The Effects of Clindamycin and Cefazolin on Osteogenesis of Periodontal Ligament Stem Cells: An In vitro Study

Introduction: Antibiotics are routinely administered in clinical setting for prevention of infections in surgeries and as a routine supplement to the culture medium. The nobility of the present study was to evaluate the effect of two commonly used antibiotics, clindamycin and cefazolin, in dental treatments, on osteogenic capability of periodontal ligament stem cells (PDLSCs). Materials and Methods: PDLSCs were isolated from periodontal ligament (PDL) of the root section out of four healthy extracted teeth. The cells were incubated in the following medium for 28 days: (1) Osteogenic medium (OM) + 5 µm clindamycin (clindamycin group), (2) OM + 5 µm cefazolin (cefazolin group) and (3) OM (control group). Alizarin red staining was performed at days 7, 14, 21, and 28 of induction. Results: Addition of cefazolin to osteogenic medium had no significant effect on osteogenesis comparing to the control group. However, Clindamycin significantly inhibited osteogenesis at days 7 and 21 comparing to the control group (P<0.05), but there was no significant differences at 14 and 28 days. Conclusion: It is demonstrated that clindamycin had inhibitory effects on osteogenesis in early stages, but it promoted osteogenesis in later stages. Cefazolin seems not inhibit osteogenic potential of the cells. Taken together, prescribing cefazolin or clindamycin did not cause any negative effect on osteogenesis for long-term

Three Dimensional Finite Element Analysis of Stress Distribution and Displacement of the Maxilla Following Surgically Assisted Rapid Maxillary Expansion with Tooth- and Bone-Borne Devices

Objectives: The aim of this study was to investigate the displacement and stress distri- bution during surgically assisted rapid maxillary expansion under different surgical conditions with tooth- and bone-borne devices. Materials and Methods: Three-dimensional (3D) finite element model of a maxilla was constructed and an expansion force of 100 N was applied to the left and right molars and premolars with tooth-borne devices and the left and right of mid-palatal sutures at the first molar level with bone-borne devices. Five CAD models were simulated as fol- lows and surgical procedures were used:  G1: control group (without surgery); G2: Le Fort I osteotomy; G3: Le Fort I osteotomy and para-median osteotomy; G4: Le Fort I osteotomy and pterygomaxillary separation; and G5: Le Fort I osteotomy, para-median osteotomy, and pterygomaxillary separation. Results: Maxillary displacement showed a gradual increase from group 1 to group 5 in all three planes of space, indicating that Le Fort I osteotomy combined with para-me- dian osteotomy and pterygomaxillary separation produced the greatest displacement of the maxilla with both bone- and tooth-borne devices. Surgical relief and bone-borne devices resulted in significantly reduced stress on anchored teeth. Conclusion: Combination of Le Fort I and para-median osteotomy with pterygomaxil-lary separation seems to be an effective procedure for increasing maxillary expansion, and excessive stress side effects are lowered around the anchored teeth with the use of bone-borne devices

Metastatic Tumors to Craniofacial Skeleton: Analysis of Two Cases and Review of the Literature

Craniofacial skeletal metastasis is a rare presentation of advanced prostate cancer. This is a report of a 69-year-old man who presented with numbness of the right lower lip and recently ill-fitting lower denture. Based on the medical history of benign prostate hyperplasia (BPH) and suspicion of a metastatic tumor, prostate core needle biopsy was performed. Histology of the prostate biopsy confirmed an adenocarcinoma with Gleason Score of 6/10. The diagnosis of metastatic prostate adenocarcinoma was established by incisional biopsy from the mandibular lesion. Androgen deprivation therapy (ADT) was administered along with bilateral orchidectomy and radiotherapy. He had a significant resolution of trigeminal nerve palsy and the other symptoms at subsequent follow-ups, but after 18 months passed away. The second case was a 65-year-old man with a history of prostate cancer since 5 years ago. He complained of painful swelling in the right side of the face. Radiographic evaluation revealed new bone formation in right mandibular ramus and condylar process as well as the left temporoparietal region. Incisional biopsy from mandibular lesion revealed metastatic prostate adenocarcinoma. Palliative radiotherapy for increasing quality of life started for the patient but he died after 9 months. The related literatures were reviewed

Comparison of Self-evaluation and Students’ Evaluation of Hamadan Dental School Faculty Members

Introduction: Surveys of students’ and faculty members’ opinion on the faculties teaching can reveal the strengths and weaknesses of their teaching performance. This study aimed to compare self-evaluation and students’ evaluation about educational performance of Hamadan dental school faculty members in 2010-2011. Methods: In this cross-sectional descriptive and analytical study, through using census sampling method, all 46 faculty members and 77 students of Dental School in Hamadan University of Medical Sciences participated . The data were gathered by two parallel, five- point Likert scale questionnaires each consisting of 18 question items. Data were analysed through Pearson correlation coefficient, paired t-test, ANOVA, and Wilcoxon tests. Results: The mean of the faculty member's self-evaluation score was 76.02± 10.5 and the mean of this evaluation by students was 71.12± 9.03 which demonstrated a significant difference (p=0.041). The correlation coefficient between the scores of self-evaluation and evaluation by students was -0.299. Conclusion: Faculty members’ self- evaluation scores were higher than those of the students. Faculty members should pay more attention to the results of this study and improve their teaching performance in order to achieve higher quality educational level