Journal of Dental Medicine
Year:2005 | Volume:17 | Issue:4 (41)|Papers Count:13

Evaluation of skeletal age and determination of growth status had important and special role in orthodontic treatment planning (such as functional orthopedic treatment and orthognatic surgery) and also in stability of it. There were several biologic indicators for the detection of the peak in mandibular growth. Due to the limitations of biological indicators application, idea of new indicators was seemed importantly. Cervical vertebral maturation (CVM) method is one of them. At first the detection of the peak in mandibular growth was based on the analysis of the second through sixth cervical vertebrae in six developmental stages. But a few improvements of the original CVM analysis were still needed. In this method, the peak in mandibular growth was determined based on the analysis of the second through fourth cervical vertebrae in five developmental stages. This method is easy, applicable and more valid than hand-wrist analysis method.

Statement of Problem: The significance of adenoid tissue in Orthodontia appeared in 1954. At that time, even as today, orthodontists had an enduring interest in the relationship between excessive amounts of adenoid tissue, the developing occlusion, and facial morphology.Purpose: The aim of this study was to evaluate effect of mouth breathing with adenoid enlargement on dentofacial cephalometric measurements.Material and Methods: A sample of 92 subjects between the ages of 6 and 15 years old were studied in two study and control groups. In study group, 46 mouth breathers (32 girls and 14 boys) with mean of 11.26 years old were examined by orthodontist and ENT specialist in order to confirmation of nasopharyngeal obstruction. Control group contained 46 nasal breathers (35 girls and 11 boys) with mean of 11.33 years old. For each patient in centric occlusion, a lateral cephalogram was taken and traced. 12 dentofacial variables were measured and statistical t-test was conducted by calculating the mean, standard deviation and p-value of parameters. Statistical t-test for mean of dentofacial variables for the two groups revealed that some of variables were significantly different.Results: In study group ÐGo.Me-SN, ÐY-Axis, ÐGo, ÐSN-PL variables were significantly higher than control group and 1toFH, SNB were significantly lower. The other dentofacial variables (ÐS, IMPA, ÐSNA, ÐANB, ÐAr and LH) didnt show any significant difference. Conclusion: Adenoid enlargement and nasopharyngeal obstruction can affect dentofacial morphology and cause facial vertical growth pattern and upper centrals retrusion.

Statement of Problem: The pulp may be exposed during remove of caries or by traumatic and iatrogenic injuries. The material used to DPC, must be biocompatible, sealable and prevent bacterial leakage. Furthermore, it is better to stimulate dentinogenesis. Calcium hydroxide is most usual material for DPC. But it cannot provide a suitable biologic seal. Mineral trioxide aggregate (MTA) is also a suitable material for DPC.Purpose: The aim of this study was to compare the clinical success of DPC done with MTA or calcium hydroxide cement. Materials and Methods: In this study eighteen posterior teeth without previous spontaneous pain that involved mechanically exposure was randomly selected and capped with MTA or calcium hydroxide.These teeth were evaluated by clinical vitality test and radiograph after 3 and 12 months, and patients were questioned about irritative or spontaneous pain in this period. Statistical analysis was carried out by fisher exact test (α=0.05).Results: This study showed that in calcium hydroxid groud three had irreversible pulpitis and two teeth had symptom and signs of reversible pulpitis, While, In MTA group all cases were normal, and no clinical sign was evident. Conclusion: MTA exhibited better results than calcium hydroxide cement for the capping of the pulp in human.

Statement of Problem: There are many risk factors for periodontal diseases and from this point the disorders of lipid metabolism also may be a risk factor for periodonontal diseases. Purpose: The purpose of this study was to evaluate the relation of periodontal disease and disorder of lipids metabolism in cardio vascular patients.Materials and Methods: In this sectional study, 45 patients who were hospitalized in shahid Rajaee hospital divided and studied in two group, (included test group with 27 patents and control group with 18 patients). In both groups the level of serum lipids including triglyceride, total cholesterol and LDL cholesterol were determined and periodontal status were estimated by CPITN index. Then statistical result processed by Mann- Whiney U test and spearman- correlation.Results: The results showed that CPITN index in high lipid group was more than low lipid group and spearman correlation between triglyceride and CPITN was 0.283 between cholesterol and CPITN was 0.372 and between LDL and CPITN was 0.230.Conclusion: In this study we found that there is a specific and significant relation between periodontal disease and serum lipids in cardio vascular patients.

Statement of Problem: Reduction of orthodontic therapy treatment time is considered an important goal in the management of malocclusion in adult patients. Corticotomy- facilitated orthodontic treatment may be considered an intermediate therapy between orthognatic surgry and conventional orthodontics for reducing treatment time.Purpose: This study was undertaken to evaluate and compare the rate of tooth movement of upper canine following corticotomy with conventional method.Materials and Methods: Ten young adult patients, 17-25 years old was selected through sequential sampling procedure in orthodontics department of Shiraz Dental School. The patients exhibited different orthodontic problems and needed extraction of premolars. Following extraction of premolars and initial phase of orthodontic treatment, corticotomy were performed unilaterally on buccual and palatal sides of extraction area as described by Takami. The other unoperated sides were used as control. After subsiding the resultant inflammation, the activated NiTi spring was used and measurement of the amount of tooth movement was assessed by using Rugae as reference point. The panoramic radiographs were super imposed for evaluation of canines tipping. For analyzing the results, Kolmogorou- simirnov and t.test were used.Results: The rate of canine tooth movement was much greater in the corticotomy sides than the unoperated (control) side (P=0.015). This was especially significant at the end of first week of tooth movement (P=0.000). Comparing the two sides, the amount of canine tipping was much lesser in corticotomy group than the control group (P=0.046). There was no significant difference concerning the anchorage loss between the two groups (P=0.410).Conclusion: Corticotomy procedure had a positive effect on the rate of tooth movement with less tipping of the canines comparing to conventional orthodontic treatment. To get more benefit from this procedure, it is recommended to select those patients who do not need canine alignment after premolars extraction, such as bimaxillary dento alveolar protrusions.

Statement of Problem: Regenerative periodontal procedures are one mode of therapy that attempts to restore the lost supporting structures of the dentition around a previously diseased root surface. Purpose: The purpose of this study was comparison between Enamel matrix proteins (EMP) used alone or in combination with autogenous bone graft (ABG) in the treatment of human intrabony periodontal defects.Materials and Methods: This clinical trial study, was done on 8 pairs of matched two wall intrabony periodontal defects with 5 mm or more probing depth and 3 mm or more depth of intrabony component following phase I therapy. In control sites Enamel matrix proteins (EMP) and in test sites EMP with autogenous bone graft (ABG) was used.Results: No differences were found in terms of oral hygiene and defect characteristics, at baseline. Six months after treatment, both procedures significantly improved the clinical probing depth and clinical attachment level. Although bone fill was significant for both groups but EMP+ABG significantly showed more bone fill and defect resolution (bone fill 2.75mm versus 1.67mm). Crestal resorption was the same for both groups and its difference was not significant. Conclusion: The results of this study demonstrate that both procedures improve clinical parameters and combined use of EMP with autogenous bone graft will promote more bone fill and more defect resolution. A difficulty in obtaining sufficient amounts of autogenous bone from intra oral sites is one of the limitations of this procedure.

Statement of Problem: According to many researches done in the field of occupational disorders dentists are considered at the risk of musculoskeletal problems. These problems may cause reduction of job length of dentists.Purpose: This study was done for evaluating the musculoskeletal disorders of dentists, practicing in Yazd.Materials and Methods: This is a descriptive cross-sectional study, conveyed in Yazd city in 1999 by survey among all of working dentists with eye-to-eye contact questionnaire reply.Results: Among dentists were interviewed 81.6% of respondents mentioned at least one of musculoskeletal problems. The mentioned disorders were respectively: Neck (47.1%) hand (36.2%), wrist (34.8%), upper and lower parts of back (33.3%), shoulder (11.59%), knee (2.8%). About 72.5% of the individuals had no familial history and just 4.5% had these disorders before working as a dentist.Conclusion: Results of this study revealed that majority of musculoskeletal disorders had significant relationship with age, gender, work place, working hours, level of exercise, direct vision and duration of the job of dental occupation.

Statement of Problem: A few decades have past from using radiographic technology as an accurate paraclinical method and always protective measurements is applicated against ionizing radiation. As dental radiography is a routine procedure in dentistry the importance of protective strategies is clear.Propose: The aim of this descriptive study is to evaluate the protection principles in centers which have intraoral radiographic devices in Yazd. Material and Methods: We have considered all three aspects of practitioner, environment and patient protection using questionnaire and visiting those centers.Results: 33/7% of dental offices, 10 clinics, 3 institution and faculty of dentistry had intraoral radiographic equipments. Stablishment of protection principles for radiographer was favorable. 7.7% of centers had x-ray room with leaded walls, 23.1% had curtain , in 69/2% of centers radiographers stood in correct position and distance while taking radiograph. Regarding to protection of environment, beams leakage control in 23.1% dental offices, 70% of clinics, all institution and faculty of dentistry have done.Conclusion: Non of the centers used rectangular localizator, thyroid shield, film holder and just some centers used leaded apron in specific circumstances. We have concluded that patient protection constitute less consideration. Generally lack of protective consideration is related to deficient knowledge of operators. Lack of information about protection equipments causes decrease of demanding of these tools and ultimately lack of these equipments in the market.

Statement of Problem: Zinc contained cements are so important among dental material as they have many indications and used in different ways therefore evaluation of their physical properties is so important in dentistry.Purpose: The purpose of this research was to measure some physical properties of zinc contained cements used in restorative dentistry. These cements included: Zinc oxide eugenol, Zinc phosphate and Zinc polycarboxylate. Physical properties measured in this research were compressive strength, and setting time also Solubility & Disintegration were evaluated.Materials and Methods: To perform these research two packs of each cement type were provided from an Iranian company products as prototypes and German HARVARD Dental GmbH company products as proof samples. For compressive strength 11 samples provided from any type of cement. For setting time test, 16 samples provided from Zinc oxide eugenol and 11 samples from two other types. For solubility & disintegration beet, 11 samples provided only from Zinc oxide eugenol cement. The results compared with standard.Results: The results of Iranian product showed that compressive strength of Zinc oxide eugenol is 12.58±3 MPa, of Zinc phosphate cement is 37.21±5.0 MPa and of Zinc polycarboxylate cement is 35.86±2.1 MPa. Setting time of Zinc oxide eugenol cement is 2 9.04 ±0.7 1 min, of Zinc phosphate cement is 5.41 ±0.55 min and of Zinc polycarboxylate cement is 2.5±0.6 min. Solubility & disintegration of Zinc oxide eugenol cement is 8.44 1.1%. None of these findings are in standard limit.Conclusion: By the use of standard charts it is concluded that: Only compressive strength of Zinc oxide eugenol cement is between standard limits and compressive strengths of two other types of the cements are less than standard limits. Also only setting time of Zincoxide eugenol cement is in standard limit and setting times of two other types of the cements aren't in standard limit. The German samples results were in standard limit. Solubility & disintegration of Zinc oxide eugenol cement isn't in standard limit. Therefore it is concluded that all types of these cements are not standard for use.

Statement of Problem: In spite of the limitations of Radiography, diagnosing of periodontal diseases without having accurate radiographs is inadequate because it provides a visible image of the supporting bone to the clinician and works as a fixed measure of the supporting bone during the study.Purpose: The aim of this study is to compare the precision of preiapical, bitewings and panoramic radiographs in determining the distance between the alveolar crest (AC) and cementoenamel junction (CEJ) of teeth.Materials and Methods: Statistically this is a survey study in which 120 interproximal surfaces of teeth were measured during surgery by periodontal probing and recorded as the actual measurement. Then 40 sites underwent bitewing, 40 sites preapical and 40 others panoramic radiography and the distance of CEJ up to the alveolar crest of bone was measured on them by periodontal probe and recorded. Then each group was analyzed separately and the Pearson's correlation coefficient was examined for the data. Results: The results of this study showed that when the thickness of the remaining bone in a millimeter limit is important for the surgeon, the bitewing radiography has a prime importance, but when bone loss is moderate, the panoramic radiography showing %89 of the cases close to the actual measure, can be acceptable. On the other hand, in anterior sites for determining the bone alteration, preiapical radiography with a 0.93 correlation coefficient is superior to the panoramic radiography with a correlation coefficient of 0.72 and we suggest it for examining the changes of bone in these sites. Conclusion: whenever the bone alteration is moderate or severe, it seems that, bitewing radiography is of particular importance, but when the bone loss is little, panoramic radiography can be used and there is no need to put the patient on unnecessary radiation.

Statement of Problem: Choosing an appropriate tooth for edentulous patients is a very important step in dentistry.Purpose: This research has been done for determination of proper procedure for tooth selection in edentulous patients. Methods and Materials: In this cross- sectional study 100 student and people who have come to a medical center (range 20-30 years old) were collected randomly and the size of their anterior teeth was determined. A gauge with 0.01 mm accuracy and flexible plastic millimeter was used in order for measurement of anatomic landmark. For achieving the relation between the sizes of teeth statistical analysis was done. Results: 50% of patients were female and the other 50% were male. We found a relationship between mesiodistal width of six maxillary anterior teeth and mesiodistal width of six mandibullary teeth that can be shown as follow: In men: six mandibular anterior teeth width= 0.83 × width of six maxillary anterior teeth -2.008 In women: six mandibular anterior teeth width= 0.56 × width of six maxillary anterior teeth + 9.53 Also strong meaningful relationships between width of six anterior maxillary teeth and the width between corners of the lip in curve position have been noticed only in men which can be show as follow: width of Six mandibular anterior teeth= 39.63 + 0.21+ the width between corners of lip in curve position for men Conclusion: Although there are different ways for prediction of teeth size, it seems these findings can be helpful in determining and prediction of it.

Statement of Problem: Craniocervical Posture is a factor in the development and function of Craniofacial Structure. Previous studies of different samples have demonstrated associations between craniocervical posture and craniofacial morphology. Purpose: This study aimed to examine whether any significant association is evident or not between craniocervical posture and the occurrence of Class II & Class III skeletal malocclusions.Materials and Methods: A sample of 76 subjects with Class II & Class III skeletal malocclusion aged 9-11 and>18 years were selected. None of them had received orthodontic treatment. Lateral cephalometric radiographs were taken in natural head position (NHP), and craniocervical and craniohorizental angels were traced and determined for analysis of craniocervical posture.Results: According to the craniocervical posture, most class II skeletal patients have flexed heads and class III skeletal patients have extended heads, as a result malocclusion in these patients seems to become more severe. With increase in age, class II skeletal patients have more flexed their heads and malocclusion become more severe, while with increase in age in class III skeletal patients, their heads become extended and once again malocclusion thought to be more severe. In class II skeletal patients, craniocervical posture has a significant correlation with the vertical growth pattern, but shows little correlation with the horizontal growth pattern. In class III skeletal patients, craniocervical posture shows no correlation to any of the vertical & horizontal growth patterns, of course the mean of vertical angles is less in these patients and probably in order to make this relation significant in Class III skeletal patients there is need for more samples. In class II & class III skeletal patients, the amount of Na.prep-point A and pog-Na.prep with craniocervical posture shows a significant correlation.Conclusion: Consideration of craniocervical posture (in addition to cephalometric angles) lead to making better treatment planning.