Palatal mucosa thickness and palatal neurovascular bundle position evaluation by cone-beam computed tomography—retrospective study on relationships with palatal vault anatomy

Background Measuring the thickness of the palatal mucosa at the planning of the surgical procedure is an important step in order to obtain the maximum width and thickness of the graft from the appropriate area. The aim of this study is to determine whether there is a relationship between palatal angle (PA) or palatal depth (PD) and palatal mucosa thickness (PMT) or palatal neurovascular bundle distance (PNBD). Methods PMT, PNBD, PD and PA were measured on cone-beam computed tomography (CBCT) images of maxillary posterior region of 200 male and 200 female patients. The mean of all parameters according to gender was compared and the significance of the difference detected between groups was evaluated. Potential relationship between PMT or PNBD and PA or PD was also evaluated. Results In females, the palatal mucosa was significantly thinner at all tooth regions (p < 0.005), and PNBD was lower only at the level of the second molar (p < 0.001). In addition, it was found that there was a significant inverse correlation between the palatal depth value and the palatal mucosal thickness, and palatal depth was correlated with the palatal neurovascular bundle distance (p ≤ 0.001). Discussion Consistent with previous studies, it was observed that the thickest mucosa in the palatal region was located in the region of the premolar teeth, and women had thinner palatal mucosa. In addition, in patients with a deeper palate vault, the palatal mucosa was thinner, but the palatal neurovascular bundle was more distant from the cemento-enamel junction.

Development of an optimal relief method for the palatal plate by stress analysis

Background Plate dentures cannot be easily modified after fabrication; therefore, the sites and magnitude of relief must be effectively assessed at the time of fabrication. However, a considerable variation exists in the magnitude of optimal relief and relief range, and there are no guidelines that present these clearly, leading the dentists to decide subjectively. Thus, this study aims to develop an optimal relief method to improve the stress bearing capacity of the palatal mucosa. Methods The objective of this study, namely, the borderline, was set in steps. A three-dimensional finite element model for the pseudopalatal plate was created and used to evaluate the changes in stress distribution in the palatal mucosa due to the selective relief of stresses above the borderline. The resulting data were used to develop the optimal relief method. Results In the relief model with a borderline of 0.04 MPa or higher, the distribution volume at which a high stress of 0.20 MPa or higher is generated was approximately 800% of that with the no-relief model, and in the relief model with a borderline of 0.06 MPa or higher, the respective ratio was approximately 280%. On the other hand, the relief models with a borderline of 0.14 MPa or higher were approximately 60%. In the mid-palatal relief model, the distribution volume at which a stress of 0.20 MPa or higher was generated was 180% of that in the relief model. Conclusions The supportive strength of plates can be increased by selectively applying optimal relief rather than standard relief, allowing for easier and more effective plate-denture treatment.

Custom fabrication of cast splint microimplant-assisted rapid palatal expansion appliances for treatment of maxillary deficiency in young adults

Background: The objective of this article was to illustrate the process in the fabrication of a custom cast splint Microimplant-Assisted Rapid Palatal Expansion (MARPE) appliance for treatment of maxillary deficiency in young adults. Findings: The fabrication of a custom-made MARPE appliance allows the casting base to design according to the shape of the patient’s palate close to the palatal mucosa. In this new design, one end consists of a casting body, inserting hole, and teeth retention device (circumferential rings) connected to the other end by a jackscrew. Connection of all parts in the integral casting unit increases the strength of the expansion appliance and avoids distortion, deformation, or damage to the palatal mucosa due to increased resistance from the oromaxillofacial area. Conclusion: This custom design can improve the clinical outcome of maxillary expansion, especially in patients with narrow and high-arched palates.

Development of an Optimal Relief Method for the Palatal Plate by Stress Analysis

Background: A maxillary-palate-shaped device for simultaneous measurement of bite force and palatal mucosal subsidence at the time of pain onset in dentate persons has been developed. However, palatal mucosal stress analysis in a simulation based on three-dimensional finite element analysis is effective for objective and efficient evaluation of various types of denture-supporting mucosa. Recently plate dentures are not easily modified after the completion of these dentures , so it is essential to effectively assess the sites and magnitude of relief at the time of preparation. However, there is considerable variation in the magnitude of optimal relief and relief range, and there are no guidelines that present these clearly, leading the surgeon to decide subjectively. Thus, this study aimed to develop an optimal relief method to improve the stress bearing capacity of the palatal mucosa.Objectives: The objective of this study, the borderline was set in steps. The changes in stress distribution in the palatal mucosa due to the selective relief of stresses above the borderline were evaluated using a three-dimensional finite element simulation. The purpose of this study was to develop an optimal relief method to improve the bearing capacity of the palatal mucosa.Methods: The objective of this study, the borderline, was set in steps. A three-dimensional finite element model for the pseudopalatal plate was prepared and used to evaluate the changes in stress distribution in the palatal mucosa due to the selective relief of stresses above the borderline. The resulting data were used to develop the optimal relief method.Results: In the relief model with a borderline of 0.04 MPa or higher, the distribution volume at which high stress of 0.20 MPa or higher is generated was approximately about 800%％ of that with the no-relief model, and in the relief model with a borderline of 0.06 MPa or higher, the respective ratio was approximately about 280％%. On the other hand, the relief models with borderline of 0.14 MPa or higher were about 60%. In the mid-palatal relief model, the distribution volume at which stress of 0.20 MPa or higher was generated was 180% of that in the relief model.Conclusions: The supportive strength of plates can be increased by selectively applying optimal relief rather than standard relief, allowing for easier and more effective plate-denture treatment.

Effect of epinephrine on the absorption of lidocaine following application to the oral mucosa in rats

Background We investigated the role of epinephrine in prolonging the localization of lidocaine on the oral mucosa and inhibiting its absorption in the blood of rats. Methods We used 7–8-week-old pathogen-free Wistar male rats (n = 128) for our study. We divided them into the control group administered with 14C-labeled lidocaine hydrochloride gel only and the study group administered with 14C-labeled lidocaine hydrochloride gel with epinephrine. The medications were administered in the palatal mucosa of the rats. The amount of mucosa, palatine bone, and serum lidocaine was measured by radioactivity using a liquid scintillation counter and was observed using autoradiograms. Results Initially, there was no significant difference in the lidocaine levels between the lidocaine and lidocaine with epinephrine groups in the palatal mucosa (751.9 ± 133.8 vs. 669.8 ± 101.6 ng/mg [2 min]). After 4 min, the values were significantly lower in the lidocaine with epinephrine group (1040.0 ± 142.8 vs. 701.2 ± 109.0 ng/mg [20 min]). After 40 min, the lidocaine level became significantly higher in the lidocaine with epinephrine group (586.8 ± 112.4 vs. 1131.3 ± 155.2 ng/mg [40 min]). Similar results were observed in the palatine bone and serum. Conclusion Epinephrine prolonged the localization of lidocaine applied to the mucosa and inhibited its absorption into the bloodstream of rats. Clinical studies are required to evaluate the use of epinephrine-containing topical anesthetics on the oral mucosa.

Elderly woman with acute necrotizing ulcerative gingivitis (Vincent disease): a case report

Acute necrotizing ulcerative gingivitis (Vincent disease) is an inflammatory disease also known as ulcerative gingivitis, necrotizing ulcerative gingivitis, fusospirochetal stomatitis, Plaut-Vincent stomatitis, and trench mouth. In case of gingival lesions the Vincent gingivitis is diagnosed; in case of simultaneous lesions of the gingivae and oral mucosa the disease is considered the Vincent stomatitis, and in case of pharyngeal tonsil it is considered the Vincent angina. Rare case of the elderly woman with the disease involving gingival and palatal mucosa is reported. Main causes of the disease are discussed, differential diagnoses are listed, and preventive measures are outlined.