AIM: To calculate age of transition of the mandibular third (M3) molar tooth stages from archived dental radiographs from sub-Saharan Africa, Malaysia, Japan and two groups from London UK (Whites and Bangladeshi).

MATERIALS AND METHODS: The number of radiographs was 4555 (2028 males, 2527 females) with an age range 10-25 years. The left M3 was staged into Moorrees stages. A probit model was fitted to calculate mean ages for transitions between stages for males and females and each ethnic group separately. The estimated age distributions given each M3 stage was calculated. To assess differences in timing of M3 between ethnic groups, three models were proposed: a separate model for each ethnic group, a joint model and a third model combining some aspects across groups. The best model fit was tested using Bayesian and Akaikes information criteria (BIC and AIC) and log likelihood ratio test.

RESULTS: Differences in mean ages of M3 root stages were found between ethnic groups, however all groups showed large standard deviation values. The AIC and log likelihood ratio test indicated that a separate model for each ethnic group was best. Small differences were also noted between timing of M3 between males and females, with the exception of the Malaysian group. These findings suggests that features of a reference data set (wide age range and uniform age distribution) and a Bayesian statistical approach are more important than population specific convenience samples to estimate age of an individual using M3.

Aim: This study investigated the prevalence and location of second mesiobuccal (MB2) canal in mesiobuccal root of maxillary first molar using cone beam computed tomography (CBCT) images in an Indian population.

Materials and methods: CBCT images of 598 three rooted maxillary first molars were studied. In each CBCT image, the floor of pulp chamber was located and advanced by 2 mm to standardize the observation for MB2 canal. Its location was determined in relation to mesiobuccal (MB1) and palatal (P) canal.

Statistical analysis: The data was analysed using descriptive statistics. The presence of MB2 canal was correlated with age, gender and tooth position using Chi square test.

Results: The prevalence of MB2 canal in three rooted maxillary first molar was 61.9%. It was seen that the prevalence of MB2 was highest in 20-40years age group (67.4%) followed by > 40 years (57.5%) and lowest in <20 years (50.6%) and the difference was statistically significant (p = 0.005). It is located mesiopalatally; 2.5 mm ± 0.6 mm palatally and 1.0 ± 0.4mmmesially to the MB1 canal or present directly on the line joining the MB1 and palatal canal.

METHODS: Ninety-six cavities were prepared in the maxillary first molars of 56 male Wistar rats. The dental pulps were intentionally exposed and randomly divided into four groups according to the application of pulp capping materials: MTAPPL; phosphorylated pullulan (PPL); a conventional MTA (Nex-Cem MTA, NCMTA; positive control); and Super-Bond (SB; negative control). All cavities were restored with SB and observed for pulpal responses at 1-, 3-, 7- and 28-day intervals using a histological scoring system. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U-test with Bonferroni's correction, and the level of significance was set at 0.05. DMP1 and CD34 antigen were used to evaluate odontoblast differentiation and pulpal vascularization, respectively.

MATERIALS AND METHODS: We searched the Pubmed, Medline, Embase and EBSCO databases for full-text, peer-reviewed journal publications from January 1965 to August 2020. Data extraction was done using preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.

RESULTS: Our search yielded 45 case reports involving 48 EMTM teeth. The mean age of the patients was 46.3 years with an age range of 22-80 years. Thirty-two cases were seen in women as compared to 13 cases in men. The majority of the cases (42) were unilateral, with only three bilateral cases. Among the 48 EMTM teeth, 21 were seen in the condylar region followed by 13 in the ramus, seven in the sigmoid notch, three in the angle and two each in the coronoid process and the lower border of the mandible. Twenty-five EMTM teeth had histopathologically confirmed dentigerous cysts, eight teeth had chronic infection/inflammation/granulation tissue, two had radicular cysts, two had infected cysts, two teeth had normal follicular spaces, and associated lesions were not mentioned for nine teeth. The most common symptoms were swelling (33 teeth) and pain (29 teeth), and six teeth were asymptomatic. Surgical removal through intraoral approach was carried out for 27 teeth, while an extra-oral approach was adopted in 15 teeth, a spontaneous regression of the pericoronal radiolucency was noticed in one tooth, four teeth were not treated and choice of treatment was not mentioned for one tooth. Mild transient paraesthesia was frequently observed; however, serious post-surgical complications were not reported.