Evaluation of mid-buccal gingival recessions and occlusal interferences.

BACKGROUND: Dental malocclusions may cause disruption in occlusal harmony, and destructive interferences during mandibular functional movements can be seen. Ideal occlusal contacts during dynamic mandibular movements may be crucial for preventing the occurrence of mid-buccal gingival recession (mbGR). While determining mbGR risk factors in young adults, the effect of occlusal interferences on mbGR has not yet been focused on. Based on this gap, this field needs to be clarified with new studies. OBJECTIVE: The aim of this case-control study was to evaluate the relationships between the presence, extent and severity of mbGRs to dental malocclusions, occlusal interferences in anterior (AG) and lateral guidance (LG) and to determine the potential risk indicators in a young population. METHODS: A total of 149 dental students were comprised and 70 of them presented mbGR(s) and 79 did not (18-25 years, 4553 teeth). Periodontal status was assessed with full mouth bleeding (FMBS) and plaque score (FMPS), probing depth, clinical attachment level, recession depth and keratinised tissue width (KTW) by a periodontist. Malocclusions and occlusal interferences were evaluated by an orthodontist. Logistic regression analyses provided data on the effect of occlusal interferences and the other indicators towards mbGR. RESULTS: The mean of the number of teeth with mbGR(s) per subject was 4.3. The mean of the overall extent of teeth with mbGR(s) was 14.2%. FMBS, decreased KTW, self-reported bruxism, group function occlusion, increased contact number of all teeth and only premolars/molars in AG or LG and Class III malocclusions were significantly associated with the presence of mbGR. Decreased KTW presenting mbGR in the mandible and non-carious cervical lesion adjunct to mbGR significantly increased the odds of the severity of mbGR. Group function occlusion revealed higher mbGRs in premolar/molars than canine guided occlusion. CONCLUSION: Increase in the occlusal interferences in premolars/molars during lateral and anterior guidance may have an effect on the presence and severity of mbGR. Further studies should be designed to confirm these findings.

The New Sub-regression Type Estimator in Ranked Set Sampling.

In this study, a new sub-regression type estimator for ranked set sampling (RSS) is proposed based on the idea of a sub-ratio estimator given in Koçyigit and Kadilar (Commun Stat Theory Methods 1-23, 2022). The proposed unbiased estimator's mean square error is obtained and compared theoretically with other estimators. The theoretical results have been supported by the different simulations and real-life data sets studies and have shown that the proposed estimator is more effective than the estimators in the literature. It is also seen that the number of repetitions in the RSS affected the effectiveness of the sub-estimators.

Improved regression in ratio type estimators based on robust M-estimation.

In this article, a new robust ratio type estimator using the Uk's redescending M-estimator is proposed for the estimation of the finite population mean in the simple random sampling (SRS) when there are outliers in the dataset. The mean square error (MSE) equation of the proposed estimator is obtained using the first order of approximation and it has been compared with the traditional ratio-type estimators in the literature, robust regression estimators, and other existing redescending M-estimators. A real-life data and simulation study are used to justify the efficiency of the proposed estimators. It has been shown that the proposed estimator is more efficient than other estimators in the literature on both simulation and real data studies.

Effects of interactive power toothbrush with or without application assistance on the plaque, gingivitis, and gingival abrasion among dental students: a randomized controlled clinical trial.

OBJECTIVE: The purpose of this randomized controlled study is to determine if an interactive power toothbrush (PTB) with application (app) promotes additional benefit on dental plaque, gingivitis, and gingival abrasion to that of a manual toothbrush (MTB). MATERIALS AND METHODS: Ninety participants (dental students) diagnosed with gingivitis were randomly assigned, into three groups, 1:1:1 ratio, given an app-assisted interactive PTB (PTB-A) (Oral-B Genius® Rechargeable 8000 PTB with CrossAction brush head) or the same PTB without app-assistance (PTB-NA) or a regular MTB for home-use. Plaque was assessed using the Turesky modification of the Quigley and Hein Plaque Index (QHPI-TM), and gingivitis was evaluated using the Bleeding on Marginal Probing Index (BOMP) at baseline (T0), week 2 (T1), and week 8 (T2). Gingival abrasions were recorded at T1 and T2. Exit survey was used to assess brushing time and visual-analogue-scale (VAS) scores. RESULTS: PTB improved QHPI-TM significantly in terms of time-dependent changes, irrespective of app-assistance. BOMP was observed to be statistically lower in PTB-A than in MTB only at T2. Brushing times were longer in PTB-A than in MTB. Gingival abrasion was less in both PTB than MTB. PTB-A had better results to MTB in cleaning ability according to subject-reported outcomes. CONCLUSIONS: Both PTBs were more effective to MTB; however, the app-assisted interactive PTB was similar to the non-assisted one in plaque removal efficacy, gingivitis reduction, and incidence of gingival abrasion, yet better than MTB in cleaning ability. CLINICAL RELEVANCE: Developing an application software to prevent gingival abrasion might be clinically beneficial regardless of the individual factor. TRIAL REGISTRATION: ClinicalTrial.gov ID: NCT05150132.