 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Do people with shortened dental arches have worse oral healthrelated quality of life than those with more natural teeth? A population-based study
Haiping Tan, Karen G. Peres and Marco A. Peres Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, Adelaide, SA, Australia
Tan H, Peres KG, Peres MA. Do people with shortened dental arches have worse oral health-related quality of life than those with more natural teeth? A population-based study. Community Dent Oral Epidemiol 2015; 43: 33–46. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. Abstract – Objective: To test whether people with shortened dental arches (SDA) have impaired oral health-related quality of life than those with more natural teeth. Method: We analysed data from the 2004–2006 Australian National Survey of Adult Oral Health (including telephone interview, oral epidemiological examinations and mailed questionnaire). Participants aged ≥15 years and with intact anterior teeth were eligible in this study. We used multivariable negative binomial regression analyses to test the association of SDA, according to two alternative definition (1. having intact teeth and 3-5 natural occlusal units; 2. having intact anterior teeth and four natural occlusal units), with OHIP-14 severity and extent, adjusting for potential confounders, including demographic variables (age and sex), socioeconomic variables (income and education), behaviour characteristics (time since last visit, reason for the last dental visit, difficult in paying $100 dental bill and dental insurance possession), and dental outcomes (coronal and root caries, and periodontal disease). Result: We analysed on 2,750 dentate participants that were eligible for the study. When SDA was classified as intact anterior teeth, four occlusal units and no dental prosthesis, no statistical difference in OHIP-14 severity or extent was identified compared with those with intact anterior teeth, over four occlusal units and no dental prosthesis. Participants who presented intact anterior teeth, 3-5 occlusal units and no prosthesis showed 50% higher rates of OHIP-14 severity than those with intact anterior teeth, over five occlusal units and no prosthesis while their OHIP-14 extent was similar to that of the reference group. Conclusion: SDA is not associated with negative impacts on quality of life, according to both OHIP-14 severity and extent, when SDA is defined as four occlusal units and no dental prosthesis. When SDA is defined as 3-5 occlusal units and no dental prosthesis, it is only associated with OHIP-14 severity, but not OHIP-14 extent.
It has been recognized that tooth loss can affect oral health-related quality of life (OHRQoL) (1). The traditional approach to restorative dentistry stresdoi: 10.1111/cdoe.12124
Key words: dental health survey(s); dental public health; epidemiology; oral rehabilitation; quality of life Haiping Tan, Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, Level 1, 122 Frome Street, Adelaide, Adelaide, SA 5000, Australia Tel: +61 8 8313 4044 Fax: +61 8 8313 3070 e-mail: [email protected] Submitted 13 February 2014; accepted 28 July 2014
ses the use of idealized morphological criteria and mechanically oriented concepts. For example, one textbook in prosthodontics emphasizes that a full
33
Tan et al.
complement of teeth is a prerequisite for a healthy masticatory system and satisfactory oral function (2). Indeed, an important issue in prosthodontic treatment of broken-down dentitions is the decision on which, if any missing teeth, should be replaced to maintain OHRQoL. Literature to date has provided conflicting evidence with regard to the effect of dentures on OHRQoL (3–7). At present, the principle aim of dental care may be considered to be maintenance of a natural functional dentition throughout life, including all the social and biological functions, such as self-esteem, aesthetics, speech, chewing, taste and oral comfort (8). The current criteria for a healthy or physiological occlusion, as developed by Ramfjord and Ash (9), reflected this shift: (i) the absence of pathologic manifestations; (ii) satisfactory function (aesthetics, chewing, etc); (iii) variability in form and function; and (iv) adaptive capacity to changing situations. Variability in form and function means that the number of teeth may vary, and thus, the number may be less than 28. Keeping a certain number of teeth, depending on their position and condition, might give more satisfaction than having the missing teeth replaced with partial dentures (10). The concept of ‘shortened dental arches’ (SDA) was first used by Kayser for a dentition with intact anterior teeth and loss of posterior teeth (11). By November 2013, when a literature search on SDA and OHRQoL was conducted, we only found two studies and they had small samples. One study tested the relationship between patterns of missing OUs and OHRQoL among SDA patients in specialist prosthodontic clinics (12). The other study tested cost-effectiveness of functionally orientated treatment based on the SDA concept, compared with a partial removable dental prosthesis, with the treatment effect measured as OHRQoL (13). It is unknown whether at a population-level people with SDA have worse OHRQoL, compared with those with more natural OUs or those with fixed or removable prosthesis. A population-based study to investigate the association between OHRQoL and the presence of SDA may provide evidence for policy makers to better understand where resources should be allocated in terms of denture treatment to improve OHRQoL. This study aimed to compare the OHRQoL by dentition status among the Australian population aged ≥15, using two alternative definitions of dentition status. The null hypothesis to be tested is that individuals with SDA have no worse OHRQoL compared with those with more natural teeth.
34
Methods Data were from the 2004–2006 Australian National Survey of Adult Oral Health (NSAOH) (14). People aged ≥15 were selected randomly from the population from all six states and two territories by a stratified, clustered, random sampling procedure. Telephonic interviews of potential participants established eligibility and collected sociodemographic and dental care information. Dentate participants were invited to an oral epidemiological examination, after the completion of which they received a questionnaire by mail. The target sample size was calculated to address different survey aims, namely 80% power with 5% type-I error in detecting reductions of 10% in age group-specific mean DMFT since the 1987–1988 national survey. The survey was approved by the University of Adelaide’s Human Research Ethics Committee and Australian Institute of Health and Welfare, and participants gave written informed consent. This manuscript is structured to address STROBE guidelines (15).
Telephonic interview survey Participants were asked questions about their sex, age (15–24, 25–34, 35–44, 45–54 or ≥55), yearly household income ($80,000+, $40,000 4 natural occlusal units with prosthesis 4 occlusal units and no prosthesis (SDA) 0.20 in the unadjusted or adjusted analysis are not included in the multivariable model). Model 1: adjusted for demographic variables (age and sex). Model 2: adjusted for model 1+ socioeconomic variables (yearly household income and education). Model 3: adjusted for model 2+ behaviour characteristics (reason for last visit, difficulty in paying $100 dental bill, insured or not and smoking status). Model 4: adjusted for model 3+ dental outcomes (coronal caries and periodontal disease). a Count ratio reflects change in the ratio of OHIP-14 extent for a unit change in the corresponding ‘Dentition Status’ groups.
one in Australia. The response rates for telephonic interview and oral epidemiology examinations were about 50%, and it was unknown about the difference in the oral health status and selfreported information between the participants and nonrespondents. There are two definitions of SDA in the literature. By November 2013, by searching for the citations via ‘Web of Knowledge’ (apps.webofknowledge.com), we found that the original definition of SDA as having intact anterior teeth and 3–5 natural OUs (18) has been cited by 71 papers, while the recent definition of SDA as having intact anterior teeth and four natural OUs (19) has been cited by 56 papers. The latter one seemed to be more commonly adopted recently. We still conservatively adopted two definitions of SDA and found that people with four OUs have equivalent OHRQoL to those with more natural teeth, while the result was not consistent when 3–5 OUs were used as a cut-off point for SDA. Thus, we supported that a SDA with four OUs was the criteria for maintaining a good OHRQoL.
In the 2004–2006 Australian NSAOH, 14.9% of adult population wear dentures and there was a threefold relative difference in the frequency of denture wearing among people eligible for public dental care (30.1%) compared with ineligible people (10.4%), which might be attributed to the subsidy of denture treatments by the dental public health system (14). Considering the high impact of denture treatments on the health system, especially within the public sector, it is necessary to consider a threshold for indication towards denture treatment to fairly allocate resources and potentially improve OHRQoL for the population. The existing literature indicates that the prognosis of free-end saddle removable partial dentures may not be predictable and may even be problematic, and its contribution to oral functions in patients with SDA is considered to be dubious (22). The current population-based study finding has important implications for oral health care at a population level. Given the evidence that the OHRQoL among people with four OUs is not inferior to that of people with more natural teeth, the treat-
39
Tan et al.
ment goals should be changed from the preservation of complete dental arches towards the preservation of a reduced natural, functional dentition such as SDA. Accordingly, the complex treatment plan involving removable prosthodontic treatment should move towards preventive and restorative treatments concentrating on the functionally strategic and sustainable parts of the existing dentition to maintain a SDA. The latter also has the advantages of being less time-consuming and less expensive (18). Although there were only 2.5% of people with four OUs in this study, the sample size was big enough for comparison of OHIP-14 among different dentition groups. The study findings are applicable for, for example, around 434 092 people aged ≥15 [about 2.5% of the 17 363 689 Australian population aged ≥15 (23)], which indicates maintaining a SDA, with the adoption of the definition as four OUs and no prosthesis, should be considered as an important oral healthcare policy, especially in the public health system. To conclude, people with SDA (when it is defined as four OUs and no dental prosthesis) have no worse OHRQoL compared with those with more natural teeth, according to OHIP-14 severity and extent.
5.
6.
7.
8. 9. 10.
11. 12.
13.
14.
Acknowledgements The NSAOH was supported by the Australian Government Health Agencies, including NHMRC Grants #299060, #349514 and #349537. Colgate Oral Care provided gifts for participants. The authors gratefully acknowledge the chief investigators of the survey, ARCPOH staff and the dental team for data collection and express thanks to all participants. The authors declare no potential conflict of interest with respect to the authorship and/or publication of this article.
15.
16. 17.
Reference 1. Brennan DS, Spencer AJ, Roberts-Thomson KF. Tooth loss, chewing ability and quality of life. Qual Life Res 2008;17:227–35. 2. Carr AB, McGivney GP, Brown DT. McCracken’s removable partial prosthodontics, 11th edn. St. Louis, Missouri: Mosby Inc.; 2005: 5–6. 3. Gilbert GH, Meng X, Duncan RP, Shelton BJ. Incidence of tooth loss and prosthodontic dental care: effect on chewing difficulty onset, a component of oral health-related quality of life. J Am Geriatr Soc 2004;52:880–5. 4. John MT, Koepsell TD, Hujoel P, Miglioretti DL, LeResche L, Micheelis W. Demographic factors, den-
40
18.
19. 20.
21.
ture status and oral health-related quality of life. Community Dent Oral Epidemiol 2004;32:125–32. Tsakos G, Marcenes W, Sheiham A. The relationship between clinical dental status and oral impacts in an elderly population. Oral Health Prev Dent 2004;2: 211–20. Wong MC, McMillan AS. Tooth loss, denture wearing and oral health-related quality of life in elderly Chinese people. Community Dent Health 2005;22: 156–61. Pallegedara C, Ekanayake L. Effect of tooth loss and denture status on oral health-related quality of life of older individuals from Sri Lanka. Community Dent Health 2008;25:196–200. Sheiham A. Public health aspects of periodontal diseases in Europe. J Clin Periodontol 1991;18:362–9. Ramfjord SP, Ash MM. Occlusion, 4th edn. Philadelphia: WB Saunders, 1995; 83–5. Ellas AC, Sheiham A. The relationship between satisfaction with mouth and number, position and condition of teeth: studies in Brazilian adults. J Oral Rehabil 1999;26:53–71. Kayser AF. Shortened dental arches and oral function. J Oral Rehabil 1981;8:457–62. Baba K, Igarashi Y, Nishiyama A, John MT, Akagawa Y, Ikebe K et al. Patterns of missing occlusal units and oral health-related quality of life in SDA patients. J Oral Rehabil 2008;35:621–8. McKenna G, Allen F, Woods N, O’Mahony D, Cronin M, Damata C et al. Cost-effectiveness of tooth replacement strategies for partially dentate elderly: a randomized controlled clinical trial. Community Dent Oral Epidemiol. 2014;42:366–74. doi: 10.1111/ cdoe.12085. Slade GD, Spencer AJ, Roberts-Thomson KF. Australia’s dental generations: the National Survey of Adult Oral Health 2004–06. Canberra: Australian Institute of Health and Welfare, 2007; AIHW cat. no. DEN 165. von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Epidemiology 2007; 18:800–4. Page RC, Eke PI. Case definitions for use in population-based surveillance of periodontitis. J Periodontol 2007;78(7 Suppl.):1387–99. Slade GD. Derivation and validation of a short-form oral health impact profile. Community Dent Oral Epidemiol 1997;25:284–90. Witter DJ, van Palenstein Helderman WH, Creugers NH, K€ ayser AF. The shortened dental arch concept and its implications for oral health care. Community Dent Oral Epidemiol 1999;27:249–58. Kanno T, Carlsson GE. A review of the shortened dental arch concept focusing on the work by the K€ ayser/ Nijmegen group. J Oral Rehabil 2006;33:850–62. Slade GD, Nuttall N, Sanders AE, Steele JG, Allen PF, Lahti S. Impacts of oral disorders in the United Kingdom and Australia. Br Dent J 2005;198: 489–93. Sabbah W, Watt RG, Sheiham A, Tsakos G. The role of cognitive ability in socio-economic inequalities in oral health. J Dent Res 2009;88:351–5.
Shortened dental arches and quality of life 22. Nassani MZ, Tarakji B, Baroudi K, Sakka S. Reappraisal of the removable partial denture as a treatment option for the shortened dental arch. Eur J Dent 2013;7:251–6.
23. Australian Bureau Statistics Census, 2011; www.abs. gov.au.
Appendices Table A1. Association between OHIP-14 severity and dentition status 1 by negative binomial multivariable analyses Unadjusted count ratioa (95% CI) Dentition status 1 >5 occlusal units Ref. and no prosthesis >5 natural occlusal 0.84 (0.60–1.17) units with prosthesis 3–5 occlusal units and 1.39 (1.12–1.73) no prosthesis (SDA)
