Tooth eruption sequence and dental crowding: a case-control study.

UNLABELLED: When cases of dental crowding are identified and diagnosed promptly, interceptive orthodontics is particularly successful. AIM: To assess the differences in the eruption sequence of the mandibular canine and first premolar teeth in children with and without dental crowding. MATERIALS AND METHODS: Children who attended the Shiraz Dental School's orthodontic clinic (Iran) from September to December 2012 were enrolled in this case-control study. Tooth size arch length discrepancy (TSALD) of all 8-10 year olds was calculated from patients' dental models. Thirty-six children were randomly selected from those with TSALD of equal or less than 4mm (those with crowding). Each selected case was matched for sex and age with another child (as control) with TSALD>-4mm attending the same clinic, in the same time period. The existing panoramic radiographs were traced and the eruption percentages were measured for mandibular canine and first premolar teeth. The mean difference between canine and first premolar eruption percentages was compared between the case and control groups using the SPSS (version PASW 18) software and a paired sample t-test. RESULTS: Canine and first premolar eruption percentages in the case group were 65.82±13.00 and 78.92±10.15 percent, respectively. The mean eruption percentages for canines and first premolars of the control group were 74.12±14.55 and 75.47±11.60 percent, respectively. There was a significant difference in pre-eruptive positions of canine and first premolar teeth in those with moderate to severe crowding when compared to the control group (p<0.001). CONCLUSION: These findings may improve the early diagnosis of children with high risk of developing moderate to severe crowding during mixed dentition

Photographic Facial Soft Tissue Analysis by Means of Linear and Angular Measurements in an Adolescent Persian Population.

To obtain objective average measurements of the profile and frontal facial soft tissue to be used as a guide for aesthetic treatment goals. Methods and Materials : This observational study included 110 females and 130 males high school students aged 16-18 years. None of the subjects had any facial deformities. All of them and their parents gave consent to take part in this study. In each case, two standard photographs of profile and frontal views were taken 27 landmarks were digitized on photographs. The mean, standard deviation, and range for a total of 43 facial indices were calculated digitally by computer software. The Student's t-test was used to compare males and females. Results : The ratio between the lower and middle facial thirds was one to one, but the height of the upper facial third was proportionally smaller than the other two-thirds in both sexes. Boys had greater nasal length, depth, and prominence than girls with statistically significant differences. Both upper and lower lips were more prominent in girls than in boys. All measurements of the chin showed sexual dimorphism characterized by greater chin height and prominence and deeper mentolabial sulcus. Boys had greater facial dimensions than girls. Mouth width, nasal base width, and intercanthal distance were significantly greater in boys. Conclusion : The labial, nasal, and chin areas showed sexual dimorphism in most of the parameters used in this study. Boys had larger faces, greater facial heights, longer nasal, labial, and chin lengths, and greater nasal, labial, and chin prominence

Evaluation of Perceived Acceptability, Beauty and Value of Different Orthodontic Brackets

Statement of Problem: Although different types of aesthetic brackets are introduced to orthodontic profession to reduce the complaints about the metallic braces, little studies have been done to assess patient's views regarding the attractiveness and acceptance of such brackets. Objectives: The goal of this study was to evaluate the perceived acceptability, beauty and value of different orthodontic brackets. Materials and Methods: In a cross-sectional study, three groups of subjects consisting of dental school clinic patients, specialty clinic patients, and art students were interviewed. Sample size was decided 116 in each group. The photographic images of six types of brackets which were placed in an adult mouth were shown to the subjects and they were asked to answer the questions that evaluate attractiveness by visual analog scale (VAS), acceptability of different brackets, and willingness to pay (WTP) for an aesthetic bracket in comparison to a regular bracket. Reliability was measured by giving questionnaires to 20 respondents by a two-week interval. VAS rating was compared by ANOVA. Mann U Whitney and Chi-square tests were used to compare the acceptability between groups when necessary. Results: The reliability measurement results performed by ICC were 0.86 for attractiveness, 0.6 for acceptability, and 0.93 for WTP questions. Lingual brackets had the highest attractiveness rating while metal brackets were considered the lowest aesthetic appliance by all groups of the study. The acceptability of ceramic bracket was highest in all groups. While most appliances evaluated had average acceptability, the large metallic brackets were rated very low. WTP for aesthetic braces was higher in art students than other groups. Conclusions: Lingual brackets were the most attractive but had very low acceptability rate. Small metal brackets had a good acceptability rate. Large metal brackets were the least attractive and had the lowest acceptability. Parents accepted aesthetic brackets for their children even when it cost more

Software Designation to Assess the Proximity of Different Facial Anatomic Landmarks to Midlines of the Mouth and Face

Statement of Problem: Recognition and determination of facial and dental midline is important in dentistry. Currently, there are no verifiable guidelines that direct the choice of specific anatomic landmarks to determine the midline of the face or mouth. Objectives: The purpose of this study was to determine which of facial anatomic landmarks is closest to the midline of the face as well as that of the mouth. Materials and Methods: Frontal full-face digital images of 92 subjects (men and women age range: 20-30 years) in smile were taken under standardized conditions; commonly used anatomic landmarks, nasion, tip of the nose, and tip of the philtrum were digitized on the images of subjects and aesthetic analyzer software used for midline analysis using Esthetic Frame. Deviations from the midlines of the face and mouth were measured for the 3 clinical landmarks; the existing dental midline was considered as the fourth landmark. The entire process of midline analysis was done by a single observer and repeated twice. Reliability analysis and 1-sample t- tests were conducted. Results: The Intra-class correlation coefficients (ICCs) for reliability analysis of RFV and RCV measures made two times revealed that the reliabilities were all acceptable. The results indicated that each of the 4 landmarks deviated uniquely and significantly (P<.001) from the midlines of the face as well as mouth in both males and females. Conclusions: There was a significant difference between the mean ratios of the chosen anatomic landmarks and the midlines of the face and mouth. The hierarchy of anatomic landmarks closest to the midline of the face is: (1) midline of the commissures, (2) nasion , (3) tip of philtrum,(4 )dental midline, and (5) tip ofthe nose. The closest anatomic landmarks to the mouth midline are: (1) tip of philtrum, (2) dental midline, (3) tip of nose, and (4) nasion

Comparison of Wear Resistance of Hawley and Vacuum Formed Retainers: An in-vitro Study

Statement of Problem: As a physical property, wear resistance of the materials used in the fabrication of orthodontic retainers play a significant role in the stability and long term use of the appliances. Objectives: To evaluate the wear resistance of two commonly used materials for orthodontic retainers: Acropars OP, i.e. a polymethyl methacrylate based material, and 3A-GS060, i.e. a polyethylene based material. Materials and Methods: For each material, 30 orthodontic retainers were made according to the manufacturers’ instructions and a 30×30×2 mm block was cut out from the mid- palatal area of each retainer. Each specimen underwent 1000 cycles of wear stimulation in a pin on disc machine. The depth of wear of each specimen was measured using a Nano Wizard II atomic force microscope in 3 random points of each specimen’s wear trough. The average of these three measurements was calculated and considered as mean value wear depth of each specimen (µm). Results: The mean wear depth was 6.10µm and 2.15µm for 3A-GS060 and Acropars OP groups respectively. Independent t-test showed a significant difference between the two groups (p < 0.001). The results show Polymethyl methacrylate base (Acropars) is more wear resistance than the polyethylene based material (3A-GS060). Conclusions: As the higher wear resistance of the fabrication material can improve the retainers’ survival time and its cost-effectiveness, VFRs should be avoided in situations that the appliance needs high wear resistance such as bite blocks opposing occlusal forces

The public attitude towards selecting dental health centers

Statement of the Problem: No published literature was found studying the people's reasons on why to choose or not to choose a dental care setting in south Iran, while understanding their attitude towards choosing their dental care center is consequential for planning a successful oral health care service system.    Purpose: To determine the factors affecting how people of the city of Shiraz choose their dental health services. Materials and Method: A cross-sectional analytic study was designed. A self-administered questionnaire was produced, tested and then distributed among 570 multistage randomly selected parents of schoolchildren of the city of Shiraz. Independent t-test, paired t-test and Spearman correlation were used to analyze the factors influencing participants in choosing clinics for their esthetic and non-esthetic dental treatments. Results: 400 questionnaires were complete and analyzed. The recommendation from others was found to be the most encouraging factor to choose a dentist or a dental clinic. More importance was reported for various factors affecting participants' choice of dental clinic when seeking non-esthetic treatments, while recommendation and reputation of dentist/dental clinic played a vital role in esthetic treatments. The cost was more important for respondents living in more deprived districts (p= 0.05), for unemployed group (p< 0.001) and for those with less education (p< 0.001). Conclusion: Factors affecting people's choice for dental care proved to be highly complicated. Recommendation was found playing an important role. Dental patients consider various factors when looking for non-esthetic treatment but would go for the best possible when seeking esthetic treatments. Findings of this study indicate that patients’ choice and utilization of dental service can be improved if dental clinics provide high quality of dental care with reasonable fees

Computer-Based Oral Hygiene Instruction versus Verbal Method in Fixed Orthodontic Patients

Statement of Problem: Fixed orthodontic appliances in the oral cavity make tooth cleaning procedures more complicated. Objectives: This study aimed to compare the efficacy of computerized oral hygiene instruction with verbal technique among fixed orthodontic patients referred to the evening clinic of Orthodontics of Shiraz Dental School. Materials and Methods: A single-blind study was performed in Orthodontic Department of Shiraz, Islamic Republic of Iran, from January to May 2015 following the demonstrated exclusion and inclusion criteria. The sample size was considered 60 patients with 30 subjects in each group. Bleeding on probing and plaque indices and dental knowledge were assessed in the subjects to determine pre-intervention status. A questionnaire was designed for dental knowledge evaluation. The patients were randomly assigned into the computerized and verbal groups. Three weeks after the oral hygiene instruction, indices of bleeding on probing and plaque index and the dental knowledge were evaluated to investigate post-intervention outcome. The two groups were compared by chi-square and student t tests. The pre- and post- intervention scores in each group were compared using paired t-test. Results: In the computerized group, the mean score for plaque index and bleeding on probing index was significantly decreased while dental health knowledge was significantly increased after oral hygiene instruction, in contrast to the verbal group. Conclusions: Within the limitations of the current study, computerized oral hygiene instruction is proposed to be more effective in providing optimal oral health status compared to the conventional method in fixed orthodontic patients

Utilization of Orthodontic Services in the Fars Province, Iran: The Reasons People Travel to the Capital for Orthodontic Treatment

STATEMENT OF THE PROBLEM: The first step towards appropriately planning orthodontic treatment and prevention services is to understand the needs and demands of the target population. However, this is ignored in most developing countries. PURPOSE: This study aims to evaluate the attitudes of patients in Fars province towards travelling to the provincial capital (Shiraz) to receive orthodontic treatments. MATERIALS AND METHOD: This cross-sectional study randomly selected 420 patients referring to two public and four private orthodontic centers in Shiraz, coming from other regions of Fars province. The patients were interviewed about their demographic status, residing area and the reasons of deciding to receive orthodontic treatment in Shiraz. Data were analyzed by SPSS software, using Chi-square and ANOVA statistical tests. RESULTS: The response rate was 96% (N=403). Near half of the patients (176; 43.7 %) lived 100-200km, and 80 (19.9%) patients lived farther than 200km from Shiraz. Having no orthodontist (54.8%) and no dentist providing orthodontic treatment (39.2%) in their region were the most important factors bringing the patients to provincial capital for orthodontic treatments. High costs of treatment in their home county and hoping to receive treatment of higher quality were the other important motives for lower and higher socio-economic backgrounds, respectively. Friends'/relatives' recommendation was a more important factor in patients using public clinics for choosing their therapist, while referral from dentists was more important for patients going to private clinics. The patients who lived in counties farther than 200km from Shiraz were more concerned about quality of treatment results than those who lived closer (p= 0.010). CONCLUSION: A multifactorial approach is needed to provide the desired orthodontic services for people in Fars province so that they would not need to travel to the capital for such treatments