OXIS Contacts and Approximal Caries in Preschool Children: A Prospective Cohort Study.

The present prospective cohort study was conducted to evaluate the susceptibility of OXIS contact areas, namely, O (open type), X (point type), I (straight type), and S (curved type) in the development of approximal caries. We conducted this study among 953 school children with 3,812 contacts in Puducherry, India. At baseline, the contacts were assessed in accordance with OXIS criteria. At the end of 12 months, two calibrated dentists measured dental caries following the International Caries Detection and Assessment (ICDAS) criteria. Information about feeding practices, diet, and oral hygiene was collected by means of a structured questionnaire from each child's parent. Data were analyzed by unadjusted and adjusted Poisson regression analysis with a multilevel approach. The two levels of analysis were tooth and child. Of 3,812 contacts observed during the follow-up, 127 (3.3%) were observed as carious. Poisson regression analysis revealed a significant association between type of contact and caries prevalence (p < 0.05). The risk ratios for the development of approximal caries in X contacts were 2.4 (0.3-17.2), p value 0.38; in I contacts 4.9 (1.2-19.9), p value 0.027; and in S contacts 8.2 (1.9-34.2), p value 0.004, when compared with the O contacts. Among the child variables, male gender (relative risk [RR] = 2.1; 95% confidence interval [CI], 1.3, 3.5), parental supervision while toothbrushing (RR = 1.6; 95% CI, 1.1, 2.4), and the use of toothpaste (RR = 1.9; 95% CI, 1.3, 3.1) were found to be associated with approximal caries after adjustment for the other variables. Among the OXIS contacts, the S type was most susceptible to approximal caries due to its complex morphology, followed by I, X, and O.

Morphological variations and prevalence of aberrant traits of primary molars.

BACKGROUND: Morphological variations in tooth structure exhibit as metric and non-metric traits which play an important role in dental anthropology. AIM: The purpose of this study was to determine the prevalence of morphometric traits and mean crown dimensions of primary molars in children. SUBJECTS AND METHODS: This cross-sectional study was carried out in 4256 sectional dye casts of caries-free children aged 2.5-4 years from Puducherry. Two calibrated examiners graded the non-metric traits utilising the Arizona State University Dental Anthropological System classification and measured the crown dimensions in primary molars. The results are expressed in the form of numbers and percentages. RESULTS: Of the eight non-metric traits studied, metaconule (30.17%), Cusp of Carabelli (90.6%), and deflecting wrinkle (87.41%) in second primary molars, and distal trigonid crest (93.06%) and parastyle (3.48%) in first primary molars, seemed to have higher prevalence, and the overall crown dimensions were found to be smaller in comparison with those in other populations. CONCLUSION: This study highlights the prevalence of aberrant dental traits in primary molars in a population. The study describes, for the first time, the existence of these traits in first primary molars, adding anthropological significance of primary dentition in various other populations.

Prevalence and correlation of OXIS contacts using Cone Beam Computed Tomography (CBCT) images and photographs.

BACKGROUND: The contact areas in between primary teeth are broader, flatter, and located further cervically when compared with the contact areas of permanent molars. AIM: We investigated the prevalence of interproximal contact area types of primary molars using CBCT images in children aged 3-10 years. Our second objective was to correlate OXIS contact areas when observed with CBCT images and clinical photographs. DESIGN: A retrospective cross-sectional study was performed with 367 CBCT images of children, aged 3-10 years, obtained from Children's Dental Centre, South Korea. The type of contacts in between primary molars was scored at various levels, specifically, occlusal, middle, and cervical thirds, according to OXIS criteria. Following this, the same patient's records were checked for the presence of clinical photographs and scored according to the same criteria. Prevalence was stated as percentages along with numbers. Chi-square test was applied to determine association of contact areas across genders and arches. The correlation between the two methods was done by Cohen's Kappa correlation test. RESULTS: The prevalence of the OXIS contacts obtained from CBCT images was as follows: I (79.7%), followed by X (10.0%), S (6.6%), and, finally, O (3.7%). The overall score of all the 1343 contact areas matched with the score observed at the occlusal third. All included contacts were of O (open) type at cervical third, and 1,231 contacts were of O (open) type at the middle third. Significant results were observed with respect to arches (P < .001). The correlation between the two methods was found to be 0.958. CONCLUSIONS: The contact area observed at the occlusal level determined the overall type of contact based on OXIS criteria. Thus, reports in the literature concluded that contact areas are broad, flat, and extend further gingivally should be revised. The study also concluded almost perfect agreement between CBCT images and clinical photographs.

Dental Erosion and its Associated Factors In 11-16-Year Old School Children.

UNLABELLED: Dental erosion currently stands as a great challenge for the clinician, regarding the diagnosis, identification of the etiological factors, prevention and execution of an adequate treatment. AIMS: To evaluate the prevalence, severity, and associated factors on dental erosion in 11-16-years old. STUDY DESIGN: A cross sectional study was conducted among 2000 school children who were randomly selected. A questionnaire was given to the children that included personal demographic details and habit of consuming acidic foods and drinks. An index specific for dental erosion given by O Sullivan was used to assess every affected tooth. The values were subjected to chi-square test and multivariate logistic regression analysis. RESULTS: The prevalence of dental erosion was found to be 1.4%. Females (1.6%) were slightly more affected than males (1.3%). Public school children (2.1%) were found to be affected a little more than private children (0.7%). Chi square test showed significant association between type of school and erosion prevalence (p = 0.015). Most commonly affected teeth were lateral incisor (59.72%). CONCLUSION: The prevalence of dental erosion was found to be low when compared to various studies done all over the world.

OXIS contacts of primary molars: do they change over time?

PURPOSE: Although a series of studies on OXIS contacts have been performed, studies regarding changes in OXIS contacts over time are lacking. Therefore, this study aimed to evaluate the change in contact type between primary molars after 3 years in children aged 3-7 years. METHODS: This longitudinal study was conducted using 2922 sectional die models of 926 children. At baseline (T0), the contact type between the primary molars was scored using replication via the sectional die model method according to the OXIS criteria. After 3 years, the sectional die models of the same children were scored using the same criteria (T1). RESULTS: McNemar's tests revealed a significant change in contacts from baseline to 3 years. The post hoc test explained specific changes in the contacts that were observed to be significant. These were O to X (p < 0.001), O to I (p < 0.001), O to S (p = 0.035), and I to X (p < 0.001). CONCLUSIONS: A significant change in OXIS contact over time was observed. The O-type contact underwent the maximum change. The least and most stable contacts are the "O" and "I" types, respectively. This change in contact type with age may alter the risk of caries in children.

Marginal Gingival Thickness Assessment in Three- To Six-Year-Old Preschool Children.

Purpose: Although gingival thickness has been extensively studied in permanent dentition, the literature regarding marginal gingival thickness in primary dentition is insufficient. The purpose of this study was to assess the variations in marginal gingival thickness in preschool-age children. Methods: A cross-sectional study of 4,109 primary teeth was conducted. Using a reamer, the transgingival probing method was employed to assess marginal gingival thickness in healthy preschoolers. Inter-examiner and intra-examiner reproducibility were assessed via the intraclass correlation coefficient. Results: Descriptive statistics revealed that primary maxillary left second molars had the highest mean marginal gingival thickness (1.06 mm), whereas primary mandibular right central incisors had the lowest mean marginal gingival thickness (0.74 mm). Gender-based independent sample t-tests revealed significant differences in the values of primary maxillary right canines (females had greater values than males; P=0.03) and primary mandibular right first molars (males had greater values than females; P=0.01). An inter-arch comparison revealed significant differences between the primary second molars (maxillary more than mandibular; P=0.001). Conclusions: This study reports the first documented marginal gingival thicknesses of primary dentition. It reveals substantial variations in the values of primary maxillary right canines and primary mandibular right first molars and between primary maxillary and mandibular second molars.

Antimicrobial efficacy of calcium silicate-based bioceramic sealers against Enterococcus faecalis and Staphylococcus aureus - An in vitro study.

Context: The main objective of endodontic therapy is to achieve a sterile environment and three-dimensional filling of the root canals. Endodontic sealers play an important role in the obturation of the root canal system as they may provide a seal, which prevents the penetration of bacteria. Sealers are meant to entomb residual bacteria, prevent leakage of nutrients, and ideally possess antibacterial properties. Aim: The aim of the study was to evaluate and compare the antimicrobial effectiveness of calcium silicate-based bioceramic root canal sealers against Enterococcus faecalis and Staphylococcus aureus using the agar diffusion method. Materials and Methods: The materials were divided into four groups of nine samples each for both E. faecalis and S. aureus. Group I (control group) - MTA-Fillapex (Angelus), Group II - BioRoot RCS (Septodont), Group III - Bio-C Sealer (Angelus), and Group IV - Dia-Root Bio Sealer (Diadent). To evaluate the antibacterial activity of the samples, the agar diffusion method was utilized. To begin, a bacterial suspension was evenly spread onto sterile Petri dishes using sterile swabs. Four wells of 4 mm diameter were then punched, and the sealers were mixed following the manufacturer's instructions and placed onto the prepared wells. The Petri dishes were then incubated at 37°C for 72 h. After incubation, the zones of inhibition around each well were measured at 24 h, 48 h, and 72 h, and the resulting values were statistically analyzed. Statistical Analysis Used: The data were analyzed using the ANOVA and post hoc Tukey's test. Results: Calcium silicate-based root canal sealers showed significantly better efficacy than the control group. BioRoot RCS (3.44 ± 1.13 mm) showed maximum antibacterial effect against E. faecalis at 24 h, 48 h, and 72 h time intervals. Bio-C Sealer (16.44 ± 1.42 mm) showed maximum antibacterial effect against S. aureus at 24 h, 48 h, and 72 h time intervals. The effectiveness of root canal sealants eventually decreased over a period. Based on analysis using the ANOVA test, a statistically significant difference (P ≤ 0.05) was observed between the mean values of antimicrobial efficacy of sealers against both E. faeca lis and S. aureus. Conclusions: The study's findings lead to the conclusion that BioRoot RCS showed a maximum antibacterial effect against E . faecal is and Bio-C Sealer showed maximum antibacterial effect against S. aureus at 24 h, 48 h, and 72 h.

Marginal Adaptation of BioRoot RCS, MTA-Fillapex, EpoxySeal, and Sealapex to Radicular Dentin: An In Vitro Study.

Introduction The primary goal of endodontic therapy is to achieve a three-dimensional filling of the root canal. The sealer plays a crucial role in filling the residual gaps between the gutta-percha and the canal wall, which prevents fluids and bacteria from entering the canal and causing complications. This study evaluates and compares the sealing ability of four root canal sealers to the root dentin. Methods and materials In this study, forty single-rooted mandibular premolar teeth with fully-formed apices were collected. The teeth were decoronated and instrumented. Later, the teeth were randomly divided into four groups, each comprising ten specimens, based on the sealer used for obturation. The first group was obturated with BioRoot RCS (Septodont, Septodont Holding, Paris, France), the second group with MTA-Fillapex (Angelus, Angelus Indústria de Produtos Odontológicos S/A, Brazil), the third group with EpoxySeal (Safe Endo, SafeEndo Dental India Pvt. Ltd., Gujarat, India), and the fourth group with Sealapex (Kerr, Kerr Corporation, Brea, CA). Following obturation, the teeth were sectioned vertically using a diamond disc, and the marginal adaptation of these sealers to the root dentin was assessed using scanning electron microscopy (SEM). The values were then statistically analyzed. Results EpoxySeal showed the maximum amount of marginal adaptation (5.22±0.47), followed by BioRoot RCS (5.48±0.58) and MTA-Fillapex (8.24±0.74), and the least amount of marginal adaptation was shown by Sealapex (11.64±1.35). Based on the analysis of variance (ANOVA), a statistically significant difference (p≤0.001) was observed. According to Tukey's post hoc test, the mean difference between all groups showed statistical significance (p≤0.05) except between BioRoot RCS and EpoxySeal. Conclusion Within the limitations of this in vitro study, it is concluded that EpoxySeal and BioRoot RCS exhibited superior marginal adaptation to the root dentin. BioRoot RCS can be recommended as a sealer of choice owing to its additional properties, such as antimicrobial and hydrophilic affinity during setting.

Child Temperament and Early Childhood Caries: A Systematic Review and Meta-Analysis.

Purpose: The purpose of this study was to perform a systematic review to assess current evidence for the association between child temperament and early childhood caries (ECC). Methods: A systematic search was conducted using MEDLINE® through PubMed®, EMBASE®, Scopus®, LILACS, Web of Science™, and EBSCO up to January 2023. Studies measuring ECC and child temperament for children younger than or equal to six years of age using questionnaires, interviews, and surveys through case-control studies, cohort studies, and cross-sectional studies were included. Literature reviews were excluded. Medical subject heading (MeSH) terms like "temperament" and "dental caries" were used by two authors who independently extracted the data, and a third author resolved disagreements. Risk of bias assessment was done using the Newcastle-Ottawa assessment scale for case-control and cohort studies and the Appraisal tool for Cross-Sectional Studies (AXIS). The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations approach (GRADE approach). A chi-square test and I-square index were used to evaluate heterogeneity. Results: A total of 5,072 records were screened, resulting in 15 included studies that yielded data for 6,667 participants; sevenstudies were high, and eight were of moderate quality. Seven studies qualified for meta-analysis, which revealed that persistence did not affectthe presence or absence of ECC. However, there was a strong association between difficult temperament and ECC (odds ratio equals 2.63). Conclusion: A positive association between a child's temperament and early childhood caries exists that is supported by quantitative findings, indicating a connection with very low certainty.

Three-dimensional evaluation of interproximal contacts of permanent dentition: a cone beam computed tomography study.

PURPOSE: To assess the various patterns of the inter-proximal contact areas of the permanent dentition using the available cone beam computed tomography (CBCT) images. METHODS: A retrospective cross-sectional study was performed on existing CBCT images from a University hospital and teaching department. Three thousand two hundred and fifty inter-proximal contacts were assessed from 125 existing CBCT scans of patients (age range: 14 years 3 months-29 years 9 months) who had matched the eligibility criteria. The types of inter-proximal contacts of the permanent dentition were scored at occlusal, middle, and cervical thirds, according to the OXIS inter-proximal contacts classification. Chi-square test was used to assess the contacts and gender/arches. RESULTS: The most prevalent contact was type I for the posterior teeth contacts, and types S1 and S2 for the anterior teeth contacts. Statistical significance was not observed between the contacts on the left and right sides (P > 0.05), while statistical significance was observed between the inter-proximal contacts of the maxilla and mandible (P < 0.05). CONCLUSION: The CBCT-based three-dimensional assessment of the inter-proximal contact areas of the permanent dentition is representative of the OXIS classification. The occlusal level contact was predominantly representative of the overall type of the contact.

Assessment of OXIS contacts-a comparison of three methods.

PURPOSE: To compare OXIS contacts by means of Replication using Sectional die Models (RSM) and Photographs of the Models (PM) with Direct Clinical Examination (DCE) in a sample of preschool children aged 3-4 years. METHODS: A retrospective cross-sectional study was performed using existing records of sectional die models and their photographs among 4257 contacts of 1104 caries-free pre-school children. Two calibrated examiners scored the contacts between the distal surface of the primary first molar and mesial surface of the primary second molar using OXIS criteria from the occlusal view using the RSM & PM methods. These were compared to the OXIS scores from DCE method which was available from previous records. Kappa agreement was used to compare results obtained RSM and PM methods with DCE. RESULTS: The kappa agreement between the RSM and DCE methods was 98.48%; and between the PM and DCE methods was 99.42%, both of which indicated perfect agreement. CONCLUSION: The RSM and PM methods were found to have an excellent agreement in scoring OXIS contacts when compared to the DCE method. PM was found to be slightly more accurate than the RSM method for scoring OXIS contacts.

Variations in Primary Molar Contact and Approximal Caries in Children: A Three-Year Prospective Cohort Study.

Purpose: To evaluate the association between the contact areas of primary molar teeth and approximal caries after three years of observation. Methods: This prospective cohort study included 1,119 caries-free children, aged three to four years, from Puducherry, India. At base- line, 4,476 contacts were assessed using the OXIS criteria, which denotes O for open contact and X, I, and S for closed contacts. X contact represents a point contact, I is a straight contact, and S is a curved contact. Two calibrated dentists measured dental caries at one-year intervals following the International Caries Detection and Assessment System for three years. Poisson regression analysis with a multilevel approach was used to determine the association between contact type and approximal caries. Results: Of 3,848 contacts observed at the end of three years, 499 (13 percent) were carious. The adjusted analysis revealed a significant association between contact type and approximal caries (P<0.05). The risk ratios for the development of approximal caries were 2.3 for X-type contacts (0.5 to 11.4, P=0.307), 12.7 for I-type (4.1 to 39.6, P<0.05), and 22.5 for S-type (7.2 to 70.6, P<0.05) when compared with O-type. Conclusions: Compelling evidence suggests that variations in contacts between teeth are significant in the development of approximal caries. The S-type contact is the most susceptible to approximal caries, followed by the I-type.

Prevalence of different types of interproximal contacts in the permanent dentition - a study cast evaluation.

Background: A new classification called OXIS was proposed for categorizing the interproximal contacts of primary molars, modified for the primary canines and its prevalence was established. No such information is available for the permanent dentition. Hence, the aim was to establish the variations in interproximal contacts of the permanent dentition and thereby modify the OXIS classification of primary molars and primary canines to the permanent dentition. Methods: We propose a study-cast-based classification of interproximal contacts of the permanent dentition. Three hundred and forty-three pretreatment casts of patients based on an inclusion and exclusion criteria were selected. Contacts of posterior teeth were classified based on OXIS classification of interproximal contacts, and its modification was used for anterior teeth. Results: Among the posterior contacts, the 'O' type of contact was least prevalent, while most prevalent was the 'S' type for second molar-first molar contact, 'I' type for the first molar-second premolar contact, and 'X' type for the second premolar-first premolar contact. Among the anterior contacts, least prevalent was 'S1' type for the first premolar-canine contact, and I type for the canine-lateral incisor and the lateral incisor-central incisor contacts. There was no statistical significance between right- and left-side contacts ( P > 0.05) while significance was seen between maxillary and mandibular contacts ( P < 0.05). Similarity of contacts ranged from 5.17% to 10.05%. Conclusion: The OXIS classification is applicable to posterior permanent teeth, and its modification is representative of anterior permanent teeth.

Modified OXIS classification for primary canines.

Background: A new classification called OXIS was proposed for categorising the interproximal contacts of primary molars, and its prevalence was established. The aim of this study was to establish the variations in interproximal contacts of primary canines and thereby modify the OXIS classification of primary molars to primary canines. Additionally, we aimed to estimate the applicability of modifications to primary anterior teeth. Methods: A retrospective study was conducted with sectional die models obtained from a previous study of 1,090 caries-free children. Two calibrated examiners evaluated a total of 4,674 contacts from the occlusal aspect. The contacts were scored according to the former OXIS classification, with two modifications incorporated to encompass the morphological differences and rotations of primary canines and other primary anterior teeth. Results: The most prevalent contact was O (62.1%), followed by X (19.6%), I (12.6%), S type I (4.1%), and S type II (1.6%). Inter-arch comparison by means of the Chi-square test revealed significant differences for all types of contacts ( P < .001). Conclusions: The interproximal contacts of canines were categorised as O, X, I, S I, and S II. The OXIS classification of primary molars was modified to befit the variations in primary canines. This study showed the presence of different types of contacts in primary canines. Identification of these contacts and their complexity has warranted a need for this to be studied as an inherent risk factor for caries risk assessment.

OXIS Contacts as a Risk Factor for Approximal Caries: A Retrospective Cohort Study.

Purpose: The purpose of the present study was to evaluate the individual susceptibility of four different types of OXIS contact areas (open [O], point [X], straight [I], and curved [S]) to approximal caries in children. Methods: A retrospective cohort study was performed using clinical photographs and cone-beam computed tomography images of children, available from January 1, 2014, to August 31, 2015, showing the presence of at least one caries-free contact area between the primary molars. A single calibrated examiner scored 1,102 selected contacts using OXIS criteria from the occlusal view and subsequently evaluated the same contacts with a minimum follow-up period of one year for the presence of approximal caries. Results: Of the 1,102 contacts, 259 (23.5 percent) were found to be carious or restored due to approximal caries. Multivariate logistic regression analysis showed that only the type of contact played a significant role in caries prevalence (P<0.05). The odds ratios of OXIS contacts for the development of approximal caries were: S contact-147.4 (95 percent confidence interval [95% CI] equals 19.7 to 1101.7); I contact-24.5 (95% CI equals 3.4 to 177.9); X contact-1.1 (95% CI equals 1.0 to 12.5); and O contact-1.00 (reference). Conclusions: Among the OXIS contacts, the S type was most susceptible to approximal caries due to its complex morphology. The broad contact areas, namely, I and S types, are at greater risk for approximal caries in primary molars than O and X contacts.

Prevalence of Cusp of Carabelli and its caries susceptibility - an ambidirectional cohort study.

BACKGROUND/AIM: To investigate the susceptibility of Cusp of Carabelli (CoC) to caries in 3- to 4-year-old children. METHODS: The prevalence of CoC was obtained, by two calibrated examiners using 2128 maxillary posterior sectional die models of 1064 caries-free children (that were prepared 8 months back). Four months after recording the CoC, prospective clinical examination of above-mentioned children was carried out by a calibrated third examiner. International Caries Detection and Assessment System was used to record caries of the mesiopalatal surfaces (site of CoC) of the primary maxillary second molars. Data were expressed in numbers and percentages and subjected to chi-square and logistic regression analyses. RESULTS: The prevalence of CoC was 90.6%. The incidence of caries in association with CoC was 10.5%, and this association was statistically significant (0.004), with an odds ratio of 4.7. A statistically significant association was found between positive and negative expression of CoC and caries (0.001), with an odds ratio of 7.7 in positive expression and 4.1 in negative expression. CONCLUSION: The prevalence of CoC was high, with an increased risk for caries with a positive cusp expression. This highlights the need for closer assessment of the mesiopalatal surfaces of primary maxillary second molars during examination.

OXIS Classification of Interproximal Contacts of Primary Molars and Its Prevalence in Three- to Four-Year-Olds.

Purpose: The purpose of this study was to investigate the prevalence of different interproximal contact areas of primary molars, as described in the OXIS classification, in a group of three- to four-year-old caries-free children. Methods: This cross-sectional study was carried out with a representative sample of 4,476 contact areas of 1,119 caries-free school children. A single calibrated examiner performed a type III examination to assess the type of contact area between primary molars, as seen from the occlusal view. The contacts were scored as O (open contact), X (point contact), I (straight contact), and S (curved contact) using OXIS classification. The prevalence of the types was expressed in the form of numbers and percentages. The findings were subjected to chi-square and McNemar's tests. Results: The most common contact type was I (75.5 percent), followed by S (15.3 percent), O (5.8 percent), and X (3.3 percent). Significant differences were obtained (P<0.001) when the inter- arch comparison was performed for all except the X type of contact. Further, 401 (35.8 percent) children had more than one type of contact in dif- ferent quadrants. Conclusions: The present study highlights the existence of four different types of interproximal contact areas, O, X, I, and S, in caries-free three- to four-year-olds.

Interproximal contact areas of primary molars based on OXIS classification - a two centre cross sectional study.

Background: Contact areas in primary teeth are known to be broader, flatter and situated farther gingivally than permanent teeth. The purpose of this study was to assess the prevalence of OXIS contact areas between primary molars using die models of children from two different ethnic populations. The research question of the present study is "What is the prevalence OXIS contact areas of primary molars in the populations studied?". Methods: A cross-sectional study was planned in a representative sample of 200 caries-free contact areas among children aged 3-6 years in two centers, Ajman and Puducherry. Data collection was performed from sectional or full-arch die stone models. The contacts were assessed according to OXIS classification by a single calibrated examiner at Center 2. Prevalence was expressed as numbers and percentages. The Chi-square test was applied to determine the association of OXIS contacts across genders and arches. Results: The prevalence of O, X, I, and S contacts were 19%, 22.5%, 53%, and 5.5% in Center 1 and 6%, 1.5%, 75.5%, and 17% in Center 2, respectively. Significant results (p=0.005) were obtained in Center 1 when inter-arch comparison was performed and between the centers with respect to type of contact. No significant difference was obtained with respect to gender and OXIS contact areas. Conclusions: The present study confirmed OXIS contacts in both the centers. The 'O' and 'X' types of contacts were observed more in Center 1, whereas 'I' and 'S' contacts were observed more in Center 2.

Risk Factors for Early Childhood Caries: A Systematic Review and Meta-Analysis of Case Control and Cohort Studies.

Purpose: The purpose of this study was to perform a systematic review to assess current evidence for association between various risk factors and the prevalence or incidence of early childhood caries (ECC). Methods: Two reviewers searched various databases until January 2019. The Newcastle-Ottawa scale was used to perform risk of bias assessment. The included studies were categorized according to the World Bank classification. Data were summarized in a meta-analysis using fixed and random effects inverse-generic meta-analyses. Results: A total of 7,034 records involving 89 studies that evaluated 1,352,097 individuals were included; 23 were high, 46 were moderate, and 20 were of low quality. A total of 123 risk factors were found. Meta-analysis revealed that the strongest risk factors found in the high-income countries were presence of dentinal caries (dmft greater than zero; odds ratio [OR] equals 4.21 [2.18 to 8.16]) and high levels of mutans streptococci (OR equals 3.83 [1.81 to 8.09]). In upper-middle-income countries, presence of enamel defects (OR equals 14.62 [6.10 to 35.03]) was found to be the strongest risk factor. Conclusion: The strongest risk factors associated with early childhood caries was the presence of enamel defects, presence of dentinal caries and high levels of mutans streptococci.

Proposed classification for interproximal contacts of primary molars using CBCT: a pilot study.

Background: Interproximal contact areas in primary teeth are known to be broader, flatter, and situated more gingivally than in permanent teeth. The objective of the present study was to evaluate the different types of intact interproximal contact areas in primary teeth using cone beam computed tomography (CBCT) among children. Methods: A cross-sectional study was designed with 74 contacts from 28 existing CBCT images of children aged between 3 and 14 years, obtained from the Indian Dental Education Academy, Chennai, India. The shape of the contact area was observed at three levels, the coronal, middle, and apical thirds, in three different sections of CBCT. Prevalence of the types of contact areas was expressed in the form of numbers and percentages. Results: The weighted Cohen's kappa values for inter-examiner reliability was 0.893 at baseline. Results exhibited four different types of contact areas between the primary molars, namely, O type, X type, I type, and S type, based on the shapes observed; hence, the proposed classification is referred to as OXIS. The most common pattern seen was I (66.2%), followed by X (21.6%), O (9.4%) and the least common was S (2.7%). Conclusion: The three-dimensional evaluation of intact interproximal contact areas between primary molars are of four types, O,X, I and S.