Journal of Research in Dental and Maxillofacial Sciences
Volume:2 Issue: 3, Summer 2017

Head and neck cancers are the tenth most common cancers worldwide. Since these cancers can cause severe complications and mortality, early diagnosis and investigation of their prevalence in various regions may be life-saving. Therefore, this study evaluated the prevalence of head and neck cancer over a 10-year period in Gilan province, Iran. This is a retrospective and descriptive study based on the data collected from the Cancer Registry Center of Gilan province, Iran, during 1999-2008. The data included age, sex, cancer type, and location of the lesion. Statistical analyses were performed by using SPSS13 software program. Of 2335 cases of head and neck cancer, 736 cases (59%) were detected in men and 511 cases (41%) were found in women. Squamous cell carcinoma (SCC) (42.6%) and Basal cell carcinoma (BCC) (23.04%) were the most prevalent types of cancer. These cancers mostly occurred during the seventh and eighth decades of life. The most common locations were the esophagus and cervical lymph nodes. In the current survey, head and neck cancers comprised 18% of all the malignancies (2335 cases out of a total of 12830 cases), which differs from the results obtained worldwide. This difference may be due to the difference in registry centers and varied risk factors in each country. In our survey, SCC was the most common head and neck malignancy, followed by BCC, which is similar to the results of the majority of the related studies.

Side effects of cigarette smoking are among the major concerns. These complications can adversely affect the oral environment. Since reduced salivary flow rate increases the incidence of tooth decay and other dental and oral problems, the present research aimed to investigate the relationship between cigarette smoking and salivary flow rate. In this historical cohort study, 50 cigarette smokers (case) and 50 non-smokers (control) were involved, who were matched according to age and gender. Non-stimulated whole saliva was measured by using the modified Schirmer test (MST) performed between 9 a.m. and 12 p.m. by a trained examiner. All the participants refrained from eating, drinking and smoking for 2 hours prior to the study. The subjects were asked to sit in an upright position and to raise and slowly retract their tongue, to avoid unintentional wetting of the Schirmer test's strip. The strip was kept vertically with the help of cotton pliers, while the bottom of the paper was in contact with the floor of the mouth. The length of the wet area on the strip was recorded at the intervals of 1, 2 and 3 minutes. Data were analyzed with Mann-U-Whitney and Chi-square tests. The quantitative value of salivary flow rate was equal to 24.8±2.4mm in controls, and 15.8±2.1mm in case group (P<0.001). 30% of non-smokers and 90% of smokers exhibited reduced salivary flow rate (P<0.000). It seems that reduced salivary flow rate is more significant in cigarette smokers than in non-smokers.

The ionizing radiation has been recognized to have deleterious effects on the DNA and induce cell death. Due to the importance of evaluating the DNA alterations in buccal mucosa cells induced by the ionizing radiation and by considering the limited volume of the samples used in previous studies, the present study aimed to assess the micronucleus (MN) incidence in the buccal mucosa of cone beam computed tomography (CBCT)-exposed patients of an oral and maxillofacial radiology center during 2016. This descriptive study was conducted by using the target-based sampling. All the subjects, corresponding to the inclusion criteria, had been exposed to CBCT radiation according to their treatment plans. The specimens were scraped from the buccal mucosa of the participants by a damp spatula and were subsequently stained by Papanicolaou staining process. The percentage of the micronucleated cells was reported after evaluation under a light microscope. Also, the multiple linear regression (MLR) method was approached to statistically analyze the correlation between the MN frequency and the age and gender of the participants. The lowest and highest percentages of the MN frequency were respectively equal to 8.20% and 27.10% with the mean MN frequency of 17.68±4.98. Also, there was no significant correlation between the age and gender of the subjects and the MN frequency (P>0.05). Based on the results of the present study, there was no significant correlation between the age and gender of the participants and the MN frequency.

Hyposalivation is one of the most common complications during menopause, which affects the quality of life. The aim of the present study was to assess the correlation between menopause and salivary flow rate. This historical-cohort study was conducted on 80 healthy women. Forty postmenopausal women were placed in the case group, while 40 premenopausal women were selected as the control group. The participants were selected from among non-smokers and non-alcoholics and had no systemic diseases. The saliva level of the participants was measured by using the Modified Schirmer’s Test (MST) and modified Fox questionnaire. The participants were asked to sit upright, swallow their saliva and hold up their tongue. A strip was placed on the floor of the mouth, and the length of the wet and discolored area on the strip was measured after 3 minutes. Data were analyzed using SPSS 22 according to Mann-U-Whitney and Chi-square tests. According to the MST, the prevalence of hyposalivation was 35% in premenopausal women and 65% in postmenopausal women, with a statistically significant difference between the two groups (P<0.001). According to the modified Fox questionnaire, the prevalence of normal salivary flow and mild xerostomia in premenopausal women was 90%, while this rate was equal to 62.5% in postmenopausal women. The prevalence of severe xerostomia was 15% in postmenopausal women, while none of the premenopausal subjects had severe xerostomia. The incidence of hyposalivation in postmenopausal women is significantly higher than that in premenopausal women (P<0.005). It seems that the unstimulated salivary flow rate decreases after menopause.

Oral squamous cell carcinoma (OSCC) accounts for approximately 3% of all cancers worldwide, and if diagnosed early, it has a five-year survival rate of around 85%; however, a late diagnosis may decrease the survival rate to 50%. Aberrant expression of several genes is associated with the hallmarks of OSCC including uncontrolled cell proliferation, poor differentiation, invasion, metastasis, and angiogenesis. The potential of molecular biomarkers for the diagnosis, prognosis, or monitoring of the treatment efficacy in OSCC has been extensively explored during the last decades. This study aimed to review the significance of salivary biomarkers in the treatment outcome of OSCC. The articles in scientific databases including Google Scholar, ScienceDirect, Medline, and PubMed, published between 2004 and 2017, were searched by using relevant keywords including OSCC, biomarkers, diagnosis, prognosis and treatment outcome. Thirty-four articles were reviewed in this study. According to the findings of the reviewed studies, several salivary biomarkers including subcutaneous adipose tissue (SAT), interleukin-8 (IL-8), Cyfra 21-1, 8-hydroxy-2-deoxyguanosine, malondialdehyde, lactate dehydrogenase (LDH), Annexin A8, ErbB2, carcinoembryonic antigen (CEA), C-reactive protein (CRP), and salivary proteomic biomarkers might be used as indicators for the detection of oral cancer and premalignant oral disease (PMOD) and as a potential marker in the prognosis of OSCC. Salivary biomarker analysis seems to be a major advancement in the diagnosis of OSCC, and it is a fast-developing field in scientific research. The results indicate that salivary biomarkers can be useful diagnostic and prognostic tools in OSCC.

Regular evaluation of the efficiency of instructors is highly important to promote the quality of instruction. This study aimed to assess the perspective of senior dental students about the priorities that must be considered in instructor evaluation. In this descriptive study, the significance of instructor assessment from the viewpoint of 132 senior dental students was evaluated in five domains of teaching skills, personal characteristics and skills, communication skills, adherence to educational regulations, and assessment skills. The frequency of the overall significance of each item and the domains as well as the effect of demographic and socioeconomic factors on the results were analyzed by Chi-square test. 84.4% of students believed that instructor assessment was important. Teaching skills acquired the highest score (90.6%), followed by communication skills (89.4%), personal characteristics and skills (83.8%), and educational regulations (70.9%) with statistically significant differences (P<0.0001). Students gave the highest score to the teaching method (98.5%), followed by the ability to well discuss the topic, conveying the topic, and mastery of the content (96.2%). The lowest score was given to the adherence to the order of educational contents set by the educational committee (42%) and to the usefulness of homework (49%). No significant association was noted between gender, age, grade point average (GPA), the parents' occupation, or interest in dentistry as a profession with the students' opinions about the instructor assessment form and the five domains (P=0.2). Educational workshops may enhance the teaching and communication skills of instructors, may increase the satisfaction of students with the instructors' performance and may yield greater educational achievements.

Cleft lip and cleft palate are among the most common orofacial abnormalities. Patients with these deformities commonly present with midface deficiency and need challenging treatment modalities that focus on improving the position of the maxilla. Tongue plate appliance is an intraoral device that has shown promising results in the treatment of growing patients with maxillary deficiency. Nonetheless, the effects of tongue plate on patients with cleft lip and cleft palate have not been evaluated yet. This study aimed to assess the effects of tongue plate on growing patients with cleft lip and palate. Twenty-four growing patients (12 girls and 12 boys) with non-syndromic unilateral cleft lip and cleft palate between the ages of 6-12 years volunteered to participate in this quasi-experiment. All the patients had undergone the preliminary stages of lip and palate closure during infancy, but none of them had received bone grafts. They were treated with tongue plate appliance for 18±3 months. Lateral cephalograms were obtained and were analyzed at the beginning and at the end of the treatment. Paired t-test was used for statistical analysis of normally-distributed data; otherwise, Wilcoxon test was used. Paired t-test showed that the Sella-Nasion-Point A (SNA) angle was increased from 76.3±0.2 to 77.3±0.14 degrees, and the Point A-Nasion-Point B (ANB) angle was enhanced from -2.26±0.17 to 0.93±0.82 degrees (P<0.001). Tongue plate appliance has shown favorable results in the treatment of class 3 malocclusion and maxillary deficiency in growing patients with cleft lip and cleft palate.