• 대한치과의사협회지
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• 제38권6호통권373호
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• pp.520-526
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• 2000

• 대한치과의사협회지
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• 제19권5호통권144호
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• pp.417-422
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• 1981

• 대한치과의사협회지
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• 제31권11호통권294호
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• pp.788-790
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• 1993

• 대한치과보철학회지
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• 제36권1호
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• pp.166-182
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• 1998

The purposes of this study are to evaluate the Korean mandibular dental arch and classify the mandibular dental arch shape and size based on the incisal angle, canine angle, inter second molar width and height. In this study the mandibular study models were fabricated using irreversible hydrocolloid impression material from 225 volunteers with a mean age 23.62 (range 19-29). And the study models were measured with 3-dimensional measuring device and the mandibular dental arch was classified by means of K-means clustering method and visual inspection, then obtained data were analyzed with t-test for the statistical analysis. The results were as follows ; 1. The average canine height was 5.19mm(s.d. 1.17) in both sex, 5.34mm in male, and 4.95mnm in female. And the sexual difference was significant($0). 2. The average second molar height was 39.81mm(s.d. 2.44) in both sex, 40.19mm in male, and 39.21mm in female. And the sexual difference was significant($0). 3. The average inter-canine width was 27.16mm(s.d. 1.78) in both sex, 27.41mm in male, and 26.77mm in female. And the sexual difference was significant($0). 4. The average inter-first molar width was 46.93mm(s.d. 2.67) in both sex, 47.72mm in male, and 45.7mm in female. And the sexual difference was significant($0). 5. The inter-second molar width was average 56.09mm(s.d. 3.01) in both sex, 57.24mm in male, and 54.32mn in woma. And the sexual difference was significant($0). 6. The arch form was classified into three shapes based on the incisal and canine angle. V-shape showed $124.88^{\circ}$ of incisal angle and $141.64^{\circ}$ of canine angle, U-shape showed $152.76^{\circ}\;and\;125.35^{\circ}$, and O-shape showed $138.03^{\circ}\;and \;33.66^{\circ}$ respectively. Each shape distribution was that the V-shape was 14.2%, the U-Shape was 14.7%, and the O-shape was 71.1% of the 225 study models. 7. It was thought that the use of second molar width is more reasonable than height for classifying the dental arch size. The arch size was classified into four sizes based on the second molar width. Size 1 showed range of 42.24-48.23mm, size 2 showed 48.24-54.23mm, size 3 showed 54.24-60.23mm, and size 4 showed 60.24-66.23mm respectively. Each arch size distribution was that the size 1 was 1.3%, the size 2 was 27.1%, the size 3 was 63.6%, and the size 4 was 8.0% of the 225 study models.

• 대한치과교정학회지
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• 제44권2호
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• pp.69-76
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• 2014

Objective: This study aimed to evaluate the accuracy and precision of polyurethane (PUT) dental arch models fabricated using a three-dimensional (3D) subtractive rapid prototyping (RP) method with an intraoral scanning technique by comparing linear measurements obtained from PUT models and conventional plaster models. Methods: Ten plaster models were duplicated using a selected standard master model and conventional impression, and 10 PUT models were duplicated using the 3D subtractive RP technique with an oral scanner. Six linear measurements were evaluated in terms of x, y, and z-axes using a non-contact white light scanner. Accuracy was assessed using mean differences between two measurements, and precision was examined using four quantitative methods and the Bland-Altman graphical method. Repeatability was evaluated in terms of intra-examiner variability, and reproducibility was assessed in terms of interexaminer and inter-method variability. Results: The mean difference between plaster models and PUT models ranged from 0.07 mm to 0.33 mm. Relative measurement errors ranged from 2.2% to 7.6% and intraclass correlation coefficients ranged from 0.93 to 0.96, when comparing plaster models and PUT models. The Bland-Altman plot showed good agreement. Conclusions: The accuracy and precision of PUT dental models for evaluating the performance of oral scanner and subtractive RP technology was acceptable. Because of the recent improvements in block material and computerized numeric control milling machines, the subtractive RP method may be a good choice for dental arch models.

• 대한치과의사협회지
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• 제10권6호
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• pp.347-349
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• 1972

The authors selected fifty children aged 2 to 4 years who had normal occlusion from the patients admitted at the Pedodontic Department in the Infirmary of Dental College, S.N.U. Study casts were taken and observed on the primate spaces and terminal planes which are characteristics of primary dentition. The results were as follows: 1. The percentages of terminal planes were 56%±7.02 in mesial step type, 38.0%±6.86 in straight step type, 6.0%±3.36 in distal step type, respectively. 2. The percentages of primate space were 80%±5.09 in maxillary dental arch and 5.0%±7.06 in mandibular dental arch. 3. The percentage of mesial step type in korean children was higher in comparison with that in foreign children and the percentage of the primate space was about the same in korean & foreign children.

• 대한치과의사협회지
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• 제47권10호
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• pp.656-668
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• 2009

It is difficult to perform orthodontic treatment for cleft lip and palate patient. Although there are many orthodontic appliances to expand narrowed maxillary arch, results are rarely successful and the possibility of relapse is increased due to severe scars. Self-ligating bracket, recently used in orthodontic treatment, suggests solution of crowding by expansion of dental arches. Light and continuous force could apply for orthodontic movement due to characteristic low friction of self ligating bracket, which gives expansion force until dentition reaches its new equilibrium position and it can be expressed as spontaneous lateral expansion with heavy labial tension. This kind of expansion force is thought to be a possibility of expanding the constricted maxillary arch of cleft lip and palate patient. Repositioning of the maxilla by Le Fort I osteotomy in case of severe maxillary deficiency, increases the possibility of relapse because of limitation in anterior movement and adaptation of soft tissue. In these cases, distraction osteogenesis(DO) can be applied for stable result. We report a case of cleft lip and palate patient with narrowed maxillary arch and maxillary deficiency using self ligating bracket and DO.

• 대한치과교정학회지
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• 제13권1호
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• pp.73-82
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• 1983

The author studied on the dental arch widths and lengths and height of palates at 3 groups of dentition: mixed dentition, early permanent dentition, young adult, having normal occlusion and dentition. The models of the 336 maxillary and mandibular case, made from alginate-base hydrocolloid impressions were measured and analyzed statistically. The result as follows; 1. The upper intercanine width increased between the mixed dentition group and early permanent dentition group but there was no change in the young adult group in both sexes. The lower intercanine width increased between the mixed dentition group and early permanent dention group in the male. 2. The upper and lower 1st bimolar width increased slightly with age in the male but there was no change in the female. 3, The sex difference found in this study was one of absolute size, the female being slightly smaller than the male in the early permanent dentition group and young adult. 4. The arch length had no notable sexual differences and decreased between the mixed dentition group and early permanent dentition group. There was no change in the arch length in the young adult. 5. The height of palate increased gradually with age.

• 대한치과의사협회지
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• 제51권6호
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• pp.330-336
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• 2013

Considering the high prevalence, transverse control in adult patients presenting relatively narrow maxillary width is a challenging issue. This study compared the pattern of arch expansion induced by either miniscrew-assisted rapid palatal expander (MARPE) or continuous archwire engaged on self-ligating brackets. Age-matched adults groups(N=15 each) were treated with respective appliance. In both groups, all intercanine, interpremolar, and intermolar widths increased, and significantly greater change was noted in the intermolar region. Buccal tipping was minimal in both groups. Subsequent arch length increase, lingual tipping of incisors and distal tipping of molars were also found in both groups. According to the results, it can be concluded that the MARPE induced generally more arch expansion, particularly in the intermolar width, indicating that the adults showing buccal crossbite of the molars may have to undergo expansion via MARPE prior to arch alignment using continuous archwire.

• 대한치과교정학회지
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• 제13권2호
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• pp.205-208
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• 1983

Widths between the first permanent molars and the mesio-distal widths of the four anterior teeth were measured on 32 lower and 33 upper dental casts of young adults aged 18-25 yerars. The casts were grouped in five categories-two where no anterior crowding existed, and three in which varying degrees of crowding were present. Subjects with a difference between arch width and anterior tooth widths greater than 4mm in the upper arch, or 10mm in the lower arch, rarely had crowding. As arch width changes very little from age 7 onwards, measurements at this age may be used as a screening mechansim for future arch crowding.