• Journal of the korean academy of Pediatric Dentistry
• /
• v.41 no.3
• /
• pp.266-271
• /
• 2014

This study was performed to evaluate the relationship between the types of maxillary labial frenum attachment and the dental age in children. The maxillary labial frenum attachment levels were examined from the children who visited Chonbuk National University Dental Hospital between April, 2010 and December, 2013. The total number of the examined children was 320 (160 males, 160 females) between the age of 2 and 12. The types of maxillary labial frenum were categorized according to Placek's classification and each type was analyzed for its relationship with both Hellman's dental age and the eruption stage of permanent maxillary anterior teeth. The observed forms of maxillary labial frenum along with their frequency were as follows: gingival (56.3%), papillary (20.6%), mucosal (18.1%) and papillary penetrating (5.0%). The frenum form showed no significant difference due to gender (p > 0.05). From IC to IIIB in Hellman's dental age, the mucosal type increased significantly (p < 0.001). There was no significant relationship between the types of maxillary labial frenum attachment and the eruption state of permanent maxillary anterior teeth (p > 0.05).

• The korean journal of orthodontics
• /
• v.13 no.1
• /
• pp.83-94
• /
• 1983

For the better orthodontic diagnosis, case analysis, and treatment plan, the author studied the cephalometric analysis of 365 Korean with normal occlusion occording to the Steiner and Tweed analysis. The subjects consisted of 162 males and 203 females from 7 to 19 years with normal occlusion and were divided into three groups according to the Hellman's dental age. The results were obtained as follows: 1. The Ideal Acceptable Compromises were determined after measurement of male and female average by the Steiner analysis in Hellman's dental age III B, IV A, IV C group. 2. The Holdaway ration were 6.5:1.0 in Group I, 6.5:1.5 in Group II, 6.5:1.5 in Group III. 3. The Tweed's triangle were $FMA\;27^{\circ}\;FMIA\;58^{\circ}\;IMPA\;95^{\circ}$ in Group I and II, $FMA\;27^{\circ}\;FMIA\;62^{\circ}\;IMPA\;95^{\circ}$ in Group III.

• The korean journal of orthodontics
• /
• v.6 no.1
• /
• pp.55-63
• /
• 1976

This study was undertaken to establish the roentgenocephalometric standards of the Korean children in Hellman dental age III C. The subjects consisted of 33 males and 33 females with the normal occlusion and acceptable profile. The lateral cephalometric films were taken with the teeth in centric occlusion, the soft tissue outline of the nose, lips, and chin was made visible by the low-speed films, 70Kvp, 100Mas. Their linear and angular measurements were performed by Jarabak's methods. The following results were obtained; 1) The author made the tables of standard deviation from the measured values. 2) Each linear measurement of the skull was greater in males than in females. 3) The maxillary basal bones were more protrusive in Korean children than in Caucasian. 4) The degree of the facial convexity was larger in Korean children than in Caucasian. 5) The labial inclination of the upper & lower incisors was greater in Korean children than in Caucasian. The labial inclination of the upper incisor was greater in females, but the labial inclination of the lower incisor was greater in males.

• The Journal of the Korean dental association
• /
• v.16 no.12 s.115
• /
• pp.923-928
• /
• 1978

The auther studied the open-bite of Hellman dental age IIIC groups of Korean childern on the roentgenocephalometry. The subjects consisted of 45 males and 45 females with normal occlusion and acceptable profile. The major conclusions may be listed as follows: 1. This study was summerized in the form of tables, mean, standard deviation, minium and maximum for 35 angular, linear and ration measurements. 2. Charts of standard deviation from the mesurements were made for the clinical application.

• The Journal of the Korean dental association
• /
• v.16 no.9 s.112
• /
• pp.689-693
• /
• 1978

A girl (Hellman dental age IIC) with anterior cross bite was treated by means of the chincap and occlusal equilibration on deciduous canines. Following results were obtained; 1) The cross bite was corrected after 12 weeks of active treatment. 2) The terminal plane of deciduous molars had become 'a class II tendency' 3) The axial inclination of lower incisors were changed significantly.

• The Journal of the Korean dental association
• /
• v.22 no.11 s.186
• /
• pp.947-951
• /
• 1984

The present study was performed to establish the cephalometric standards of linear measurements in Hellman dental age II C groups of Korean on the roentgenocephalometry. The subjects consisted of 21 males 31 females with normal occlusion and acceptable profile. The major conclusions were as follows. 1. The means and standard deviations of the measurements in males and females were made. 2. No sex difference was made in all items, except in U₁-Y and U₁-X.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.3
• /
• pp.359-366
• /
• 2010

It was easy to find that children of a skeletal anterior crossbite in the early mixed dentition period showed a stark difference in the dental maturity between their maxillary and mandibular teeth, if they have stronger physical characteristics. If the difference of dental age between maxillary and mandibular teeth which can be identified via panoramic radiographs may serve as an early sign of class III malocclusion, this is considered valuable as a tool of early detection diagnosis. We obtained lateral cephalometric radiographs, panoramic radiographs, working model and clinical images of patients of Hellman dental age IIA and IIC who visited the department of pediatric dentistry, Pusan National University Dental Hospital and examined them to select 50 patents for normal occlusion group and skeletal anterior crossbite group, respectively. Their panoramic radiographs were used for the Demirjian's method to figure out dental ages of maxillary and mandibular teeth of each group and the eruption rate of the first molars. Their differences are as follows: 1. In both groups, the dental ages from Demirjian's method were advanced than the chronological ages. No sexual dimorphism was detected for the chronological or dental age in either group (p>0.05). 2. The difference of dental age of maxillary and mandibular teeth between the normal occlusion group and crossbite group was 0.22 and 0.69 years, respectively, with a higher difference in crossbite group(p<0.05). 3. Compared to the normal occlusion group, the crossbite group showed a higher difference in the eruption rate between maxillary and mandibular first molar(p<0.05).

• The korean journal of orthodontics
• /
• v.18 no.1 s.25
• /
• pp.105-112
• /
• 1988

To predict duration of orthodontic treatment of malocclusion, 304 male and female patients whose orthodontic treatment was finished in department of orthodontics, Infirmary of dental college, Chosun University were studied. The duration of treatment was studied according to types of malocclusion, beginning ages of treatment, Hellman's dental ages, the determination of tooth extraction, types of tooth extraction and types of orthodontic appliance. The following results were obtained. 1. The duration of treatment was 18 months in Class I malocclusion, 20 months in Class II malocclusion and 24 months in Class III malocclusion. 2. The more early treatment was done, the more duration of treatment was needed according to beginning age of treatment and Hellman's dental ages. 3. Treatment of tooth extraction case was needed for 78 days more than that of non-extraction case. 4. The duration of treatment with unilateral extraction of premolars was the shortest (598 days) and that with single arch extraction of premolars was the longest (685 days) according to types of tooth extraction. 5. The duration of treatment by removable appliance was the shortest (237 days) and the combination of removable appliance, headgear and full banded appliance was the longest (1425 days) according to types of orthodontic appliance. 6. The duration of treatment was 18 months in typical orthodontic treatment with 4 extraction of premolar and full banded appliance.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.40 no.1
• /
• pp.21-27
• /
• 2013

In growing children it is frequently found that dental maturation is strongly influenced by the growth rate of maxilla or mandible. If there is evidence to prove this, it might be utilized as a criterion in the early diagnosis of skeletal malocclusion, even before the object's real skeletal features are yet revealed. The purpose of this study was to find out if the difference of dental maturation in over-grown mandible in children with skeletal Class III has any relationship with some skeletal features of mandible. 50 patients in Hellman dental age IIIA with normal occlusion and Class III malocclusion of mandibular over-growth type respectively were selected as study objects. The age estimation was performed on maxillary and mandibular teeth, eruption rate of the 2nd molars of each group have been measured on panoramic radiography, and the differences in dental age of the upper and lower jaw were analyzed under Demirijian's method. The results were as follows: The difference of dental age of maxillary and mandibular teeth between the two groups was 0.66 and 1.20 years respectively, with a higher difference in the experimental group (p < 0.05). The difference of eruption rate of the maxillary and mandibular second molar was not found between two group (p >0.05).

• The korean journal of orthodontics
• /
• v.12 no.2
• /
• pp.177-191
• /
• 1982

The study was performed to establish the cephalometric standards of Hellman dental age III B, IV A, IV C groups of the age of puberty and to aid for the case analysis and diagnosis of malocclusion. A roentgenocephalometric study was made from 365 subjects, that consist of 162 males, 203 females with normal occlusion, acceptable profile and no history of orthodontic and prosthodontic treatment. The results of this study were obtained as follows: 1. The tables of standards from the measurements by age, sex group were made. 2. All linear measurements of skeletal pattern in male were greater than in females. 3. The Bjork's sum was reduced gradually by aging in group I $396^{\circ}$, group II $395^{\circ}$, and group III $393^{\circ}$. 4. Posterior facial height to anterior facial height was 63% in group I, 64% group II, and 67% in group III. 5. The angulation of SNA and SNB were $81^{\circ}$ & $78^{\circ}$ in group I, $81^{\circ}$ & $78^{\circ}$ in group II, and $82^{\circ}$ & $79^{\circ}$ in group III.