Involvement of Different Nerve Branches in Trigeminal Neuralgia on Right and Left Sides- A Retrospective Study

One of the most common symptoms in the orofacial region is pain. Trigeminal neuralgia is characterized by pain affecting the trigeminal nerve and its related areas of distribution and is known to have significant impact on the quality of life. Misdiagnosis of trigeminal neuralgia has been reported by dentists in several previous studies in the literature. With this rationale, the aim of the present study is to determine the most commonly involved nerve branch and the side affected in trigeminal neuralgia patients. The present retrospective study involved 72 patients diagnosed with trigeminal neuralgia who reported from October 2013 to October 2014. Data regarding the age of onset, gender, side of involvement was analyzed from their clinical records. Out of the 72 patients, males were 42(58.3%) and females were 30(41.7%). In our study, a total of 56 % (i.e., 40) patients showed involvement on the right and 44% (i.e., 32) (i.e, 32) patients on the left side of the face. In this retrospective study, ophthalmic branch (V1) was affected only in 3 patients. Mandibular nerve (V3) alone was involved in 24 patients. Involvement of all the three divisions V1, V2 and V3 was seen in 16(22.3%) of patients. Clinical similarities of trigeminal neuralgia that have an impact on different populations were demonstrated in this study. Detailed history and proper identification of involved nerve branch play an important role in the diagnostic accuracy and treatment satisfaction. Most involved branch in our study was the mandibular (V3) branch and the most affected side was the right side. Correlation of systemic factors with trigeminal neuralgia can be attempted in future research.

The effects of altered BMP4 signaling in first branchial-arch-derived murine embryonic orofacial tissues

The first branchial arch (BA1), which is derived from cranial neural crest (CNC) cells, gives rise to various orofacial tissues. Cre mice are widely used for the determination of CNC and exploration of gene functions in orofacial development. However, there is a lack of Cre mice specifically marked BA1’s cells. Pax2-Cre allele was previously generated and has been widely used in the field of inner ear development. Here, by compounding Pax2-Cre and R26R-mTmG mice, we found a specific expression pattern of Pax2+ cells that marked BA1’s mesenchymal cells and the BA1-derivatives. Compared to Pax2-Cre; R26R-mTmG allele, GFP+ cells were abundantly found both in BA1 and second branchial arch in Wnt1-Cre;R26R-mTmG mice. As BMP4 signaling is required for orofacial development, we over-activated Bmp4 by using Pax2-Cre; pMes-BMP4 strain. Interestingly, our results showed bilateral hyperplasia between the upper and lower teeth. We also compare the phenotypes of Wnt1-Cre; pMes-BMP4 and Pax2-Cre; pMes-BMP4 strains and found severe deformation of molar buds, palate, and maxilla-mandibular bony structures in Wnt1-Cre; pMes-BMP4 mice; however, the morphology of these orofacial organs were comparable between controls and Pax2-Cre; pMes-BMP4 mice except for bilateral hyperplastic tissues. We further explore the properties of the hyperplastic tissue and found it is not derived from Runx2+ cells but expresses Msx1, and probably caused by abnormal cell proliferation and altered expression pattern of p-Smad1/5/8. In sum, our findings suggest altering BMP4 signaling in BA1-specific cell lineage may lead to unique phenotypes in orofacial regions, further hinting that Pax2-Cre mice could be a new model for genetic manipulation of BA1-derived organogenesis in the orofacial region.

Substance P/ Neurokinin-1 Receptor, Trigeminal Ganglion, Latency, and Coronavirus Infection-Is There Any Link?

Novel Severe Acute Respiratory Syndrome-Corona Virus-2 infection (SARS-CoV-2) is an acute respiratory and infectious disease. This perspective aims to provide a basic understanding of the inflammation caused by SARS-CoV-2 and its relation to the trigeminal ganglion (TG). The virus enters through the mucous membranes of the orofacial region and reaches the TG, where it resides and takes control of its peptides including Substance P (SP). SP is the main neuropeptide, neuromodulator, and neuro-hormone of TG, associated with nociception and inflammation under noxious stimulus. SP release is triggered and, consequently, affects the immune cells and blood vessels to release the mediators for inflammation. Hence, cytokine storm is initiated and causes respiratory distress, bronchoconstriction, and death in complicated cases. Neurokinin-1 Receptor (NK-1R) is the receptor for SP and its antagonists, along with glucocorticoids, may be used to alleviate the symptoms and treat this infection by blocking this nociceptive pathway. SP seems to be the main culprit involved in the triggering of inflammatory pathways in SARS-CoV-2 infection. It may have a direct association with cardio-respiratory rhythm, sleep-wake cycle, nociception, and ventilatory responses and regulates many important physiological and pathological functions. Its over-secretion should be blocked by NK-1R antagonist. However, experimental work leading to clinical trials are mandatory for further confirmation. Here, it is further proposed that there is a possibility of latency in SARS-CoV-2 virus infection if it is acting through TG, which is the main site for other viruses that become latent.

Occurrence of the Elongated Styloid Process on Digital Panoramic Radiographs in the Riyadh Population

Background. Patients with an elongated styloid process might present with dysphagia and pain in the cervicofacial region. These patients could be misdiagnosed as other orofacial pathologies. Aim. The present study attempted to assess the prevalence of the elongated styloid process on digital panoramic radiographs in the Riyadh population. Materials and Methods. The present prospective randomized study was conducted on the panoramic digital radiographs of 300 randomly selected patients visiting a private dental hospital to identify any elongation of the styloid process. Only the radiographs without any magnification errors were considered. The styloid process length was measured using the Sidexis measuring tool and entered in an Excel spreadsheet with other demographic data. A length beyond 30 mm was considered styloid process elongation. The data were subjected to statistical analysis. Results. The symptoms of styloid process elongation were higher among females (78.6%), and this difference was statistically significant (χ2 = 7.182; P = 0.007 ). No statistically significant association was observed between styloid process elongation and symptoms between different age groups. Females exhibited a significant longer mean length of the styloid process than males. The present study exhibited a 27.3% prevalence for the elongation and calcification of the styloid process. Conclusion. Given the significant prevalence of the elongated styloid process in our study, we recommend it to be considered as one of the differential diagnosis for pain or discomfort in the orofacial region.

Spatiotemporal Expression and Functional Analysis of miRNA-22 in the Developing Secondary Palate

Objective Normal development of the embryonic orofacial region requires precise spatiotemporal coordination between numerous genes. MicroRNAs represent small, single-stranded, non-coding molecules that regulate gene expression. This study examines the role of microRNA-22 (miR-22) in murine orofacial ontogeny. Methods Spatiotemporal and differential expression of miR-22 (mmu-miR-22-3p) within the developing secondary palate was determined by in situ hybridization and quantitative real-time PCR, respectively. Bioinformatic approaches were used to predict potential mRNA targets of miR-22 and analyze their association with cellular functions indispensable for normal orofacial ontogeny. An in vitro palate organ culture system was used to assess the role of miR-22 in secondary palate development. Results There was a progressive increase in miR-22 expression from GD12.5 to GD14.5 in palatal processes. On GD12.5 and GD13.5, miR-22 was expressed in the future oral, nasal, and medial edge epithelia. On GD14.5, miR-22 expression was observed in the residual midline epithelial seam (MES), the nasal epithelium and the mesenchyme, but not in the oral epithelium. Inhibition of miR-22 activity in palate organ cultures resulted in failure of MES removal. Bioinformatic analyses revealed potential mRNA targets of miR-22 that may play significant roles in regulating apoptosis, migration, and/or convergence/extrusion, developmental processes that modulate MES removal during palatogenesis. Conclusions Results from the current study suggest a key role for miR-22 in the removal of the MES during palatogenesis and that miR-22 may represent a potential contributor to the etiology of cleft palate.

Transcutaneous Electrical Nerve Stimulation: A Review of Dental Applications

Transcutaneous electrical nerve stimulation or TENS is a nonpharmacologic method that is used to alleviate pain from various acute and chronic conditions. TENS works through activation of descending inhibitory neurons of the central nervous system. In dentistry, TENS has applications for pain reduction in temporomandibular disorders and postherpetic neuralgia. It has also been studied for its role in increasing salivary secretion in subjects with xerostomia and as a local anesthetic agent in pediatric dentistry. Its wide applications in the orofacial region make it an important treatment modality. The purpose of the present review was to describe the general principles and its applications in dentistry along with its indications, advantages, and disadvantages. A web-based search was conducted using the keywords “transcutaneous electrical nerve stimulation,” “temporomandibular joint,” “TENS,” “TMJ,” “orofacial pain,” and “Management.” The manuscripts thus obtained were evaluated and used for compiling the present narrative review. The present review focuses on the mechanism of action, applications, and effectiveness of TENS in the management of diseases of the maxillofacial region.

Uso da aprendizagem colaborativa como ferramenta para avaliar anomalias craniofaciais sindrômicas

Almost 30% of oral clefts are associated with other structural abnormalities. However, little is known on orofacial characteristics associated with these cases since they are not systematically reported. To close this gap, we developed a collaborative learning approach supported by an interprofessional team aiming to carefully describe oral findings and impact the training of future professionals that hopefully will incorporate these descriptions on their clinical practice. The methodological proposal consisted of small group sessions focusing on a particular syndrome or group of syndromes followed by the examination of patients with those conditions. Twenty cases were examined and studied over the course of one semester and a set of conditions to be identified in the orofacial region was defined. Here, we present a guideline that we suggest that dentists and dental institutions use. We also present the advantages of using collaborative learning as a tool in the training of the clinician.

Dog bite of the orofacial region- Case series and update

Animal bites are a significant cause of morbidity and mortality across the globe and when involving the orofacial region, they commonly present to dental surgeons. Literature on their initial management provides a plethora of conflicting views and results and it is necessary to be up to date with the latest modalities of management of such facial injuries to give best functional and surgical outcomes to the patients. Antibiotics and anti-tetanus and anti-rabies vaccinations and immunoglobulins should be judiciously administered along with appropriate wound management.

Dog bite of the orofacial region- Case series and update

Animal bites are a significant cause of morbidity and mortality across the globe and when involving the orofacial region, they commonly present to dental surgeons. Literature on their initial management provides a plethora of conflicting views and results and it is necessary to be up to date with the latest modalities of management of such facial injuries to give best functional and surgical outcomes to the patients. Antibiotics and anti-tetanus and anti-rabies vaccinations and immunoglobulins should be judiciously administered along with appropriate wound management.