Minimising mechanical prosthodontic interventions for adult patients with a shortened dental arch

308 Pages·2017·7.12 MB·English

Minimising mechanical
prosthodontic interventions
for adult patients with a shortened
dental arch in South Africa
by
Saadika Khan
Dissertation presented for the degree of
Doctor of Philosophy
Faculty of Medicine and Health Sciences
Division of Health Systems and Public Health,
Department of Global Health
at Stellenbosch University
Supervisor: Professor Usuf ME Chikte
Co-supervisor: Professor Ridwaan Omar
December 2017
Stellenbosch University https://scholar.sun.ac.za
Declaration
By submitting this dissertation electronically, I declare that the entirety of the
work contained therein is my own, original work, that I am the sole author thereof (save to
the extent explicitly otherwise stated), that reproduction and publication thereof by
Stellenbosch University will not infringe any third party rights and that I have not previously
in its entirety or in part submitted it for obtaining any qualification.
“This dissertation includes six original papers published in accredited peer-
reviewed journals. The development and writing of these published papers were the
principal responsibility of myself and for each of the cases where this is not the case a
declaration is included in the dissertation indicating the nature and extent of the
contributions of co-authors.”
Date: December 2017
Copyright © 2017 Stellenbosch University
All rights reserved
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Summary
Background
A large body of high-end evidence suggests that shortened or posteriorly reduced dental
arches (SDA or PRDA) are adequate for oral function. Such a finding has positive implications
for patients from resource-constrained communities. Indeed, in the context of South Africa
(SA), the SDA or PRDA concept has been embedded within its oral health policies since 1994,
although no context-specific evidence appears to have informed this policy. The SDA
concept, considered as a non-interventionist therapeutic approach, may be seen as a
significant evidence-based primary healthcare solution for the underprivileged and under-
resourced majority of SA, when applied appropriately.
The cost of current prosthodontics interventions, including removable, fixed or implant-
retained prostheses are very high and not within the reach of the underprivileged majority.
These prosthodontic appliances are not constructed at public health clinics and patients
may only obtain these from dental teaching institutions and private practitioners.
From a human rights perspective, evidence-based research should guide practitioners and
their practices as it can ensure patients’ right of access to healthcare and the appropriate
use of beneficial evidence whilst eliminating harmful ones. This stance has been made more
explicit within the amended National Oral Health Strategy of SA.
Objectives
To determine the effectiveness (viz. oral function, patient satisfaction and OHRQoL) of a SDA
or PRDA compared to a complete dental arch, with a view to minimizing expensive
prosthodontic interventions for the South African partially dentate adult community.
Methods
A step-wise approach in study designs was implemented amongst a South African cohort. A
systematic review, followed by an overview of systematic reviews was conducted to guide
researchers with the literature, and in turn provide a scaffold for the cross-sectional
questionnaires and cross-sectional clinical study for this cohort. Studies were conducted
among dental practitioners, clinical teachers, and dental students to determine what was
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currently taught and clinically practiced. A randomized controlled trial was subsequently
conducted to determine patient satisfaction and quality of life with a SDA or PRDA.

Results
Studies conducted were from the top-end of the hierarchical evidence pyramid; thus their
results are expected to have evidence of strong reliability and validity with respect to the
benefits of the SDA or PRDA. The generalizability of outcomes obtained related to settings,
subject, intervention, results and costs which were acceptable for this cohort. Aspects of
knowledge translation (KT) such as diffusion (creating awareness of the SDA concept) and
dissemination (publishing and conference presentations of the different research studies)
were fulfilled.

Conclusions
This step-wise research approach highlighted the absence of the implementation aspect of
KT, namely the application of the SDA or PRDA concept to clinical practice. The implication
of this on the potential to positively impact patients’ treatment costs, satisfaction and oral
health-related quality of life within the SA context, is noteworthy. The evidence obtained
and presented strongly questions the current non evidence-based aspects of prosthodontic
curricula such as rehabilitation to complete arch status at the largest dental teaching
institution in Africa. Moreover, the efficiency of the system is based on informed healthcare
policies, emphasizing the need for evidence-based research both at an institutional and
private practice level. Additionally, the contextual evidence derived from the research
performed towards the present PhD highlighted key areas that may be grouped into
important human rights, academic and economic aspects of all those who are impacted.

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Opsomming
'n Groot aantal hoë-end bewyse dui daarop dat verkorte of posterior verminderde
tandbogen (VT of PVT) voldoende is vir mondelinge funksie. So 'n bevinding het positiewe
implikasies vir pasiënte uit hulpbronbeperkte gemeenskappe. In die konteks van Suid-Afrika
(SA) is die VT - of PVT-konsep inderdaad in sy mondgesondheidsbeleid sedert 1994 ingebed,
hoewel geen konteks-spesifieke getuienis hierdie beleid ondersteun nie.

Die PVT-konsep, wat beskou word as 'n nie-intervensionele terapeutiese benadering, kan
gesien word as 'n belangrike bewys-gebaseerde primêre gesondheidsorg oplossing vir die
minderbevoorregte meerderheid van SA, wanneer dit toepaslik toegepas word. Die koste
van huidige prostodontiese ingrypings, insluitend verwyderbare, vaste of
inplantaatbevestigde prosteses, is baie hoog en nie binne die bereik van die
minderbevoorregte meerderheid nie. Hierdie prostodontiese toestelle word nie by
openbare gesondheidsklinieke aangebied nie en pasiënte kan dit slegs by tandheelkundige
onderwysinrigtings en privaat praktisyns ontvang.
Uit 'n menseregte perspektief moet getuienis-gebaseerde navorsing praktisyns en hul
praktyke rig, aangesien dit pasiënte se reg op toegang tot teopaslike en voordelige
gesondheidsorg verseker, terwyl skadelike praktyke elimineer word. Hierdie houding is meer
eksplisiet gemaak binne die gewysigde Nasionale Mondgesondheidstrategie van SA.

Doelwitte
Om die effektiwiteit (nl. Mond funksie, pasiënttevredenheid en mondgesondheidverwante
lewensgehalte) van 'n VT of PVT te bepaal in vergelyking met 'n volledige tandheelkundige
boog, met die doel om duur prostodontiese intervensies vir die Suid-Afrikaanse gedeeltelik
dentate volwasse gemeenskap te verminder.

Metodes
'n Stewige benadering in studieontwerp is onder 'n Suid-Afrikaanse kohort geïmplementeer.
'n Sistematiese oorsig, gevolg deur 'n oorsig van sistematiese resensies, is gedoen om
navorsers met die literatuur te lei en op sy beurt 'n steierwerk vir die dwarssnitte-vraelyste
en kruis-seksie-kliniese studie vir hierdie kohort te verskaf. Studies is onder tandheelkundige
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praktisyns, kliniese onderwysers en tandheelkundige studente gedoen om te bepaal wat
tans onderrig en klinies toegepas word.

'n Gekontroleerde proef is gevolglik uitgevoer om die pasiënttevredenheid en
lewensgehalte met 'n VT of PVT te bepaal. Studies wat uitgevoer is, was van die top-einde
van die hiërargiese bewyse-piramide; dus word verwag dat hulle resultate bewyse het van
sterk betroubaarheid en geldigheid ten opsigte van die voordele van die VT of PVT.
Die veralgemeenbaarheid van uitkomste wat verkry is met betrekking tot instellings, vak,
intervensie, resultate en koste was vir hierdie kohort aanvaarbaar. Aspekte van
kennisvertaling (KV) soos diffusie (bewustheid van die VT-konsep) en verspreiding
(publikasie en konferensie aanbiedings van die verskillende navorsingsstudies) is vervul.

Gevolgtrekkings
Hierdie stapsgewyse navorsingsbenadering het die afwesigheid van die
implementeringsaspek van kennis vertaling (KV) beklemtoon, naamlik die toepassing van die
VT- of PVT-konsep by die kliniese praktyk.
Die implikasie hiervan op die potensiaal om die pasiënt se behandelingskoste, bevrediging
en mondgesondheidsverwante lewenskwaliteit binne die SA konteks positief te beïnvloed, is
opmerklik. Die bewyse wat verkry en aangebied word, rig die huidige nie-bewysgebaseerde
aspekte van prostodontiese leerplanne soos rehabilitasie om boogstatus by die grootste
tandheelkundige onderwysinrigting in Afrika te voltooi.
Daarbenewens is die doeltreffendheid van die stelsel gebaseer op ingeligte
gesondheidsorgbeleid, wat die behoefte aan bewysgebaseerde navorsing beklemtoon,
sowel op institusionele as privaatpraktyk vlak.
Daarbenewens het die kontekstuele bewyse wat afgelei is van die navorsing wat na die
huidige verhandeling (PhD) gedoen is, belangrike sleutelgebiede uitgelig in die belangrike
menseregte-, akademiese en ekonomiese domein.

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Acknowledgements
I dedicate this PhD dissertation to my parents (the late Dawood and Kulsum Khan) who
instilled in me and my siblings the love and importance for all types of education and
lifelong learning.

A Thesis towards a PhD is not possible without the guidance and wisdom of many
individuals; those for whom giving advice and sharing knowledge come easily and
unselfishly. And here I specifically refer to my Supervisors:
 Professor Usuf Chikte and
 Professor Ridwaan Omar
Without their guidance, critical input and knowledge related to aspects of research and
academic writing, my work (research protocols, publications and dissertation) would not
have been accepted at the level it has. Moreover, their experiences and progressiveness
guided me to learn from the world, including the many distinguished personalities from
different universities I visited, to the many conferences I attended the world over. All of
these encounters have enriched me, expanded my world and transformed me to become
confident and generous with what I have learnt.

Finally, I would like to include all those who supported me, enquired about my progress and
well-being and shared in my joys (and at times moments of anguish):
 My family who showed extreme patience, understanding, interest and support,
 My friends who have shared my successes throughout this journey, and
 Colleagues from the University I work at and those from other Institutions I have met
over the years at Conferences and/ or Workshops.

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Table of Contents
Page
Declaration ii
Summary iii
Opsomming v
Acknowledgements vii
List of Appendices ix
List of PhD Articles x
List of Abbreviations xi
Definition of Terms xii

Chapter 1: Introduction and Scope of Research 1
Chapter 2: Perceptions regarding the shortened dental arch among 18
practitioners in the Western Cape Province, South Africa
Chapter 3: From Classroom Teaching to Clinical Practice: Experiences 39
Of Senior Dental Students regarding the Shortened Dental Arch Concept
Chapter 4: Differences in Functional Outcomes for Adult Patients 59
With Prosthodontically -Treated and –Untreated Shortened Arches:
A Systematic Review
Chapter 5: Impact of removable dental prostheses on the function and 97
oral health-related quality of life of a South African cohort with varied
distributions of missing posterior teeth
Chapter 6: Outcomes of interventions with a posterior reduced dental arch 115
Randomized Controlled Trial
Chapter 7: An Overview of Systematic Reviews related to a shortened dental 138
arch in Adults
Chapter 8: Discussion and Conclusions 165

Appendices 187
PhD References 233
PhD Articles 243

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List of Appendices
1.1. Registration for a PhD in Community Health at Stellenbosch University 189

2.1. Survey with Practitioners: Questionnaire 190
2.2. Survey with Practitioners: Informed Consent Form 193
2.3. Survey with Practitioners: Ethics Approval 194

3.1. Mixed-Methods Education Research: Questionnaire 195
3.2. Mixed-Methods Education Research: Individual and Group Interview Questions 196
3.3. Mixed-Methods Education Research: Informed Consent Form 197
3.4. Mixed-Methods Education Research: Ethics Approval 198

4.1. Systematic Review: Ethics Approval 199
4.2. Systematic Review: PRISMA Statement 200

5.1. Cross-Sectional Quality of Life Study: OIDP-2012 Bilingual Questionnaire 202
5.2. Cross-Sectional Quality of Life Study: Informed Consent Form 208
5.3. Cross-Sectional Quality of Life Study: Ethics Approval 210

6.1. Randomized Controlled Trial: Information Letter 211
6.2. Randomized Controlled Trial: Demographic Details 212
6.3. Randomized Controlled Trial: Global Visual Analogue Scale 213
6.4. Randomized Controlled Trial: Informed Consent Form 214
6.5. Randomized Controlled Trial: Ethics Approval 215
6.6. Randomized Controlled Trial: Registration with clinicaltrials.gov 218
6.7. Randomized Controlled Trial: CONSORT Statement 219
6.8. Randomized Controlled Trial: Sample Size Estimation 221

7.1. Overview of Systematic Reviews: AMSTAR Checklist 224
7.2. Overview of Systematic Reviews: Ethics Approval 226

8.1. List of Presentations 227
8.2. Posters 228
8.3. List of References 233
8.4. Published Articles 243
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List of PhD Articles

1. Perceptions regarding the shortened dental arch among dental
Practitioners in the Western Cape Province, South Africa.
Khan SB Omar R Chikte UME. SADJ (2012) 67 (2): 60-68

2. From classroom teaching to clinical practice: Experiences of senior dental
students regarding the shortened dental arch concept.
Khan SB. Chikte UME. Omar R. J Dent Educ 2014 78 (6); 906-913.
Impact Factor: 1.018

3. Functional outcomes and relevance of prosthodontic interventions for
shortened dental arches in adults: A Systematic Review.
Khan SB. Chikte UME. Omar R. PLOS ONE J 2014 9 (7); e101143.
Impact Factor: 4.092

4. An Overview Of systematic reviews related to aspects of the shortened dental
arch and its variants.
Khan SB. Chikte UME. Omar R. Int J Prosthodontics 2017 30 (4); 357-366,
doi: 10.11607/ijp.5287
Impact Factor: 1.376

5. Outcomes with a Posterior Reduced Dental Arch: A Randomized Controlled Trial.
Khan SB. Chikte UME. Omar R. J Oral Rehabilitation 2017
(Accepted), August doi: 10.1111/joor.12549
Impact Factor: 1.926

6. Impact of removable prostheses on function and oral health-related quality
of life of a South African cohort with varied partial dentate states.
Khan SB. Chikte UME. Omar R. J Prosthodontics 2017
(Accepted) June doi: 10.1111/jopr.12692
Impact Factor: 1.133

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