The advent of regenerative medicine has brought us the opportunity to regenerate, modify and restore human organs function. Stem cells, a key resource in regenerative medicine, are defined as clonogenic, self-renewing, progenitor cells that can generate into one or more specialized cell types. Human dental pulp stem cells (HDPSCs) are ectodermal-derived stem cells, originating from migrating neural crest cells and are capable of providing enough cells for potential cell-basedtherapies. During last decade, HDPSCs have received extensive attention in the field of tissue engineering and regenerative medicine due to their accessibility and ability to differentiate in severalcell phenotypes. In this review, we have described the potential of HDPSCs to differentiate into odontoblasts, osteoblasts, hepatocytes, neuroblasts and angioblasts in response to different bioactive factors. Therefore, the culture and selective differentiation of HDPSCs should provide furtherunderstanding of dental pulp progenitors and their potential use for new therapeutic approaches in regenerative medicine. Keywords: Human dental pulp stem cells (HDPSCs), Differentiation, Bioactive factors, Inductive factors.

Statement of Problem: The need to subject Monson’s spherical theory to further mathematical investigation is imperative in view of its clinical importance in dental occlusion. Purpose: The main goal of this study was to test the following hypotheses: 1. Monson’s pyramid is the 3D unifying geometric figure for Bonwill’s, Spee’s, Monson’s, and Hall’s theories of occlusion. 2. Monson’s sphere is made up of four regular tetrahedrons (Monson’s pyramids). 3. The radius of Monson’s sphere is greater than the radius of circumsphere of Monson’s pyramid. Materials and Methods: Bonwill’s triangle was used as the basis of geometrical model for constructing other 3D objects in this study; and it was assumed that the length of each side of Bonwill’s triangle was 10cm. A regular tetrahedron was constructed from Bonwill’s triangle. Then, linear and angular parameters were calculated for the constructed tetrahedron and its associated geometric figures. The calculated values were then subjected to statistical analysis using SPSS version 20; and comparisons of parameters were made using student’s t-test. Results: It was found that the theoretical geometrical figures that were proposed and demonstrated by Bon will, Spee, Monson and Hall were interconnected geometrically by means of a 3D geometric figure known as tetrahedron. Conclusion: Monson’s pyramid was established as the unifying 3D geometric figure for the analyzed geometric models of occlusion. Monson’s sphere is made up of four Monson’s pyramids while the radius of Monson’s sphere is also found to be greater than the radius of circumsphere of Monson’s pyramid. The clinical significance of this study is that some important linear and angular parameters, that are required in the fabrication of dentures, can be calculated from a regular tetrahedron and its associated geometric figures based on individual patient’s bicondylar distance. Keywords: Connectivity, Mathematics, Occlusion, Theory.

Introduction: Pain control by local anesthesia plays a critical role in success of most dental treatments. Due to the unpleasant pain experience related to the use ofthe conventional syringe injection, some computerized techniques have been developed for local anesthetic injection. Thisstudy aimed to compare the pain score following infiltration anesthesia of the maxillary premolar teeth administered by the conventional syringe and automatic. Materials and Methods: This single-bind randomized clinical trial was performed on 35 patients whose average age was 38. Requiring bilateral extraction of maxillary premolars. The patients’ dental anxiety was scored and they received infiltration anesthesia with the iCT injection SE (Dentium, South Korea) at one side and conventional syringe at the contralateral side. The pain level was recorded during needle insertion, anesthetic delivery and 5 hours after the injection using visual analog scale (VAS) and the face rating scale (FRS). The data were subjected to Wilcoxonsigned-rank test. Results: Significant differences were found between the automatic and conventional method sregarding pain scores duringneedle insertion (P<0.01) and anesthetic delivery (P<0.0001) while nosignificant differences were notedat 5 hours after the injection. Pain scores were significantly lower during supra-periosteal injections in the maxillary premolar region using iCT injection. Conclusion: Both FRS and VAS in iCT injection showed that frequency of severe pain during needle insertion and anesthetic delivery was noticeably lower than that in conventional injectionmethod but findings revealed that there was no significant difference between these two technics after 5 hours of injection. Keywords: Pain scores, Automatic injection, Infiltration anesthesia.

Introduction: This study aimed to assess the knowledge and attitude of patients presenting to dental school about the acquired immunodeficiency syndrome (AIDS) in 2017-2018. Materials and Methods: This descriptive, cross-sectional study was conducted on 450 patients presenting to dental school of Tehran University of Medical Sciences, International Campus, in 2017. The patients had a mean age of 33 years (range 11-66 years). The Farsi version of the international AIDS questionnaire with 18 questions (13 questions about knowledge and five questions about attitude) was used for data collection. Each correct response was allocated a score of 1.Regression analysis was used to assess the effect of age, sex, level of education and financial status on the knowledge and attitude scores. The Pearson’s correlation coefficient was used to assess thecorrelation between knowledge and attitude scores. Results: The mean knowledge and attitude scores were 10.55 and 4.1, respectively. By an increase in the knowledge score, the attitude score significantly increased and vice versa (r=0.376,P<0.0001). Age, sex and financial status had no significant effect on knowledge about HIV/AIDS,and only the effect of level of education was significant (P=0.0001). Age had no significant effect on attitude score but gender (P=0.001), level of education (P=0.001) and financial status (P=0.038) significantly affected the attitude score. The attitude score was higher in females. Discussion: In general, participants had favorable knowledge and attitude towards AIDS. However, the knowledge and attitude of the Iranian population should be further enhanced in this respect. Keywords: Knowledge, Attitude, AIDS.

Introduction: Epilepsy is one of the most common chronic neurologic diseases. It has a great influence on quality of life, as it engages 1-3% of a society. Normally, 10% of the people of the society have experienced seizure once or several times during their lives. Regardingalldentistry aspects, they receive insufficient treatments, which might be due to the medical and economic status of them. Oral health is of paramount importance. Objective: This research aims at examining oral health status of the patients with epilepsy, comparing them with the non-patient ones from systemic point of view, and evaluating periodontal treatment needs. Materials and Methods: Sixty patients were randomly includedin this cross-sectional study. They were divided into 2 subgroups of partial and general (based on frequencies of seizures, type of seizure, and mental status). Sixty systemically non-patient people who referred to the Imam Khomeini Hospital for blood donation were randomly included in the study as the control group. They were medical and epilepsy history. Oral examinations were carried out. The Simplified Oral Hygiene Index (OHI-S), decay-missing-filled tooth (DMF-T), normal teeth abrasion rate (Abrasion Index), Prosthetic Index; periodontal treatment needs (CPITN) and Muhleman index were evaluated and a statistical comparison was made between the patient group and the control group and between the epilepsy subgroups. Results: OHI-S index, DMF-T index, Muhlemman index and Prosthetic index of the patient group was considerably higher than the one of the control group. About CPITN index, In mandible, the patient group has a significant difference with the control group, except in the area of the second left molar. Conclusion: Several factors contributed to worsening oral health status in the patient group as compared with the control group. For example, the effect of seizure itself, negative attitudes of dentists, and social and economic conditions. We propose to start oral treatments concurrent with the  treatments concerning epilepsy. Some special dental interventions were proposed for each subgroup. Keywords: Epilepsy, Oral healt, Periodontal.

Introduction: The aim of this study was to evaluate the radiographic features of stafne bone defects in patients referred to a private radiology center from March 2013 to 2016 in Mashhad, Iran. Materials and Methods: In this retrospective cross-sectional study 5000 CBCTs were evaluated with the definitive diagnosis of SBD. Radiolucencies between the molar region and angle of mandible were considered as SBD and if no increase in the size of the depressions was observed in the second panoramic view, the diagnosis of SBD was made. After selecting the radiographs with SBD, all their radiographic characteristics were recorded. Results: Among the 5000 CBCT radiographs, 10 (0.2%) SBD cases were diagnosed, 9 in males and only 1 case in a female. All SBDs were between the molar regions and the angle of mandible and were categorized as the posterior variant of SBD. In our studied cases SBD was near the inferiorborder of mandible and in 3 cases the depressions disrupted the continuity of the inferior mandibular border. The lesion’s shape was oval in 7 cases and round in the others. In total 5 cases were categorized as type I, 4 as type II and one case as type III of SBD. Conclusion: According to our findings, SBD is an uncommon lesion in the mandible and CBCT can be used as a non-invasive method to detect this defect. Keywords: Stafne bone defect (SBD), Cone beam computed tomography (CBCT), Panoramic radiography.

Pyogenic granuloma is a common tumor-like growth of the oral cavity that traditionally has been considered to be non-neoplastic in nature. The pyogenic granuloma is a smooth or lobulated mass that is usually pedunculated, although some lesions are sessile. Pyogenic granuloma of the gingival is frequently developed in pregnant women, hence the terms pregnancy tumor and/or granuloma gravidarum are often used. The pyogenic granuloma has been reported to be associated with port-wine stain particularly during pregnancy, and after trauma, or laser treatment. The  pathogenesis of pyogenic granuloma is unclear. This report describes the presentation of a large pregnancy tumor in a patient with an isolated facial port-wine stain. Keywords: Port-wine stain, Pregnancy, Pyogenic granuloma.

TMJ ankylosis is a partial or complete loss of movement in mandible that occurs as a result of several causes. Trauma is the most common cause of TMJ ankylosis. Surgical procedures are aimed at restoring anatomic structure, function and providing growth potential as well as preventingreoccurrences. In this paper, we are introducing a case of 28 years old woman, who suffered from unaesthetic appearance and TMJ ankylosis since the age of 5 but her treatment has been delayed due to misdiagnosis of her problem. She underwent two bilateral condylectomies with and without costochondral grafting, condylar shaving, and orthognathic surgery to solve a problem that could have been avoided. Costochondral graft has been suggested as the “Gold Standard” for TMJ reconstructionin the growing patient but overgrowth and reankylosis are two of its unwanted outcomes that happened after her first and second surgeries. Although the results of TMJ reconstruction is not fully in surgeons hand, with respect to our knowledge about these operations, it seems reankylosis, overgrowing and all other post-operative complications can become preventable.