Showing 27 results for Molar
J. Mahmodian , A. Kowsary , Sh. Javadi-Nejad ,
Volume 11, Issue 4 (8-1998)
Abstract
Eruption is a kind of development move of tooth from the place of its formation to its functional position in the mouth.Time and sequence of permanent's teeth eruption from the point of health diagnosis and orthodontic treatments is very important.Because of this, we decided to evaluate and determine the mean eruption time of canine and premolars from gum penetrations toward occlusion and also their sequence of eruption.The average time of eruptions in this study was higher than other similar studies.Our findings showed that the mean eruption time of canine and premolars in girls is earlier than boys lower canines erupt earlier than upper ones and maxillary premolars erupt before mandibular premolars in boys.
H. Afshar , Y. Baradaran Nakhjavani , P. Akhavan ,
Volume 12, Issue 1 (8-1999)
Abstract
In this study, by cluster simple random sampling, the prevalence of ectopic of first permanent molar in 8 years old Tehran school children is considered and determined as 0.87 percent The involvement of maxilla was more than mandible and the difference was significant. Bilateral involvement was more than unilateral and boys were more- than girls, how ever the differences were not significant.
As for as the geographical distribution is considered, the differences were not noticeable, either.
M. Paknejad , R. Amini ,
Volume 12, Issue 2 (9-1999)
Abstract
The root trunk (RT) of molar teeth is important diagnostic parameter that has a key roll in diagnosis and treatment planning.The purpose of this study is presenting a normal index of RT in mandibular molar teeth in different buccal (B). distal (D), Lingual (Li) and mesial (M) entrances, and to compare them with each other.It is a case series study that 351 extracted molar teeth, after removal of soft tissue and debridement of calculus, evaluated with gauge (with accuracy 0.1 mm) According to our measurement:In maxilla: M-side: 3.88± 0.15 mm, B-side: 4.7± 1.7. D- side: 4.87± 0.13mm. So with P.value <0.05 M and D RT are longer than and M RT is shorter than D RT.In mandibule: B- side: 2.73± 0.11mm and L side: 4.03±- 0.13mm. So with P.value < 0.01 Li RT is longer than B RT.According to ochsenbine classification our studying teeth have medium to long RT. We prescribe for educating the crater therapy in periodontal surgery the emphasize must be focused on craters with medium and long RT.The shortness of RT in B-side of lower molars needed the most attention during osteoctomy in resective procedures. Because RT not depended to underlying factors such as age, social and economic situation,and for large amount of sample size in our study, the result could be extended in Tehran.
Ms. Ahmad Akhondi ,
Volume 14, Issue 2 (8-2001)
Abstract
The purpose of this study was to evaluate Y shape appliance for expansion on maxillary arch of patients in their mixed dentition age. Eight patients, 6 girls and 2 boys, with maxillary constriction, retrusion of maxillary anteriors, and space deficiency of upper canine were treated by Y-plate expansion. For each patient 8 parameters on upper cast and 7 parameters on lower cast were measured. Statistical analysis was conducted by calculating the mean, standard deviation and p-value, of parameters. Since these parameters change during natural growth, the results were compared to normal growth changes of similar patients group form another study as control. Results showed significant increase in maxillary and mandibular cervical and coronal intercanine and intermolar width (P<0.005). The results also showed significant increase in maxillary arch length and perimeter.
B. Seraj ,
Volume 14, Issue 4 (1-2002)
Abstract
Whenever the first permanent molar is extracted or its long- term prognosis is poor, before taking any steps, a full clinical and radiographic evaluation associated with patient's dental models investigation is necessary to determine the following cases:The quality and quantity of dentition, teeth missing, occlusion, buds position, orthodontic problems, the level of parents and patient cooperation for future long term orthodontic treatment and finally patient's oral hygiene. On the basis of this information, a decision is taken about the first permanent molar extraction with poor prognosis, either of balancing or compensatory type, especially when future orthodontic treatment is improbable. The aim of this article is to explain the principles of time and sequence of first permanent molar extraction.
F. Aghahosseini , M. Enshaei ,
Volume 14, Issue 4 (1-2002)
Abstract
Epidemiologic studies have shown that caris or "infective damage of hard tissues in teeth" are the most common type of infection in human. In Iran, a few studies have investigated this hygienic problem, but no practical results have been defined yet. In this research, the conditions of the first upper and lower permanent molars (it contains four minor variables), have investigated. For this reason, in a descriptive analytic study, which was of retrospective and cross- sectional type, one thousand files were chosen systematically. The data were analysed by SPSS packages. The mean values of DMFT for permanent first molars were 3.47±0.50 (MT-1.23, FT=0.86, DT-1.38). The number of extracted teeth in mandible was moer than maxilla and the number of untreated caries teeth in maxilla was more than mandible (PO.001). DMFT ratio of the first molars to total DMFT, was approximately 29%, which indicates that caries and that complications on the first molars, make the main part of the overall DMFT. Therefore, hygiene training, preventive methods and the improvement of ecomonical status seem necessary in dental services.
L. Eslamian ,
Volume 15, Issue 4 (1-2003)
Abstract
According to researches, premolar extraction and anterior teeth retraction result in temporomandibular joint disorder due to posterior position of mandible. The aim of this study was to evaluate the effect of premolar extraction on TMJ disorder. In this interventiond study, 4 groups (10 patients for each group) were treated.They were classified as 1- non extraction, 2- extraction of two upper first premolars, 3- extraction of four first premolars, 4- combined extraction groups. Helkimo scores were evaluated before treatment, after treatment, one and two years after treatment. The results were analyzed with ANOVA and paired t-test. At the end of the treatment and two years after treatment in comparison with before treatment, Helkimo score had Significant differentce in all groups (PO.001). In the second year after debanding in comparison with the first year after debanding, no significant differences were seen in each group. No significant difference was seen between the four groups in the final appraisal of TMD. It seems that extraction had no adverse effect on TMD.
M. Ramezanian ,
Volume 16, Issue 1 (4-2003)
Abstract
Statement of Problem: One of the important indications for the extraction of mandibular impacted third molar is to preserve the periodontal health of the adjacent second molar from the destructive effects of plaque accumulation, acute and chronic inflammation.
Aim: The purpose of this study was to determine the effect of mandibular third molar surgery on the PDL of the adjacent molar.
Materials and Methods: Thirty patients, referred to the department of maxillofacial surgery, Tehran University of Medical Sciences, were selected, based on the desirable conditions. They had no history of systemic diseases and their adjacent molar was healthy. Probing depth (PD) at seven points and attachment level (AL) at three points were measured preoperatively. Standardized periapical radiographics were taken regularly for all patients. All the above-mentioned procedures repeated after three months of surgery. Findings were analyzed by Paired t-test.
Results: A significant difference in probing depth (PD) was observed before and after surgery, meaning that probing depth decreased after mandibular third molar surgery. Attachment level was also decreased post operatively moreover. Intrabony defects (IBD) showed healing after surgery.
Conclusion: Considering the limitations of the present study, impacted third molar surgery is suggested to prevent periodontal problems of the adjacent molar.
V. Talebi , H. Mahmood Hashemi , H. Gahani Hashemi ,
Volume 16, Issue 2 (5-2003)
Abstract
Statement of Problem: One of the easiest and most practical methods to predict the size of permanent canines and premolars, is of Tanaka-Johnston, but their research has been only performed on white skin North Europeans and it should be noted that the size of teeth, in various races, differ from each other.
Purpose: The aim of this study was to determine the validity of Tanaka-Johnston method, in a sample population taken from Ghazvin city.
Materials and Methods: The numbers of 235 pairs of study casts, prepared before any kind of treatment, were selected. The size of lower permanent incisors and permanent canines and premolars of both arches were measured. To analyze the results, "regression analysis" and "t test" were used.
Results: Based on the findings obtained from this study, new prediction equations as Y=12.9+0.4(X) and Y=]0.6+0.5(X) were presented for maxilla and mandible, respectively. However, these equations did not differ from Tanaka-Johnston equations statistically.
Conclusion: Tanaka- Johnston equations can be acceptably applied for the sample population taken from Ghazvin city, if the predictions are not overestimated.
M.e. Daneshvar ,
Volume 16, Issue 4 (1-2004)
Abstract
Statement of Problem: Pain control is of high importance in dentistry. Prescribing sedatives such a Diazepam, as an anti-depressant and pain threshold elevator drug is able to influence the patient's reaction to pain and reduce it.
Purpose: The aim of the current study was to evaluate the effect of Diazepam in pain reduction following mandibular impacted third molar surgery.
Materials and Methods: In this study, which was conducted in the department of Oral and Maxillofacial surgery Faculty of Dentistry, Tehran University of Medical sciences. The patients were divided into two equal groups (n=30). For controls, antibiotics and analgesics were prescribed after surgery. However, except the aforementioned drugs, Diazepam (5mg), three times per day, was prescribed for the experimental group. The amount of mouth opening was also measured as an auxiliary sign after one week. The data were compared by
X2 test after one week.
Results: 60% of the experimental group and 13.8% of the control group felt a weak pain. Statistically significant differences were observed regarding pain feeling between two groups (P<0.001). Severe pain feeling was 34.5% and 10%, for control and experimental groups, respectively.
Conclusion: It is suggested that Diazepam is an effective pain reduction drug following third molar surgery.This drug has also a relative effect on temporary trismus resulting probably from muscle trauma or pain.
M. Aeinehchi , S. Dadvand ,
Volume 19, Issue 4 (1-2007)
Abstract
Background and Aim: Vital pulpotomy in primary teeth is performed to maintain the vitality of the pulp and tooth until normal exfoliation. Different materials such as zinc oxide- eugenol, calcium hydroxide and formocresol are used in this procedure. The aim of this study was to evaluate the application of formocresol (FC) and mineral trioxide aggregate (MTA) in pulpotomy of primary molars.
Materials and Methods: In this clinical trial, one hundred and twenty six children (aged 5 to 9 years old) with dental caries that were candidate for pulpotomy were selected and randomly divided into two groups. After removing the roof of the pulp chamber, coronal pulp was cut at the orifices and bleeding controlled. In control group, formocresol was applied for 5 minutes. In case group, MTA paste was used as pulpotomy agent. The crowns of both groups were restored with amalgam and the teeth were evaluated clinically and radiographically after 3 and 6 months follow up. Data were analyzed by Fisher test with p<0.05 as the limit of significance.
Results: No sign of clinical failure was observed after 3 and 6 months follow-up. Comparison between the two methods revealed no significant difference in radiographic findings of the teeth and surrounding tissues after 3 months follow-up. However, after 6 months follow-up, internal resorption was observed radiographically in four cases of formocresol group.
Conclusion: Based on the results of this study, pulpotomy with MTA showed more successful results than formocresol radiographically. MTA is recommended as a good substitute for formocresol in pulpotomy of primary molars.
A. Kowsari , Sh. Azadedel , N. Akhondi ,
Volume 20, Issue 1 (5-2007)
Abstract
Background and Aim: Formocresol (FC) has been a popular pulpotomy medicament for primary dentition in recent decades. Concerns have been raised about the toxicity and potential carcinogenicity of FC, and alternatives have been proposed. Recently, the physical and biological properties of mineral trioxide aggregate (MTA) have been described in many studies. The aim of this study was to compare the success rate of pulpotomy with MTA (made in Iran) and FC in primary molars.
Materials and Methods: In this clinical trial, 30 primary molars needing pulpotomy treatment were selected and randomly divided into two groups: (15 teeth in FC and 15 in MTA group). The teeth were then pulpotomized and restored. Clinical and radiographic results were recorded at 1-3-6-9 and 12 months and success rates of two groups were compared using Fisher’s exact test with p<0.05 as the level of significance.
Results: After 12 months, there was no statistical significant difference between MTA group (85.8%) and FC group (93.3%) (P 1.0). The only observed radiographic failure was internal resorption.
Conclusion: Based on the results of this study, MTA can be used as an alternative to formocresol in primary teeth pulpotomy.
Sh. Javadinejad, M. Zarejahromi, A. Mirenayat,
Volume 21, Issue 3 (12-2008)
Abstract
Background and Aim: The role of applying rotary instruments in reducing preparation time and proper root canal preparation have been approved in permanent teeth. The aim of this study was to compare the rotary instruments (Hero642) and K-files in root canal preparation of primary molars. Time and canal transportation were compared.
Materials and Methods: In this experimental, invitro study, 30 human extracted primary molars with 8 mm length were selected and divided into two equal groups. After preparing access cavity, group 1was prepared by K-files and group 2 by Hero642 systems. Before canal preparation, with # 15 K-file and after canal preparation, with master apical file, canal curvature was evaluated by Weine technique using Radiovisiography. Apical transportation was calculated. Time taken for preparation was recorded by chronometer. The results were analyzed with T-test and Mann-Whitney. P<0.05 was considered as the level of significance.
Results: The average canal transportation angle was 3.42 for Hero642 group and 7.33 for K-file group (p<0.04). The mean instrumentation time was 4.28 for Hero642 group and 8.76 minutes for K-file group (p<0.001). There was a significant difference between two groups.
Conclusion: Based on the findings of this study, it is suggested to apply Hero642 rotary instrument for primary molar canal preparation due to less preparation time and less canal transposition.
R. Haghgoo, F. Mollaasadolla, F. Abbasi,
Volume 22, Issue 2 (11-2009)
Abstract
Background and Aim: Several agents were used for pulpotomy in primary molars. Formocresol is the most common drug in this procedure. In some studies it has been shown that, this material has potential some side effects, so it is essential to find other alternatives. The aim of this study was to evaluate clinical and radiographic success rates of mineral trioxide aggregate and formocresol.
Materials and Methods: In this randomized clinical trial study, 70 carious primary teeth of 4 to 7-year-old children were pulpotomized, and remaining pulp was dressed with Root MTA and formocresol. The clinical and radiographic follow up evaluations were performed at 6, 12 months by a blind dentist. The data were analyzed by Fisher's exact test.
Results: At the end of 1-year follow-up period, in formocresol group sinus tract and tenderness to percussion were seen in 2 teeth, internal resorption was seen in 1 tooth, and furcation radiolucency was seen in 2 teeth. Clinical and radiographic signs of failure were not seen in any case of (Iranian) Root MTA group.
Conclusion: Based on the results of this study, Iranian MTA can be used for pulpotomy in primary molars.
J. Chalipa, Mh. Hosseini, Mk . Hosseinian Serajelou, A. Khorshidian,
Volume 23, Issue 1 (6-2010)
Abstract
Background and Aims: One of the common human evolutionary anomalies is dental Missing. Evolution of dental system is toward deduction of teeth number. The Missing of third molar is interesting subject for dentists and genetic researches because of its variety in different races. Consideration of bilateral effect of third molar Missing with jaw relation is an important subject. The aim of this study was to evaluate the third molar missing in Cl I and Cl II skeletal (without rotation) and comparison of them together.
Materials and Methods: The patients of the orthodontic department of school of Dentistry (Tehran University of Medical Sciences) were analyzed. About 121 patients had Cl I and 60 patients had ClI jaw relation. This relation identified based on cephalometric lateral radiographic ANB corner angle. Patient who had rotation in maxilla or mandible based on SN-Go Gn angle were excluded. The incidence of third molars agenesis in individual dentition quadrants, upper and lower jaw and right and left side of dentition was examined from panoramic radiography. AChi-square test was used for statistical analysis of data.
Results: Missing of one or more third molar in skeletal Cl I and Cl II was 43% and 33.3%, respectively. Missing of one or more third molar in Cl II was fewer than Cl I, but no statistically significant differences were seen between them.
Conclusion: There was not a direct relationship between jaw relation and third molar Missing.
M. Salapoor, N. Farhad Mollashahi,
Volume 23, Issue 3 (12-2010)
Abstract
The goal of each root canal therapy is cleaning and obturating the entire root canal system. A thorough knowledge of root and root canal morphology and a good anticipation of their possible morphologic variations are essential and will help to reduce endodontic failure caused by incomplete root canal preparation and obturation. In this study, one case of maxillary molar with two palatal roots has been reported in a a 40-year-old woman is reported..
Mohammad Ebrahimi Saravi, Yushiaho Refoa, Yunes Nazari Dashlibrun, Reza Sharifi,
Volume 26, Issue 4 (1-2014)
Abstract
Background and Aims: Impacted third molar reduces the bone level in the distal aspect of second molar, and sometimes it can lead to root resorption of the adjacent tooth. The purpose of this study was to determine this resorption using panoramic and periapical radiographs.
Materials and Methods: In this cross-sectional descriptive study 54 patient (28 men, 26 women) above 15 years old with the average of 22 years in Oral and Maxillofacial Department of Tehran University were studied. A periapical radiography from the third molar and a panoramic radiograph were taken from each patient (Because of their routine use and evaluation of accuracy of panoramic compared with periapical), and the magnitude of the root resorption for the second molar was determined by 2 observers and written in a questionnaire. Data were analyzed using Fisher test.
Results: The prevalence of the root resorption of the second molar adjacent to the impacted third molar in the panoramic and the periapical radiographies, with respect to the limitation of the sample size were 46.3% and 31.5%, respectively, with 95% confidence(P>0.05). Most of these resorptions were in the cervical third of the second molar roots and in cases in which the third molars were mesially oriented or horizontal. There was also no significant difference between panoramic and periapical radiographs.
Conclusion: Due to the increased risk of the resorption of the second molar adjacent to the third molar, extraction of the impacted third molars, especiall y mesially oriented or horizontal ones are recommended.
Mehrdad Panjnoosh, Farnoosh Taghavi, Ahmad Reza Shamshiri,
Volume 27, Issue 3 (9-2014)
Abstract
Background and Aims: There is a risk of nerve injury during the extraction of the impacted third molars, in cases with proximity of the inferior alveolar nerve and this tooth. The aim of this study was to evaluate the effect of different various factors on the degree of vulnerability using CBCT (Cone Beam Computed Tomography) imaging technique.
Materials and Methods: CBCT images of 191 patients referred for the exact assessment of the relationship between the mandibular canal and impacted mandibular third molars were selected. The position of these anatomical structures was evaluated at their contact point. The possible effect of gender, impaction form of the third molars, anatomical relationship between the third molars and the mandibular canal and the age differences were studied. Data were analyzed using Chi-square and Student’s t-test.
Results: There was a close relationship between the mandibular canal and impacted third molars in 81.7% of the patients. The contacts were shown to be significantly higher in females than males (P=0.01) and in the cases with the lingually position of the third molar and the mandibular canal (P<0.001). However, the age and impaction form of the teeth did not have a significant influence (P>0.05).
Conclusion: The risk of nerve damage or exposure is increased in females and lingual position of the mandibular canal to the third molar in cases with higher proximity between these 2 structures in panoramic radiographs using CBCT images. Therefore, the surgeon must pay enough attention in these cases of third molar extraction.
Behrad Tanbakuchi, Sepideh Arab,
Volume 29, Issue 3 (10-2016)
Abstract
Background and Aims: The first permanent molar is susceptible to caries, endodontic complications and developmental anomalies. Compromised teeth with poor prognosis could cause the clinician to face dilemmas. The aim of this review article was to assess recent guidelines on the treatment planning of compromised first permanent molars in mixed dentition period.
Materials and Methods: The design of the study was based on review of literature by searching the MEDLINE, Web of science and Google scholar. Key words (permanent first molar, extraction, treatment plan) were used. This search was limited to the English articles published after the year 2000.
Conclusion: A number of factors influenced decision-making process regarding compromised first permanent molars including the restorative status of the tooth, dental age of the patient, degree of crowding and occlusal relationships were assessed. The ideal time for removal of these teeth was 8-9 years of age. However, the current evidence for managing compromised first permanent molars demands clinical trials.
Imaneh Asgari, Neda Ghanea,
Volume 30, Issue 2 (8-2017)
Abstract
Background and Aims: First molar has an important role at individual’s dental health. Among the known risk factors, the experience of previous caries is of the best predictors for future caries. The aim of this study was to examine the association of primary teeth caries and other risk factors with the incidence of permanent teeth caries by considering the caries extent and severity.
Materials and Methods: This case-control study was done on 150 students from second and third grade with 9 years old. Cases included children with at least one carious permanent molar. Caries-free students who were matched based on the gender and mother education was considered as control group. Examination was done on dental unit under the unit light with blunt explorer and mirror for visual assessment. DMFT, dmft and caries severity (D1-D3) were recorded based on WHO standards. Data were calculated using SPSS18, Correlation, Chi Square Analysis, Odds ratio and Logistic regression.
Results: Linear correlation between dmft in primary teeth and DMFT in permanent molars was obtained with r:0.34 (P<0.001). Decay in permanent molars in students with active caries in primary molars was 3.3 times more probable than others. In regression model, the other risk factors such as cariogenic diet, mother`s education, brushing with toothpaste, flossing, using flouride, and regular dental visiting were not significant (P>0.05).
Conclusion: Caries-free primary teeth predicts permanent teeth without decay with a high possibility. It could be helpful in caries risk assessments.
