Comparison of the efficacy of intra-articular injections of hyaluronic acid and lactoferrin in mono-iodoacetate-induced temporomandibular joint osteoarthritis: A histomorphometric, immunohistochemistry, and micro-computed tomography analysis.

OBJECTIVES: This study aims to evaluate the efficacy of high-molecular-weight hyaluronic acid (HMWHA) and lactoferrin (LF) injections on temporomandibular joint (TMJ) cartilage and subchondral bone in mono-iodoacetate (MIA)-induced temporomandibular joint osteoarthritis model in rats. MATERIALS AND METHODS: In this in vivo study, a total of 24 rats were divided into three groups as follows: saline group (Group 1), HMWHA group (Group 2), and LF group (Group 3) including eight rats in each group. The intra-articular injections were administered once a week for three weeks after osteoarthritis was induced. All animals were euthanized 28 days after induction of osteoarthritis, and TMJs were harvested for histomorphometric, immunohistochemical, and micro-computed tomography (CT) analysis. RESULTS: There was no significant difference between the HMWHA and LF groups in terms of the histomorphometric and immunohistochemical analysis results (p>0.05). According to the micro-CT analysis, the LF group had the highest mean bone volume fraction (74.9±0.5) and trabecular thickness (0.122±0.002), while the saline group had the lowest mean values (55.0±0.3 and 0.071±0.002, respectively) (p<0.001). There was no significant difference between the HMWHA and LF groups according to the micro-CT analysis (p>0.05). Both groups had better healing effects than the saline group in all analyses. CONCLUSION: Lactoferrin has a healing effect at least as much as HMWHA in MIA-induced TMJ osteoarthritis. We suggest that LF may be evaluated in future clinical studies as a promising agent in the treatment of osteoarthritis.

Possible sleep and awake bruxism, chronotype profile and TMD symptoms among Turkish dental students.

It was hypothesized that an individual's chronotype profile has an effect on the performance of work or study tasks. Dental students have to cope with both academic and clinical workloads, and the latter requires extra concentration. The first aim was to evaluate the association of sleep bruxism (SB) and awake bruxism (AB) with sleep related items, temporomandibular disorder (TMD) complaints, and chronotype profile; the second aim was to evaluate the association between complaints of TMD and chronotype profile among dental students. The present cross-sectional descriptive study involved 218 dental students whose ages ranged between 18 and 30 years. In order to gather data, students were required to respond to a questionnaire, which aimed to evaluate possible SB and possible AB occurrence and demographics, sleep-related items and complaints of TMD. For the assessment of the chronotype profile, the morningness-eveningness questionnaire (MEQ) was used. The chi-square test, the Mann-Whitney U test, and t-test analyses were performed to evaluate the factors associated with SB, AB and chronotype profile. The frequency of self-reported SB was 25.2% and AB was 28.9%. The prevalence in the eveningness profile who reported possible AB was 45.3%, while it was 24.2% in intermediate individuals and 18.8% in the morningness profile. An association was also found between possible AB and eveningness chronotype profile (p = .009). No association was found between other temporomandibular joint (TMJ) pain and noise and chronotype profiles (p > .05). An association was found between possible AB and eveningness chronotype profile but no association was found between possible SB and chronotype profile. Moreover, complaint of TMD (face, head, neck pain) was observed particularly in students with an eveningness profile.