Risk Factors for Third Molar Occlusal Caries: A Longitudinal Clinical Investigation

Improved Wisdom Tooth Diagnosis Can Reduce Dental Disease and Nonbattle Injuries

INTRODUCTION

Wisdom teeth are a frequent cause for dental disease and nonbattle injuries (D-DNBIs) during expeditionary deployments. Improved diagnosis and timely treatment before deployment can reduce the need to evacuate a D-DNBI while in a theater. This study proposed key identifiers to diagnose wisdom teeth as Dental Readiness Classification (DRC) 3.

MATERIALS AND METHODS

This study was a retrospective chart review conducted to measure concurrence among Army dentists when assigning DRC for wisdom teeth. This study also recorded demographic data and physical findings among the observed patients. Concurrence, or inter-rater reliability, was measured using Cohen's kappa (κ).

RESULTS

A Cohen's κ of 0.04 suggested that there was no concurrence among Army dental providers in the diagnosis of wisdom teeth. The study concluded that caries and pericoronitis accounted for 37% and 13% of class 3 nondeployable troops, respectively. Forty-one percent of tobacco users had caries. Fifty-eight percent of the population was diagnosed as DRC 3.

CONCLUSIONS

This study proposed DRC 3 criteria for wisdom teeth and measured concurrence among dental providers' diagnoses. Dental Readiness Classification 3 criteria include caries, pericoronitis, infection, and pathology. A Cohen's κ of 0.04 indicated there was a lack of concurrence in examining dentists compared to the DRC 3 criteria. Caries and pericoronitis were the most frequent diagnoses for third molars. Early diagnosis and treatment of these key identifiers can help reduce a significant source of D-DNBIs in the deployed environment.

Does Retaining Third Molars Result in the Development of Pathology Over Time? A Systematic Review

PURPOSE

The present systematic review was conducted to assess the available literature on pathologies associated with third molar retention.

MATERIALS AND METHODS

A systematic literature search was conducted in MEDLINE (PubMed), Embase, and Cochrane Library and reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Relevant reports were selected using predefined inclusion and exclusion criteria. Pathology related to third molar retention included caries, periodontal pathology, second molar external root resorption, and pathologic widening of the third molar pericoronal space. The methodologic quality of each study was reviewed using a pathology-specific tool to assess the risk of bias.

RESULTS

A total of 37 studies were included for qualitative analysis. The available data showed that asymptomatic retained third molars frequently become diseased with increasing age of the patient and increased retention time. Caries and periodontal pathology were most frequently observed, especially in partially erupted third molars and mesially inclined mandibular third molars. Overall, the available data were regarded as medium to fair quality evidence.

CONCLUSIONS

The available data have revealed that retained asymptomatic third molars rarely remain disease-free over time. Increasing age and, thus, increasing retention time seemed associated with greater disease prevalence. Well-designed, prospective follow-up studies are needed to substantiate the clinical management of asymptomatic disease-free third molars.

Prophylactic removal of impacted mandibular third molars: a systematic review and economic evaluation

BACKGROUND

Impacted third molars are third molars that are blocked, by soft tissue or bone, from fully erupting through the gum. This can cause pain and disease. The treatment options for people with impacted third molars are removal or retention with standard care. If there are pathological changes, the current National Institute for Health and Care Excellence guidance states that the impacted third molar should be removed.

OBJECTIVE

The objective of this study was to appraise the clinical effectiveness and cost-effectiveness of the prophylactic removal of impacted mandibular third molars compared with retention of, and standard care for, impacted third molars.

METHODS

Five electronic databases were searched (1999 to 29 April 2016) to identify relevant evidence [The Cochrane Library (searched 4 April 2016 and 29 April 2016), MEDLINE (searched 4 April 2016 and 29 April 2016), EMBASE (searched 4 April 2016 and 29 April 2016), EconLit (searched 4 April 2016 and 29 April 2016) and NHS Economic Evaluation Database (searched 4 April 2016)]. Studies that compared the prophylactic removal of impacted mandibular third molars with retention and standard care or studies that assessed the outcomes from either approach were included. The clinical outcomes considered were pathology associated with retention, post-operative complications following extraction and adverse effects of treatment. Cost-effectiveness outcomes included UK costs and health-related quality-of-life measures. In addition, the assessment group constructed a de novo economic model to compare the cost-effectiveness of a prophylactic removal strategy with that of retention and standard care.

RESULTS

The clinical review identified four cohort studies and nine systematic reviews. In the two studies that reported on surgical complications, no serious complications were reported. Pathological changes due to retention of asymptomatic impacted mandibular third molars were reported by three studies. In these studies, the extraction rate for retained impacted mandibular third molars varied from 5.5% to 31.4%; this variation can be explained by the differing follow-up periods (i.e. 1 and 5 years). The findings from this review are consistent with the findings from previous systematic reviews. Two published cost-effectiveness studies were identified. The authors of both studies concluded that, to their knowledge, there is currently no economic evidence to support the prophylactic removal of impacted mandibular third molars. The results generated by the assessment group's lifetime economic model indicated that the incremental cost-effectiveness ratio per quality-adjusted life-year gained for the comparison of a prophylactic removal strategy with a retention and standard care strategy is £11,741 for people aged 20 years with asymptomatic impacted mandibular third molars. The incremental cost per person associated with prophylactic extraction is £55.71, with an incremental quality-adjusted life-year gain of 0.005 per person. The base-case incremental cost-effectiveness ratio per quality-adjusted life-year gained was found to be robust when a range of sensitivity and scenario analyses were carried out.

LIMITATIONS

Limitations of the study included that no head-to-head trials comparing the effectiveness of prophylactic removal of impacted mandibular third molars with retention and standard care were identified with the assessment group model that was built on observational data. Utility data on impacted mandibular third molars and their symptoms are lacking.

CONCLUSIONS

The evidence comparing the prophylactic removal of impacted mandibular third molars with retention and standard care is very limited. However, the results from an exploratory assessment group model, which uses available evidence on symptom development and extraction rates of retained impacted mandibular third molars, suggest that prophylactic removal may be the more cost-effective strategy.

FUTURE WORK

Effectiveness evidence is lacking. Head-to-head trials comparing the prophylactic removal of trouble-free impacted mandibular third molars with retention and watchful waiting are required. If this is not possible, routine clinical data, using common definitions and outcome reporting methods, should be collected.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016037776.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 30. See the NIHR Journals Library website for further project information.

Socioeconomic Factors and Caries in People between 19 and 60 Years of Age: An Update of a Systematic Review and Meta-Analysis of Observational Studies

This study is aimed to perform an update of a systematic review and meta-regression to evaluate the effect modification of the socioeconomic indicators on caries in adults. We included studies that associated social determinants with caries, with no restriction of year and language. The Newcastle-Ottawa Scale was used to evaluate the risk of bias. With regard to the meta-analysis, statistical heterogeneity was evaluated by I², and the random effect model was used when it was high. A subgroup analysis was conducted for socioeconomic indicators, and a meta-regression was performed. Publication bias was assessed through Egger's test. Sixty-one studies were included in the systematic review and 25 were included in the meta-analysis. All of the studies were published between 1975 and 2016. The most frequent socioeconomic indicators were schooling, income, and socioeconomic status (SES). In the quantitative analysis, the DMFT (decayed, missing, filled teeth) variation was attributed to the studies' heterogeneity. The increase of 10.35 units in the proportion of people with lower SES was associated with an increase of one unit in DMFT, p = 0.050. The findings provide evidence that populations with the highest proportions of people with low SES are associated with a greater severity of caries. The results suggest the need for actions to reduce the inequalities in oral health (PROSPERO [CRD42017074434]).

Contrasting Patterns for Missing Third Molars in the United States and Sweden

PURPOSE

The purpose of this study was to compare the prevalence of third molars from the US National Health and Nutrition Examination Survey (NHANES) and the Swedish survey.

MATERIALS AND METHODS

This cross-sectional study involved the comparison of the only published data on third molar prevalence. The number of visible third molars in the NHANES of 2011 through 2012 were assessed in nonclinical settings by trained, calibrated dental hygienists and reported by age decade (approximately 5,000 patients). Similar data were reported for the Swedish population with data collected in clinical settings (approximately 700 patients). The primary outcome variable was the number of third molars (0 to 4); the predictor variables were age cohorts (20 to 29 through 70 to 79 yr). Outcome data were reported with descriptive statistics.

RESULTS

In the youngest cohort (20 to 29 yr), having no visible third molars was more likely in the US population than in the Swedish population (47 vs 2%, respectively). By 50 to 59 years, outcomes for no third molars were similar in the United States and Sweden (53 and 57%, respectively).

CONCLUSION

The presence or absence of third molars reported from the US and Swedish populations presented contrasting patterns, particularly in the younger cohorts. More comprehensive and detailed data are required in future surveys as population studies on third molars become more important for clinicians and other stakeholders.

What is the risk of future extraction of asymptomatic third molars? A systematic review

PURPOSE

The purpose of our report was to determine clinically whether young adults who elect to retain their asymptomatic third molars (M3s) have a risk of undergoing 1 or more M3 extractions in the future.

MATERIALS AND METHODS

To address our clinical question, we designed and implemented a systematic review. The studies included in the present review were prospective, had a sample size of 50 subjects or more with at least 1 asymptomatic M3, and had at least 12 months of follow-up data available. The primary study variables were the follow-up duration (in years) and the number of M3s extracted by the end of the follow-up period or the number of subjects who required at least one M3 extraction. The annual and cumulative incidence rates of M3 removal were estimated.

RESULTS

Seven studies met the inclusion criteria. The samples sizes ranged from 70 to 821 subjects, and the follow-up period ranged from 1 to 18 years. The mean incidence rate for M3 extraction of previously asymptomatic M3s was 3.0% annually (range 1 to 9%). The cumulative incidence rate for M3 removal ranged from 5% at 1 year to 64% at 18 years. The reasons for extraction were caries, periodontal disease, and other inflammatory conditions.

CONCLUSIONS

The cumulative risk of M3 extraction for young adults with asymptomatic M3s is sufficiently high to warrant its consideration when reviewing the risks and benefits of M3 retention as a management strategy.

The impact of gender on caries prevalence and risk assessment

Dental caries remains a common disease worldwide. There is evidence indicating that many caries risk factors provide a gender bias, placing women at a higher caries risk. Generally, dental caries disproportionally affects the poor and racial or ethnic minorities worldwide, with women suffering more from the disease. Differences in access to care as reflected by untreated caries rates also reflect gender disparities. There is a lack of evidence in regard to gender differences and dental caries. Therefore, there is an urgent need to develop the evidence necessary to meet the oral health needs of both women and men worldwide.

The association between orthodontic treatment with removal of premolars and the angulation of developing mandibular third molars over time

OBJECTIVE

To assess changes in mandibular third molar angulation during orthodontic treatment in subjects having either first or second premolars or neither removed.

MATERIALS AND METHODS

In a retrospective study approved by the institutional review board, right and left mandibular third molar angulations were compared to the vertical axis of adjacent second molars before and at the end of orthodontic treatment. The sample included 25 subjects with first premolars removed, 25 subjects with second premolars removed, and 24 subjects with no premolars removed. A decrease in angulation over time of at least 5°, so that the third molar became more vertical, was considered clinically favorable. Data were assessed by a linear mixed effect model and a proportional odds model with significance set at P < .05.

RESULTS

Prior to treatment, the average mandibular third molar angulation did not differ significantly among the three study groups (P  =  .97). The average change during treatment was not significantly affected by group (P  =  .59), but a higher proportion of mandibular third molars were more vertical by at least 5° in the second premolar extraction group compared to the other two groups at the completion of treatment.

CONCLUSION

Although creating space for third molars to erupt and function has intuitive appeal, clinicians should not assume that third molars will move upright to a vertical position even if premolar removal is performed as part of an orthodontic treatment plan.

A longitudinal study of occlusal caries in Newark New Jersey school children: relationship between initial dental finding and the development of new lesions

OBJECTIVE

Dental caries is a significant public health problem especially amongst children from low-income backgrounds. This longitudinal study examined the development of new occlusal caries in 227 Newark, NJ children ages 10-18. The role of previous caries experience and the presence of occlusal white and dark lesions in predicting the development of new lesions were examined.

DESIGN

At each visit, the patient's teeth were given a visual-tactile examination and the subject's decayed, missing and filled (DMFS) score was determined. Next, molars lacking probeable caries or restorations were examined using transillumination for occlusal white and dark spots. This examination was repeated periodically. A Cox proportional hazard was used to analyse data concerning the development of new occusal caries in molars.

RESULTS

The longitudinal data indicates that patients who were caries free at visit-1 developed significantly fewer occlusal caries during the longitudinal study. The hazard ratio for subjects who had first-visit caries was 2.27 compared to caries free subjects. Intact molars with occlusal white or dark lesions had caries hazard ratios of 0.78 and 1.49 respectively, compared to molars lacking initial colour changes.

CONCLUSION

Having a prior caries history places the subject at increased risk of developing future caries. Teeth with dark lesions but not white lesions are at significantly increased risk for developing decay. White lesions may represent remineralizing or slowly progressing lesions. The results of this study can help identify patients and tooth surfaces at risk for future occlusal decay.