• Journal of Technologic Dentistry
• /
• v.8 no.1
• /
• pp.91-99
• /
• 1986

In order to evaluate the community dental health level the actual health capacity of the lower-first permanent molar is suitable as a indicator for assessment. So we had surveyed decayed, missed and filled lower permanent first molar of 460 persons who were in the age from 20 to 29 in Iri City. The obtained results were as follows: 1. The DMFT indices of the lower first permancent molars showed in 1.40 in the age group of from 20 to 24 and 1.44 from 25 to 29. 2. The actual dental health capscities of the lower first permanent molars showed in 84.86% in the age group of from 20 to 24 and 81.03% from 25 to 29. 3. The DMF indices of the lower first permanent molars showed 15.15% in the age group of from 20 to 24 and 18.98% of from 25 to 29. 4. The DMF rates of the lower first permanent molars showed 85.66% in the age group of from 20 to 24 and 88.70% of from 25 to 29. 5. The DMF rates of the lower first permanent molars showed 70.00% in the age group of from 20 to 24 and 71.96% of from 25 to 29. 6. The DT rates of the lower first permanent molars showed 48.84% in the age group of from 20 to 24 and 39.55% of from 25 to 29. 7. The FT rates the lower first permanent molars showed 40.22% in the age group of from 20 to 24 and 43.98% of from 25 to 29. 8. The MT rates of the lower first permanent molars showed 10.94% in the age group of from 20 to 24 and 16.17% of from 25 to 29.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.21 no.2
• /
• pp.555-560
• /
• 1994

Among the permanent teeth. the first permanent molars play the greatest role in occlusion and function. So, the congenital missing, abnormal reuption or abnormal formation of the first permanent molars in the course of arch development would inflict normal development of dental arches. Therefore, early detection of abnormal cases related to first permanent molars and understanding of current and predictable clinical problems are essential for proper occlusal guidance in children. With the aim of investigating the clinical patterns of delayed eruption of first permanent molars in children, panoramic tomograms of the childern in mixed and early permanent dentition were observed and analyzed. The results were as follows: 1. Among the delayed eruption of first permanent molars, on tooth or bilateral teeths were affected most frequently. Delayed eruption was more prevalent in maxilla than in mandible. 2. The formation of tardily erupted teeth were also delayed. 3. Delayed eruption was generally limited in first molars or molar segments. 4. Delayed eruption of first permanent molars is accompanied by abnormal position of tooth germs, for example, ectopic eruption, delayed dental age, delayed localized tooth formation and generalized congenital missing. 5. There was a tendency of delayed formation or congenital missing of second molars distal to tardily erupted 1st molars. And that was more marked in maxilla than in mandible. 6. There was reported that affected 1st molars show various size and shapes. Maxillary 1st molars showing delayed eruption showed a tendency of having 3 cusps. But, tardily erupted mandibular 1st molars showed no significant reduction in mesiodistal dimension, as reported. 7. In some cases, the delayed eruption of 1st permanent molars was associated with ectopic eruption, but their formation was not usually retarded. 8. In skeletal class III cases, there showed a tendency of mandibular 1st molars to erupt earlier than maxillary 1st molars with greater interval than in normal occlusion.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.3 no.1
• /
• pp.7-11
• /
• 1976

The author measured the degree of development and the eruption pattern of first permanent molars with orthopantomography in 553 Korean children(male; 302, female; 251) from 4 to 9 years old. The orthopantomographs were obtained from dept. of pedodontics, college of dentistry, Seoul National University. The results of the studies were as follows: 1. Upper first permanent molars were erupted with distal inclination of about 30 degrees in the early stage and they gradually moved in the mesial direction by bodily movement of the tooth to be in contact with the disto-proximal surface of primary secondary molars in the late stage. 2. Lower first permanent molars were erupted with mesial inclination in the early stage and moved mesially by tipping movement of the tooth to be in contact with the disto proximal surface of the second primary molars in the late stage. 3. The eruptive forces were considered to be main etiologic factors of space closure after the premature loss of primary molars.

• The Journal of the Korea Contents Association
• /
• v.10 no.11
• /
• pp.209-216
• /
• 2010

The purpose of this study was analyzing the first permanent molars condition that was how catch on general oral health of the children in primary school, to make use of the basic data on dental health policy project for the school oral health. The sampling was done at the primary school in Suncheon. It made a survey on the first permanent molars of 823 person who had attended in March, 2009. By using the WHO standards and Clune's dental health capacity, the conditions of first permanent molars calculated. DMFT index and it's condition of first molars statistically are analyzed by Pearson's correlation. 1. The dental health capacity of the first permanent molars was 92.2%. 2. The DMFS index of first permanent molars was 3.97. 3. The dental health capacity of first permanent molars have related with DMFT index(r= -0.895). 4. DMFS index of the first molars have positive relation with DMFT index(r= 0.902). In this repory, I would like to suggest that the evaluation of dental health project for the school aged children should be considered including the healthy status of the first molars.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.23 no.4
• /
• pp.859-866
• /
• 1996

It is a relatively rare clinical experience to see the impacted first molar. The first permanent molar is the key in normal occlusion. Abnormal eruption of the first permanent molars would inflict normal development of dental arches and give rise to abnormal root resorption of the adjacent teeth. Therefore, the abnormally erupted first permanent molars should be detected and treated early in order to obtain proper occlusal guidance in mixed dentition period. This report presents two cases on distally tilted and impacted mandibular first molars which were treated by surgical exposure and orthodontic traction using facial mask.

• The korean journal of orthodontics
• /
• v.46 no.3
• /
• pp.171-179
• /
• 2016

Objective: The primary aim of the study was to generate new prediction equations for the estimation of maxillary and mandibular canine and premolar widths based on mandibular incisors and first permanent molar widths. Methods: A total of 2,340 calculations (768 based on the sum of mandibular incisor and first permanent molar widths, and 1,572 based on the maxillary and mandibular canine and premolar widths) were performed, and a digital stereomicroscope was used to derive the the digital models and measurements. Mesiodistal widths of maxillary and mandibular teeth were measured via scanned digital models. Results: There was a strong positive correlation between the estimation of maxillary (r = 0.85994, $r^2=0.7395$) and mandibular (r = 0.8708, $r^2=0.7582$) canine and premolar widths. The intraclass correlation coefficients were statistically significant, and the coefficients were in the strong correlation range, with an average of 0.9. Linear regression analysis was used to establish prediction equations. Prediction equations were developed to estimate maxillary arches based on $Y=15.746+0.602{\times}sum$ of mandibular incisors and mandibular first permanent molar widths (sum of mandibular incisors [SMI] + molars), $Y=18.224+0.540{\times}(SMI+molars)$, and $Y=16.186+0.586{\times}(SMI+molars)$ for both genders, and to estimate mandibular arches the parameters used were $Y=16.391+0.564{\times}(SMI+molars)$, $Y=14.444+0.609{\times}(SMI+molars)$, and $Y=19.915+0.481{\times}(SMI+molars)$. Conclusions: These formulas will be helpful for orthodontic diagnosis and clinical treatment planning during the mixed dentition stage.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.22 no.4
• /
• pp.239-254
• /
• 2022

The high success rate of dental treatment is dependent on the cooperation of pediatric patients during procedures. Dental treatment often causes pain, particularly in children. The factors in providing treatment to pediatric patients include the characteristics and location of the tooth, profoundness of the anesthesia including the type of local anesthetic, and cooperation of the patient. Previous studies have examined several techniques to successfully achieve profound pulpal anesthesia in maxillary permanent teeth. The dentist should select the injection technique to be used based on patient needs. In children, either buccal with palatal injections or buccal with intra-septal injections may be used to anesthetize the permanent maxillary first molar. Buccal with palatal injections are commonly used prior to routine maxillary dental procedures. Currently, there are only a few studies on the employment of buccal with intra-septal injections to anesthetize permanent maxillary first molars in pediatric patients. This review will focus on efficacy of buccal with palatal versus buccal with intra-septal pulpal anesthesia of the permanent maxillary first molars in pediatric patients and aim to determine which technique should be used during routine dental procedures.

• The korean journal of orthodontics
• /
• v.17 no.2
• /
• pp.311-320
• /
• 1987

The purpose of this study was to investigate the growth changes of maxilla and mandible and position changes of first permanent molars of growing children The author analyzed the data using cephalometric roentgenogram of 43 boys and 39 girls age of 6 to 11 with normal occlusion The obtained results were as follows 1 The eruption path of maxillary and mandibular first permanent molar superimposed on TM-ANS and mandibular plane shows individual variation 2 There was no correlation between horizontal and vertical changes of maxillary first permanent molar, but positive correlation in mandibular first permanent molar 3 As the eruption, the forward changes of mandibular first permanent molar was significantly greater than that of maxillary first permanent molar 4 As the ages were increased, there were irregular growth changes of maxilla and mandible 5 Growth changes of lower anterior facial height was relatively stable 6 N-S-${\bar{6}}$ was stable after age 7.

• Journal of Oral Medicine and Pain
• /
• v.3 no.1
• /
• pp.11-22
• /
• 1977

In order to evaluate the normal eruption time of the Korean permanennt teeth, the author had examined the eruption phases of permanent first molars in 778 males and 653 female children aged from 5 to 9-year old and analysed. The eruption was divided into 4 phases; the tip of the crown can be seen, the dull occlusal surface of the crown can be easily seen, the crown is not in contact with its antagonist, and the crown is in contact with its antagonist. The obtained results were as follows : 1. It seemed that percentage of the eruptingand erupted permanent first molar in female by age was higher than that of male. 2. In general, percentage of the erupting and erupted permanent first molar by age was higher than that of upper first molar. 3. In the correlation of age with the eruption phase, the regression equation were "y=0.43x+5.61" on male upper first molar, "y=0.41x+5.60" on male lower first molar, "y=0.44x+5.47" on female upper first molar, and "y=0.38x+5.57" on female lower first molar respectively.n female lower first molar respectively.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.42 no.2
• /
• pp.172-179
• /
• 2015

The developmental mechanism of root formation is a complex process. Hereditary and environmental factors may affect the morphology of the developing root. A total of 12 cases was presented with permanent first molars with abberant root morphology. Clinically, these teeth appeared as a normal crown. However, radiographically, the root was slender, twisted and characterized by irregular lengths. In addition, root trunk length was shorter and pulp chamber was obliterated. In these cases, periapical radiolucency and loss of lamina dura were often observed. In 6 cases, an abnormal root of the primary second molars were also present, as well as root malformation of permanent first molars. In 3 cases, permanent central incisors also had a dysmorphic crown. These cases almost all had medical history, such as premature birth, brain infection or congenital heart disease in infants. The present paper describes cases of permanent first molars with an abnormal root that are rarely reported in literature. This case may intensify the variation in the permanent first molar and is intended to reinforce the clinician's awareness of rare morphology of the roots.