• The korean journal of orthodontics
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• v.31 no.3 s.86
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• pp.347-355
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• 2001

Maxillary and mandibular anterior dental arches often have the problems of occlusal relation and esthetics by malformations of teeth, congenital missing, et at. Though the clinician usually use the anterior ratio to overcome this problems, he has the limitation of a direct application this ratio to the prediction of anterior occlusal relationship by the change of anterior ratio as dental arch form, intercanine width, segment depth and arch perimeter. So this study examine maxillary and mandibular anterior dental arch forms by least square method using Korean normal occlusion models(man : 20 casts, woman : 20 casts). Maxillary and mandibular anterior dental arches of Korean normal occlusion models are curve fitted to polynomial function, beta function, hyperbolic cosine function in order. And this accuracy of curve fitting is constant regardless of man/woman and maxilla/mandible. The relationships between intercanine width, segment depth, and arch perimeter based on this owe fitted dental arch form are acquired. This relationships will give the prediction of anterior dental arch form and the information of more accurate anterior ratio according to intercanine width.

• The Journal of Korean Academy of Prosthodontics
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• v.9 no.1
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• pp.9-15
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• 1969

The purpose of this study was to examine arch form, occlusion in centric occlusion. Male 561 case, Female 305 case were impressioned with alginate impression material, and plaster models were made. Occlusion and maxillary dental arch were studied on plaster models in Korean adults aged from 18 to 60 Years. The results were as follows. 1. The upper dental arch was U-type(57.77%), O-type(23.52%), V-type(18.71%) in male, and U-type(60.66%), O-type(27.11%), V-type(12.13%) in female. 2. The commonest type of the anterior bite was 1-form($68.09{\pm}1.97%$) in male, ($72.46{\pm}2.56%$) in female, and posterior bite was 1-form($65.06{\pm}2.01%$) in male, ($69.51{\pm}2.64%$ in female. 3. In the maxillary dental arch U-type was frequented and the relationship of occlusion in upper and lower dental arch was mainly 1-form.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.273-285
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• 1992

The purpose of this study was to evaluate facial form, arch form and tooth form in young adults to determine if a correlation exists. 115 subjects who had healthy natural maxillary incisors and good occlusion consisted of 71 males and 44 females ranging from 20-30 years of age. Facial photographs and, intraoral photographs of upper anterior teeth and dental casts of upper jaws were taken to demonstrate facial form, dental arch form and tooth form. Form analysis is determined by comparing the ratio of the widths of the faces, dental archs and the teeth. The Chi-square test of independence between facial form, arch form and tooth form, was executed and the significance level determined. The results were as follows : 1. The distribution of facial forms was 66.1% square-tapering, 27.0% square, 5.2% ovoid, 2% tapering-square. 2. The distribution of tooth forms was 65.2% ovoid, 20.0% square-tapering, 11.3 % tapering-square, 3.5 % square. 3. The distribution of arch forms was 50.4 % square-tapering, 48.7 % tapering, 0.9 % reverse tapering-square. 4. There was no large differences in the distribution of facial forms, dental arch forms and tooth-forms between male and female. 5. No relationship existed between the tooth form and the facial form. 6. No relationship existed between the facial form and the dental arch form. 7. No relationship existed between the tooth form and the dental arch form. 8. This gave the impression that dental arch form and facial form could not be used as a true index in tooth selection.

• Imaging Science in Dentistry
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• v.52 no.2
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• pp.197-207
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• 2022

Purpose: This study evaluated the associations of the dental arch form, age-sex groups, and sagittal root position (SRP) with alveolar bone thickness of the maxillary central incisors using cone-beam computed tomography (CBCT) images. Materials and Methods: CBCT images of 280 patients were categorized based on the dental arch form and age-sex groups. From these patients, 560 sagittal CBCT images of the maxillary central incisors were examined to measure the labial and palatal bone thickness at the apex level and the palatal bone at the mid-root level, according to the SRP classification. The chi-square test, Kruskal-Wallis test, and multiple linear regression were used for statistical analyses. Results: Significant differences were found in alveolar bone thickness depending on the arch form and SRP at the apex level. The square dental arch form and class I SRP showed the highest bone thickness at both levels of the palatal aspect. The taper dental arch form and class II SRP presented the highest bone thickness at the apex level of the labial aspect. No association was found between the dental arch form and SRP. Elderly women showed a significant association with thinner alveolar bone. Age-sex group, the dental arch form, and SRP had significant associations with alveolar bone thickness at the apex level. Conclusion: The patient's age-sex group, dental arch form, and SRP were associated with alveolar bone thickness around the maxillary central incisors with varying magnitudes. Therefore, clinicians should take these factors into account when planning immediate implant placement.

• The Journal of Korean Academy of Prosthodontics
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• v.8 no.1
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• pp.30-36
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• 1968

The measurements on the various items, such as arch form, kinds of anterior dental arch, degree of curvature in anterior dental arches, relationship between direction of the disto-incisal edge of the canine and first premolar, and kinds of posterior dental arch in upper dental arches were studied on 311 cases of the Korean adults aged from 20 to 30years. The results were as follows. 1. The commonest type of the upper dental arches was U-type (53.7%), the remaining were O-type (25.4%) and V-type (20.0%). 2. A slight curvature type (71.87%) prevailed against angulated curvature type in upper anterior dental arches. 3. The degree of curvature from $121^{\circ}$ to $160^{\circ}$ in anterior dental arches was common, and the degree of curve of 1-type with on curvature was smaller than 4, 5 type with two curvature. 4. The direction of the disto-incisal edge of canine went between the tip of the buccal cusp and the lingual incline of the buccal cusp of the first premolar in most dental arches and went lingual incline of the buccal cusp of the first premolar in U-type, from buccal cusp to lingual cusp of the first premolar in O-type and were distributed from buccal edge to central groove of the first premolar in V-type. 5. A posterior dental arch with almost straight curvature was common in 60.87%, and 4-type with a half rounded curve from first premolar to second molar was next.

• The korean journal of orthodontics
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• v.3 no.1
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• pp.7-13
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• 1972

Many geometric curves are presented as representative form of normal dental arches by many authors; circle, ellipse, parabola or catenary curve. Among them those except circle seems difficult to be adopted as a guide in ideal arch form construction and practically many orthodontists chose circle as a standard. Author preferred circle of Bonwill's theory in study of anterior teeth alignment of Korean adults. Eighty three dental models which possess proper occlusion and good arch form were selected and copies of their occlusal surfaces obtained by Ricopy machine. The use of Ricopy machine made it possible to draw arch form exactly. Mesiodistal widths of six anterior teeth were measured and they were added to combined mesiodistal width of six anterior teeth. Circle, that include the points of two cuspal tips of canines and one incisal edge of central incisor were drawn. Distances of lateral incisors that are deviated from arc of this circle were measured and classified into four grades by degree and three groups by kind of teeth deviated. By counting the number of samples involved degree of fit of the circle to arch contour of Korean adult was described. Then, size of radius of circle, intercanine width and intermolar width were measured and evaluated their ratios to combined mesiodistal width of six anterior teeth. In normal occlusion of Korean adult anterior teeth seems to be arranged on an arc of circle the radius of which is similar to combined mesiodistal width of six anterior teeth. Intercanine width and intermolar width have rather constant ratios to combined width of six anterior teeth.

• The korean journal of orthodontics
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• v.45 no.2
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• pp.74-81
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• 2015

Objective: The purposes of this study were 1) to classify lingual dental arch form types based on the lingual bracket points and 2) to provide a new lingual arch form template based on this classification for clinical application through the analysis of three-dimensional virtual models of normal occlusion sample. Methods: Maxillary and mandibular casts of 115 young adults with normal occlusion were scanned in their occluded positions and lingual bracket points were digitized on the virtual models by using Rapidform 2006 software. Sixty-eight cases (dataset 1) were used in K-means cluster analysis to classify arch forms with intercanine, interpremolar and intermolar widths and width/depth ratios as determinants. The best-fit curves of the mean arch forms were generated. The remaining cases (dataset 2) were mapped into the obtained clusters and a multivariate test was performed to assess the differences between the clusters. Results: Four-cluster classification demonstrated maximum inter-cluster distance. Wide, narrow, tapering, and ovoid types were described according to the intercanine and intermolar widths and their best-fit curves were depicted. No significant differences in arch depths existed among the clusters. Strong to moderate correlations were found between maxillary and mandibular arch widths. Conclusions: Lingual arch forms have been classified into 4 types based on their anterior and posterior dimensions. A template of the 4 arch forms has been depicted. Three-dimensional analysis of the lingual bracket points provides more accurate identification of arch form and, consequently, archwire selection.

• The korean journal of orthodontics
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• v.32 no.1 s.90
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• pp.43-49
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• 2002

When we deal with maxillary and mandibular anterior dental arches showing problems in occlusal relation and aesthetics caused by malformations of teeth and congenital missing, et al during the orthodontic treatment, we could not often decide the functional occlusion by only relying on the orthodontic treatment. If orthodontists can predict what kinds of treatments are needed for functional occlusion in maxillary and mandibular anterior dental arches, they can not only effectively treat patients but also facilitate the cooperation with other field during the treatment, Our previous research showed the correlation among intercanine width, segment depth and arch perimeter by using the Korean normal occlusion model. At this time, we produced the computer application program by taking advantage of this correlation. And then, we applied this program to setting up the treatment plans for 2 patients with the damaged maxillary and mandibular dentures. With the help of this program, we could not only easily acquire the information about the change of variables required by treatment plans but also intercanine width, segment depth and arch perimeter. Later, if we can the information about the relationship between the change of the angle of incisors depending on facial types and arch forms and, in addition, can acquire the appropriate intercanine width, we can have the ability to produce the 3 dimensional occlusogram for the anterior dental arch forms.

• The Journal of the Korean dental association
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• v.53 no.7
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• pp.450-456
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• 2015

Even the adult cleft lip and palate patient who has not had timely treatment during the growth period, can be treated with orthodontic treatment without the necessity of orthognathic surgery if only the patient is treated under correct diagnosis and fitting appliances. Initially, maxillary arch form is established by constructing trifocal circles. Posterior region can be expanded and derotated laterally with pentahelix and anterior teeth are aligned with Tiggle brackets and "ㄷ"-shaped spring. Thereafter, anterior and posterior regions are consolidated. Mandibular intercanine width should be adjusted to maxillary intercanine width which was unavoidably reduced. Mandibular anterior tooth extraction will be helpful to attain proper mandibular intercanine width and better anterior dental showing.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.2
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• pp.235-248
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• 1994

There were many studies that distribute the partial edentulous states and examine the removable partial denture designs in the planning of removable partial denture treatment. This study was performed in the point of removable partial denture prescription to evaluate partial edentulism and its removable partial denture designs. The data was collected from the dental laboratory of each three dental colleges in Seoul and from two dental laboratories only for removable partial dentures as a prescription form. A total of 1411 cases with prescription form collected from dental laboratories were distributed for this study, then 788 cases were selected for this study. The case selection was done according to the contents of prescription form. The selected cases were divided into maxillary arch and mandibular and classified in terms of types of major connector and direct retainer, unbroken anterior teeth, Kennedy classification, the number of remaining teeth, and distribution of age and sex. The analyzed results were as follows : 1. The Kennedy classification I showed highest frequency both in maxilla and mandible. 2. The arch distribution of removable partial denture was 50.08% for maxilla and 49.92% for mandible. 3. The highest frequency in the distribution of direct retainer was the RPA clasp design. 4. The frequency of unbroken anterior 6 was 73.36% for maxilla and 82.30% for mandible. 5. The design of broad palatal strap and lingual bar revealed the highest prevalence in the major connector construction. 6. The mean number of remaining teeth per arch was 8.25 for maxilla and 8.37 for mandible. 7. The mean age of the patients supplied with removable partial denture was 52.25 years for men, 51.68 years for women, 52.11 years for maxilla, and 51.76 years for mandible and women showed more prevalence.