Periodontal disease incidence, progression and rate of tooth loss in a general dental practice: the results of a 12-year retrospective analysis of patient's clinical records

SMARTp: A SMART design for nonsurgical treatments of chronic periodontitis with spatially referenced and nonrandomly missing skewed outcomes

This paper proposes dynamic treatment regimes (DTRs) as effective individualized treatment strategies for managing chronic periodontitis. The proposed DTRs are studied via SMARTp-a two-stage sequential multiple assignment randomized trial (SMART) design. For this design, we propose a statistical analysis plan and a novel cluster-level sample size calculation method that factors in typical features of periodontal responses such as non-Gaussianity, spatial clustering, and nonrandom missingness. Here, each patient is viewed as a cluster, and a tooth within a patient's mouth is viewed as an individual unit inside the cluster, with the tooth-level covariance structure described by a conditionally autoregressive structure. To accommodate possible skewness and tail behavior, the tooth-level clinical attachment level (CAL) response is assumed to be skew-t, with the nonrandomly missing structure captured via a shared parameter model corresponding to the missingness indicator. The proposed method considers mean comparison for the regimes with or without sharing an initial treatment, where the expected values and corresponding variances or covariance for the sample means of a pair of DTRs are derived by the inverse probability weighting and method of moments. Simulation studies are conducted to investigate the finite-sample performance of the proposed sample size formulas under a variety of outcome-generating scenarios. An R package SMARTp implementing our sample size formula is available at the Comprehensive R Archive Network for free download.

Drug-Loadable Calcium Alginate Hydrogel System for Use in Oral Bone Tissue Repair

This study developed a drug-loadable hydrogel system with high plasticity and favorable biological properties to enhance oral bone tissue regeneration. Hydrogels of different calcium alginate concentrations were prepared. Their swelling ratio, degradation time, and bovine serum albumin (BSA) release rate were measured. Human periodontal ligament cells (hPDLCs) and bone marrow stromal cells (BMSCs) were cultured with both calcium alginate hydrogels and polylactic acid (PLA), and then we examined the proliferation of cells. Inflammatory-related factor gene expressions of hPDLCs and osteogenesis-related gene expressions of BMSCs were observed. Materials were implanted into the subcutaneous tissue of rabbits to determine the biosecurity properties of the materials. The materials were also implanted in mandibular bone defects and then scanned using micro-CT. The calcium alginate hydrogels caused less inflammation than the PLA. The number of mineralized nodules and the expression of osteoblast-related genes were significantly higher in the hydrogel group compared with the control group. When the materials were implanted in subcutaneous tissue, materials showed favorable biocompatibility. The calcium alginate hydrogels had superior osteoinductive bone ability to the PLA. The drug-loadable calcium alginate hydrogel system is a potential bone defect reparation material for clinical dental application.

Factors contributing to tooth loss among the elderly: A cross sectional study

BACKGROUND

The present study evaluates the influence of several demographic, health, personal, and clinical factors on the number of missing teeth in old age sample.

METHODS

The number of patients included was 259; they received a full mouth examination and answered a questionnaire provided by one examiner. All the variables related to teeth loss based on the literature were included. These variables focused on age, gender, race, marital status, clinical attachment level, pocket depth, year of smoking, number of cigarettes smoked per day, number of medications, root decay, coronal decay, health status, and year of education. Statistical analysis involved stepwise multivariate linear regression.

RESULTS

Teeth loss was statistically associated with clinical attachment level (CAL)(p value 0.0001), pocket depth (PD) (0.0007) and education level (0.0048). When smoking was included in the model, age was significantly associated with teeth loss (0.0037). At least one of these four factors was also related to teeth loss in several specific groups such as diabetes mellitus, male, and White. The multiple linear regressions for all the proposed variables showed that they contributed to teeth loss by about 23%.

CONCLUSIONS

It can be concluded that less education or increased clinical attachment level loss may increase number of missing teeth. Additionally, age may cause teeth loss in the presence of smoking.

A nonparametric spatial model for periodontal data with non-random missingness

Periodontal disease progression is often quantified by clinical attachment level (CAL) defined as the distance down a tooth's root that is detached from the surrounding bone. Measured at 6 locations per tooth throughout the mouth (excluding the molars), it gives rise to a dependent data set-up. These data are often reduced to a one-number summary, such as the whole mouth average or the number of observations greater than a threshold, to be used as the response in a regression to identify important covariates related to the current state of a subject's periodontal health. Rather than a simple one-number summary, we set forward to analyze all available CAL data for each subject, exploiting the presence of spatial dependence, non-stationarity, and non-normality. Also, many subjects have a considerable proportion of missing teeth which cannot be considered missing at random because periodontal disease is the leading cause of adult tooth loss. Under a Bayesian paradigm, we propose a nonparametric flexible spatial (joint) model of observed CAL and the location of missing tooth via kernel convolution methods, incorporating the aforementioned features of CAL data under a unified framework. Application of this methodology to a data set recording the periodontal health of an African-American population, as well as simulation studies reveal the gain in model fit and inference, and provides a new perspective into unraveling covariate-response relationships in presence of complexities posed by these data.

Refining definitions of periodontal disease and caries for prediction models of incident tooth loss

AIM

To assess the suitability of different definitions of caries and periodontitis for inclusion in tooth loss prediction models.

MATERIALS AND METHODS

The Study of Health in Pomerania (SHIP) is a population-based cohort study conducted in 1997-2001 (SHIP-0) and 2002-2006 (SHIP-1). This sample comprised 2,780 subjects aged 20-81 years with complete information on dental and periodontal status [DMFS status, clinical attachment loss (CAL) and probing depth (PD)]. Analyses on five-year tooth loss were limited to half-mouth data.

RESULTS

The predictive value of tested definitions was markedly age- and gender-dependent: in 20-39-aged men, the number of decayed or filled surfaces best predicted the number of lost teeth, whereas in young women CAL≥4 mm performed best. In older subjects, periodontal definitions were superior to caries definitions: mean CAL performed best in 40-59-year olds, whereas AL- or PD-related definitions predicted best in 60-81-year olds. On tooth level, mean CAL was the superior definition to assess 5-year incident tooth loss in all strata except for young men.

CONCLUSIONS

Caries parameters best predicted incident tooth loss in men aged 20-39 years; in the intermediate and oldest age group and in young women, mean AL was most informative. Therefore, prediction models need to be developed for different age and gender groups.

A retrospective study of compliance (adherence) with a care pathway in periodontal therapy in a primary care setting

OBJECTIVE

Recently the issue of patient adherence with prolonged periodontal therapy and the importance of smoking and its influence as a significant co-factor in the outcome of treatment for patients with periodontal disease has been of interest to health care professionals. This paper is an audit of adherence in regard to both smoking cessation for those who admitted to a smoking habit at the initial examination and patient compliance with a periodontal treatment protocol.

DESIGN

During the initial examination, patients referred to the practice with periodontal problems were photographed both with and without lip retractors as part of their clinical record, and a charting of the teeth made with any 5 mm or greater probing depths recorded. Tooth mobility and furcation involvement of molar teeth were also charted. Two separate time periods (Series 1 and Series 2) were audited in this study. Patients enrolled in Series 2 were routinely asked about their smoking habits at the initial examination. Two time periods were audited, as the initial purpose of the investigation was to audit the success of the practice in treating this group of patients, and to identify any improvements that could be made in care provision as each audit cycle was completed.

SETTING

Primary care setting.

RESULTS

Patient adherence rates were high through all the various stages of periodontal therapy, even though the treatment protocol took over 18 months to complete. Approximately 55% of patients in both time periods presented for the one-year post treatment re-evaluation appointments. 56.5% of the patients reported they had smoked to within five years of their initial consultation, of which 38% reported that they had stopped by the time they had completed the initial hygiene phase of treatment.

CONCLUSIONS

With a comprehensive and clearly defined supportive periodontal care programme (SPC), this paper demonstrates that high adherence levels can be achieved in a primary care setting. The results suggest that treatment should include not only the teaching of an effective oral hygiene regime, but also include giving advice in relation to smoking cessation for those patients who admit to a smoking habit at the initial examination. Patients who smoked and chose to have treatment for their periodontal condition went on to report good adherence with smoking cessation advice. Continuing supportive smoking cessation (SSC) advice should be part of any effective SPC programme. New methods of treating periodontal disease that become available to practitioners in the future should use established benchmarks against which to evaluate the success of any new treatment strategy.