Prevalence of retromolar foramen in nineteenth century Spanish population.

Among the non-metrical variants of the mandible that have been proven to be a key issue for dental practitioners, the retromolar foramen constitutes one of the most controversial details regarding its prevalence and associated variables. Thus, this study evaluated the prevalence of the retromolar foramen and the variables associated with its presence in a large Spanish collection of human dry mandibles from the nineteenth century. Six hundred Spanish human dry mandibles (1200 sides) belonging to an osteology collection were examined. The presence of teeth, the presence or absence of retromolar foramen, as well as its side, diameter, number, and location were evaluated. Descriptive analysis and analysis of the associations between the variables were performed. The retromolar foramen was observed in 184 mandibles (31%) and was predominantly present unilaterally (60.8%). Most mandibles (54.9%) had a single foramen. The most common location was the retromolar trigone region (84%). On analysis of the association of variables, it was observed a strong association (p < 0.001) between the presence or absence of the foramen and the presence of teeth. Moreover, a significant association was also found between sex vs. presence of teeth (p = 0.033), sex vs. presentation side of the foramen (p = 0.028), sex vs. number of foramina found (p = 0.004), and diameter vs. number of foramina found (p < 0.001). This study reveals that the retromolar foramen showed a high prevalence of 31% in nineteenth century Spaniards and was located primarily in the retromolar trigone, suggesting that dentists should be aware of and consider the relevant findings of this study.

Initial stages of development of the submandibular gland (human embryos at 5.5-8 weeks of development).

The aim of this study was to determine the main stages of submandibular salivary gland development during the embryonic period in humans. In addition, we studied submandibular salivary gland development in rats on embryonic days 14-16 and expression in the submandibular salivary gland region with the monoclonal antibody HNK-1. Serial sections from 25 human embryos with a greatest length ranging from 10 to 31 mm (Carnegie stages 16-23; weeks 5.5-8 of development) and Wistar rats of embryonic days (E) 14-16 were analysed with light microscopy. Five stages of submandibular salivary gland development were identified. The prospective stage (1), between weeks 5.5 and early week 6, is characterized by a thickening of the epithelium of the medial paralingual groove in the floor of the mouth corresponding to the primordium of the submandibular salivary gland parenchyma. At this stage, the primordium of the parasympathetic ganglion lies below the lingual nerve. The primordium of the submandibular salivary gland parenchyma is observed in rats on E14 in the medial paralingual groove with mesenchymal cells, underlying the lingual nerve. These cells are HNK-1-positive, corresponding to the primordium of the parasympathetic ganglion. The bud stage (2), at the end of week 6 in humans and on E15 in rats, is characterized by the proliferation and invagination of the epithelial condensation, surrounded by an important condensation of the mesenchyme. The pseudoglandular stage (3) at week 6.5 is characterized by the beginning of the formation of lobes in the condensed mesenchyme. The canalicular stage (4), between week 7 and 7.5, is characterized by the appearance of a lumen in the proximal part of the submandibular duct. The innervation stage (5) occurs during week 8, with the innervation of the submandibular and interlobular ducts. Nervous branches arriving from the parasympathetic ganglion innervate the glandular parenchyma. Numerous blood vessels are observed nearby. Our results suggest that submandibular salivary gland development requires interactions among epithelium, mesenchyme, parasympathetic ganglion and blood vessels.

Craniofacial and three-dimensional palatal analysis in cleft lip and palate patients treated in Spain.

Growth alterations have been described in patients operated on for oral clefts. The purpose of this work was to analyze the craniofacial and palate morphology and dimensions of young adults operated on for oral clefts in early childhood in Spain. Eighty-three patients from eight different hospitals were divided into four groups based on their type of cleft: cleft lip (CL, n = 6), unilateral cleft lip and palate (UCLP, n = 37), bilateral cleft lip and palate (BCLP, n = 16), and cleft palate only (CPO, n = 24). A control group was formed of 71 individuals. Three-dimensional (3D) digital models were obtained from all groups with an intraoral scanner, together with cephalometries and frontal, lateral, and submental facial photographs. Measurements were obtained and analyzed statistically. Our results showed craniofacial alterations in the BCLP, UCLP, and CPO groups with an influence on the palate, maxilla, and mandible and a direct impact on facial appearance. This effect was more severe in the BCLP group. Measurements in the CL group were similar to those in the control group. Cleft characteristics and cleft type seem to be the main determining factors of long-term craniofacial growth alterations in these patients. Prospective research is needed to clearly delineate the effects of different treatments on the craniofacial appearance of adult cleft patients.

Three-dimensional descriptive study of the pterygomaxillary region related to pterygoid implants: A retrospective study.

The objective of this study was to analyze three-dimensionally the morphological characteristics of the pterygomaxillary region related to pterygoid implants. Volume, height, width and bone density were studied in relation to age, sex and dental status. This retrospective observational study analyzed the CBCT of 52 hemi-maxillas three-dimensionally (females n = 28, males n = 24; dentate = 31, edentulous = 21). Patients were exposed between September 2009 and October 2014, and data collection was performed between November 2015 and May 2016. Bone density, volume, height and width were analyzed in various locations of the maxilla and pterygoid process, and the variables age, gender and dental status patients were compared. The results show that the mean width of the pterygomaxillary joint was 7.5 mm (SD 1.00 mm), mean height was 12.51 mm (SD 1,82 mm) and mean volume was 321.7 mm3 (SD 142.02 mm3). Statistically significant differences between dentate and edentulous patients were found, showing a higher osseous density in dentate patients in the pterygoid process (758.2, SD 106.8, 95% CI 729.2 to 787.3 GSD - Gray Scale Density - compared to 689.9, SD 107.3, 95% CI 660.8 to 719.1 GSD; P = 0.022). In the maxilla, density was statistically significant lower in female subjects (571.0, SD 74.1, 95% CI 594.9 to 645.4 GSD) than in male subjects (620.2, SD 93.8, 95% CI 594.4 to 645.4 GSD, P = 0.047). In conclusion, due to the significant variation in the morphological characteristics of the pterygomaxillary region among subjects, personalized pre-surgical radiological assessment should always be performed. Gender, age and dental status are critical factors as they significantly affect bone density in this region.