spaP gene of Streptococcus mutans in dental plaque and its relationship with early childhood caries.

AIM: Streptococcus mutans and Streptococcus sobrinus are the main pathogens associated with the development of dental caries in humans. Recently, the real-time polymerase chain reaction (qPCR-TR) has been used for fast and exact quantification of these bacteria species. This molecular biology method has made the detection of these bacteria in saliva and dental plaque possible; additionally, it aids the development of illness risk prediction. The purpose of this prospective, analytic, transversal, observational and unicenter study was to quantify the spaP gene of the Streptococcus mutans and its correlation with caries in a group of children using isolated DNA from plaque samples processed through qPCR-TR, using specific oligonucleotides for this gene detection. MATERIALS AND METHODS: The cariogenic potential of Streptococcus mutans in the dental plaque was analysed in a group of patients aged 12 to 46 months. A descriptive statistical analysis was performed. The Spearman's correlation coefficient was used to establish the correlation between caries (dmft) index (decayed/missing/filled primary teeth), spaP gene and age group. The Wilcoxon test was used to compare MSB cultivation technique and qPCR-TR. RESULTS: In the molecular trials, a close association between caries prevalence in childhood and the presence and high proportion of the spaP gene of S. mutans was found. The average caries prevalence was 3.71, and it increased as age range increased. The highest caries prevalence was observed in female patients and in the oldest age range studied (40 46 months) which contrasts with the 12-18 months age that had a caries (dmft) index of zero. The amplification using as initiator the gene spaP of the nucleic acids extracted from the S. mutans resulted positive in 91.3% of the cases. Every child with caries was positive for the spaP and only 8.75% were negative, this group included children without caries. CONCLUSION: In conclusion, there was a correlation with infant caries prevalence and S. mutans.

Comparison of triple image area using panoramic radiography of child and adult dry skull.

AIM: The objective of this study was to compare the zone of simple, double and triple images in a dry infant cranium against an adult completely formed one when panoramic X-ray photography's were taken. STUDY DESIGN: We took 96 panoramic X-ray photography's to a dry infant cranium placing a metallic spherical object of 8mm in different anatomical points for later to observe, identify and analyse the image of the object in each of them and determine if the images appeared as simple, double or triple. RESULTS: The 57.15% of images obtained were simple, 16.66 % were double and 26.19% triple. The area of triple and double images in the infant cranium did not involve anatomical important structures. CONCLUSIONS: The area where triple and double images appear was located in the occipital part in the infantile cranium with respect to the adult skull. On the basis of these results we can suggest that the X-ray photography must not be used as the main radiological support in the making of decisions in patients with craniofacial alterations.