Biomimetic Scaffolds for Regeneration of Temporomandibular Joint Disc: A Narrative Review.

Defects and dysfunctions of temporomandibular joint (TMJ) disc are responsible for the majority of TMJ diseases. Current treatments in this matter are usually short-term and only palliative, thus an alternative treatment that offers long-lasting repair is in great demand. In recent years great attempts have been made to prepare an ideal scaffold, which best resembles the native TMJ disc in characteristics such as mechanical, physical and biological properties. This narrative review focuses on developments of the recent ten years in fabrication of scaffolds using decellularized tissues, natural and synthetic biomaterials for regeneration of TMJ disc and compared their properties. PubMed and Google Scholar databases were searched using the following keywords ("TMJ" OR "temporomandibular joint" OR "TMD" OR "temporomandibular disease") AND ("scaffold" OR "hydrogels"). Randomized controlled trials, randomized clinical trials, case-controls, case reports, and animal studies were included. Comments, systematic reviews, meta-analyses, and non-English papers were excluded. The study concluded that hybrid scaffolds have exhibited favorable cell attachment and proliferation. Synthetic scaffolds have shown promise in providing better control over structural properties; however, additional processes are often required to provide biomimetic cell signaling. While there is still much to learn about the ideal scaffold for TMJ disc regeneration, both natural and synthetic scaffolds have shown promise in achieving the functional, structural, biological, and mechanical properties of a native TMJ disc.

Effect of lactobacillus reuteri-derived probiotic nano-formulation on recurrent aphthous stomatitis: a double-blinded randomized clinical trial.

OBJECTIVES: We aimed to assess the therapeutic effects of a topical probiotic nano-formulation derived from Lactobacillus reuteri on treating recurrent aphthous stomatitis. MATERIALS AND METHODS: 60 participants were randomly allocated into two groups (control and probiotic). Probiotic group administered topical probiotic nano-formulation three times a day for seven days. The control group administered a standard analgesic oral rinse. The size of ulcer(s) and pain severity were recorded on days 0, 3, 5, and 7 after intervention. RESULTS: Before the intervention, the groups had no significant differences in terms of pain severity (P-value = 0.28) and lesion size (P-value = 0.24). Both groups exhibited significant reductions in pain severity and lesion size over the course of the intervention. After one week, the probiotic group had a notably larger lesion size reduction than the control group (P-value = 0.01). The probiotic group also showed a significantly greater reduction in pain severity than the control group (P-value = 0.04). CONCLUSIONS: Applying topical probiotic nano-formulation derived from Lactobacillus reuteri three times a day decreased lesion size and pain severity in RAS patients faster than the local analgesic oral rinse. CLINICAL RELEVANCE: Lactobacillus reuteri-derived probiotic nano-formulation might be a promising treatment option for RAS.

A novel chitosan-based doxepin nano-formulation for chemotherapy-induced oral mucositis: a randomized, double-blinded, placebo-controlled clinical trial.

OBJECTIVES: Considering the prevalence of oral mucositis, we aimed to use the analgesic effects of doxepin with chitosan's antimicrobial and bio-adhesive nature to fabricate a nano-formulation for treating chemotherapy-induced oral mucositis. MATERIALS AND METHODS: Nanogel was fabricated via ionic gelation and characterized. Sixty patients were randomly divided and received four different treatments for 14 days: diphenhydramine + aluminum-magnesium mouthwash (control), doxepin mouthwash (DOX MW), chitosan nanogel (CN), and doxepin/chitosan nanogel (CN + DOX). Lesions were assessed with four indices, National Cancer Institute (NCI), World Health Organization (WHO), World Conference on Clinical and Research in Nursing (WCCNR) and visual analog scale (VAS) before and 3, 7, and 14 days after interventions. Kruskal-Wallis test was used for pairwise comparison. RESULTS: CN had semisolid consistency, uniform spherical shape, an average size of 47.93 ± 21.69 nm, and a zeta potential of + 1.02 ± 0.16 mV. CN + DOX reduced WHO, WCCNR, and VAS scores significantly more than the control three days after the intervention. Seven days after the intervention, CN + DOX reduced NCI and WCCNR considerably more than the control; it reduced WCCNR significantly more than CN. Fourteen days after the intervention, CN + DOX decreased NCI markedly more than the control. CONCLUSION: Chitosan-based doxepin nano-formulation might be a promising alternative for routine treatments of oral mucositis.

Evaluation of the osteoconductive properties of scaffold containing platete-enriched-fibrin (PRF) with three calcium phosphate (TCP) in the alveolar socket repair after tooth extraction: An animal study.

Bone regeneration can be accomplished through osteogenesis, osteoinduction, and osteoconduction mechanisms. This study aimed to investigate the properties of the PRF scaffold with tricalcium phosphate nanoparticles in socket preservation in an animal model. Fabrication of PRF performed. In this experimental study, 18 rats were divided into three negative control, PRF, and PRF/TCP groups. The mechanical and chemical tests including swelling rate, degradation time, and MTT tests were applied to the scaffolds. In each animal, the first maxillary right molar was extracted, and extraction sites of test groups were filled with a resorbable biocompatible biomaterial in situ hardening bone substitute. After 2 and 4 weeks all animals were sacrificed and examined histopathologically and with qRT-PCR. Histological results showed TCP in combination with PRF accelerates bone regeneration with the highest amount of lamellar bone and collagen formation compared to the control and PRF alone. Mechanical and chemical tests on the scaffolds showed the addition of TCP to the PRF scaffold decreases the swelling rate and increases the degradation time. qRT-PCR showed expression of osteogenic genes increased significantly (p < 0.05) in PRF/TCP and PRF, respectively. In conclusion, the gelatin hydrogel containing PRF/TCP scaffold led to more bone formation after tooth extraction. Therefore, the injectable PRF\TCP hydrogel is a promising candidate for bone repair and regeneration.

Clinical Symptoms of COVID-19 and Their Association with Disease Outcome.

Background: COVID-19 pandemic placed immense pressure on health systems. The current study aimed to evaluate the symptoms of COVID-19 in Isfahan province and their association with disease outcome. Materials and Methods: In this cross-sectional study, which was conducted on patients with a definite diagnosis of COVID-19, as a part of the investigations performed by the Deputy for Public Health of the Isfahan University of Medical Sciences, the frequency of underlying diseases, and general, respiratory, gastrointestinal, neurological, renal, cardiac, dermal, hearing symptoms are assessed using a checklist. The participants were followed up 1 month after definitive diagnosis, and the outcome of the disease (recovery or death) was recorded. Results: Of 300 patients, 143 (47.4%) were male and 157 (52.6%) were female. The mean age of patients was 43 ± 17.84 years. Muscle pain and fatigue were the most common early symptoms (63% and 60.3%, respectively). Age, sex, level of education, and occupation of patients and general, respiratory, and gastrointestinal symptoms and underlying diseases of respiratory disease showed a statistically significant association with the disease outcome (P < 0.05). Conclusion: General, respiratory, and gastrointestinal symptoms were associated with an increased risk of death due to COVID-19. General, visual, and hearing symptoms, and diabetes, cardiovascular diseases, and respiratory disease had a statistically significant association with the hospitalization of patients.

Odontogenic myxoma with pain and uncommon histological feature in the mandible: A case report and review the literature.

Odontogenic myxoma (OM) is a rare benign painless, slow-growing lesion with local aggressive behavior. Pain and sensory disturbance and fibro-osseous appearance in histopathology have been rarely reported in OM. The authors reported a 52-year-old male case presented with a large gingival mass around a mobile mandibular right first molar extended to the distal aspect of the third molar. Microscopic examination of the incisional and excisional biopsy revealed an OM with numerous newly formed bone or cementum-like material present throughout the specimen like those seen in fibro-osseous lesions. For avoiding to recurrence, a segmental mandibulectomy was performed and a metal plate was inserted to the right mandible defect under general anesthesia. Rehabilitation was completed with the placement of implants. We review and discuss about this variety.

Salivary Level of Trace Element in Oral Lichen Planus, A Premalignant Condition.

Background: Oral Lichen Planus (OLP) is a common inflammatory disease of unknown cause that knows also as a premalignant condition. Recent studies contributed nutritional factors to the pathogenesis of many autoimmune disorders. Objective: The aim of present study was to investigate the salivary levels of Magnesium (Mg), Calcium (Ca), Iron (Fe), Zinc (Zn) and Copper (Cu) in this disorder. Materials and Methods: In this observational case-control study, the unstimulated saliva of 40 patients with OLP and 40 age and sex matched healthy control subjects were collected. The salivary levels of Mg, Ca, Fe, Zn and Cu were determined using ICP-AES. Results: Mg levels were significantly lower in OLP patients than in healthy controls, although it didn't differ significantly between erosive and non-erosive types of Lichen Planus. Also there was no meaningful relationship between the levels of Ca, Fe, Zn and Cu in case and control groups. Conclusion: Trace elements such as Mg may have a role in ethiopathogenesis of OLP.

Oral manifestations of asthmatic patients.

The effect of asthma on oral health is the subject of debate among dental practitioners. The current study was planned to investigate the oral manifestations of asthmatics compared to healthy subjects. The study group composed of 100 asthmatics and 100 age-matched healthy controls. The caries status based on Decayed/Missing/Filled Teeth (DMFT) criteria and oral lesion were evaluated in all subjects. The mean age of the asthmatics group was 47.5±3.5 years and in the control group it was 43.5±3.0 years. Asthmatics included 45(45%) males and 55(55%) females. There was no statistical difference between caries prevalence in both groups. The most prevalent oral lesions in asthmatics group were geographic tongue 10(10%), fissured tongue 13(13%), chronic atrophic candidiasis13(13%), and in the control group were fissured tongue(11%) and lichenoid reaction(2%). The dental professional must be familiar with all signs and symptoms of this disease in order to offer effective and safe treatment.

Thermally induced phase mismatching in a repetitively Gaussian pulsed pumping KTP crystal: a spatiotemporal treatment.

Thermally induced phase mismatching (TIPM) has been proven to be an influential issue in nonlinear phenomena. It occurs when refractive indices of crystal are changed due to temperature rise. In this work, the authors report on a modeling of spatiotemporal dependence of TIPM in a repetitively pulsed pumping KTP crystal. Gaussian profiles for both spatial and temporal dependences of pump beam were used to generate second-harmonic waves in a type II configuration. This modeling is of importance in predicting the nonlinear conversion efficiency of crystals when heat is loaded in the system. To this end, at first, an approach to solve the heat equation in a repetitively pulsed pumping system with consideration of the temperature dependence of thermal conductivity and realistic cooling mechanisms such as conduction, convection, and radiation, is presented. The TIPM is then calculated through the use of experimental thermal dispersion relations of KTP crystal. The results show how accumulative behaviors of temperature and TIPM (with its reverse sign) happen when the number of pulses is increased. Fluctuations accompanying temperature and TIPM were observed which were attributed to the off-time between successive pulses. Moreover, in this work, a numerical procedure for solving a repetitively pulsed pumped crystal is introduced. This procedure enables us to solve the problem with home-used computing machines.

Temperature increase effects on a double-pass cavity type II second-harmonic generation: a model for depleted Gaussian continuous waves.

In this work, the effect of temperature increase on the efficiency of a double-pass cavity type II second-harmonic generation (SHG) is investigated. To this end, a depleted wave model describing the continuous-wave SHG process with fundamental Gaussian waves was developed. First, six coupled equations were proposed to model a double-pass cavity to generate the second harmonic of a Gaussian fundamental wave in type II configuration. Then, the effect of temperature increase in the nonlinear crystal due to the optical absorption was modeled. To do this, a mismatched phase arising from changes in refractive indices was added to the coupled equations. Although the nondepleted assumption is usually used in such problems, a simultaneous solving of coupled equations with assumption of fundamental beam depletion was performed. The results were obtained by a homemade code written in Intel Fortran, and show how the efficiency of the SHG process decreases when the crystal is warmed up by 5, 10, and 15 K. Dramatic reductions in SHG efficiency were observed due to small changes in temperature. The results show excellent agreement with the experimental data [Opt. Commun.173, 311-314 (2000)].

Complete anisotropic time-dependent heat equation in KTP crystal under repetitively pulsed Gaussian beams: a numerical approach.

In this work, a thorough and detailed solution for the time-dependent heat equation for a cylindrical nonlinear potassium titanyl phosphate (KTP) crystal under a repetitively pulsed pumping source is developed. The convection and radiation boundary conditions, which are usually ignored in the literature, have been taken into account, and their importance on the temperature distribution has been discussed in detail. Moreover, the temperature dependence of thermal conductivity of KTP was considered in the calculations, and its impact is discussed. It is shown that the radiation term has a negligible effect and can be dropped safely, while the temperature dependence of thermal conductivity is more influential, such that ignorance of it brings some errors into the modeling. The time evolution of the temperature while the crystal is pumping with a train of successive Gaussian pulses until reaching equilibrium is shown. To accomplish numerical calculations, we developed a homemade code written with the finite difference time domain method in Intel Fortran (ifort) and ran it with the Linux operating system.

Heat coupled Gaussian continuous-wave double-pass type-II second harmonic generation: inclusion of thermally induced phase mismatching and thermal lensing.

A model describing the thermal effects in type II second harmonic generation (SHG) of Gaussian continuous-wave (CW) in a double-pass cavity is presented. The thermally induced phase mismatching (TIPM) along with thermal lensing was included in the classical SHG formalism through the interposing the heat and TIPM equations. To this end, eight equations were coupled together and solved simultaneously to reveal how the SHG is affected in time when heat is generated in the crystal. The model showed an excellent agreement with experimental data [Opt. Laser Tech.34, 333-336 (2002)]. Furthermore, a numerical procedure, which was developed in this work, is introduced for simultaneously solving the SHG, heat, and TIPM equations with home-used computing machines.

Pulsed Bessel-Gauss beams: a depleted wave model for type II second-harmonic generation.

In this work, a three-dimensional and time-dependent nonlinear wave model to describe the generation of pulsed Bessel-Gauss second-harmonic waves (SHWs) is presented. Three coupled equations, two for ordinary and extraordinary fundamental waves and one for extraordinary SHWs, describing type II second-harmonic generation (SHG) in a KTiOPO4 (KTP) crystal were solved by considering the depletion of fundamental waves (FWs). The results examined the validity of nondepleted wave approximation against the energy of pulses, beam spot size, and interaction length. It was shown that for pulses with spot sizes of ωf=80 µm and energy of 0.8j, the nonlinear interaction was accomplished over a distance of ∼5 mm. Therefore, for KTP crystals with lengths longer than 5 mm, the nondepleted wave approximation can no longer be valid. To be valid, the crystal must be shorter than the interaction length, i.e., 5 mm.