Agenesia of salivary glands: incidental findings in multidetector computerized tomography.

Agenesis of the salivary glands is an extremely uncommon finding, and in the majority of cases, it is associated with facial syndromes or malformations. Reports in the literature have, however, indicated that agenesis of the major salivary glands can occur in isolation, and this anomaly is believed to occur due to a failure in the developmental process. Herein, we present two cases of isolated unilateral agenesis of major salivary glands.

Novel FGF10 mutation in autosomal dominant aplasia of lacrimal and salivary glands.

OBJECTIVE: Aplasia of lacrimal and salivary glands (ALSG) is a rare autosomal dominant inherited disease, characterized by aplasia, atresia, or hypoplasia of the lacrimal and salivary systems with variable expressivity. The purpose of this study was to identify genetic etiology of an ALSG family. MATERIALS AND METHODS: We recruited a Turkish family with ALSG and performed a mutational analysis, based on the candidate gene approach, to clarify the molecular genetic etiology. RESULTS: The candidate gene sequencing of the FGF10 gene identified a novel heterozygous nonsense mutation (c.237G > A, p.Trp79*) in the exon 1. CONCLUSION: The identified novel mutation would result in a haploinsufficiency of the FGF10, because of nonsense-mediated mRNA decay caused by a premature stop codon. This report further confirms that ALSG is caused by the haploinsufficiency of functional FGF10. CLINICAL RELEVANCE: Identification of the genetic etiology of the ALSG will help both the family members and dentist understand the nature of the disorder. Therefore, it will positively motivate oral health care to avoid further destruction of the tooth due to the lack of salivary production.

Congenital Absence of Salivary Glands in Fetuses with Trisomy 21.

BACKGROUND: The congenital absence of salivary glands has been reported in children but never in fetuses with trisomy 21. OBJECTIVES: To determine whether the congenital absence of salivary glands can be detected prenatally between 13 and 16 weeks of gestation in normal and trisomy 21 fetuses using transvaginal ultrasound. METHODS: We performed a retrospective analysis of recordings of normal and trisomy 21 fetuses. Inclusion criteria were a single viable fetus and good visualization of the anatomic area of the salivary glands on both sides of the fetal face. All videos were reviewed by one examiner who reported the presence or absence of one or more salivary glands and was blinded to the fetal karyotype. RESULTS: Of the 45 videos reviewed, 4 were excluded from the study: namely, a non-viable fetus, twin pregnancy, and in 2 there was unsatisfactory visualization of the anatomic area of the salivary glands. Of the remaining 41 fetuses, 24 had trisomy 21 and 17 were normal. In the trisomy 21 fetuses, 8 (33.3%) had congenital absence of one or more salivary glands compared to 1 of 17 normal fetuses (5.9%) (P < 0.05). CONCLUSIONS: Congenital absence of the salivary glands has a high specificity but low sensitivity for detecting trisomy 21 fetuses.

Dry mouth: Xerostomia and salivary gland hypofunction.

BACKGROUND: Mouth dryness may present as salivary gland hypofunction (SGH), xerostomia or both. It is considered one of the most underappreciated, underdiagnosed and undermanaged oral health conditions. Despite its common presentation and adverse impact on life quality, it is also generally poorly understood. Increased awareness of the condition is important in addressing these problems. OBJECTIVE: This article discusses SGH and xerostomia, and the associated intra-oral and extra-oral implications. It also summarises currently available management approaches and the evidence behind them. DISCUSSION: SGH and xerostomia are complex problems. None of the currently available management approaches are entirely satisfactory. Addressing the causative or contributing factors is therefore paramount. While oral health complaints are generally left up to the dental professional to manage, the nature of mouth dryness necessitates increased dialogue between the dental and medical professions to ensure optimal patient care.

Mutations in the gene encoding fibroblast growth factor 10 are associated with aplasia of lacrimal and salivary glands.

Autosomal dominant aplasia of lacrimal and salivary glands (ALSG; OMIM 180920 and OMIM 103420) is a rare condition characterized by irritable eyes and dryness of the mouth. We mapped ALSG to 5p13.2-5q13.1, which coincides with the gene fibroblast growth factor 10 (FGF10). In two extended pedigrees, we identified heterozygous mutations in FGF10 in all individuals with ALSG. Fgf10(+/-) mice have a phenotype similar to ALSG, providing a model for this disorder. We suggest that haploinsufficiency for FGF10 during a crucial stage of development results in ALSG.

Bilateral aplasia of the major salivary glands and unilateral atresia of lacrimal duct.

Aplasia of the major salivary glands, especially the parotid gland, is a rare disorder. Up to now, few cases have been reported. Clinically, patients may present with xerostomia, irritable eyes, severe dental caries, or asymptomatic manifestations.According to clinical and radiologic findings, we reported a case of a 20-year-old girl with bilateral aplasia of the major salivary glands and unilateral atresia of the lacrimal duct and made telephone follow-up 1 year later.

Bilateral submandibular gland aplasia with hypertrophy of the sublingual glands of a patient with a cleft lip and palate: case report.

Aplasia of major salivary glands is a rare disorder with only a handful of cases reported in the literature. The cause of congenital absence of the salivary glands has not been determined, but it may be associated with ectodermal defects of the first and second branchial arches. Patients may be asymptomatic or may experience dysphagia, xerostomia, several periodontal disease, or multiple caries. There are few reports of patients with congenital gland aplasia with cleft lip and palate. We document the case of a 41-year-old patient with repaired unilateral cleft lip palate, bilateral submandibular gland aplasia, and compensatory hypertrophy of the sublingual glands. To the best of our knowledge, there are no previous reports that can be found in the literature with a combination of such findings.

Dacryocystorhinostomy precipitating keratoconjunctivitis sicca in aplasia of lacrimal and major salivary glands (ALSG).

We report a 16-month-old girl referred for bilateral epiphora and sticky eyes since birth. Examination revealed a refluxible left lacrimal sac mucocele, agenesis of the left lower punctum, and agenesis of both puncta on the right side. Complete bony obstruction was noted on probing of the left nasolacrimal duct. At 4 years of age, she underwent left external dacryocystorhinostomy (DCR) with silicone intubation because of chronic dacryocystitis. Her epiphora and stickiness improved significantly in the first postoperative year, but she subsequently developed dryness of the left eye, dry mouth, and dental caries. CT and MRI scans revealed the absence of the lacrimal and salivary glands. The clinical signs and symptoms improved with plugging the left upper punctum and topical lubricants. Aplasia of the lacrimal and salivary glands may present with symptoms of congenital lacrimal obstruction, and failure to make an early diagnosis will result in inappropriate lacrimal surgery and dry eye.

Abnormalities in periodontal and salivary tissues in conditional presenilin 1 and presenilin 2 double knockout mice.

We used forebrain-specific conditional presenilin 1 (PS1) and presenilin 2 (PS2) double knockout mice (dKO mice), which exhibit neurodegenerative disease-like symptoms, including inflammation of the brain and periphery, to investigate whether periodontal and salivary tissues display alterations. Mandibles were dissected for alveolar bone height analysis. Maxillae were fixed and decalcified for histological observation and osteoclast detection. Submandibular glands were fixed for histological observation. The submandibular gland and the gingiva of the mandibular incisor teeth were used to assay inflammatory mediators. At 9 months, the number of osteoclasts had significantly increased in the periodontal ligament and the periodontal tissues exhibited obvious histomorphological abnormalities in the dKO mice compared to the control mice at the same age. Alveolar bone loss in dKO mice increased with age. The salivary tissues in dKO mice exhibited obvious age-dependent histomorphological abnormalities. The levels of the inflammatory mediators IL-1ß, TNF-α, and GM-CSF in the submandibular gland and gingiva also increased in an age-dependent manner. These findings suggest that inflammation in the dKO brain could expand to the periphery, including the oral tissue, which could ultimately induce abnormalities in the periodontal and salivary tissues.

Agm1/Pgm3-mediated sugar nucleotide synthesis is essential for hematopoiesis and development.

Carbohydrate modification of proteins includes N-linked and O-linked glycosylation, proteoglycan formation, glycosylphosphatidylinositol anchor synthesis, and O-GlcNAc modification. Each of these modifications requires the sugar nucleotide UDP-GlcNAc, which is produced via the hexosamine biosynthesis pathway. A key step in this pathway is the interconversion of GlcNAc-6-phosphate (GlcNAc-6-P) and GlcNAc-1-P, catalyzed by phosphoglucomutase 3 (Pgm3). In this paper, we describe two hypomorphic alleles of mouse Pgm3 and show there are specific physiological consequences of a graded reduction in Pgm3 activity and global UDP-GlcNAc levels. Whereas mice lacking Pgm3 die prior to implantation, animals with less severe reductions in enzyme activity are sterile, exhibit changes in pancreatic architecture, and are anemic, leukopenic, and thrombocytopenic. These phenotypes are accompanied by specific rather than wholesale changes in protein glycosylation, suggesting that while universally required, the functions of certain proteins and, as a consequence, certain cell types are especially sensitive to reductions in Pgm3 activity.

Lacrimo-auriculo-dento-digital syndrome is caused by reduced activity of the fibroblast growth factor 10 (FGF10)-FGF receptor 2 signaling pathway.

Lacrimo-auriculo-dento-digital (LADD) syndrome is characterized by abnormalities in lacrimal and salivary glands, in teeth, and in the distal limbs. Genetic studies have implicated heterozygous mutations in fibroblast growth factor 10 (FGF10) and in FGF receptor 2 (FGFR2) in LADD syndrome. However, it is not clear whether LADD syndrome mutations (LADD mutations) are gain- or loss-of-function mutations. In order to reveal the molecular mechanism underlying LADD syndrome, we have compared the biological properties of FGF10 LADD and FGFR2 LADD mutants to the activities of their normal counterparts. These experiments show that the biological activities of three different FGF10 LADD mutants are severely impaired by different mechanisms. Moreover, haploinsufficiency caused by defective FGF10 mutants leads to LADD syndrome. We also demonstrate that the tyrosine kinase activities of FGFR2 LADD mutants expressed in transfected cells are strongly compromised. Since tyrosine kinase activity is stimulated by ligand-induced receptor dimerization, FGFR2 LADD mutants may also exert a dominant inhibitory effect on signaling via wild-type FGFR2 expressed in the same cell. These experiments underscore the importance of signal strength in mediating biological responses and that relatively small changes in receptor signaling may influence the outcome of developmental processes in cells or organs that do not possess redundant signaling pathway.

Quantitative Assessment of Salivary Gland Parenchymal Vascularization Using Power Doppler Ultrasound and Superb Microvascular Imaging: A Potential Tool in the Diagnosis of Sjögren's Syndrome

Background: Primary Sjögren's syndrome is a chronic inflammatory autoimmune disease. Minor salivary gland biopsy is the gold standard for the diagnosis of primary Sjögren's syndrome. Superb microvascular imaging, power Doppler ultrasound, and color Doppler of the salivary glands represent non-invasive, non-irradiating modality for evaluating the vascularity of the salivary glands in the diagnosis and follow-up of primary Sjögren's syndrome. Aims: To evaluate the efficacy of superb microvascular imaging and vascularity index in salivary glands for the sonographic diagnosis of primary Sjögren's syndrome. Study Design: Prospective case-control study. Methods: Twenty participants with primary Sjögren's syndrome and 20 healthy subjects were included in the study. Both parotid glands and submandibular glands were evaluated by superb microvascular imaging, power Doppler ultrasound, and color Doppler. The diagnostic accuracy of superb microvascular imaging was compared using these techniques. Results: In the patient group, the vascularity index values of superb microvascular imaging in parotid glands and submandibular glands were 3.5±1.66, 5.06±1.94, respectively. While the same values were 1.0±0.98 and 2.44±1.34 in the control group (p≤0.001). In the patient group, the vascularity index values of power Doppler ultrasound in parotid glands and submandibular glands were 1.3±1.20 and 2.59±1.82, respectively. While the same values were 0.3±0.32 and 0.85±0.68 in the control group (p≤0.001). The superb microvascular imaging vascularity index cut-off value for the diagnosis of primary Sjögren's syndrome in parotid glands that maximizes the accuracy was 1.85 (area under the curve: 0.906; 95% confidence interval: 0.844, 0.968), and its sensitivity and specificity were 87.5% and 72.5%, respectively. While the superb microvascular imaging vascularity index cut-off value for the diagnosis of primary Sjögren's syndrome in submandibular gland that maximizes the accuracy was 3.35 (area under the curve: 0.873; 95% confidence interval: 0.800, 0.946), its sensitivity and specificity were 82.5% and 70%, respectively. Conclusion: Superb microvascular imaging with high reproducibility of the vascularity index has a higher sensitivity and specificity than the power Doppler ultrasound in the diagnosis of primary Sjögren's syndrome. It can be a noninvasive technique in the diagnosis of primary Sjögren's syndrome when used with clinical, laboratory and other imaging methods.

Ribbon modulates apical membrane during tube elongation through Crumbs and Moesin.

Although the formation and maintenance of epithelial tubes are essential for the viability of multicellular organisms, our understanding of the molecular and cellular events coordinating tubulogenesis is relatively limited. Here, we focus on the activities of Ribbon, a novel BTB-domain containing nuclear protein, in the elongation of two epithelial tubes: the Drosophila salivary gland and trachea. We show that Ribbon interacts with Lola Like, another BTB-domain containing protein required for robust nuclear localization of Ribbon, to upregulate crumbs expression and downregulate Moesin activity. Our ultrastructural analysis of ribbon null salivary glands by TEM reveals a diminished pool of subapical vesicles and an increase in microvillar structure, cellular changes consistent with the known role of Crumbs in apical membrane generation and of Moesin in the cross-linking of the apical membrane to the subapical cytoskeleton. Furthermore, the subapical localization of Rab11, a small GTPase associated with apical membrane delivery and rearrangement, is significantly diminished in ribbon mutant salivary glands and tracheae. These findings suggest that Ribbon and Lola Like function as a novel transcriptional cassette coordinating molecular changes at the apical membrane of epithelial cells to facilitate tube elongation.

Exposure to spinosad induces histopathological and cytotoxic effects on the salivary complex of the non-target predator Podisus nigrispinus.

In integrated pest management systems, biological and chemical controls must be compatible. The insecticide spinosad affects some non-target insects and might compromise their fitness. The objective of this study was to evaluate the histopathological and cytotoxic effects of spinosad on the salivary complex of the predatory bug Podisus nigrispinus (Heteroptera: Pentatomidae). Spinosad toxicity and insect survival were determined using six concentrations of insecticide. Ultrastructural changes and cell death of salivary glands were analyzed after P. nigrispinus exposure to spinosad LC50 (3.15 µg L-1). The insecticide caused toxicity to P. nigrispinus; survival was 32% after 48 h of exposure to LC50. The main histological changes in the salivary complex were disorganization of the epithelium, cytoplasmic vacuolization, and apocrine secretion into the gland lumen. Cytotoxic effects, such as release of granules and vacuoles into the lumen, presence of autophagosomes, enlargement of basal plasma membrane infoldings, and apoptosis, were observed. Spinosad causes toxicity, decreases survival, and changes the histology and cytology of the P. nigrispinus salivary complex. The results suggest that the cellular stress induced by the insecticide affects extra-oral digestion, compromising the potential of P. nigrispinus as a biological pest control agent.

A Salivation Abnormality with Trigeminal Nerve Dysfunction in Dogs.

Trigeminal nerve pathology can lead to sensory and motor dysfunction to structures of the head that are easily recognized. The trigeminal nerve is a conduit for the distribution of postganglionic parasympathetic innervation to structures of the head. Parasympathetic innervation to the salivary glands is provided by preganglionic parasympathetic neurons of the facial and glossopharyngeal nerves. Postganglionic axons course with branches of the mandibular branch of the trigeminal nerve to reach the salivary glands. Denervation of the salivary glands impacts glandular function, leading to a reduction in the volume and composition of the saliva produced. Saliva plays an important role in oral health. Poor oral health has widespread systemic implications. This article describes a group of dogs with unilateral or bilateral dysfunction of the trigeminal nerve and/or its branches. In all dogs, an accumulation of thick, foamy saliva was observed accumulating in the dorsal aspect of the caudal oral cavity on the ipsilateral side to the affected nerve. In dogs with magnetic resonance imaging (MRI), there was a reduction in size based on the largest cross-sectional area measurement and an increase in mean signal intensity of the salivary glands ipsilateral to the affected nerves compared to the glands on the normal side. The authors hypothesize that the abnormal saliva and MRI changes observed were consequent to parasympathetic denervation of the salivary glands. The recognition of this clinical observation is the first step in understanding the impact that denervation has on salivation and ultimately on overall oral and systemic health in dogs.

An intronic alteration of the fibroblast growth factor 10 gene causing ALSG-(aplasia of lacrimal and salivary glands) syndrome.

BACKGROUND: A combined aplasia, hypoplasia or atresia of lacrimal points and salivary glands is rarely diagnosed. Those patients suffer from epiphora, xerostomia and severe dental caries. This phenotype represents the autosomal-dominant aplasia of lacrimal and salivary glands syndrome (ALSG). Recently, aberrations of the Fibroblast Growth Factor 10 (FGF10) gene have been identified to be causative for this disorder. METHODS: We performed a sequence analysis of the FGF10 gene of a patient with ALSG-syndrome and his also affected brother as well as 193 controls. The FGF10 transcript was analyzed using RNA extracted from primary fibroblasts of the patient's mucosa. RESULTS: We detected a novel heterozygous sequence variation in intron 2 (c.430-1, G > A) causing the ALSG syndrome. The alteration derogates the regular splice acceptor site and leads to the use of a new splice acceptor site 127 bp upstream of exon 3. The aberration was detected in the genomic DNA derived from two affected brothers, but not in 193 control individuals. Furthermore, no diseased member of the family displayed additional abnormalities that are indicative for the clinically overlapping lacrimo-auriculo-dento-digital syndrome (LADD). CONCLUSION: This family-based approach revealed an intronic variation of the FGF10 gene causing ALSG-syndrome. Our results expand the mutational and clinical spectrum of the ALSG syndrome.

Effect of N-Acetylcysteine on Antioxidant Defense, Oxidative Modification, and Salivary Gland Function in a Rat Model of Insulin Resistance.

Oxidative stress plays a crucial role in the salivary gland dysfunction in insulin resistance (IR). It is not surprising that new substances are constantly being sought that will protect against the harmful effects of IR in the oral cavity environment. The purpose of this study was to evaluate the effect of N-acetylcysteine (NAC) on oxidative stress and secretory function of salivary glands in a rat model of insulin resistance. Rats were divided into 4 groups: C-normal diet, C + NAC-normal diet + NAC, HFD-high-fat diet, and HFD + NAC. We have demonstrated that NAC elevated enzymatic (superoxide dismutase, catalase, and peroxidase) and nonenzymatic antioxidants (reduced glutathione (GSH) and total antioxidant capacity (TAS)) in the parotid glands of HFD + NAC rats, while in the submandibular glands increased only GSH and TAS levels. NAC protects against oxidative damage only in the parotid glands and increased stimulated salivary secretion; however, it does not increase the protein secretion in the both salivary glands. Summarizing, NAC supplementation prevents the decrease of stimulated saliva secretion, seen in the HFD rats affected. NAC improves the antioxidative capacity of the both glands and protects against oxidative damage to the parotid glands of IR rats.

New pathogenic variant in the FGF10 gene in the agenesis of lacrimal and salivary gland syndrome: Ophthalmological and genetic study.

Aplasia/agenesis of lacrimal and salivary glands is a rare congenital defect that has been associated with disturbances in fibroblast growth factor 10 (FGF10). It can present with symptoms of congenital lacrimal obstruction, dry eye, and dry mouth. We report the ophthalmological and genetic study of a 19-year-old woman and her relatives suffering from this syndrome. A new probably pathogenic variant is described in the FGF10 gene.