Molar-Incisor Hypomineralization: Prevalence Comparative Study in 6 Years of Interval.

The aim of this study was to evaluate the prevalence evolution rate of MIH (molar-incisor hypomineralization) after a 6-year period in Araraquara/SP, Brazil. This population-based study evaluated MIH in 545 schoolchildren (6-12 years of age) and other associated alterations, dental caries and dental fluorosis (DF). A semistructured questionnaire was sent to the schoolchildren's parents/guardians with the purpose of identifying the socioeconomic profile. Associations between MIH and the clinical characteristics were analyzed by the Poisson analysis of regression with robust variance, estimating the RPc (crude prevalence ratio) with CI 95%. The level of significance of 5% was adopted. The MIH prevalence in Araraquara/SP in 2016 was 14.3% (n = 78), and at this time, an increase of 2% was observed, in comparison with the data of the first prevalence study conducted in 2010 (12.3%). The mild degree compromise was the most prevalent diagnosis in the affected teeth (82.0%). Among children with MIH, the mean number of affected teeth was 2.78. Of the total number of children with MIH, 32.0% presented alterations in both first permanent molars and permanent incisors. There is no significant association between MIH and dental caries experience on permanent dentition (PRc = 1.141; CI 95% 0.709-1.835) or on primary dentition (PR c = 1.132; CI 95% 0.749-1.709). Children with MIH presented significantly less prevalence of dental fluorosis (PR c = 0.505; CI 95% 0.268-0.950). There is no association between MIH and monthly Brazilian minimal wage income (PR c = 1.130; CI 95% 0.655-1.949). It was concluded that the number of MIH cases had increased, revealing a greater need for defining the etiological factors and establishing a correct diagnosis to make it possible to institute early intervention.

Dental Fluorosis according to Birth Cohort and Fluoride Markers in an Endemic Region of Colombia.

OBJECTIVES: To analyze changes in the dental fluorosis (DF) incidence according to a birth cohort and explore current exposure to DF in a case series. METHODS: Repeated cross-sectional study of two periods: 2015 and 2018. Two standardized examiners registered DF using the Thylstrup-Fejerskov index in permanent teeth of children aged 7-18 years. Period and birth cohort frequencies were estimated by a generalized linear model, binomial family, and logarithmic link function. Period estimates are presented as prevalence ratios (PR) and birth cohort estimates as cumulative incidence ratios (RR); 95% confidence intervals and P values are reported. In a subsample of 37 volunteers (12.29 ± 2.63 years), the fluoride (F) concentration in toenails was measured using the HMDS diffusion method and an ion-specific electrode. Other samples from the local environment such as food, soil, and coal were also collected. RESULTS: In 274 children, we found that nonsignificant increases between periods (PR = 1.17; 95% CI: 0.89-1.55) were not explained by birth cohort effects. A total of 37.8% of the subsample had a toenail F concentration ≥2 µg F/g. The salty snacks and seasoning had the highest F concentrations among local environmental samples. CONCLUSION: In this population with a high DF frequency according to birth cohort and the evaluated period, the study of soil, coal, and food samples indicated a continued F exposure. F concentration found in the toenails shows a moderate F exposure; nearly a third of the children and adolescents exceeded the adopted threshold of 2 µg F/g. It is important to monitor and explore changes in exposure in highly affected population.

Clinical changes in the severity of dental fluorosis: a longitudinal evaluation.

BACKGROUND: Dental fluorosis (DF) has been one of the most prevalent pediatric dental conditions associated with aesthetic concern and treatment needs. This study aimed to identify the longitudinal clinical change in the severity of DF in 8-12-year-old children and its association with gender, age, severity, and tooth type. METHODS: This observational study assessed the dental aspects of the 92 Colombian children in 2015 (mean age at beginning 9.71 years ± 1.23) and 2018 (mean age 13.69 years ± 1.41), from an area with high DF prevalence. DF was recorded in all permanent teeth by two calibrated examiners using the Thylstrup and Fejerskov Index (TFI). DF severity change (maximum-TFI-score) was analyzed with descriptive analysis at the tooth level. Associated factors were evaluated with the generalized linear model, binomial family, and logarithmic link function. RESULTS: TFI scores ranged between 1 (very mild) to 6 (severe), being score 2 (41.7%) the most prevalent. After three years, 29.6% of the teeth presented score reduction, 24.1%, increased and 46.3% did not change; the significant association was related to increasing of the basal TFI = 1 score (44.2%) (RR = 9.7; 95% CI 1.7-56.5; p = 0.01) and with canines, premolars and second-permanent-molars teeth group (RR = 3.3; 95% CI 1.9-5.6; p = 0.005). CONCLUSION: The present study based on clinical features about DF confirms the dynamic post-eruptive nature of this condition. After three years of follow-up, a considerable proportion of the teeth changed to a higher score. Furthermore, the canines, premolars, and second-permanent-molars showed a higher incidence of an increase in severity of TFI score.

Effect of erosive challenge before and after the restoration of primary teeth.

The aim of this in vitro study was to investigate the erosive effect of a soft drink on primary teeth before and after restoration. Enamel blocks were obtained from 64 primary canines (N = 144) and divided into 3 groups (n = 48): 1, erosive challenge before and after restoration; 2, erosive challenge after restoration; and 3, no erosive challenge (control). The blocks received standardized preparations and were restored with 1 of 4 materials (n = 12): composite resin, bulk-fill composite resin, conventional glass ionomer cement, or resin-modified glass ionomer cement. The erosive challenge consisted of immersing the blocks in a cola soft drink for 1 minute at 25°C, 4 times a day for 5 days. The microhardness, roughness, marginal infiltration, and marginal adaptation of the specimens in all 3 groups were evaluated. Data were analyzed with the Kruskal-Wallis and Bonferroni tests. The results showed that the erosive challenge significantly altered all of the evaluated properties of all of the restorative materials (P < 0.05). The erosive challenge decreased the microhardness and marginal adaptation and increased the roughness and marginal infiltration of the tested materials. Composite resin had the highest values for microhardness and marginal adaptation as well as the lowest roughness value and dye infiltration score both with and without the erosive challenge. Subjecting teeth to erosive challenge before and after restoration altered the enamel microhardness and roughness significantly more than did erosive challenge only after restoration. Composite resin was the material least affected by the erosive challenge.

Esthetic rehabilitation of anterior teeth with molar-incisor hypomineralization and dental fluorosis: a case report.

This case report describes the treatment of a patient who had molar-incisor hypomineralization associated with dental fluorosis, a diagnosis established through a comprehensive review of the clinical record, an intraoral clinical examination, and assessment of photographic records. First, dental hypersensitivity was treated with fluoride varnish, which was applied separately to each dental quadrant. Subsequently, the functional and esthetic reconstruction of the permanent maxillary central incisors was completed in a single session through the placement of direct composite resin veneers. After the treatment, the patient was reexamined monthly for 12 months to evaluate the durability of the restorations. At the 12-month follow-up, no fractures or pigmentations were observed, and only a slight loss of brightness of the restorations was noted. The dental hypersensitivity had been eliminated. When an adhesive restorative technique with composite resin is well executed, it is possible to obtain satisfactory and long-lasting esthetics and relief of painful symptoms.

Esthetic reconstruction of teeth with enamel hypoplasia.

Hypoplasia is an enamel developmental defect characterized by a quantitative disturbance in the formation of mineralized tissue. Among its etiologic factors are local and systemic causes, trauma and dental infections being the most common. This case report presents the functional and esthetic rehabilitation of a 12-year-old boy diagnosed with hypoplasia in the maxillary central incisors. His chief complaints were the unesthetic appearance and sensitivity of the affected teeth. The teeth were restored with composite resin placed with the aid of a direct silicone palatal guide, and the patient was followed up for 12 months. The treatment plan allowed the restoration and improvement of function and esthetics, resulting in patient satisfaction.

Genes Regulating Immune Response and Amelogenesis Interact in Increasing the Susceptibility to Molar-Incisor Hypomineralization.

Ameloblasts are sensitive cells whose metabolism and function may be affected by inflammatory stimuli. The aim of this study was to evaluate the possible association between polymorphisms in immune response-related genes and molar-incisor hypomineralization (MIH), and their interaction with polymorphisms in amelogenesis-related genes. DNA samples were obtained from 101 nuclear families that had at least 1 MIH-affected child. Eleven single-nucleotide polymorphisms (SNPs) were investigated in immune response genes using TaqMan® technology allele-specific probes. A transmission disequilibrium test was performed to verify overtransmission of alleles in all MIH families, as well as in families only with mild or severe MIH-affected children. Gene-gene interactions between the immune-related and amelogenesis-related polymorphisms were analyzed by determining whether alleles of those genes were transmitted from heterozygous parents more often in association than individually with MIH-affected children. In severe cases of MIH, significant results were observed for rs10733708 (TGFBR1, OR = 3.5, 95% CI = 1.1-10.6). Statistical evidence for gene-gene interactions between rs6654939 (AMELX) and the SNPs rs2070874 (IL4), rs2275913 (IL17A), rs1800872 (IL10), rs1800587 (IL1A), and rs3771300 (STAT1) was observed. The rs2070874 SNP (IL4) was also significantly overtransmitted from heterozygous parents with the rs7526319 (TUFT1) and the rs2355767 (BMP2) SNPs, suggesting a synergistic effect of the transmission of these alleles with susceptibility to MIH. This family-based study demonstrated an association between variation in TGFBR1 and MIH. Moreover, the polymorphisms in immune response and amelogenesis genes may have an additive effect on the risk of developing MIH.

Rabdomyosarcoma of the Mandible: An Uncommon Clinical Presentation.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents. Most patients present with a mass in the head and neck region, urogenital region, or with distal extremity involvement. The authors describe a challenging case of a 6-year-old male patient presenting with mandibular RMS. The clinical/radiographic/tomographic evaluations classified the tumor as an advanced stage (stage IV), with a mass of 6.0 cm involving the left side of the mandible and parotid region. The biopsy revealed round, spindled, and pleomorphic cells with hyperchromatic nuclei and rare larger rhabdomyoblasts with eosinophilic cytoplasm. The diagnosis was of embryonal RMS. The patient was referred for treatment with cycles of chemotherapy; however, pulmonary and bone marrow metastasis were identified. Radiotherapy and local surgery with microvascular reconstruction were performed later; however, the patient died after a few months. Early diagnosis is critical for a good prognosis and cure of patients with RMS. Correct diagnosis considering also the histological subtype is important for adequate treatment, which according to the literature is not uniform probably because of the rarity of this neoplasm.

Eighteen-month clinical performance of composite resin restorations with two different adhesive systems for molars affected by molar incisor hypomineralization.

INTRODUCTION: The restorative management of molars with molar incisor hypomineralization (MIH) represents a challenge in the clinical practice with high failure rate. OBJECTIVE: The aim of this study is to evaluate the clinical survival of direct composite resin restorations in first permanent molars (FPMs) that are affected by MIH, comparing two adhesive systems. MATERIAL AND METHODS: We selected 41 FPMs with MIH from children aged 6-8 years. FPM fully erupted and with restorative treatment needed were the inclusion criteria. We excluded FPMs with destroyed crowns. The FPMs were randomly assigned to two groups: self-etching adhesive (SEA) and total-etch adhesive (TEA). Clinical evaluation was performed by a blinded examiner during 18 months according to the modified US Public Health Service (USPHS) criteria. The actuarial method was used to evaluate survival of the restorations, and Chi-square and Fisher's exact tests were used to compare differences between the groups (α = 5 %). RESULTS: The cumulative survival rates were 100 % at 1 month, 89 % at 6 months, 73 % at 12 months, and 68 % at 18 months in SEA, and 95 % at 1 month, 72 % at 6 months, 59 % at 12 months, and 54 % at 18 months in TEA; there was no significant difference between groups. CONCLUSIONS: There was no difference in clinical survival of restorations in FPMs affected by MIH using TEA or SEA adhesives in the end of 18 months. CLINICAL RELEVANCE: It was suggested that SEAs as well as TEAs can be applied to restore molars affected by MIH, when it is performed a conservative cavity preparation. Once, cavosurface margins (cavity design) in hypomineralized enamel have less bonding capability.

Family-Based Genetic Association for Molar-Incisor Hypomineralization.

Despite some evidence of genetic and environmental factors on molar-incisor hypomineralization (MIH), its aetiology remains unclear. This family-based genetic association study aimed more comprehensively to investigate the genetic carriage potentially involved in MIH development. DNA was obtained from buccal cells of 391 individuals who were birth family members of 101 Brazilian nuclear families. Sixty-three single nucleotide polymorphisms (SNPs) were investigated in 21 candidate genes related to amelogenesis using the TaqMan™ OpenArray™ Genotyping platform. All SNPs were genotyped in 165 birth family members unaffected by MIH, 96 with unknown MIH status and 130 affected individuals (50.7% with severe MIH). Association analysis was performed by the transmission/disequilibrium test (TDT), and statistical results were corrected using the false discovery rate. Significant results were obtained for SNPs rs7821494 (FAM83H gene, OR = 3.7; 95% CI = 1.75-7.78), rs34367704 (AMBN gene, OR = 2.7; 95% CI = 1.16-6.58), rs3789334 (BMP2 gene, OR = 2.9; 95% CI = 1.34-6.35), rs6099486 (BMP7 gene, OR = 2.2; 95% CI = 1.14-4.38), rs762642 (BMP4 gene, OR = 2.3; 95% CI = 1.38-3.65), rs7664896 (ENAM gene, OR = 2.1; 95% CI = 1.19-3.51), rs1711399 (MMP20 gene, OR = 0.4; 95% CI = 0.20-0.72), rs1711423 (MMP20 gene, OR = 2.1; 95% CI = 1.18-3.61), rs2278163 (DLX3 gene, OR = 2.8; 95% CI = 1.26-6.41), rs6996321 (FGFR1 gene, OR = 2.7; 95% CI = 1.20-5.88), and rs5979395 (AMELX gene, OR = 11.7; 95% CI = 1.63-84.74). Through this family-based association study, we concluded that variations in genes related to amelogenesis were associated with the susceptibility to develop MIH. This result is in agreement with the multifactorial idea of the MIH aetiology, but further studies are necessary to investigate more thoroughly the factors that could influence MIH.

Amoxicillin diminishes the thickness of the enamel matrix that is deposited during the secretory stage in rats.

BACKGROUND: The use of amoxicillin during early childhood has been associated with molar incisor hypomineralization. AIM: The objective of this study was to determine whether the use of amoxicillin interferes with enamel development, during secretion and early mineralization stages. DESIGN: Fifteen pregnant rats were randomly assigned to three groups that received physiological solution (sham group), 100 mg/kg/day amoxicillin (A100G), and 500 mg/kg/day amoxicillin (A500G). After birth, the pups in each group received the same treatment until post-natal day 7 or 12. The upper first molars were analyzed histomorphometrical and immunostaining with amelogenin on day 7, and MMP-20 on day 12 was performed using a semiquantitative method (H-score). RESULTS: At 7 days, several vacuolar structures were observed in the ameloblasts in the A100G and A500G groups. A significant reduction of the enamel thickness (P < 0.001) was found in amoxicillin-treated rats compared with the sham group. Significant differences were not observed in enamel thickness (P > 0.05) between the groups of 12-day-old rats. Moreover, significant differences were not observed in the number of amelogenin- and MMP-20-immunolabeled ameloblasts (P > 0.05) between groups. CONCLUSION: The present results suggest that amoxicillin interferes with the initial stages of amelogenesis by causing structural changes in the ameloblasts and a reduction of the enamel matrix.

Effect of Fluoride Varnish on Enamel Remineralization in Anterior Teeth with Molar Incisor Hypomineralization.

OBJECTIVE: The objective of this study was to investigate the effect of fluoride varnish on remineralization of anterior teeth affected by Molar-Incisor Hypomineralization (MIH) by means of Quantitative Light-Induced Fluorescence- QLF. STUDY DESIGN: Fifty-one healthy 9 - 12- year-old children were selected according to different clinically diagnosed levels of MIH, proposed by the European Academy of Pediatric Dentistry (2003) (considering the most severe lesion per patient, n= 51 lesions), and randomly divided into two groups: (1) four applications of 5% NaF varnish, with one-week interval, and (2) usual home care- control. At each visit, the mean change in fluorescence and area of lesion were measured by QLF. The data were analyzed by repeated measures ANOVA and Tukey's test. RESULTS: All patients showed enamel alterations in first permanent molars and incisors, frequently with two molars affected by MIH (41.1%). There was no statically significant difference in the mean of fluorescence and area of lesion between groups over the studied time. CONCLUSION: We observed no favorable effect on the remineralization of MIH lesions in anterior teeth after four applications of fluoride varnish.

Longitudinal Evaluation of the Structural Integrity of Teeth Affected by Molar Incisor Hypomineralisation.

The aim of this prospective cohort study was to evaluate the risk of posteruptive breakdown and the development of caries lesions in teeth with molar incisor hypomineralisation (MIH). A total of 367 permanent incisors and first molars, affected and not affected by MIH lesions, of 45 children with MIH from Araraquara, São Paulo, Brazil, were evaluated at intervals from 6 to 12 months by assessing the severity of MIH, the presence of tooth caries lesions and the treatment needed. During the study period, all patients received preventive care. The data were analysed using Fisher's exact test and actuarial method survival analysis. Significant associations were also found in teeth between the presence of MIH and a DMFT index >0 in all periods and also between the need for treatment and the presence of MIH. The teeth affected by MIH opacities were healthy in 99% of incisors and 93% of molars at the end of the 12-month period. Due to the high likelihood of maintaining the tooth structure in opacities, the complete or premature removal of the affected area is not justified.

Longitudinal effect of curcumin-photodynamic antimicrobial chemotherapy in adolescents during fixed orthodontic treatment: a single-blind randomized clinical trial study.

White spot lesions are one of the concerns during the fixed orthodontic treatment. Thus, the aim of the present study was to evaluate the antimicrobial/anti-inflammatory effect of curcumin-photodynamic antimicrobial chemotherapy (c-PACT) and chlorhexidine varnish on the plaque accumulation and gingival bleeding in adolescents under fixed orthodontic treatment. A randomized clinical trial was performed with an initial number of 45 patients being distributed into three groups: group I-chlorhexidine varnish 2%, group II-placebo varnish, and group III-c-PACT (curcumin at 1.5 mg.mL(-1)) exposed to blue Light-emitting diode (LED) light at 450 nm (power density = 165 mW.cm(-2), fluency = 96 J.cm(-2), total dose = 150.7 J). The treatments were performed for four consecutive times with an interval of 1 week each. After the interventions, two calibrated examiners (Kappa value = 0.75) analyzed the dental plaque accumulation by plaque index (PI) and gingivitis condition by gingival bleeding index (GBI) with 1 and 3 months of follow-up after the treatments comprised a final sample of 35 patients. No significant difference was found to PI between the groups during baseline and 1-month period. Group III (1.52 ± 0.51) presented significance difference from group I (0.91 ± 0.75) and group II (1.03 ± 0.51) at 3 months of follow-up. In this same period, there was more plaque accumulation with significant statistical difference (P ≤ 0.05) in comparison to the other periods to all studied groups. There was a GBI reduction statistically significant to groups I and III at 1-month follow-up in comparison to other periods. No effect was verified to dental plaque accumulation after the photodynamic application mediated with curcumin activated with a blue LED light.

Digital radiography for determination of primary tooth length: in vivo and ex vivo studies.

BACKGROUND: Methods for determining the root canal length of the primary tooth should yield accurate and reproducible results. In vitro studies show some limitations, which do not allow their findings to be directly transferred to a clinical situation. AIM: To compare the accuracy of radiographic tooth length obtained from in vivo digital radiograph with that obtained from ex vivo digital radiograph. METHOD: Direct digital radiographs of 20 upper primary incisors were performed in teeth (2/3 radicular resorption) that were radiographed by an intraoral sensor, according to the long-cone technique. Teeth were extracted, measured, and mounted in a resin block, and then radiographic template was used to standardise the sensor-target distance (30 cm). The apparent tooth length (APTL) was obtained from the computer screen by means of an electronic ruler accompanying the digital radiography software (CDR 2.0), whereas the actual tooth length (ACTL) was obtained by means of a digital calliper following extraction. Data were compared to the ACTL by variance analysis and Pearson's correlation test. RESULTS: The values for APTL obtained from in vivo radiography were slightly underestimated, whereas those values obtained from ex vivo were slightly overestimated. No significance was observed (P ≤ 0.48) between APTL and ACTL. CONCLUSION: The length of primary teeth estimated by in vivo and ex vivo comparisons using digital radiography was found to be similar to the actual tooth length.

Control of white spot lesion adjacent to orthodontic bracket with use of fluoride varnish or chlorhexidine gel.

The aims of this study were to compare the effectiveness of fluoride varnish and chlorhexidine gel in controlling white spot lesions (WSLs) adjacent to orthodontic brackets and to compare the ability of Quantitative Light-Induced Fluorescence (QLF) to measure mineral uptake with that of transverse microradiography (TMR). Thirty premolars with artificially induced WSLs were randomly assigned to three groups: (1) two applications of 5% NaF-varnish (F), with one-week interval, (2) two applications of 2% chlorhexidine gel (CHX), with one-week interval, and (3) control (CO), no treatment. QLF was used to measure changes in fluorescence before and after caries induction, 1 week after each application and 1, 2, and 3 months after the last application of F or CHX. TMR was performed to quantify lesion depth and mineral content after caries induction to evaluate the effects of F, CHX, and CO 3 months after the last application of agents. The data were analyzed by repeated measures ANOVA and Tukey's test. All treatments increased the mineral content during the experimental period; however, F induced faster remineralization than CHX. The correlation between QLF and TMR was significantly moderate. Two applications of fluoride varnish or 2% chlorhexidine gel at one-week intervals were effective in controlling WSLs.

Plaque control improves the painful symptoms of oral lichen planus gingival lesions. A short-term study.

BACKGROUND: Lichen planus is a mucocutaneous disease with manifestation in the oral mucosa, the gingiva being one of the most affected regions. In some cases, the lesion may be painful and lead to fragility of the tissues, so that precise diagnosis and adequate treatment are indispensible factors for improving the clinical condition. The aim of this study was to evaluate the effectiveness of plaque control in the improvement of clinical features and painful symptoms of oral lichen planus with gingival involvement. METHODS: Twenty patients diagnosed with gingival lichen planus confirmed by histopathological examination were selected. The patients were evaluated by a trained examiner, with regard to the clinical features of the lesions [Index of Escudier et al. (Br J Dermatol, 157, 2007, 765)]; painful symptoms (Visual Analog Scale); and periodontally, as regards the visible plaque and gingival bleeding indices. Periodontal treatment consisted of supragingival scaling and oral hygiene instruction, with professional plaque removal afterward for a period of 4 weeks. The entire sample was evaluated at the baseline and at the conclusion of treatment, and the results were analyzed by the Wilcoxon nonparametric test. RESULTS: The data demonstrated that the majority of patients were women (90%), with a mean age of 55.9 years. Periodontal treatment resulted in statistically significant reduction (P < 0.05) in the periodontal indices, with consequent improvement in the clinical features and painful symptoms of the lesions. CONCLUSIONS: It was demonstrated that plaque control was effective in improving the clinical features and painful symptoms of oral lichen planus with gingival involvement.

Dental caries experience and Molar-Incisor Hypomineralization.

OBJECTIVE: This cross-sectional study assessed the prevalence and severity of the enamel defects, known as Molar-Incisor Hypomineralization (MIH) and its relationship to dental caries. MATERIALS AND METHODS: A sample of 1157 schoolchildren (population based), aged 6-12 years, of the Araraquara city-Brazil, was evaluated according to the European Academy of Paediatric Dentistry (EAPD) criteria by two trained examiners. The dental impact caused by MIH was evaluated with the Decayed, Missing and Filled Teeth (DMFT) index (WHO). Data were analyzed using ANOVA and Chi-square tests (p < 0.05). The socioeconomic status was collected using a questionnaire answered by parents. RESULTS: The prevalence of MIH was 12.3%. Mild impairment was the most frequent diagnosis. DMFT of children with MIH was 0.89 (± 1.18), which are higher than those of the unaffected group (0.43 ± 1.01). An association was found between dental caries only in the permanent dentition of children with MIH (p = 0.0001). Family income was considered low in 85% of the families of children with MIH in the public system, while in private school it was 18% (p < 0.05). CONCLUSION: The prevalence of MIH in Araraquara was associated with greater caries experience in the permanent dentition.

Increase in severity of molar-incisor hypomineralization and its relationship with the colour of enamel opacity: a prospective cohort study.

BACKGROUND: Predicting risk of posteruptive enamel breakdown (PEB) of molar-incisor hypomineralization (MIH) opacity is a difficult but important clinical task. Therefore, there is a need to evaluate these aspects through longitudinal studies. OBJECTIVE: The aim of this longitudinal study was to analyse the relationship between colours of MIH opacity of children aged 6-12 (baseline) and other clinical and demographic variables involved in the increase in severity of MIH. MATERIALS AND METHODS: A blinded prospective 18-month follow-up was conducted with 147 individuals presenting mild MIH. Tooth-based incidence of increase in severity of MIH (PEB or atypical restorations) was used as dependent measurement. Enamel opacities were recorded according to colour shades of white, yellow and brown, allowing assessment of susceptibility to structural loss over time, according to colour of MIH opacity. Poisson regression models were used to adjust the results for demographic and clinical variables. RESULTS: Brown and yellow MIH opacities were at higher risk for PEB and atypical restorations than those of white ones, even after adjustment for clinical and demographic variables. CONCLUSION: Teeth presenting mild MIH severity associated with yellow and brown enamel opacities were at high risk for increase in severity of MIH than lighter ones. This result could help clinicians determine a risk-based treatment for children with MIH.

Influence of lateral excursion on vestibular cervical dental abfraction.

A study was performed to evaluate the influence of mandibular lateral excursion, group function and canine guidance on vestibular cervical dental abfraction (VCDA). Thirty-six individuals of both sexes, aged 20 to 45 years, with full natural dentition with at least one tooth with VCDA were selected at the San Marcos University Clinic. We evaluated number of teeth with VCDA per side (left and right), tooth type and lateral excursive movement (canine guidance or group function) affecting it. The results showed no statistical difference (p > 0.05). The tooth type most often showing VCDA was the first lower premolar, with 30.8% on the right side and 36.4% on the left. Moderate positive correlation was found between age and VCDA (R = 0.40). It is concluded that group function during lateral excursion may contribute to presence of VCDA.