Root and root canal diversity in human permanent maxillary first premolars and upper/lower first molars from a 14th-17th and 18th-19th century Radom population

Prevalence of Taurodontism in Contemporary and Historical Populations from Radom: A Biometric Analysis of Radiological Data

Taurodontism is a morphological anomaly of multirooted molars characterized by apical displacement of the pulp chamber, shortened roots, and the absence of constriction at the dentoenamel junction. It can negatively impact the outcome of dental treatment plans. This study aimed to compare the prevalence of taurodontism among contemporary and historical populations from Radom, Poland. Five hundred eighty-two panoramic radiographs of contemporary patients and 600 radiographs of historical individuals were analyzed using the Shifman and Chanannel index. Group differences were determined with Pearson's chi-square tests according to sex, site, tooth group, and historical period. The study also evaluated the degree of severity of taurodontism in relation to dental groups, gender, and the periods from which contemporary patients as well as historical individuals originated. In the contemporary population, taurodontism was observed in 34% of individuals. In the historical data, the highest prevalence of taurodontism (31%) was observed among individuals from the 18th and 19th centuries, while earlier periods exhibited considerably lower prevalence rates. Across contemporary and historical populations, the maxillary molars were the most commonly affected teeth. Hypotaurodontism was the most prevalent form of taurodontism. The prevalence of taurodontism has gradually increased from the 11th century to the current day. The results of the research are of great importance for the clinician in terms of planning comprehensive dental treatment.

The global prevalence of middle mesial canal in mandibular first and second molars assessed by cone beam computed tomography: A systematic review and meta-analysis

BACKGROUND

This meta-analysis sought to identify the in vivo prevalence and influencing factors of middle mesial canal (MMC) in mandibular first and second molars based on cone-beam computed tomography (CBCT) scans.

METHODS

MEDLINE/PubMed, Web of Science, Scopus, SciELO, Google Scholar databases/search engines were searched in period between 15^th and 21^st November 2022, to retrieve the in vivo CBCT-based studies that assessed the prevalence of MMC in mandibular first and/or second molars. The studies were strictly assessed using pre-defined inclusion and exclusion criteria for relevancy and eligibility through screening the title and abstract, and then assessed through reading the full texts using the same criteria. Subsequently, the fulfilled studies were assessed qualitatively using the Newcastle-Ottawa Quality Assessment Scale, and quantitatively using meta-analysis to calculate the pooled prevalence rates of MMC. The publication bias was assessed using funnel plot and Egger's test.

RESULTS

Out of 1,122 studies, 33 studies comprised 13,349 and 7,624 mandibular first and second molars, respectively, were eligible for inclusion. Twenty studies scored high quality, while thirteen scored moderate quality. The global prevalence of MMC in the first molar was 4.4% (95% CI = 0.035-0.053, P<0.001), significantly higher than that of the second molar which was 1.3% (95%, CI = 0.008-0.018, P<0.001). Gender, molar side, and age were not influencing factors of MMC prevalence.

CONCLUSION

The prevalence of MMC is not uncommon, being higher in the mandibular first molar compared to the mandibular second molar. The prevalence of MMC is not influenced by age, molar's side, and gender.

Automatic Pulp and Teeth Three-Dimensional Modeling of Single and Multi-Rooted Teeth Based on Cone-Beam Computed Tomography Imaging: A Promising Approach With Clinical and Therapeutic Outcomes

Background Cone-beam computed tomography (CBCT) imaging offers high-quality three-dimensional (3D) acquisition with great spatial resolution, given by the use of isometric voxels, when compared with conventional computed tomography (CT). The current literature supports a median reduction of 76% (up to 85% reduction) of patients' radiation exposure when imaged by CBCT versus CT. Clinical applications of CBCT imaging can benefit both medical and dental professions. Because these images are digital, the use of algorithms can facilitate the diagnosis of pathologies and the management of patients. There is pertinence to developing rapid and efficient segmentation of teeth from facial volumes acquired with CBCT. Methodology In this paper, a segmentation algorithm using heuristics based on pulp and teeth anatomy as a pre-personalized model is proposed for both single and multi-rooted teeth. Results A quantitative analysis was performed by comparing the results of the algorithm to a gold standard obtained from manual segmentation using the Dice index, average surface distance (ASD), and Mahalanobis distance (MHD) metrics. Qualitative analysis was also performed between the algorithm and the gold standard of 78 teeth. The Dice index average for all pulp segmentation (n = 78) was 83.82% (SD = 6.54%). ASD for all pulp segmentation (n = 78) was 0.21 mm (SD = 0.34 mm). Pulp segmentation compared with MHD averages was 0.19 mm (SD = 0.21 mm). The results of teeth segmentation metrics were similar to pulp segmentation metrics. For the total teeth (n = 78) included in this study, the Dice index average was 92% (SD = 13.10%), ASD was low at 0.19 mm (SD = 0.15 mm), and MHD was 0.11 mm (SD = 0.09 mm). Despite good quantitative results, the qualitative analysis yielded fair results due to large categories. When compared with existing automatic segmentation methods, our approach enables an effective segmentation for both pulp and teeth. Conclusions Our proposed algorithm for pulp and teeth segmentation yields results that are comparable to those obtained by the state-of-the-art methods in both quantitative and qualitative analysis, thus offering interesting perspectives in many clinical fields of dentistry.

Frequency of occurrence of taurodontism in the historical population of Radom (11th-19th centuries)

OBJECTIVE

The aim of the work was to trace possible changes in the frequency of taurodontism in individuals who inhabited historical Radom from the early Middle Ages to modern periods.

DESIGN

The research was based on the analysis of X-ray images of 640 molars of individuals from the 11th/12th c. (n = 120), 14th/17th c. (n = 76), and 18th/19th c. (n = 444). Radiological images were made with the use of a portable X-ray machine, and the results were biometrically analysed using the Shiffman and Chanannel index.

RESULTS

The highest frequency of taurodontism was observed in the 18th/19th c. (31 %, 138/444). In the 11th/12th and 14th/17th centuries, this percentage was significantly lower (22 %, 26/120 vs. 16 %, 12/76). In subsequent chronological periods, no statistically significant differences between sexes in the occurrence of taurodontism were observed. The highest number of taurodontal teeth was observed among the second and first upper molars (73 % and 52 %, respectively), and the lowest number was observed among the first and second lower molars (16 % and 23 %, respectively). In all historical periods, hypotaurodont forms were most often observed.

CONCLUSIONS

Variations in the frequency of taurodontism may result from many reasons, for example environmental factors. However, it cannot be ruled out that the observed differences result from the increased migration of people to Radom in the 18th/19th century.

Maxillary molar root and canal morphology of Neolithic and modern Chinese

OBJECTIVE

This study aimed to characterize Neolithic human maxillary molars from archeological remains at the Jiaojia site, Shandong, China, and compare their ultrastructural features with sex and age-matched modern locals.

DESIGN

Maxillary first (n = 86) and second (n = 80) molars in 5000-year-old individuals (n = 50) from the Jiaojia site were scanned by cone-beam computed tomography (CBCT). Sex and age-matched control groups were assigned from oral surgical patients at Shandong University. Images were analyzed for crown size, root length, root morphology, canal inter-orifice distances, mesiobuccal canal morphology, and second mesiobuccal (MB2) canal prevalence and location. Neolithic and modern values were compared statistically using Chi-squared and Mann-Whitney test at p < .05.

RESULTS

Crown and root size were smaller, and canal inter-orifice distances were shorter in Neolithic maxillary molars than their modern counterparts. For mesiobuccal roots, Weine's Type I single canals were the most prevalent in Neolithic and modern first and second molars. MB2 canal prevalence were not significantly different (p > .05) in Neolithic (53.3%) or modern (60.5%) first molars, and Neolithic (11.3%) or modern (21.3%) second molars. But, MB2 prevalence was significantly higher for modern than ancient male first (p = .032) and second (p = .005) molars. Additionally, MB2 were located more mesially and closer to MB1 in Neolithic than modern molars.

CONCLUSIONS

Maxillary molar root and canal morphology of ancient 5000-year-old remains at the Jiaojia site resemble that of local patients. A trend towards larger tooth size, and more dispersed MB2 canals over this short evolutionary period warrants additional investigation.

Mandibular molar C-shaped root canals in 5th millennium BC China

OBJECTIVE

The aim of this study was to analyze the occurrence and variations in C-shaped canals in ancient Chinese teeth and compare the differences of these features between ancient and age-matched modern populations.

DESIGN

Approximately 5000-year-old craniofacial bone remains were collected from the fossils of 38 individuals (total: 68 mandibular second molars) excavated from the Jiaojia site. The control group comprised of an equal number of randomly selected modern samples. We used cone-beam computed tomography to scan the mandible along the apex-crown axis and analyzed the canal morphology, based on Fan's categorization criterion, at 2 mm, 5 mm, and 8 mm to the apical level. Grooves on the lingual and buccal sides were also recorded.

RESULTS

The proportion of C-shaped roots among ancient samples on the left and right sides were 48.57 % (17/35 teeth) and 54.55 % (18/33 teeth), respectively, and 51.47 % (35/68 teeth) in the total sample. Conversely, in the control group, 44.12 % (15/34) and 38.24 % (13/34) occurred on the left and right sides, respectively, and 41.18 % (28/68) in the total sample. Among the C-shaped canals from the Jiaojia site samples, the classification type changed between two adjacent levels in 84.31 % of samples. Approximately 35 (51.5 %) teeth had a fused root, 20 (29.41 %) had one shallow buccal and one deep lingual groove. The occurrence of C-shape variation was not significantly correlated with time (p＞0.05).

CONCLUSIONS

This study identified a high rate of C-shaped root canals among individuals of Jiaojia who lived approximately 5000 years ago.