Machine Learning Study in Caries Markers in Oral Microbiota from Monozygotic Twin Children.

In recent years, the etiology of caries has evolved from a simplistic infectious perspective based on Streptococcus mutans and/or Lactobacillus activity, to a multifactorial disease involving a complex oral microbiota, the human genetic background and the environment. The aim of this work was to identify bacterial markers associated with early caries using massive 16S rDNA. To minimize the other factors, the composition of the oral microbiota of twins in which only one of them had caries was compared with their healthy sibling. Twenty-one monozygotic twin pairs without a previous diagnosis of caries were recruited in the context of their orthodontic treatment and divided into two categories: (1) caries group in which only one of the twins had caries; and (2) control group in which neither of the twins had caries. Each participant contributed a single oral lavage sample in which the bacterial composition was determined by 16S rDNA amplification and further high-throughput sequencing. Data analysis included statistical comparison of alpha and beta diversity, as well as differential taxa abundance between groups. Our results show that twins of the control group have a closer bacterial composition than those from the caries group. However, statistical differences were not detected and we were unable to find any particular bacterial marker by 16S rDNA high-throughput sequencing that could be useful for prevention strategies. Although these results should be validated in a larger population, including children from other places or ethnicities, we conclude that the occurrence of caries is not related to the increase of any particular bacterial population.

Accuracy assessment of dental age estimation with the Willems, Demirjian and Nolla methods in Spanish children: Comparative cross-sectional study.

BACKGROUND: The objective of this study was to evaluate and compare the validity and accuracy of the Willems, Demirjian and Nolla methods in predicting chronological age in a Spanish ethnicity population. METHODS: A sample of 604 orthopantomographs of Spanish children aged 4 to 13 years was evaluated by two independent evaluators. Descriptive statistics were applied to calculate the chronological age and dental age, presenting the mean and standard deviation. The difference between dental age and chronological age was calculated for each method. A positive result indicated an overestimation and a negative figure indicated an underestimation. The Wilcoxon test for paired data and Spearman's correlation coefficient were applied by age groups and sex to compare the chronological age and dental age of each method (that of Willems, Demirjian and Nolla). Statistical tests were performed at a 95% confidence level. RESULTS: The interexaminer agreement was 0.98 (p = 0.00), and the intraexaminer agreement was 0.99 (p = 0.00). The Willems method significantly overestimated the age of boys (0.35 years (0.93)) and girls (0.17 years (0.88)). The Demirjian method significantly overestimated the age of boys (0.68 years (0.95)) and girls (0.73 years (0.94)). The Nolla method significantly underestimated age in boys (0.44 years (0.93)) and girls (0.82 years (0.98)). CONCLUSIONS: In the Spanish population, the use of the Demirjian method for legal and medical purposes is frequent. This study reveals that the Willems method is more appropriate due to its greater precision in estimating dental age.

Las tres caras de la sonrisa gingival. Revisión bibliográfica / The three faces of the gummy smile. Literature review

Hablamos de sonrisa gingival cuando se altera la armonía establecida entre los dientes, labios y encía, exponiendo más allá de 2 mm de encía coronal a los incisivos maxilares, una circunstancia que, en ocasiones, genera un problema estético para algunos pacientes. La etiopatogenia de dicha condición se resume en tres facetas: dentoperiodontal (erupción pasiva alterada y erupción activa alterada), ósea (esquelética y/o dentoalveolar) y muscular (labio superior corto e hipermovilidad labial).Una condición multifactorial como la sonrisa gingival precisa un abordaje multidisciplinar: cirugía plástica periodontal, ortodoncia, cirugía ortognática, reposición labial, infiltración de toxina botulínica y tratamiento estético complementario

The excessive gingival display when a patient smiles (from 2 mm or more) is known as gummy smile. When the harmony established between the teeth, lips and gum is altered, exhibiting short clinical crown of the maxillary anterior teeth, in occasions generates an aesthetic problem for some patients.There are different etiologies of gummy smile, it concludes in three facets: dentoperiodontal (Altered Passive Eruption and Altered Active Eruption), bone defect (excessive vertical bone growth, dentoalveolar extrution) and muscular (short upper lip and upper lip hyperactivity), and the combination of some of these factors.A multifactorial condition requires a multidisciplinary boarding: plastic periodontal surgery, orthodontic, orthognathic surgery, lip reduction, infiltration of Botulinum toxin and complementary aesthetic treatment

Forensic identification in teeth with caries.

Human teeth are biological structures that resist extreme conditions thus becoming a useful source of DNA for human forensic identification purposes. When it is possible, forensic prefer only non-damaged teeth whereas those with cavities are usually rejected to avoid both external and internal bacterial contamination. Cavities are one of the most prevalent dental pathology and its incidence increases with ageing. The aim of this study was to validate the use of teeth with cavities for forensic identification. A total of 120 individual teeth from unrelated patients (60 healthy and 60 with cavities, respectively) extracted by a dentist as part of the normal process of treatment, were submitted for further analysis. Dental pulp was obtained after tooth fragmentation, complete DNA was extracted and the corresponding human identification profile was obtained by the AmpFlSTR® NGM SElect™ kit. Cariogenic microbiota was determined by PCR-DGGE with bacterial universal primers and bands were excised, re-amplified and sequenced. From the 120 dental pieces analyzed, a defined genetic profile was obtained in 81 (67.5%) of them, with no statistical differences between the healthy and the cavities-affected teeth. Statistical association between teeth status, DNA content and genetic profiles was not observed. Complex bacterial communities were only detected in the cavities group, being the Streptococcus/Enterococcus, and Lactobacillus genera the most represented. We conclude that teeth with cavities are as valid as healthy dental pieces for forensic human identification. Moreover, the severity of the cariogenic lesion as well as associated bacterial communities seems not to influence the establishment of human dental profiles.

Eficacia y efectos adversos de los aparatos intraorales en el tratamiento de la apnea obstructiva del sueño / Effectiveness and adverse effects of the intraoral devices in the treatment of sleep apnea

Los pacientes con alteraciones obstructivas durante el sueño, representan para los odontólogos y estomatólogos un tipo de paciente diferente convencional puesto que en ello el tratamiento va dirigido a mejorar la saturación de oxígeno. La utilización de los aparatos intraorales durante el sueño reposicionando la mandíbula y/o lengua en una posición más anterior contribuye a evitar el ronquido y reducir significativamente, en determinados casos, el índice de apneashipopneas (AHI). La efectividad de los aparatos de avance mandibular (MAD) en el tratamiento del síndrome de apnea hipopnea obstructiva del sueño varía a lo largo de toda la literatura con un rango entre el 40% - 60%. La adaptación de los pacientes está por encima del 80%, cifra que los hacen comparables a los aparatos de presión positiva (CPAP) para la reducción de los trastornos respiratorios durante el sueño, siendo los aparatos mejores al CPAP en cuanto a conformidad por parte de los pacientes y menores efectos secundarios (AU)

Patients with obstructive alterations during sleep represent for orthodontists and dentists a different conventional type of patient since in it the treatment is aimed at improving the saturation of oxygen. The use of the intraoral devices during sleep by repositioning the jaw and/or tongue in a more forward position contributes to avoiding snoring and to significantly reducing, in certain cases, the apnea-hypopnea index (AHI). The effectiveness of the mandibular advance devices(MAD) in the treatment of the obstructive sleep apnea hypopnea syndrome varies throughout all the literature with a range of 40% - 60%. The adaptation of the patients is over 80%, a figure which make them comparable to the continuous positive airway pressure (CPAP) devices for the reduction of the respiratory disorders during sleep, with the devices being better than the CPAP as regards patient conformity and fewer side effects (AU)