The randomized shortened dental arch study: oral health-related quality of life

Outcome measurements and quality of randomized controlled clinical trials of tooth-supported fixed dental prostheses: A systematic review and qualitative analysis

STATEMENT OF PROBLEM

The lack of consensus regarding a standardized set of outcome measurements and noncompliance with current reporting guidelines in clinical trials of tooth-supported fixed dental prostheses (FDPs) hamper interstudy comparability, compromise scientific evidence, and waste research effort and resources in prosthetic dentistry.

PURPOSE

The primary objective of this systematic review was to identify all primary and secondary outcome measurements assessed in randomized controlled trials (RCTs) of tooth-supported FDPs. Secondary objectives were to assess their methodological quality by using the Cochrane Collaboration's risk of bias tool (RoB, v2.0) and their reporting quality by means of a standardized 16-item CONSORT assessment tool through published reports.

MATERIAL AND METHODS

An electronic search was conducted in MEDLINE, EMBASE, and Cochrane library to identify all RCT-related articles published in the past 10 years. Differences in RoB were tested with the Pearson chi-squared test, and those in CONSORT score with the Student t test.

RESULTS

A total of 64 RCTs from 79 publications were deemed eligible. The diversity of outcome measures used in the field is apparent. Twenty percent of the included studies had a low RoB, 79% showed some concerns, and 1% had a high RoB. The mean ±standard deviation CONSORT compliance score was 22.56 ±3.17. Trials adhered to the CONSORT statement reported lower RoB than those that did not adhere (P<.001). RCTs with a low RoB reported more comprehensive adherence to CONSORT guidelines than those with some concerns (MD 4 [95% CI 1.52-6.48]; P=.004).

CONCLUSIONS

A standardized core outcome reporting set in clinical research on tooth-supported FDPs remains evident. Adherence to the CONSORT statement continues to be low, with some RoB concerns that can be improved.

Association between the treatment choice of implant-supported fixed partial dentures and oral health-related quality of life in patients with a shortened dental arch: A preliminary observational study

Background/purpose

In cases of missing posterior teeth, treatment modalities based on the shortened dental arch (SDA) concept may be a viable alternative. However, the association between oral health-related quality of life (OHRQoL) and patients' treatment decisions remains unclear. This study aimed to investigate the association between OHRQoL and the decision to be treated with implant-supported fixed partial dentures (IFPDs) or take a wait-and-see approach in patients with an SDA missing a single second molar and to clarify the impact of IFPD treatment on the OHRQoL.

Materials and methods

The Oral Health Impact Profile (OHIP) questionnaire was administered twice (pre- and post-treatment) and once to 41 patients with a unilateral SDA missing a single second molar who chose IFPD treatment (IFPD group, n = 22) and the wait-and-see approach (no treatment group, n = 19), respectively. Logistic regression analysis was performed with IFPD treatment choice as the objective variable and the four OHIP dimension scores, age, and sex as covariates. The pre- and post-treatment values of the OHIP summary and four-dimension scores were compared using a paired t-test.

Results

The IFPD treatment choice was significantly associated with sex (male), higher Oral Function dimension scores, and lower Psychosocial Impact dimension scores (all P < 0.05). The OHIP summary and four-dimension scores were significantly lower following IFPD treatment (all P < 0.05).

Conclusion

IFPD treatment for a single missing second molar may be clinically beneficial for improving the OHRQoL of patients with an SDA who experience a decline in masticatory function.

Oral health-related quality of life of conventional removable partial dentures, unilateral nonmetal clasp dentures, and shortened dental arch with 2- or 3-tooth unilateral distal extension tooth loss in the mandible: A randomized, crossover, clinical trial

STATEMENT OF PROBLEM

Conventional removable partial dentures with metal clasps are still a common option for patients with distal-extension tooth loss. However, unilateral nonmetal clasp dentures fabricated by using a thermoplastic denture base resin are increasingly being used. Furthermore, the shortened dental arch concept remains controversial, in spite of being advocated for many years. Nevertheless, these treatment options remain controversial, particularly in patients with the loss of a few distal teeth unilaterally.

PURPOSE

The purpose of this randomized, crossover, clinical trial was to investigate the oral health-related quality of life of participants who requested a new dental prosthesis (unilateral nonmetal clasp dentures or conventional removable partial dentures) at a private practice.

MATERIAL AND METHODS

A 3-period, randomized, crossover design was used in a within-subject, controlled, clinical trial. Twenty-four participants (mean age 59.0 years [7 men: 62.6 {45-85} years; 17 women: 57.5 {24-75} years]) were enrolled. All experimental procedures were approved by the Ethics Committee of Nagasaki University Hospital (#15022313) and registered in the International Standard Randomized Controlled Trial Number registry (ISRCTN49105064). All participants were fully dentate in the maxilla and had unilateral distal-extension loss of 2 or 3 teeth in the mandible. Participants were allocated to 1 of 6 groups and treated with prescribed options in accordance with their allocated sequences and used a dental prosthesis or nothing for 2-week periods. At the end of each intervention, the participants were asked to answer the Oral Health Impact Profile questionnaire. Differences in Oral Health Impact Profile scores among groups were estimated with a mixed-effects model (α=.05).

RESULTS

Total Oral Health Impact Profile scores were higher for unilateral nonmetal clasp dentures (P=.002) and shortened dental arch (P=.049) than for conventional removable partial dentures, with medium and small effects. The unilateral nonmetal clasp dentures had a similar effect compared with shortened dental arch (P>.05). unilateral nonmetal clasp dentures (P=.011) and shortened dental arch (P=.005) demonstrated medium effects in the oral function dimension compared with conventional removable partial dentures. Unilateral nonmetal clasp dentures exhibited large and medium effects in the orofacial appearance dimension compared with conventional removable partial dentures (P=.001) and shortened dental arch (P=.006). In the orofacial pain dimension, shortened dental arch showed effects similar to those of conventional removable partial dentures and unilateral nonmetal clasp dentures (P>.05), and no significant differences were observed in the psychosocial impact dimension (P>.05), but the unilateral nonmetal clasp denture score was lower than the conventional removable partial denture score, with a small effect. Men had significantly lower total Oral Health Impact Profile scores for shortened dental arch than women (P=.033).

CONCLUSIONS

Unilateral nonmetal clasp dentures and shortened dental arch were better than conventional removable partial dentures for the oral health-related quality of life of individuals with unilateral distal-extension tooth loss in the mandible, and sex had a significant effect on removable prosthetic planning.

HOW TO IDENTIFY SUBGROUPS IN LONGITUDINAL CLINICAL DATA: TREATMENT RESPONSE PATTERNS IN PATIENTS WITH A SHORTENED DENTAL ARCH

BACKGROUND

When dental patients seek care, treatments are not always successful,that is patients' oral health problems are not always eliminated or substantially reduced. Identifying these patients (treatment non-responders) is essential for clinical decision-making. Group-based trajectory modeling (GBTM) is rarely used in dentistry, but a promising statistical technique to identify non-responders in particular and clinical distinct patient groups in general in longitudinal data sets.

AIM

Using group-based trajectory modeling, this study aimed to demonstrate how to identify oral health-related quality of life (OHRQoL) treatment response patterns by the example of patients with a shortened dental arch (SDA).

METHODS

This paper is a secondary data analysis of a randomized controlled clinical trial. In this trial SDA patients received partial removable dental prostheses replacing missing teeth up to the first molars (N = 79) either or the dental arch ended with the second premolar that was present or replaced by a cantilever fixed dental prosthesis (N = 71). Up to ten follow-up examinations (1-2, 6, 12, 24, 36, 48, 60, 96, 120, and 180 months post-treatment) continued for 15 years. The outcome OHRQoL was assessed with the 49-item Oral Health Impact Profile (OHIP). Exploratory GBTM was performed to identify treatment response patterns.

RESULTS

Two response patterns could be identified - "responders" and "non-responders." Responders' OHRQoL improved substantially and stayed primarily stable over the 15 years. Non-responders' OHRQoL did not improve considerably over time or worsened. While the SDA treatments were not related to the 2 response patterns, higher levels of functional, pain-related, psychological impairment in particular, and severely impaired OHRQoL in general predicted a non-responding OHRQoL pattern after treatment. Supplementary, a 3 pattern approach has been evaluated.

CONCLUSIONS

Clustering patients according to certain longitudinal characteristics after treatment is generally important, but specifically identifying treatment in non-responders is central. With the increasing availability of OHRQoL data in clinical research and regular patient care, GBTM has become a powerful tool to investigate which dental treatment works for which patients.

IMPACT OF SHORTENED DENTAL ARCH ON ORAL HEALTH-RELATED QUALITY OF LIFE

BACKGROUND

A shortened dental arch (SDA) is an established treatment concept for patients with missing molars. However, little is known regarding long-term course of oral health-related quality of life (OHRQoL) in patients with SDA and the benefits from replacement of missing molars.

OBJECTIVE

Purpose of this multi-center randomized clinical trial was to assess OHRQoL over a period of 15 years in patients with molar replacement by a removable partial denture (RPD) compared to patients with a restored SDA without molar replacement.

METHODS

Patients at least 35 years of age with all molars missing in 1 jaw and at least the canine and one premolar present on each side were included. Patients received either a precision attachment-retained, RPD for replacement of missing molars (n = 79), or the dental arch ended with the second premolar (SDA) that had to be present or replaced by a cantilever fixed dental prosthesis (n = 71). Follow-up examinations continued for 15 years. OHRQoL was assessed with the 49-item Oral Health Impact Profile (OHIP). OHIP summary and dimension scores were longitudinally modeled in the statistical analyses to assess course of OHRQoL over time applying an intention-to-treat approach. In addition, scores for the OHRQoL dimensions Oral Function, Orofacial Pain, Orofacial Appearance, and Psychosocial Impact were analyzed.

RESULTS

After an initial improvement in OHRQoL indicated by a mean decrease of 20.0 OHIP points with an effect size of 0.61 in the entire study population, OHRQoL stayed relatively constant over the entire follow-up period. Assuming a constant time and treatment effects over the study period, OHRQoL did not differ statistically significant between the 2 treatments (0.4 OHIP points; 95%-CI: 7.1 - 6.2). OHRQoL after treatment did not change notably over 15 years and was statistically nonsignificant as well (P = .872). Similar findings were observed in all 4 OHRQoL dimensions.

CONCLUSIONS

In patients, missing all molars in one jaw OHRQoL improved providing RPD or restoring SDA to a clinically relevant degree. Treatment-related improvement remained mostly stable over a period of at least 15 years. Therefore, patients can be informed that both treatment concepts are equivalent concerning long-term OHRQoL. Accordingly, patients' preferences regarding treatment options should be granted priority in treatment decision making with the SDA treatment option being the default.

Impact of rehabilitation versus edentulism on systemic health and quality of life in patients affected by periodontitis: A systematic review and meta-analysis

AIM

To investigate the effect of rehabilitation in fully/partially edentulous patients with stage IV periodontitis on oral-health-related quality of life (OHRQoL) and systemic health.

MATERIALS AND METHODS

A systematic electronic and manual search was conducted. Three authors independently reviewed, selected, and extracted the data. Outcomes were OHRQoL (Oral Health Impact Profile 14 [OHIP-14] and OHIP-49, General Oral Health Assessment Index [GOHAI], visual analogue scale, symptoms registration) and systemic health-related outcomes (incidence and prevalence of systemic diseases, values of systemic disease indicators). Qualitative data were synthesized for OHRQoL and systemic health-related outcomes. Meta-analysis was conducted on available quantitative data.

RESULTS

The search identified 59 articles (6724 subjects in total). OHRQoL improved across all the studies, irrespective of the number of missing teeth, their location, or treatment modality. Meta-analysis showed significant improvement of OHIP-49 (36.86, p < .01) in manuscripts including subjects affected by periodontitis, consistently with the remaining literature (reduction of score points post rehabilitation: OHIP-14 = 10.52, OHIP-49 = 56.02, GOHAI = 5.40, p < .01 for all). Non-rehabilitated subjects exhibited inferior cognitive status, higher medication intake, and frailty. However, our data are limited and should be interpreted with caution.

CONCLUSIONS

Oral rehabilitation improves OHRQoL and, potentially, systemic health in edentulous patients. It is unclear whether these findings may be extrapolated to patients with stage IV periodontitis.

Analysis of the relevant factors associated with oral health-related quality of life in elderly denture wearers

PURPOSE

The purpose of the present study was to explore the factors related to oral health-related quality of life (OHRQoL) in elderly patients who underwent prosthetic treatment with removable dentures through several objective and subjective examinations and to analyze their interrelationships.

METHODS

The current study involved 78 denture wearers, aged 65 years or above, who underwent treatment at the clinic of prosthodontics and undertook routine checkups. The present study used eight age-matched patients with healthy dentition as controls. The following items were evaluated: OHRQoL (Oral Health Impact Profile), main occluding area, maximal occlusal force, masticatory performance, and masticatory ability. Spearman's rank correlation coefficient was used to assess the correlation between the OHIP score and each item and multiple linear regression analysis with the backward elimination method was used to analyze the factors affecting the OHIP score (α = 0.05).

RESULTS

The OHIP summary score was significantly correlated with the number of occlusal supports, number of remaining teeth, maximal occlusal force, and the masticatory ability score. The multiple regression analysis revealed that the number of occlusal supports, the number of remaining upper teeth, whether the upper main occluding area was the remaining tooth or not, and the masticatory ability score were the significant independent variables that affected the OHIP summary scores.

CONCLUSIONS

The present study verified the relationship between the OHRQoL and the occlusion of remaining teeth or the items derived from the main occluding areas. The current results suggest that retaining the maxillary first molar is a key factor in the OHRQoL.

Functional oral health-related quality of life impact: A systematic review in populations with tooth loss

Patients perceive the impact of oral disorder in four major areas, the dimensions of oral health-related quality life (OHRQoL) Oral Function, Orofacial Pain, Orofacial Appearance, and Psychosocial Impact. The functional aspect is essential given the need of chewing, biting, speech and swallowing. The objective of this study was to identify OHRQoL information for dental subjects with functional oral health problems. In a systematic review, distinct and clinically relevant groups of dental subject samples, in this study called "population groups," with such functional OHRQoL information based on the Oral Health Impact Profile (OHIP) were identified (PROSPERO registration: CRD42017064033). The search strategy was "Oral Health Impact Profile" or OHIP. Searches were conducted in the PubMed interface of the Medline database, EMBASE, Cochrane, CINAHL and PsyINFO on 8 June 2017 and updated on 14 January 2019. Published OHIP domain data of different versions were recalculated into OHIP-14`s Physical Disability domain score, characterising the subject's Oral Function impact. 3,653 potentially abstracts were screened. We identified 78 publications reporting dimensional information on 154 subject samples with 52 populations. A typical mean functional impact for partially dentate subjects was 1.6 units on a 0 to 8 unit metric, while for edentate subjects, the mean functional impact was 2.6 units. The functional impact score ranged from 0 to 7.9 units with 50% of the patient samples located between 0.8 and 2.6 units. For the first time, we provide normalised and therefore comparable metric information about the functional OHRQoL impact for a substantial number of functional oral conditions.

Impact of shortened dental arch on oral health-related quality of life over a period of 10 years - A randomized controlled trial

OBJECTIVES

To compare oral health-related quality of life (OHRQoL) in patients with either molar replacement by partial removable dental prostheses (PRDP) or with restored shortened dental arches (SDA) over a period of 10 years.

METHODS

In this multi-center RCT, a consecutive sample of 215 patients with bilateral molar loss in at least one jaw was initially recruited in 14 prosthodontic departments. Of those patients, 150 could be randomly allocated to the treatment groups (SDA: n = 71; PRDP: n = 79), received the allocated treatment, and were available for follow-up assessments. OHRQoL was assessed using the 49-item version of the Oral Health Impact Profile (OHIP) before treatment (baseline) and at follow-ups after treatment (4-8 weeks and 6, 12, 24, 36, 48, 60, 96, and 120 months). To investigate the course of OHRQoL over time, we longitudinally modelled treatment and time effects using mixed-effects models.

RESULTS

OHRQoL substantially improved from baseline to first follow-up in both groups indicated by a mean decrease in OHIP scores of 20.0 points (95%-CI: 12.5-27.5). When compared to the SDA group, OHRQoL in the PRDP group was not significantly different (-0.6 OHIP points; 95%-CI: -7.1 to 5.9) during the study period when assuming a constant time effect. OHRQoL remained stable over the 10 years with a statistically insignificant time effect (p = 0.848).

CONCLUSIONS

For patients requesting prosthodontic treatment for their lost molars, treatments with SDA or PRDP improve clinically relevantly OHRQoL and maintain it over a period of 10 years with no option being superior to the other.

CLINICAL SIGNIFICANCE

Since there was no significant difference between the two treatment options over the observation period of 10 years, and since results have stayed stable over time, patients can be informed that both treatment concepts are equivalent concerning OHRQoL.

Restoring root-canal treated molars: Cost-effectiveness-analysis of direct versus indirect restorations

OBJECTIVES

Root-canal treated molars can be directly restored, usually using resin-based-composite restorations (RBCs), or indirectly restored using full or partial crowns (FCs/PCs). Both the initial treatment costs and the risks of restorative and endodontic complications differ between RBCs and FCs/PCs. We aimed to assess the cost-effectiveness of RBCs versus FCs/PCs for restoring root-canal treated molars.

METHODS

A mixed public-private payer's perspective within German healthcare was taken. Risks of complications were extracted from large cohort studies or systematic reviews. Costs were estimated using fee-items catalogues of public and private German insurance. A Markov-model was constructed to follow up a root-canal treated molar receiving different restorations in an initially 50-year-old patient over his lifetime. Monte Carlo-microsimulations were performed to assess lifetime costs and effectiveness (tooth retention time), and the resulting cost-effectiveness.

RESULTS

RBCs were less costly than FCs/PCs (749 Euro versus 782 Euro), but also less effective (22 years versus 24 years), the incremental-cost-effectiveness-ratio was 10.80 Euro/year. This ratio increased if costs for direct restorations decreased, or costs for indirect restorations increased. If no teeth were replaced, RBC was far more cost-effective (the incremental cost-effectiveness ratios was 52.95 Euro/year). If all teeth were replaced, FC was both more effective and less costly.

CONCLUSIONS

RBCs showed lower costs, but also lower effectiveness than FCs/PCs. Consequently, the cost-effectiveness of both strategies depended on the willingness-to-pay of patients or other payers, i.e. their willingness to invest in higher effectiveness. Clinically, a large number of tooth, patient and dentist-related factors will impact on decision-making and should be considered.

CLINICAL SIGNIFICANCE

We found composite restorations to be less costly, but also less effective than indirect restorations for root-canal treated teeth. Over a long-term period, the initial treatment costs and associated cost-differences between strategies may be outweighed by costs of follow-up treatments.

Influence of functional dentition on satisfaction with oral health and impacts on daily performance among Brazilian adults: a population-based cross-sectional study

BACKGROUND

Dental esthetics, chewing and speech should be preserved in a dentition denominated functional and are closely related to satisfaction with oral health (SOH), impacts caused by oral problems and have a possible association with Oral Health-Related Quality of Life. Thus, the purpose of the present study was to investigate the influence of different concepts of functional dentition (FD) on both SOH and impacts on daily performance (IDP) among Brazilian adults.

METHODS

A cross-sectional study was conducted with 9564 adults (35-44 years). SOH and IDP were evaluated using the Oral Impacts on Daily Performance (OIDP) questionnaire. FD was considered based on four different definitions: I-classification of the World Health Organization (FDWHO = ≥20 teeth); II-well-distributed teeth (WDT = ≥10 teeth in each arch); III-classified by esthetics and occlusion (FDClass5 = sequential presence of one tooth in each arch, ≥10 teeth in each arch, 12 anterior teeth, ≥three posterior occluding pairs [POPs] of premolars and ≥one POP molar bilaterally); and IV-classified by esthetics, occlusion and periodontal status (FDClass6 = FDClass5 plus all sextants with CPI ≤ 3 and/or CAL ≤ 1). The proportion of adults satisfied with oral health and without overall impact (OIDP = 0) was calculated for each definition of FD. Multiple Poisson regression models were adjusted by demographic-socioeconomic characteristics, self-reported oral problems and the use of dental services for each dependent variable.

RESULTS

When FDClass5 and FDClass6 were considered a greater proportion of adults reported being satisfied (52.1 and 53.1%, respectively) and have OIDP = 0 (52.4 and 53.3, respectively). In the multiple models, SOH was associated with FDClass5 (RP = 1.21) and FDClass6 (RP = 1.24) and OIDP = 0 was associated with WDT (RP = 1.14) and FDClass6 (RP = 1.21).

CONCLUSIONS

The greater influence of WDT, FDClass5 and FDClass6 on aspects related to quality of life in comparison to FDWHO demonstrates the need for the establishment of a broader definition of FD that encompasses subjective aspects.

The randomized shortened dental arch study: influence of two different treatments on interdental spacing over 5 years

OBJECTIVES

Being a secondary outcome in a multicenter randomized controlled trial, the present analysis focused on interdental spacing in the shortened dental arch (SDA). The aim was to evaluate changes in interdental spacing in dependence of two different treatments after an observation period of up to 5 years.

MATERIAL AND METHODS

Patients were either treated with a partial removable dental prosthesis (PRDP) for molar replacement (PRDP group) or according to the SDA concept aiming at a premolar occlusion (SDA group) in a randomized manner. Interdental spacing in the anterior region was measured with gauges and categorized as "0" (<0.1 mm), "1" (<0.5 mm), "2" (0.5-1 mm), and "3" (>1 mm). The statistical analysis was performed with analysis of variance models followed by linear contrast.

RESULTS

Ninety-one patients (SDA n = 41, PRDP n = 50) were included. Changes of interdental spacing were detected in 70.7 % of all cases. A significant difference between the mean score changes was found in the mandible comparing the PRDP group and the SDA group. The respective mean score changes from baseline to 5 years were 0.23 (SD 0.49) for the PRDP group and 0.02 (SD 0.30) for the SDA group (p = 0.023).

CONCLUSIONS

Major interdental spacing could be observed in neither of the groups. The SDA concept resulted in a slightly better outcome.

CLINICAL RELEVANCE

When deciding whether to replace missing molars, the present results give further support to the SDA concept.

Retention of Teeth and Oral Health–Related Quality of Life

The authors aimed to critically review the literature regarding the relationship between retention of teeth and oral health–related quality of life (OHRQoL) and the extent to which tooth retention can ensure OHRQoL among adults. The authors investigated studies that assessed the relationship between number of teeth and OHRQoL and how the position, type, and/or pattern of the teeth is related to OHRQoL. Relevant papers published in English from January 2004 to September 2015 were searched via PubMed and EMBASE. Twenty-nine papers—including cross-sectional, longitudinal, clinical trial, and case-control studies—were included and categorized according to 4 subthemes to achieve the stated aim: 1) number of teeth or missing teeth and OHRQoL, 2) occluding pairs or functional units and OHRQoL, 3) position of remaining or missing teeth and OHRQoL, and 4) shortened dental arches (SDAs) and OHRQoL. The main findings for each subtheme were as follows: 1) A significant association between number of teeth and OHRQoL was shown in most studies; however, those studies found different cutoff points regarding the number of teeth that affect OHRQoL, after adjusting for other factors in the analyses (e.g., age, sex, cultural background, and study locations). 2) The number of occluding pairs and the location of remaining teeth have great impacts on OHRQoL. 3) Having fewer anterior occluding pairs had a greater negative impact on aesthetics and thus affected OHRQoL. 4) Two randomized clinical trials on SDAs indicated that people with SDAs do not show worse OHRQoL than do those with removable dentures. The only 2 population-based studies on SDAs showed that adults with SDAs have no impaired OHRQoL when compared with those having more natural teeth. To conclude, this review found evidence that retention of teeth is associated with better OHRQoL. The number of occluding pairs and the location of remaining teeth have great impacts on OHRQoL. People with SDAs maintain an acceptable level of OHRQoL.

Differences in functional outcomes for adult patients with prosthodontically-treated and -untreated shortened dental arches: a systematic review

This review examined differences in functional outcomes and patient satisfaction when shortened dental arches are left untreated compared to their restoration to complete arch lengths with different prosthodontic interventions.

METHODS

A protocol was developed according to the criteria for a systematic review. All relevant databases were searched to identify appropriate clinical trials regardless of language or publication status. Predetermined eligibility criteria were applied, trial quality assessed and data extracted for each study. Relevant outcomes assessed were: functioning ability, patient satisfaction and harmful effects on oral structures.

RESULTS

Searches yielded 101 articles: 81 from electronic databases and 20 from reference lists of retrieved articles (PEARLing searches). Sixty-nine citations were assessed for eligibility after removing 32 duplicate records. After reading titles and abstracts, a total of 41 records were excluded and the full-texts of the remaining 28 records were read. Only 21 records were included for the SR because 7 records were excluded after reading the full-text reports. These 21 records report the outcomes of four randomized controlled trials (RCTs) and one non-randomized clinical trial (CT) which were pre-specified and used for this review. No on-going studies were found and no eligible studies were excluded for failure to report the reviewer's pre-specified outcomes. Outcomes were reported in the retrieved 21 articles. A narrative explanation of the pre-specified outcomes is reported for the 3 comparison groups (which were based on the different interventions used for the individual clinical trials). The shortened dental arch as a treatment option is encouraging in terms of functioning, patient satisfaction and cost-effectiveness. By using only high quality studies it was expected that the results would be more reliable when making conclusions and recommendations, but some of the included studies had to be downgraded due to methodological errors.

Dental status and oral health-related quality of life. A population-based study

Oral health-related quality of life (OHRQoL) is associated with tooth wear and tooth loss. This study investigated the association between OHRQoL and dental status (in terms of natural dentition, partial or complete dentures, or edentulism). Sixteen hundred and twenty-two persons who participated in a large-scale Dutch dental survey were interviewed. Dentate persons (n = 1407) were additionally invited for a clinical examination (response rate: 69%). Dental status was based upon the combined data from this clinical examination and the questionnaire (seven dental status groups were defined). OHRQoL was measured by the Dutch translation of the short version of the Oral Health Impact Profile, the OHIP-NL14. Kruskal-Wallis tests and Mann-Whitney U tests were used to investigate differences in OHRQoL between the dental status groups. For all OHIP-NL14 scales, differences in OHRQoL were found between the dental status groups (all P-values <0·001). The Mann-Whitney U tests revealed no differences between persons with a complete natural dentition and persons with a fixed prosthetic replacement. The latter group, however, did show a significantly better OHRQoL as compared to persons with a removable partial denture. Surprisingly, edentulous persons with an overdenture had a more impaired OHRQoL than edentulous persons with non-supported complete dentures. The results demonstrated that impaired dental status is associated with deteriorations in OHRQoL, especially concerning functional limitations, physical pain and social disability.

Management of shortened dental arches and periodontal health: 5-year results of a randomised trial

In a multicentre randomised trial (German Research Association, grants DFG WA 831/2-1 to 2-6, WO 677/2-1.1 to 2-2.1.; controlled-trials.com ISRCTN97265367), patients with complete molar loss in one jaw received either a partial removable dental prosthesis (PRDP) with precision attachments or treatment according to the SDA concept aiming at pre-molar occlusion. The objective of this current analysis was to evaluate the influence of different treatments on periodontal health. Linear mixed regression models were fitted to quantify the differences between the treatment groups. The assessment at 5 years encompassed 59 patients (PRDP group) and 46 patients (SDA group). For the distal measuring sites of the posterior-most teeth of the study jaw, significant differences were found for the plaque index according to Silness and Löe, vertical clinical attachment loss (CAL-V), probing pocket depth (PPD) and bleeding on probing. These differences were small and showed a slightly more unfavourable course in the PRDP group. With CAL-V and PPD, significant differences were also found for the study jaw as a whole. For CAL-V, the estimated group differences over 5 years amounted to 0.27 mm (95% CI 0.05; 0.48; P = 0.016) for the study jaw and 0.25 mm (95% CI 0.05; 0.45; P = 0.014) for the distal sites of the posterior-most teeth. The respective values for PPD were 0.22 mm (95% CI 0.03; 0.41; P = 0.023) and 0.32 mm (95% CI 0.13; 0.5; P = 0.001). It can be concluded that even in a well-maintained.patient group statistically significant although minor detrimental effects of PRDPs on periodontal health are measurable.