• Journal of dental hygiene science
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• v.13 no.2
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• pp.197-202
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• 2013

The purpose of this study was to examine the relationship between the physique of 147 dental hygiene students and the size of their dental arch. A survey was conducted, and impression taking was carried out at the same time to measure the arch length and width of the students. The findings of the study were as follows: 1. 74.8 percent of the students got a dental checkup over the past year. 86.4 percent breathed through the nose. 18.4 percent had ever received orthodontic treatment, and 49.7 percent had ever had their tooth extracted. 94.6 percent were fond of refined food, and 52.4 percent had a liking for hard food. 2. There were no statistically significant differences in arch length and width according to all the variables that related the size of dental arch. 3. Out of the physique variables, weight was identified as a variable to make a statistically significant difference to arch length and width. A heavier weight led to larger mandibular inter-canine width and larger maxillary inter-molar width. 4, A heavier weight had a weaker positive correlation to inter-canine width and inter-molar width. Arch length and width were most closely linked to maxillary inter-molar width and mandibular inter-molar width. The above-mentioned findings show that weight exerted an influence on the form of dental arch among the physique variables. In the future, sustained research efforts should be made to keep track of the relationship between the change of physique and the change of dental arch to improve the stability of occlusion and promote oral health.

• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.65-72
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• 2007

Objective: This study was performed to investigate the influences of extraction and nonextraction treatment on smile esthetics by measuring dental arch width changes. Methods: Pretreatment and posttreatment study models of 30 first premolar extraction cases and 30 nonextraction cases were randomly selected to determine whether extraction treatment results in narrow dental arches, and a consequent unaesthetic smile. Arch widths were measured from the cusp tips of the canines and the first molars. Posterior arch widths were also measured at a constant arch depth derived by averaging randomly chosen nonextraction models. Results: The intercanine widths increased significantly in the extraction sample, whereas the intermolar widths decreased significantly. The arch width at a standardized arch depth was significantly wider in the extraction subjects. Conclusion: These results elucidate that constriction in arch width is not a materialized consequence of extraction treatment. It leads to postulate that an esthetically compromising effect from narrow dental arches on smile is hardly anticipated with extraction treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.510-521
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• 2006

This investigation was undertaken to examine the extent to which tooth size and arch dimension each contribute to dental crowding. The sample included 50 subjects with well aligned dentition (25 males, 25 females) and those of 40 subjects with gross dental crowding(20 males, 20 females). Plaster model and digital model made from alginate impression taken at the one visit. Tooth size, arch length, arch perimeter, intercanine width and intermolar width was measured on the plaster and digital models. The findings in this study lead to the following conclusions. 1. In maxilla, the mesiodistal diameters of lateral incisor and premolars of the crowded group were significantly larger than those of the normal occlusion group (P<0.05). 2. In mandible, the mesiodistal diameters of central incisor, canine and premolars of crowded group were significantly larger than those of the normal occlusion group (P<0.05). 3. In maxilla, arch perimeter and intermolar width of crowded group were significantly smaller than normal occlusion group but intercanine width of crowded group were larger than normal occlusion group (P<0.05). There was no significantly difference in arch length (P>0.05). 4. In mandible, arch perimeter of crowded group was smaller than normal occlusion group(P<0.05). There were no difference in arch length intermolar width and intercanine width (P>0.05) 5. In the analysis of correlation coefficients of arch length discrepancy with variables, arch perimeter, intermolar width and mesiodistal width of 2nd premolar showed positive correlations in maxilla. 6. There was a significant difference between tooth width measurements made by the 2 methods, with all the digital model measurement larger than plaster model measurements (P<0.05) : the magnitude of the differences does not appear to be clinically relevant. 7. In the analysis for reproducibility, the plaster model measurement was showed lower degree of correlation between 1st and 2nd measurement than digital model.

• The korean journal of orthodontics
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• v.33 no.1 s.96
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• pp.41-49
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• 2003

This study examined the relations between degree of posterior dental compensation and skeletal discrepancy in Class III malocclusion. The pretreatment lateral cephalogras and dental casts of 87 skeletal Class III adults were selected to provide a random sampling of skeletal Class III malocclusion. Skeletal discrepancy was described with ANB angle, Wits appraisal, SN-Mn plane angle, FMA and ratios of basal arch width. Degree of posterior dental compensation was described with maxillary intermolar angle, mandibular interolar angle and sum of intermoloar angle. The relationships between skeletal discrepancy and degree of posterior dental compensation were analyzed with simple correlation analysis, stepwise multiple regression analysis. The results were as follows 1. A strong association was found between the variation in the anteroposterior measure, ANB angle and the variation of posterior dental compensation measures, sum of intermolar angle and mandibular intermolar angle in skeletal Class III malocclusion. 2. There was no statistically significant relationship between the variation in the vertical measures and the variation of posterior dental compensation measures in skeletal Class III malocclusion. 3. There was no statistically significant relationship between the variation in the anteroposterior and vortical measures and degree of basal arch width discrepancy.

• The korean journal of orthodontics
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• v.26 no.3
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• pp.225-239
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• 1996

This study was carried out as a part of the semi-longitudinal study on growth and development of Korean children, with purpose of observing the growth change in arch form., 736 pairs, of study models were taken for 3 years. Mesio-distal diameter of each tooth, intercanine width, intermolar width, canine arch depth, molar arch depth and arch perimeters were measured. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and corresponding graphs were drawn. The following conclusions were obtained : 1. Mesio-distal diameters of maxillary central incisor, maxillary 2nd molar, mandibular canine, and mandibular 2nd molar showed statistical difierences between boys and girls. 2. Intercanine width shows a gradual increase until age of 11. 3. Intermolar width in maxilla shows continuous increase, and the tendency of increase is more apparent between age of 9 and 14. In mandible, various pattern was shown until age of 9, and after, a slight increase. 4. Canine arch depth shows the increasing tendency until age of 13 in maxilla and 11 in mandible. 5. Molar arch depth shows the pattern of increase until age of 10 in male and 9 in female, which is more apparent in maxilla. After age of 9 or 10,dereasing pattrn was significantly shown until age of 15 in maxilla and age of 12 in mandible. 6. Arch perimeters in maxilla and mandible showed gradual increase until age of 10, and the tendency of increase was more apparent in maxilla; however, between the age of 10 and 14, arch perimeters of maxilla and mandible showed gradual decrease which was more apparent in mandible.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.17-27
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• 1998

Study on growth change of dental arch is considered to both an important data in orthodontic diagonsis and treatment planning as well as analysis of treatment results , also, arch form is important in anthropology and dentistry, even more so in prosthodontics and orthodontics. In the field of orthodontics, studies on the functional aspect of upper and lower teeth and maintenance of stability of dentition and occlusion were carried out from the early days. Some of the early studies include explanation of growth change in dental arch from measuring directly fom human stroll, and afterwards, cephalometrics x-rays were introduced; accordingly, studies using cephalometric measurement and linear measurements of study models were often performed. By this method, arch width, arch depth and perimeters were measured, and growth change or dental arch was studied. The subject ror this study were sn children(boys and girls or ages from 3 yens to 12 years from Kang-won district and Seoul, who has no history of orthodontic treatment and who show healthy status and normal growth and development. Cephalometric x-ray, panoramic x-ray, and study model were taken for each subject consecutively for 2 years, and the subjects are still followed up. 400 pairs of study models from the past two years were used in this study; mesio-distal diameater of each tooth, intercanine width, intermolar width, canine depth, molar depth and arch perimeters were measured. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and representation graph were drawn. The following conclusion were obtained. 1. Intercanine width showed gradual increase until the age of 10-years and after that, showed no increase. 2. Intermolar width in upper arch showed gradual increase : intermolar width in lower arch showed no significant chang, and after the age of 9-years, showed increase. 3. Cainine arch depth showed relatively rapid increase after the age of 6-years, and this pattern was more obvious in lower arch. 4. Molar arch depth increased gradually in both archs and it decrease after the age of 10-years : this phenomenon was more prominent in the lower arch. 5. Arch perimeter showed gradual inerease and convert to plateau at the age of 10-years, after that, it decreased. this pattern was more prominent in lower arch.

• The korean journal of orthodontics
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• v.36 no.1 s.114
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• pp.84-90
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• 2006

The aims of this study were to investigate the prevalence of spaced, closed, and crowded primary dentitions by sex and arch in Korean children from Kanghwa, and to determine the frequency of the primate and developmental spaces. The differences in the mesiodistal crown diameters and the arch dimensions between the spaced, closed, and crowded primary dentitions were also evaluated. Dental casts of 102 preschool children (57 males and 45 females, aged $4{\sim}5$ years) were studied. The prevalence of spacing in the primary dentition was 63.2% In males and 57.8% in females. The frequency of spacing was greater in males than in females, and greater in the maxillary arch than in the mandibular arch. The crowns were significantly larger and the arches significantly narrower in closed and crowded dentitions than in those with spacing (p<0.05). The results showed that the prevalence of spacing was lower than that found in previous studies and the presence of spacing in the anterior region was related to the mesiodistal crown diameter and the intercanine width.

• The korean journal of orthodontics
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• v.36 no.1 s.114
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• pp.45-54
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• 2006

Recent beauty trends have caused an increase in the number of bialveolar protrusion patients seeking treatment of lip protrusion. But studies of these patients are not common. Studies using their dental models are especially rare. Dental models have been measured manually or through a computer by digitizing two dimensional images of models. Nowadays, we are able to study dental models more easily and accurately by utilizing the three-dimensional (3-D) laser scanner in dentistry. An investigation was carried out to evaluate the characteristics of the dental arch in a bialveolar protrusion group in comparison with a normal group using 3-D digital models. The normal group was composed of 20 subjects who were selected from students of the School of Dentistry, Kyungpook National University. The bialveolar protrusion group was composed of 20 subjects who visited for treatment at the Department of Orthodontics, Kyungpook National University Hospital. Tooth size, arch width and arch length were measured digitally, and arch shape and the shape of the palate were drawn. Based on the results of this study, the differences of the arch characteristics in the bialveolar protrusion group were that the size of the teeth was larger, mandibular canine width and 1st premolar width were wider, and arch length was longer than in the normal group. And there were differences in the arch shape and the shape of palate between the bialveolar protrusion and normal groups.

• The korean journal of orthodontics
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• v.29 no.4 s.75
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• pp.425-433
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• 1999

Dr. Youn-Sic Chun and coworkers invented the new machine for getting information about the relative effectiveness of the orthodontic appliances and we named it Calorific machine. The author and colleagues used this machine to compare with tooth moving mechanism by 3 types of the insertion method of precision-TPA for derotating the posterior teeth. We measured the distance of tooth movement and found out the rotational center on the occlusal X-ray film and the tooth movement on the occlusogram and then processed paired t-test by SAS program, The results were as follows : 1. In the intermolar width, the mesial insertion method showed the loss oi distance, and the other methods(-distal insertion method, mesial expansion method-) showed the increase of distance. 2. In the arch length, the distal insertion method was exhibited as most recommandable way for increasing the arch length .3. The rotation center of the mesial insertion method for derotating the molar, was located between mesial pit and central pit of the lower End molar. And, in the distal insertion method, it was located between distal pit and distolingual cusp, and in the mesial expansion method was located at distal pit.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.2
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• pp.234-240
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• 2022

Floating-Harbor syndrome (FHS) is a rare genetic disorder. This report introduced in a patient with FHS. Distinctive facial characteristics, severe skeletal class 3 malocclusion with underdeveloped maxilla and protruded mandible, congenital missing teeth, microdontia and ectopic positions of maxillary teeth were presented in the patient. In his twin sister, mild skeletal class 3 malocclusion with protruded mandible was observed but congenital missing teeth and microdontia were not observed. High-arched palate, narrow V-shaped maxillary arch compared to wide and ovoid mandibular arch and inverse relationship between the maxillary and mandibular intermolar width resulted in posterior crossbite were confirmed by model analysis of the patient. These were not observed in the twins. Behaviorally, poor cooperation during dental treatment because of mental retardation was observed in the patient.