Is there an association between dental caries and genetics? Systematic review and meta-analysis of studies with twins.

OBJECTIVE: This review aimed to assess the agreement of dental caries experience between monozygotic (MZ) and dizygotic (DZ) twins. DATA RESOURCES: This systematic review was performed by reviewers in the databases Embase, MEDLINE-PubMed, Scopus, Web of Science and manual searches and gray literature Google Scholar® and Opengray. Observational studies that evaluated dental caries in twins were included. The risk of bias was analyzed using the Joanna Briggs checklist. Meta-analyses were performed to assess the pooled Odds Ratio to estimate the agreement values of dental caries experience and DMF index between pairs of twins (p < 0.05). To assess the certainty of evidence, the GRADE scale was used. STUDY SELECTION: 2533 studies were identified, of which 19 were included in the qualitative analysis, six in the quantitative synthesis, with two meta-analyses being carried out. Association between genetics and the development of the disease was observed in most studies. In the risk of bias analysis, 47.4% had moderate risk. Higher agreement of dental caries experience was observed in MZ twins than DZ in both dentitions (OR: 5.94; 95% CI: 2.00-17.57). However, there was no difference between the MZ and DZ twin groups in the analysis comparing DMF index agreement (OR: 2.86; 95%CI: 0.25-32.79). The certainty of evidence was considered low and very low for all studies included in meta-analyses. CONCLUSION: With very low certainty of the evidence, the genetic factor seems to influence the agreement of the caries experience. CLINICAL RELEVANCE: Understanding the genetic influence on the disease has the potential to contribute to the development of studies that may use biotechnologies for prevention and treatment as well as guide future research involving gene therapies aiming to prevent the occurrence of dental caries.

Hypomineralized Teeth Have a Higher Frequency of Dental Hypersensitivity.

Purpose: The purposes of this study were to: (1) compare dental hypersensitivity (DH) between hypomineralized permanent first molars and unaffected controls molars in patients with molar-incisor hypomineralization (MIH); and (2) assess the influence of opacity, color, and subject age on DH. Methods: This cross-sectional study identified 40 children/adolescents, who were attending a children's dental clinic and had one to three first permanent molars hypomineralized (demarcated opacities). The severity and color of the hypomineralized lesions were also evaluated. The assessment of DH was made using evaporative stimulus using a jet of compressed air applied by a dental syringe for one second, perpendicular to the occlusal surface employing the visual analogue scale (VAS) and the Schiff cold air sensitivity scale (SCASS). To verify the association between the presence or absence of DH and MIH, Pearson's chi-square and Fisher's exact test (P<0.05) were performed. Results: The frequency of DH was 28.0 percent in hypomineralized teeth and 9.4 percent in normal controls (by VAS; P=0.002). A higher frequency of opacities was observed (P<0.001). Older individuals had DH more frequently (P<0.05). Conclusions: Hypomineralized molars presented a higher frequency of dental hypersensitivity than control teeth, and dental hypersensitivity was associated with darker opacities of the lesion and older-aged subjects.

Association Between Duration of Breastfeeding and Malocclusion in Primary Dentition in Brazil.

Purpose: To evaluate the relationship between type and duration of breastfeeding and the development of malocclusion in primary dentition.
Methods: A cross-sectional observational study was conducted with children of both sexes, aged 30 to 48 months, who attended to a dental program for maternal and child care. The mothers completed a questionnaire about the form (exclusive breast-feeding or not) and duration of breastfeeding, their children's non-nutritive sucking habits, and their sociodemographic information. The clinical examination was done by a calibrated examiner in the knee-to-knee position and under indirect light to evaluate the primary occlusion. Pearson's chi-square test or Fisher's exact test and Poisson regression were performed for statistical analysis.
Results: Over 45 percent of 252 children who were evaluated had malocclusion, such as anterior open bite (13.6 percent), posterior crossbite (3.6 percent), anterior crossbite (2.8 percent), midline shift (21.5 percent), overbite (19.8 percent), and overjet (32.9 percent). Children who were exclusively breastfed for less than six months had a 50 percent higher prevalence of anterior open bite (P =0.009) compared to those who had exclusive breastfeeding for more than six months.
Conclusion: Exclusive breastfeeding for less than six months was associated with anterior open bite. The other malocclusion types were not associated with the time and type of feeding the children received in the early phase of the primary dentition. (J Dent Child 2019;86(1):17-23)
Received August 29, 2018; Last Revision November 20, 2018; Accepted January 3, 2019.

Distraction osteogenesis in Goldenhar Syndrome: Case report and 8-year follow-up

Goldenhar syndrome is a well-known condition featuring the following triad of anomalies: ocular abnormalities, microtia and vertebral anomalies. This syndrome involves structures arising from the first and second branchial arches. Craniofacial anomalies, including mandibular, zygomatic and/or maxillary hypoplasias are found in 50% of patients with Goldenhar syndrome. Patients with this syndrome may present unilateral or bilateral underdevelopment of the mandible. Severaltreatments for the correction of the dento-facial deformity have been described, among them distraction osteogenesis is one that shows promising results. Distraction osteogenesis is the process of bone formation that occurs during slow separation of the segments of bone after an osteotomy and it has been used to alleviate facial asymmetry. Mandibulardistraction osteogenesis has been applied for many years, but long-term reports present controversial results. The purpose of the case report is to describe the immediate and long-term effects of distraction osteogenesis used to treat mandible asymmetry in a 5-year-old boy with Goldenhar syndro