Journal of Research in Dental

Background and Aim: Temporomandibular disorder (TMD) is a multifactorial problem caused by many reasons. There is still controversy about the effect of different types of occlusal disorder on TMD. This study was designed to determine the effects of centric and assisted and unassisted non-working interferences on TMD.
Materials and Methods: In this cross-sectional study, 100 dental students, including 64 males and 36 females with the age range of 18 to 24 years old, were examined. Subjects with a history of systemic or muscular diseases and orthodontic treatment were excluded. TMD signs and symptoms including maximum mandibular opening limitation, maximum lateral movement limitation, maximum protrusion limitation, deviation and deflection, joint pain and tenderness, joint sounds, and masticatory muscle tenderness were examined. Subjects were also examined for having centric interferences and eccentric interferences including assisted and unassisted non-working interferences. Data were analyzed using the chi-square test and independent-sample T-test.
Results: Subjects with centric interference had a significantly higher number of clicks (P=0.02), medial pterygoid tenderness (P=0.009), and right medial pterygoid tenderness (P=0.007). We could also find a significantly higher number of clicking in subjects with assisted non-working interference (P=0.002).
Conclusion: The findings of the present study suggest that different types of occlusal interference, specially centric and assisted non-working interferences, can lead to TMD signs and symptoms.

Background and Aim: Dental treatments may have adverse effects on patients with a previous history of coronary heart disease and lead to cardiac complications. Different biomarkers have been investigated to assess the relationship between dental treatments and cardiovascular complications. The present study was conducted to evaluate the troponin changes before and after dental surgery in patients with a history of ischemic heart disease.   Materials and Methods: This cross-sectional study was conducted on 25 patients referred for dental surgery with a history of ischemic heart disease. The patients' demographic information including their age and gender was collected, and serum levels of troponin were measured before surgery and at 4 hours after surgery, and the results were compared. The study data were entered into SPSS version 23 and analyzed by the Student t-test and McNemar test. Results: In the present study, 25 patients including 11 males and 14 females with a mean age of 44.78 years were evaluated. The mean level of troponin was 8.01±5.94 before surgery and 6.16±4.84 after surgery. Statistically, no significant difference was found between troponin levels before and after surgery in patients (P=0.274). Conclusion: based on the results of the present study, no significant change was noted in troponin levels of patients with a previous history of ischemic heart disease at 4 hours after dental surgery.