Dentists'attitudes to the shortened dental arch concept

summary The aim of restorative dentistry in high-risk groups tends to shift over time from the preservation of complete dental arches towards the preservation of functional dental arches, using a functionally oriented approach. An example of this approach, aimed at limited treatment goals, is the shortened dental arch (SDA) concept. The objective of this study was to investigate dentists' attitudes to the SDA concept in general practice. A questionnaire seeking information pertaining to the attitudes and application of the SDA concept in clinical practice was sent to all dentally qualified members of staff in the field of restorative dentistry in the Nijmegen School of Dentistry ( n = 64). From a 64% response, it was found that all but one of the respondents view the SDA concept as having a useful place in clinical practice. Although the respondents indicated only regular or occasional use of SDA in <10% of patients, the outcome of SDA management was generally satisfactory or at least sufficient, notably in the care of special category patients. The findings support the view that the SDA concept has a role in contemporary clinical practice.     

Caries incidence following restoration of shortened lower dental arches in a randomized controlled trial

OBJECTIVE: The objective of this study was to investigate the outcome of conventional root canal treatment in a general practice setting within the Royal Air Force dental service. Design Retrospective review. METHODS: Teeth that had been root-filled for 12 months or more by Royal Air Force dental practitioners in patients attending a large Royal Air Force dental centre were included in the study. Following clinical and radiographic review the root fillings were classified as 'definitely successful', 'probably successful' or 'failed' The effect on success of several variables on the outcome was investigated. RESULTS: Out of a total of 406 teeth, 59% were maxillary teeth and 41% were mandibular teeth. Sixty-nine per cent of the total sample had pre-existing periapical radiolucencies. Cold lateral condensation of gutta-percha was the most widely used filling technique (64% of all cases). Fifty per cent of the teeth had root fillings within 2 mm of the radiographic apex, 32% were greater than 2 mm from the radiographic apex and 18% were overfilled. Cold lateral condensation was the most successful (92% overall) filling technique. Maxillary anterior teeth had a better success rate (96%) than other tooth types. Teeth with pre-existing periapical radiolucencies had a higher success rate (87%) than those cases where there was no pre-existing periapical radiolucency (80%). Root fillings that were less than 2 mm from the radiographic apex of the tooth had a higher success rate (88% overall) than those that were greater than 2 mm from the radiographic apex (77% overall). Of the 406 cases, 57% (n=231) were classified as definitely successful, 28% (n=114) were classified as probably successful and 15% (n=62) were classified as failures. Thus, the overall success rate combining definitely successful and probably successful root fillings was 85% (n=344). CONCLUSIONS: Root fillings placed using cold lateral condensation of gutta-percha to within 2 mm of the radiographic apex of the tooth were associated with the best outcome.     

短牙弓修复方法在牙周病患者中的临床应用

目的:将短牙弓(Shortened dental arch,SDA)治疗法应用于修复牙周病患者的牙列缺损。方法:对象为采用SDA治疗法修复的11例牙周病牙列缺损的患者,戴牙时间为6个月。检测方法为X线检查、牙齿松动度检查、测量咀嚼效率以及问卷调查。结果:11例患者对SDA修复表示满意,咀嚼功能明显改善,能满足患者的日常饮食要求。结论:SDA治疗法合理经济,易于适应,有利于牙周病患者余留牙的稳定和恢复。     

Attitudes toward the shortened dental arch concept among Swedish general dental practitioners

PURPOSE: The purpose of this investigation was to obtain the opinions and assess the attitudes of Swedish general dental practitioners in private practice versus a public health care setting regarding management of patients with a shortened dental arch (SDA). MATERIALS AND METHODS: A questionnaire containing different statements regarding the SDA concept was sent to a random sample of 189 clinicians. Differences between male and female practitioners and between private practitioners (PPs) and those employed by the Public Dental Health Service (PDHS) were tested for statistical significance by the Student t test. RESULTS: The response rate was 54% (102 clinicians). Among the respondents, 62% were men and 38% were women. Fifty-six percent were PPs and 44% were employed by the PDHS. The results showed small differences in attitudes between various groups of practitioners but large individual variations. In general, Swedish general practitioners had a positive attitude toward the SDA concept with respect to oral function and oral comfort. They recognized few risks with a dentition lacking molar support, although female clinicians were more risk conscious. PPs expressed fewer advantages in using the SDA concept than PDHS practitioners with respect to the reduced risk for overtreatment, better patient economy, and the ability for older patients to keep their teeth. CONCLUSION: The results from this questionnaire study indicate that, overall, Swedish general practitioners have an affirmative opinion toward the SDA concept.     

The shortened dental arch: a review of the literature

The functional demands of patients are highly variable and individual, requiring dental treatment to be tailored to the individual's needs and adaptive capability. The World Health Organization indicates that a functional, esthetic, natural dentition has at least 20 teeth, while the literature indicates that dental arches comprising the anterior and premolar regions meet the requirements of a functional dentition. The English-language peer-reviewed literature pertaining to the short dental arch (SDA) was identified through the Medline search engine covering the period between 1966 and the present and critically reviewed. This treatment option for the partially dentate patient may provide oral functionality, improved oral hygiene, comfort, and, possibly, reduced costs.     

Clinical performance of cantilevered fixed dental prostheses abutments in the shortened dental arch

Objectives

This article is part of a randomized clinical trial on different treatments in the shortened dental arch (SDA). It focused on the abutment tooth prognosis with cantilevered fixed dental prostheses (CFDPs).

Methods

Sixty-two patients with a bilaterally SDA up to the first or second premolar in the mandible or maxilla were evaluated. In 57 of 124 quadrants, second premolars were replaced by a CFDP (cantilever group). In the remaining 67 quadrants, a natural second premolar was present and thus no need for a CFDP was given (non-cantilever group). Patients were recalled annually up to 5 years.

Results

The mean observation period was 56.3 months (min. 3.0, max. 76.2, SD 16.1). Kaplan–Meier survival rates concerning tooth loss and tooth fracture were 93.9%/94.0% in the cantilever group and 91.9%/92.8% in the non-cantilever group. Differences between both groups were not significant. The survival rate concerning loss of retention of CFDP retainers was 92.1% in the cantilever group.

Conclusion

After 5 years of clinical service, CFDPs for the replacement of the second premolar showed no negative impact on the abutment tooth prognosis.

Clinical significance

Cantilevered fixed dental prostheses present a viable treatment option in the shortened dental arch without compromising the medium-term abutment tooth prognosis.     

短牙弓对口腔功能的影响

在短牙弓概念被正式提出之后的20余年里，国内外大量研究证实短牙弓能够满足患者口腔咀嚼、美观和舒适等各种口腔功能的需求，同时不影响咬合稳定性和颞下颌关节的稳定性，不损伤牙周支持组织。总之，包括前牙区和前磨牙区的短牙弓被证实能够满足功能性牙列的需求，为后部牙列缺失提供了一种新的修复治疗选择，因此受到各国口腔医师的重视。本文就短牙弓对口腔各功能和牙周支持组织的影响作一综述，以期为临床治疗提供理论依据。     

The shortened dental arch concept: a treatment strategy for the mutilated dentition

The minimum number of teeth needed to satisfy functional demands has been subject of several studies. However, since functional demands can vary from individual to individual, this number cannot be defined exactly. It has been demonstrated that shortened dental arches comprising the front teeth and the premolars, can meet the requirements of a functional dentition. The shortened dental arch concept may be considered a strategy to reduce the need for complex restorative treatment in the posterior regions of the mouth. It implies that the prompt replacement of absent molars by a removable partial denture leads to overtreatment and discomfort. The shortened dental arch concept is based on circumstantial evidence, and not contradict current theories of occlusion and fits well in a problem-solving approach.     

Chewing performance and occlusal contact area with the shortened dental arch

The aim of this study was to investigate the effect of the loss of posterior teeth on the effectiveness of mastication. To evaluate this, chewing performance and occlusal contact area were investigated in 10 edentate subjects having implants stabilising a mandibular overdenture. A copy of the original lower denture was made for each subject, with removable teeth, which could be separated to convert a complete dental arch to a shortened dental arch, an extremely shortened dental arch, or a broken dental arch. Both post canine occlusal contact area and chewing performance demonstrated significant differences between the different arches. It was concluded that chewing performance is reduced by removing posterior teeth from implant stabilised mandibular complete dentures.     

Observational study investigating tooth extraction and the shortened dental arch approach

The shortened dental arch (SDA) provides a cost‐effective dentition, considering the population is ageing and retaining teeth for longer. The aims were to observe the reasons and sites of tooth extraction and assess the functional dentition over 15 years in dental practice. Subjects were recruited who required permanent tooth extractions between 2000 and 2015. The reasons for extractions were chosen from twelve extraction codes. Data were also collected for demographics, tooth position, root treated teeth and functional pairs remaining. Patient‐centred factors on reasons for tooth extraction and comments on chewing ability and aesthetics following extractions were recorded. Nine hundred and fifty‐one teeth were extracted in 900 patients. The mean age was 60 years (SD 20, SE 7, 95% CI 46, 74). Reasons for extraction were periodontal disease (n = 361, 38%), periapical infection (n = 288, 34%) or tooth and tooth‐root fractures (15%). Extractions included 201 (21%) second molars, 179 (19%) first molars, 152 (16%) second premolars, 95 (10%) first incisors, 86 (9%) second incisors, 76 (8%) canines and 67 (7%) first premolars. Following extractions, median functional pairs were 12, interquartile range (IQR) 19–7. Individuals with ≥10 functional pairs including anterior teeth (60%, n = 571) had no complaints with chewing ability or aesthetics. They did not require additional prostheses. Periodontal disease and periapical infection were the main causes for the extraction. First and second molars followed by second premolars were the most commonly extracted teeth. This study supports the SDA in creating a cost effective, functional dentition in an aging population, provided remaining teeth and restorations are preserved/maintained, oral health is promoted, and anterior aesthetic tooth replacement is ensured.     

The shortened dental arch concept and its implications for oral health care

The minimum number of teeth needed to satisfy functional demands has been the subject of several studies. However, since functional demands--and consequently the number of teeth needed--can vary from individual to individual, this minimum number cannot be defined exactly. In general, occlusion of a complete dental arch is preferable. However, this goal might be neither attainable, for general, dental or financial reasons, nor necessary. Many studies demonstrate that shortened dental arches comprising the anterior and premolar regions can meet the requirements of a functional dentition. Consequently, when priorities have to be set, restorative therapy should be aimed at preserving the most strategic parts of the dental arch: the anterior and premolar regions. This also implies that in cases of a shortened dental arch, the prompt replacement of absent posterior molars by free-end removable partial dentures leads to overtreatment and discomfort. The shortened dental arch concept is based on circumstantial evidence: it does not contradict current theories of occlusion and fits well with a problem-solving approach. The concept offers some important advantages and may be considered a strategy to reduce the need for complex restorative treatment in the posterior regions of the mouth.     

The randomized shortened dental arch study: temporomandibular disorder pain

Objectives

The aim of this multi-center, randomized controlled trial was to assess the impact of missing posterior support on the risk for temporomandibular disorder (TMD) pain by comparing patients with either shortened dental arches (SDA) or molar replacement by removable dental prostheses (RDP).

Methods

A sample of 215 patients with bilateral molar loss in at least one jaw was consecutively recruited in 14 prosthodontic departments of dental schools in Germany. Of the initial sample, 152 patients (mean age: 59.7 years; 53.9 % female) received randomly allocated interventions (SDA: n?=?71; RDP: n?=?81). Presence of TMD pain was assessed using patients’ self-reports and was verified by physical examination and by pain intensity, as the mean of current pain, worst pain, and average pain in the last 6 months, with 10-point ordinal rating scales. Assessments were performed before treatment and at follow-ups until 60 months after treatment. Impact of interventions on TMD risk and pain intensity was computed by applying logistic and linear random-intercept models.

Results

Tooth replacement (RDP) did not significantly change the risk for self-reported (odds ratio [OR]: 1.1; confidence interval [CI]: 0.4 to 3.4) or clinically verified (OR: 0.7; CI: 0.1 to 4.3) TMD pain compared to no tooth replacement (SDA). Mean characteristic pain intensity was virtually identical in both groups (Coeff: 0.01; CI: ?0.30 to 0.32).

Conclusion

Retaining or preservation of an SDA is not a major risk factor for TMD pain over the course of 5 years when compared to molar replacement with RPDs.

Clinical relevance

Seemingly, missing molars do not have to be replaced in order to prevent TMD pain.     

The shortened dental arch revisited: from evidence to recommendations by the use of the GRADE approach

Clinicians must frequently decide whether or not to treat patients with loss of posterior teeth, a condition called the shortened dental arch (SDA). Although many studies have been reported, there are no clear recommendations for the management of SDA cases. In this work, therefore, an innovative system, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, was used to grade the evidence and strength of recommendations for clinical intervention. An extensive literature search for longitudinal studies was conducted on 17 November 2010 in the PubMed and LILACS electronic databases using the term shortened dental arch. A 'snowballing' strategy, for example, manual searching of the reference lists of included papers, was also conducted. Unpublished and published studies were sought in ClinicalTrials.gov and in the search engine 'Google' (Scholar) in English, French, German, Italian, Portuguese and Spanish. Finally, grey literature was searched in OpenSIGLE (System for Information on Grey Literature in Europe). Titles and abstracts of 133 articles were initially assessed. Nine studies were finally included. Although there was no difference between the effectiveness of restorative and non-restorative approaches for SDA, fixed partial dentures seem better than removable prostheses. The overall body of evidence was, however, graded as low quality. Two different clinical scenarios are used to illustrate recommendations in the management of SDA cases by the use of the GRADE system. The GRADE approach may improve transparency in a shared decision-making process, mainly under conditions in which the quality of evidence is low or unclear.     

Effect of the lower third molars on the lower dental arch crowding

Increasing lower dental arch crowding with the age is a recognized clinical problem, and one that has become more apparent in recent years as more adults retain their teeth longer. One of the theories is that the erupting third molars push anterior teeth forward and cause their crowding. On the other hand, a number of studies found no correlation between lower third molars and lower incisor crowding. Because of all these contrasting findings this study was started to re-evaluate correlation between third molars presence and lower dental arch crowding. The study group consisted of 91 subjects with an average age 21.01+/-4.13 years. The individual, quantitative and cast-based analytical registration of crowding was based on the measurements of mesiodistal width of teeth and related to the length of the appropriate segment of the lower dental arch. No statistically significant third molar presence-specific differences were recorded in the lower dental arch crowding between the groups with erupted, unerupted and agenesis of third molars. Although differences between the groups were not statistically significant, some tendency for crowding in the anterior part of lower dental arch was more expressed in the groups with the presence (erupted 0.57 mm and unerupted 0.74 mm) of third molars, than with agenesis (surplus space 0.03 mm). Nevertheless, the present study do not provide enough evidence to incriminate third molars as being the only or even major etiologic factor in the late lower dental arch crowding.     

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

Objectives

Although the shortened dental arch (SDA) concept is a widely accepted strategy to avoid overtreatment, little is known on its impact on oral health-related quality of life (OHRQoL). This multicenter randomized controlled trial aimed to investigate the OHRQoL for removable partial dental prostheses (RPDP) with molar replacement versus the SDA concept.

Material and methods

In both groups, missing anterior teeth were replaced with fixed dental prosthesis. Two hundred fifteen patients with bilateral molar loss in at least one jaw were included. The Oral Health Impact Profile (OHIP-49) was completed before; 6 weeks (baseline), 6 months, and 12 months after treatment; and thereafter annually until 5 years.

Results

Of the initial cohort, 81 patients were assigned to the RPDP group and 71 to the SDA group (age, 34 to 86 years). Before treatment, the median OHIP score was similar in both groups (RPDP, 38.0; SDA, 40.0; n.s.). Results indicate marked improvements in OHRQoL in both groups between pretreatment and baseline (RPDP, 27.0; SDA, 19.0; p?≤?0.0001) which continued in the RPDP group until the 1-year follow-up (p?=?0.0002). These significant reductions in OHIP scores are reflected in its subscales. No further differences were seen within and between groups during the remainder observation period.

Conclusion

Both treatments show a significant improvement in OHRQoL which continued in the RPDP group until the 1-year follow-up. No significant differences were seen between groups.

Clinical relevance

For improving OHRQoL, it is not necessary to replace missing molars with a RPDP.     

A systematic review of prosthetic restoration in patients with shortened dental arches

The literature regarding the effect of prosthetic restoration in patients having distal extension edentulous space in posterior area (shortened dental arch: SDA) is reviewed in the following article. Information retrieval followed a systematic approach using PubMed. Articles in English published between 1966 and March 2011 describing the outcome of treatment with various prostheses were evaluated. From the search results of 98 articles, 21 articles met the inclusion criteria. Treatment with removable partial dentures (RPDs) improved masticatory function, patient satisfaction and oral health-related quality of life (OHRQoL). However, no significant difference was found in the outcomes between patients with RPDs and with cantilever fixed partial dentures (CFPDs). Caries developed more frequently after treatment with RPDs than CFPDs. The time to survival for CFPDs was not longer than that for RPDs, while more visits to maintain RPDs were required than for CFPDs. No significant difference was found in masticatory function, OHRQoL, and occlusal stability between patients with RPDs and those without restoration of missing molars. Consequently, treatment with RPDs for SDA seems to be less advantageous than CFPDs or no restoration for missing molars. Further research is required to validate treatment with implant-supported fixed partial dentures for SDA.     

The randomized shortened dental arch study: tooth loss over five years

Objectives

The study was designed to provide clinical outcome data for two treatments of the shortened dental arch (SDA).

Material and Methods

In a multicenter randomized controlled clinical trial, patients with complete molar loss in one jaw were provided with either a partial removable dental prosthesis (PRDP) retained with precision attachments or treated according to the SDA concept preserving or restoring a premolar occlusion. No implants were placed. The primary outcome was tooth loss.

Results

Of 152 treated patients, 132 patients reached the 5-year examination. Over 5 years, 38 patients experienced tooth loss. For the primary outcome tooth loss, the Kaplan–Meier survival rates at 5 years were 0.74 (95 % CI 0.64, 0.84) in the PRDP group and 0.74 (95 % CI 0.63, 0.85) in the SDA group. For tooth loss in the study jaw, the survival rates at 5 years were 0.88 (95 % CI 0.80, 0.95) in the PRDP group and 0.84 (95 % CI 0.74, 0.93) in the SDA group. The differences were not significant. No Cox regression models of appropriate fit explaining tooth loss on the patient level could be found.

Conclusions

The overall treatment goals of a sustainable oral rehabilitation and the avoidance of further tooth loss over longer periods were not reliably achievable. The influence of the type of prosthetic treatment on tooth loss might have been overestimated.

Clinical Relevance

Regarding our results, the patient’s view will gain even more importance in the clinical decision between removable and fixed restorations in SDAs.