JOURNAL OF DENTISTRY (SHIRAZ UNIVERSITY OF MEDICAL SCIENCES)
Year:2003 | Volume:4 | Issue:1 (6)|Papers Count:9

Background: Nursing caries (NC) syndrome is a severe form of tooth decay, which is primarily due to bad feeding habits, “feeding in bed while sleeping”. This kind of tooth decay usually affects the anterior teeth of 2-5 year-old children. Both bottle-feeding and breast-feeding have been implicated in the initiation of dental caries. The decrease in salivary flow rate during sleep, which reduces the diluting and buffering effects of saliva as well as the pooling of sweet fluids around the teeth, results in a highly cariogenic environment for acidegenic microorganism such as streptococcus mutants and lactobacilli. The first visit to the pediatric dentist should be done before the child's first birthday.Materials and Methods: The prevalence of NC was determined in 2-5 year-old children in Shiraz drawn from private and public nursing schools.Results: The prevalence of NC in this sample was 9.4 percent, which is acceptable in comparison with the results of other studies.Conclusion: There is no significant difference between sexes, parental education and occupation with respect to the occurrence at NC. However, the addition of sugar to milk, prolonged bottle and breast-feeding, sweet snacks between meals and neglected dental care, appear to be the most important etiological factors.

Background: The range of mandibular movements is a reliable indicator for evaluation of the function of the masticatory system and any limitation in movement of this system could be a sign of temporomandibular disorders (TMD). The purpose of this study was to determine the range of mandibular movements in healthy Iranian dental students in different directions.Materials and Methods: 114 healthy dental students with a symptom free masticatory system were selected and measurements were performed in different planes.Results: The results were: 1) 36.5 to 65 mm for minimum and maximum jaw opening in females. 2) 1.50 to 10.200 mm for minimum and maximum protrusion in females. 3) 4.200 to 10.600 mm for minimum and maximum movement to the right in females. 4) 5.800 to 12.200 mm for minimum and maximum movement to the left in females. 5) 42.500 to 80.000 mm for minimum and maximum jaw opening in males. 6) 2.600 to 12.000 mm for minimum and maximum protrusion in males. 7) 4.100 to 12.400 mm for minimum and maximum movement to the right in males. 8) 4.5000 to 13.400 mm for minimum and maximum movement to the left in males.Conclusion: We hope that we can use these normal ranges as a reference for diagnosis and management of patients with temporomandibular disorders.

Background: Anomalies in shape, size and number of teeth are a big problem for orthodontic patients. Peg shaped teeth and other anomalies are seen in orthodontic patients, therefore we decided to study this matter. The purpose of this study was to evaluate dental anomalies such as peg-shaped teeth, enamel hypoplasia, palatal cusp in laterals (talon cusp), misshaped and extra cusps in posterior teeth.Materials and Methods: This investigation was a cross-sectional study using direct observation and a questionnaire. In this investigation, 906 students (416 girls and 490 boys) in the 15 to 18 year-old age range were selected in a random cluster sampling method from seven different school districts. Data were analyzed by SPSS. Statistical analysis was performed using Fisher’s extact test.Results: 1) In the total sample population anomalies were 3.6% in boys and 2.5% in girls. 2) In total, 28 teeth had anomalies (18 in boys and 10 in girls). The difference was not significant. 3) In boys the total anomalies were 64.3% and in girls 35.7%. The difference was not significant. Frequencies of anomalies were as follows: 4) Overall peg shaped laterals were seen in 39.3% (21.4% in girls and 17.9% in boys). The difference was not significant. 5) Misshaped teeth were 3.6% in girls and 17.9% in boys (total of 21.4%). The difference was not significant. 6) Overall talon cusps were seen in 21.43% (10.7% boys and 10.7% in girls). The difference was not significant. 7) Extra cusps were seen in (14.3% in boys and 0% in girls). The difference was not significant. 8) Overall enamel dysphasia was seen in 3.6%. 9) The Overall frequency of dental anomalies were as follows: Peg shaped laterals in 39.3%, misshaped teeth in 21.4%, talon cusp in laterals in 21.4%, extra cusp in posterior teeth in 14.3% and enamel dysphasia in 3.6%.Conclusion: In this investigation we concluded that some teeth anomalies are more common in boys than in girls. In boys, teeth anomalies were more than in girls. Peg shaped laterals were more than any other kind of teeth anomaly and seen more commonly in girls than in boys. Other kinds of anomaly such as extra cusp in posterior teeth and enamel hypoplasia were only seen in boys. Talon cusps were equally observed in girls and boys. Although there were differences in the frequency of an anomaly with respect to gender, these differences were not statistically significant.

Background: DMFT is the most important index of dental caries. According to the meeting held by WHO and FDI in RiodeJenerio in 1981, the following criteria were proposed universally: 1) 50% of children should be caries free. 2) DMFT index should not be more than 3 in 12 year-old children. 3) 85% of 18 year-olds should not have an extracted tooth.Materials and Methods: The aim of this investigation was to determine the prevalence of dental caries and DMFT in 11-16 year-old school children in Bavanat. A total of 407 children (271 males and 136 females) were examined in Bavanat schools.Results: The mean DMFT in 11-16 year-old children was 2.25%, although 95.8% of the DMFT score was related to decayed teeth (D) and only 2% of decayed teeth were filled.The means of DMFT for ages 12+1 and 15+1 were 1.9 and 2.7 respectively, which were statistically significant. The results of this study demonstrated that DMFT was 2.33 among males and 2.09 among females.Conclusion: The results of our investigation showed that the DMFT index in an experimental population was relatively acceptable.

Background: Gingival recession or apical migration of gingival margin is a common periodontal lesion. A number of methods have been used to treat Miller's Class I & II gingival recessions with a notable success in root coverage. However in the treatment of Miller's Class III & IV gingival recessions, a predictable method has not been presented. It seems that the application of connective tissue grafts combined with various kinds of pedicle flaps may bring about satisfying results. In this study, a combination of palatal free connective tissue graft and a special kind of coronally positioned flap was used to treat Miller's Class III & IV gingival recessions.Materials and Methods: Eight patients including 6 females and 2 males with a total number of 28 anterior affected teeth with an average age of 35 years old were included in this study. The depths of recessions were between 0.8 and 5.6 mm (with an average depth of 3.2 mm). The following parameters were measured before and 1,3 and 6 months after the procedure: probing pocket depth, the depth of gingival recession from C.E.J and stent, width of attached gingival, clinical attachment level (CAL) and root sensitivity. In the surgical procedure, a coronally positioned flap was done with the first incision MGJ and continued with an epically directed partial thickness incision up to 5 mm. Then, it was followed by a second incision, which dissected the periosteum from the bone at the bottom of the buccal vestibule. Consequently, an intracervicular incision ran around the affected teeth, and the flap complex was pushed coronally. Prepared free connective tissue graft was placed beneath the flap on interdentally areas and denuded root surfaces, and then it was sutured to the superficial flap. The apical end of the flap was sutured to the depth of vestibule.Results: The results showed an average of 1.21-mm root coverage on the distobuccal side of the teeth. The amount of root coverage on midbuccal, mesiobuccal, mesial papilla and distal papillaes were 1.74, 1.25, 1.17and 0.93 mm respectively. The increase of CAL on mesiobuccal and midbuccal sides was significant with p<0.001. The width of keratinized gingival remained unchanged but the width of attached gingival increased considerably, from 4.5 mm at the baseline to 8.27 mm after the procedure.Conclusion: The surgical procedure can be used successfully for papilla reconstruction and root coverage in Class III and IV gingival recessions.

Background: Casting is one of the most popular processes for preparation of dental appliances and structures. The effect of melting and casting process on the corrosion behavior of dental appliances and prosthetics is important since the corrosion behavior of the dental metallic alloy is an indication of their biocompatibility in the mouth. The aim of this investigation was to evaluate the effect of laboratory casting and the recasting and use of return materials on the corrosion resistance of dental casting alloys.Materials and Methods: The ingot of two types of dental alloys (Co-Cr-Mo and Ni-Cr-Mo alloys) was used and enough coupons were prepared using the lost wax molding technique and centrifugal casting process. The same process, using remelting and recasting of the alloys, was performed to prepare the other samples for evaluating the effect of the recasting and use of casting returns and scrape materials on the corrosion resistance of the casting alloys. Electrochemical potentiodynamic tests were performed in physiological solution in order to determine and compare the corrosion behavior of dental casting alloy samples as an indication of biocompatibility.Results: The results showed no statistically significant difference between the mean corrosion current density values of two groups of the Cr-Co-Mo alloy (melted once and melted four times). There were statistically significant differences between the mean corrosion current density values of three groups (melted once, melted four times, and melted five times) of the Ni-Cr-Mo alloy (p<0.05). The five times melted dental casting alloy possessed the lowest corrosion resistance. This was due to the undesired effect of recasting process on the corrosion characteristics of dental casting alloys and it seems that the condition and parameters of the casting process is not stable every time.

Introduction: In this investigation, the distal movement of maxillary canine through distraction of periodontal ligament was clinically evaluated. In addition, a newly designed retraction device was developed and evaluated.Materials and Methods: This study was carried out on 10 patients who were selected through a selective available sampling procedure, in the orthodontic department of Shiraz Dental School. Removal of interseptal bone and extraction of upper first premolars were performed at the same time for each patient. Then a rigid, segmental, tooth-borne appliance was designed and used to rapidly retract canines 0.75mm per day.Results: After analyzing radiographs, dental casts and clinical findings, it was shown that the anchorage units were able to withstand the retraction force with minimal anchorage loss (0.10+0.25mm) and the canines were retracted (6.25+0.75mm) into the extraction space within 2- 3 weeks. Distal movement of canines were associated with a few tippings which were within acceptable limits a few tippings in all orthodontic movements such as tooth sliding and or orthodontics associated corticotomy. New alveolar bone was generated and remodeled rapidly in the mesial side of the canine during and after distraction. No clinical and radiographic evidence of periodontal defects or endodontic lesions was observed throughout and after distraction.Conclusion: This method can be considered as a useful method instead of routine ones because of reduction in treatment duration, rapid tooth movement and anchorage control without patient cooperation.

Pyknodysostosis is a rare sclerosing bone disorder with autosomal recessive inheritance. It is characterized by short stature, brachycephaly, short and stubby fingers, open cranial sutures and fontanelle and diffuse osteosclerosis. Here, we report a case of pyknodysostosis with characteristic physical and radiographical findings. A large skull and generalized bonehyperdensification are typical features. This malformation shows a loss of the normal mandibular angle. The patient had a small face, with a big nose and a large head. Irregularity of the teeth and a wide arched furrowed palate are other intra-oral findings. Although the profile showed to be convex, the patient had a skeletal and dental class III relation.