دکتر شهرام همدانی

Medical emergencies, though rare, may occur unpredictably in a dental office during or after dental procedures. It may occur accidentally or subsequent to systemic problems of patients. These series of clinical events entail instantaneous management to evade any potential consequences. Basic life support measures require sufficient knowledge, expertise, skills, and equipment. Several medications and equipment are necessary to be available for immediate reach in any dental office. Health authorities of different countries usually propose these lists to dental practitioners. However, the best emergency kit is the one, which is arranged and maintained by the dentists based on their needs and easily accessible for immediate use. Considering the importance of this subject and the results yielded from the regular visits of the Dental Supervision Department (Vice Chancellor for treatment of Shiraz University of Medical Sciences) to the dental centers of Shiraz in the spring and summer of 2023, we decided to recall the importance of emergency medicines and equipment through a brief communication.

Dear SirOral Squamous Cell Carcinoma (OSCC) is the most common cancer involving the oral and maxillofacial area [1]. OSCC is reported to exert the worst quality of life among the patients suffering from head and neck cancers [2]. Moreover, the rate of survival in these cases and the prognosis of OSCC are the concerning issues among the oncologists and oral and maxillofacial surgeons [3]. The current proposed treatment options can be a combination of surgical removal, chemotherapy, and radiotherapy [4-5]. Despite the success of the mentioned treatment protocols employed in these cases, many patients still suffer from low quality of life and short-time survival rate after the surgeries in resistant and metastatic cases [2, 6-7]. These shortcomings have motivated scientists to look for novel treatment options to alleviate the symptoms and improve the patients’ quality of life, especially in resistant and recurrent cases [7].One of the noticeable parts of OSCC leading to its development, metastasis, chemo-resistance, and survival is the cancer stem cells (CSCs) at the core of the tumor [8-9]. CSCs are highly potent cells resembling other stem cells in terms of self-renewal, producing heterogeneous and differentiated cells [10]. These CSCs have been shown to have an exceptionally high potential for survival and proliferation in hypoxic conditions and under high doses of medications [11]. The study of these CSCs can provide valuable insights into the prognosis and chemoresistance potential of OSCC [12].Due to the high potency of CSCs and their critical role in the development of cancers, especially OSCC, few treatment options are suggested to minimize the activity and survival of CSCs [10, 13]. In this regard, targeting the CSCs surface markers, signaling pathways, miRNA-based treatments, and immunotherapy are the proposed strategies to deal with CSCs [10]. Among the mentioned treatment options, the application of antibiotics can be a possible option due to their advantage of availability, low-cost, and their extensively studied mechanisms of action [14]. Concurrently, the antibiotics that target the mitochondria are shown to be a viable option. In the study by Lamb et al. [14], it was demonstrated that erythromycins, tetracyclines, glycylcyclines, an antifungal drug, and chloramphenicol are the groups of antibiotics which have been proven to be effective in this regard. Among these groups, azithromycin, doxycycline, tigecycline, pyrvinium pamoate, and chloramphenicol were verified to be the proof-of-concept examples [14]. Concerning the mechanism of action, it is demonstrated that erythromycin and chloramphenicol target 39S large mitochondrial ribosome, tetracycline and glycylcyclines target 28S small mitochondrial ribosome, and pyrvinium pamoate targets the mitochondrial oxidative phosphorylation system [14]. In general, the application of these types of antibiotics results in inhibition of mitochondrial biogenesis or oxidative phosphorylation system [14].The emergence of resistant cases is due to the genetic variations of the cancer genotype to optimally adjust to the new environment [15]. Therefore, the approach of phenotypic targeting (instead of genotypic) of cancer stem cells would be a novel solution in resistant cases with OSCC. The logic behind this approach arises from the fact that all the genetic changes making the tumor resistant against various treatments are ascribed to the presence of CSCs [14]. Therefore, targeting the CSCs would probably provide a novel treatment option for OSCC. Furthermore, this concept can be likely employed, as a preventive approach in avoiding the possible metastasis or recurrence in OSCC.Application of mitochondria-targeting antibiotics in patients suffering from OSCC may provide a possible innovative option in minimizing the activity of CSCs in OSCC tumors, which would finally result in prevention of further metastasis, tumor recurrence, genetic-based tumor resistance, and tumor development. Further studies in in vitro and in vivo settings are encouraged to evaluate the prospect of this hypothesis.

Statement of the Problem:

 Orthodontic removable appliances can facilitate the accumulation of certain microorganisms and microbial plaque on tooth surfaces and appliance components. Since long-term use of chemical agents is not recommended, an alternative option would be medicinal plants for disinfection of the oral cavity.

The aim of this study was to assess the efficacy of thymus vulgaris (T. vulgaris) essential oil to decrease the count of candida albicans (C. albicans) accumulated on removal orthodontic appliances

In this 2-arm parallel controlled clinical trial, forty-four patients whose removable orthodontic appliances were contaminated with C. albicans were randomly divided into two groups by electronic random sampling. In the first group, T. vulgaris essential oil spray and in the second group, 0.2% chlorhexidine (CHX) spray was applied to the appliances. Thereafter, the C. albicans colony count was measured at baseline (T0) and at 2 (T1) and 5 (T2) days after the intervention. Microbial samples were collected by a sterile swab from 3 spots on the internal surface of orthodontic appliances. The Friedman test was used for within-group comparisons and the Mann Whitney test was employed to compare the efficacy of T. vulgaris essential oil with CHX.

The results of this study revealed that continuous use of 2%T. vulgaris essential oil or 0.2% CHX significantly decreased the colony count of C. albicans on removable orthodontic appliances; Howevere, no significant difference was noted in the efficacy of 2% T. vulgaris essential oil and 0.2% CHX in decreasing the C. albicans colony count.

T. vulgaris essential oil and CHX have favorable antimicrobial activity against C. albicans. Moreover, 2% T. vulgaris essential oil can be considered as an alternative to 0.2% CHX to eliminate fungal contamination of orthodontic appliances.

High-Power Lasers (HPLs) are capable of creating a plume containing tissue debris, vapor, and viruses (HPV, HIV, etc.) which is liberated into the surrounding environment and may have a potential role in infection transmission. The employment of these dental lasers is an equivocal concern during the new Coronavirus Disease 2019 (COVID-19) outbreak. Since many oral tissues are highly potential reservoirs of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), this study was conducted to scrutinize the possibility of dissemination of this virus through the plume in dental laser treatments during the COVID-19 pandemic. The current evidence shows while the employment of laser is an effective and comfortable tool for dental treatments, it holds some inherent hazards such as producing airborne contaminants. With HPV, HIV, and other viruses already detected in laser plume and considering the presence of ACE2 receptors in the oral cavity, there is a potential risk in laser treatments to produce infectious plume, which may possibly contain SARS-CoV-2. The SARS-CoV-2 virus can potentially be liberated in the plume during dental application of HPLs in suspected or confirmed cases of COVID-19. While the amount of aerosol may be different from other routine dental instruments, this modality should be used with crucial care during the COVID-19 outbreak.In this regard, safety precautions in laser application should be rigorously maintained during the COVID-19 outbreak.

Statement of the Problem: Temporomandibular joint disorders (TMD) may show a poor correlation between their clinical findings and radiological characteristics.
The aim of this study was to assess the osseous alterations of temporomandibular joint (TMJ) in symptomatic and asymptomatic subjects by employing cone beam computed tomography (CBCT) images.
In this study, CBCT images of 120 temporomandibular joints in 30 patients with TMJ disorder and 30 age- and sex-matched individuals without TMJ complaints were evaluated. Osteoarticular derangements of the joint were assessed by two experienced examiners. Data was statistically analyzed with SPSS software using chi-square test (p Out of 120 CBCT images (60 in each group), at least one osseous change was observed in 90% and 86.7% joints in symptomatic and asymptomatic subjects, respectively. There were no significant differences between symptomatic and asymptomatic subjects regarding frequency of osteoarticular changes including flattening (73.3% vs. 75%), irregularity (36.7% vs. 48.3%), sclerosis (20% vs. 8.3%), cyst (3.3% vs. 3.3%), erosion (13.3% vs. 21.7%), hypoplasia (3.3% vs. 5%), ankylosis (1.7% vs. Zero), osteophyte (43.3% vs. 40%), decrease joint space (3.3% vs. 3.3%), and increase joint space (5% vs. 5%). (p> 0.05)
By employing CBCT as a modern diagnostic imaging tool, findings of this study revealed that the frequency of various temporomandibular joint alterations on CBCT images is comparable in patients with and without TMD complaints, suggesting that some people with TMJ structural damage may not display clinical manifestations. Moreover, CBCT imaging might not be necessary for TMD patients and more attention should be given to clinical examination.

Statement of problem: Numerous studies report significant changes in tooth color that occur during orthodontic treatment. The adverse effects of bleaching procedures during orthodontic treatments have not been studied comprehensively.
This study investigated the effects of two methods of dental bleaching on the degree of microleakage beneath orthodontic brackets.
We selected 45 extracted premolar teeth and bonded them to orthodontic brackets. These teeth were stored in normal saline for 24 hours and thermocycled. We randomly divided the samples into 3 groups of 15 teeth per group. The first group (control) received no bleach treatment; the second group (office bleaching) was treated with 35% hydrogen peroxide (Whiteness HP Maxx); and the third group (home bleaching) was treated with 22% carbamide peroxide (Whiteness Perfect). The apices were sealed with sticky wax, rinsed in tap water, and air-dried. We applied nail varnish to the entire surface of each tooth, except for an area approximately 1 mm away from the brackets. The samples were immersed in basic fuchsine and cleaned after 24 hours. Microleakage was determined by direct measurement using a stereomicroscope. Kruskal-Wallis and Dunn post-hoc statistical tests, and SPSS software were used for statistical analysis. The significance level was set at P≤0.05.
The office bleaching group had significantly more microleakage scores under the brackets at both the occlusal (P=0.04) and gingival (P =0.040) margins of the brackets compared to the home bleaching group. The home bleaching group showed statistically more significant microleakage scores than the control group in both the gingival (P=0.006) and occlusal (P=0.014) margins of the brackets. All three groups had statistically more significant microleakage at the gingival margins of the brackets than the occlusal margins.
Office bleaching caused the most microleakage under the brackets and home bleaching caused more microleakage than the control group. We observed more microleakage at the gingival margins of the brackets compared to the occlusal margins.

Introdouction: This study investigated the potential relationship between vertical facial growth patterns and airway volumes in a sample of Iranian adult patients.
This cross sectional study was conducted on 72 adult patients (44 females, 28 males), ages 18–45 years, who had been referred to the Department of Oral and Maxillofacial Radiology at the Shiraz University of Medical Science. The vertical growth pattern was assessed by a lateral cephalometric radiograph using two indices: morphological facial index (defined as the ratio of N-Mn and Zy-Zy distance) and Jarabak index (defined as the ratio of S-Go and N-Gn). The sizes of the superior and inferior airway compartments were measured by employing cone beam computed tomography. Data were analyzed on SPSS 21 using the Shapiro–Wilk test, p-p plot test, one-way ANOVA, t-test, and chi square tests (P The total airway volume for all individuals was 21.72 ± 6.69 mm. There were no statistically significant differences between subjects with long, medium, or short faces regarding lower (p = 0.160) or upper (p = 0.183) airway sizes. The gender of the participants did not have a significant relationship with the lower, upper, or total airway sizes.
Based on the findings of the current study, we found that the cone beam computed tomography data did not indicate any correlation between airway volume and vertical facial growth pattern.

Statement of the Problem: Anatomic variations of the maxillary sinus can be detected in cone-beam computed tomography (CBCT) and may assist to locate the posterior superior alveolar artery (PSAA) and define the maxillary sinus morphology more accurately for a more strict surgical treatment plan.
The study aimed to determine normal variations of the maxillary sinus with the aid of CBCT in a sample population in south of Iran.
This cross-sectional prevalence study was based on evaluation of 198 projection data of CBCT scans of some Iranian patients aged 18-45, referred to a private oral and maxillofacial radiology center in Shiraz from 2011 to 2013. CBCT scans were taken and analyzed with NewTom VGi device and software. The anatomic variations which were evaluated in the axial images included the presence of alveolar pneumatization, anterior pneumatization, exostosis, and hypoplasia. Moreover, the location and height of sinus septa and the location of PSAA were assessed. SPSS software (version 17.0) was used to analyze the data.
In a total of 396 examined sinuses, maxillary sinus alveolar pneumatization was the most common anatomic variation detected. Anterior pneumatization was detected in 96 sinuses (24.2%). Antral septa were found in 180 sinuses (45.4%) and were mostly located in the anterior region. Meanwhile, PSAA was mostly detected intra-osseous in 242 sinuses (65.7%).
Anatomic variations of the maxillary sinus were common findings in CBCT of the maxilla. Preoperative imaging with CBCT seems to be very helpful for assessing the location of PSAA and the maxillary sinus morphology; Its data might be used to adjust the surgical treatment plan to yield more successful treatments.

Statement of the Problem: Prediction of child cooperation level in dental setting is an important issue for a dentist to select the proper behavior management method. Many psychological studies have emphasized the effect of birth order on patient behavior and personality; however, only a few researches evaluated the effect of birth order on child’s behavior in dental setting. This study was designed to evaluate the influence of children ordinal position on their behavior in dental setting. A total of 158 children with at least one primary mandibular molar needing class I restoration were selected. Children were classified based on the ordinal position; first, middle, or last child as well as single child. A blinded examiner recorded the pain perception of children during injection based on Visual Analogue Scale (VAS) and Sound, Eye and Movement (SEM) scale. To assess the child's anxiety, the questionnaire known as “Dental Subscale of the Children's Fear Survey Schedule” (CFSS-DS) was employed. The results showed that single children were significantly less cooperative and more anxious than the other children (p<0.001). The middle children were significantly more cooperative in comparison with the other child's position (p< 0.001). Single child may behave less cooperatively in dental setting. The order of child birth must also be considered in prediction of child’s behavior for behavioral management.

Statement of the Problem: Cardiovascular disease and osteoporosis are major health dilemmas. Osteoporotic patients frequently display vascular calcification that consequently increases the cardiovascular morbidity and mortality. This study aimed to investigate the relation of osteoporosis, vascular calcification (atheroma, intima-media thickness (IMT)) and elongated styloid process (ESP) in a sample of osteoporotic and normal female individuals. This study recruited 78 women who were assessed for bone mass density (BMD). Sample included individuals with normal BMD (n=13, 17 %), osteopenia (n=36, 46 %), and osteoporosis (n=29, 37%). The presence of atheroma and IMT was examined using color Doppler ultrasonography (CD-US). In addition, digital panoramic radiographs (PRs) were obtained to assess ESP. In this study, 55 subjects (70%) with low BMD exhibited at least one side ESP. Femoral BMD decreased significantly in subjects with ESP (p= 0.03). Bilateral ESP was correlated with the presence of atheroma (p= 0.029). The CIMT was greater in patients with ESP, although the relation was not significant. The obtained data suggest referring the aged individuals with ESP for BMD assessment and individuals with low bone mass and ESP for more cardiovascular risk assessment.

The early computer-aided design/computer-aided manufacturing (CAD/CAM) systems were relied exclusively on subtractive methods. In recent years, additive methods by employing rapid prototyping (RP) have progressed rapidly in various fields of dentistry as they have the potential to overcome known drawbacks of subtractive techniques such as fit problems. RP techniques have been exploited to build complex 3D models in medicine since the 1990s. RP has recently proposed successful applications in various dental fields, such as fabrication of implant surgical guides, frameworks for fixed and removable partial dentures, wax patterns for the dental prosthesis, zirconia prosthesis and molds for metal castings, and maxillofacial prosthesis and finally, complete dentures. This paper aimed to offer a comprehensive literature review of various RP methods, particularly in dentistry, that are expected to bring many improvements to the field. A search was made through MEDLINE database and Google scholar search engine. The keywords; ‘rapid prototyping’ and ‘dentistry’ were searched in title/abstract of publications; limited to 2003 to 2013, concerning past decade. The inclusion criterion was the technical researches that predominately included laboratory procedures. The exclusion criterion was meticulous clinical and excessive technical procedures. A total of 106 articles were retrieved, recited by authors and only 50 met the specified inclusion criteria for this review. Selected articles had used rapid prototyping techniques in various fields in dentistry through different techniques. This review depicted the different laboratory procedures employed in this method and confirmed that RP technique have been substantially feasible in dentistry. With advancement in various RP systems, it is possible to benefit from this technique in different dental practices, particularly in implementing dental prostheses for different applications.