• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.179-188
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• 2009

Aim of this study is to examine correlation between size of the coronal pulp cavity and chronological age in adult. Total 716 teeth (218 mandibular canines, 230 first premolars, 268 second premolars) free from pathologies and dental restorations were selected from 276 patients (111 males, 165 females), ranging from 20-69 years. Using periapical X-ray, the height (mm) of the crown (CH=coronal height) and the height (mm) of the coronal pulp cavity (CPCH=coronal pulp cavity height) of the teeth were measured. The tooth-coronal index (TCI) after Ikeda et al (Jpn. J. For. Med. 1985;39:244-250) was computed for each tooth and regressed on real age. With increasing age, the TCI was relatively decreased, indicating the reduction of length of the pulp chamber. Even reduction of the TCI with aging was found in combined group rather than in each sex and type of tooth separately. The most definite reduction was in canine of combined group. The correlation coefficient was strongest when measurement from canines of females (r2=0.247).

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.235-245
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• 1995

The purpose of this paper is to review two recently reported, long-term studies of several chemical methods to control gingivitis and decalcification in adolescent orthodontic patients. The first study(gingivitis study) was designed to determine whether conventional toothbrushing and twice daily use of a brush-on 0.4 per cent $SnF_2$ gel containing more than 90 per cent available $Sn^{2+}$ would be more effective for controlling plaque accumulation and gingivitis in the presence of orthodontic appliances than conventional toothbrushing alone. The second study(decalcification study) was designed to compare the effectiveness of controlling decalcification in orthodontic patients with either a II00 ppm F tooth paste used alone, this same toothpaste and a 0.05 percent NaF rinse or this toothpaste and a 0.4 percent $SnF_2$ gel. In the gingivitis study, sixty-five consecutively treated adolescents who were to receive full-mouth fixed orthodontic appliances were assigned to two groups according to age and sex criteria. In the decalcification study an additional 30 subjects(95 total) were similarly assigned to a third group. The first group(control, n=35) used only toothbrushing with a standard fluoride(1100 ppm F) toothpaste. The second group used toothbrushing with a similar dentifrice supplemented with a 0.4 percent $SnF_2$ gel($SnF_2$ gel group, n=30) used twice daily for the entire 18-month study period. The third group(in the decalcification study only) used a similar toothpaste and 0.05 percent NaF rinse(NgF rinse group, n=30). Clinical assessments of plaque accumulation using the Plaque Index, gingival inflammation using the Gingival Index, and coronal staining were completed single-blinded before appliances were placed and 1, 3, 6, 9, 12 and 18 months after appliances were placed. Decalcification was assessed single blind on all labial surfaces of all erupted teeth before appliances were placed and 3 months after appliances were removed. The results of the gingivitis study indicated that the $SnF_2$ gel gorup had significantly lower scores for the Plaque Index(p<0.01) and Gingival Index(p<0.001) at all examinations during orthodontic treatment than did the control group. In the $SnF_2$ gel group, one subject developed mild coronal staining and two subjects developed moderate staining. In the decalcification study, when pre-treatment levels of decalcification were subtracted from post-treatment values, significantly lower decalcification scores(p<0.05) were found for both whole mouth and first molars in the NaF rinse and gel groups as compared with the control gorup(toothpaste alone). Although the gel group consistently had less decalcification than the rinse group, this difference only approached statistical significance.

• Journal of Oral Medicine and Pain
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• v.39 no.2
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• pp.69-77
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• 2014

Purpose: It aims to verify the applicability of existing age estimation methods derived from data of foreign population groups to Korean population groups. Moreover it is to suggest a new way applicable to practical age estimation on the basis of newly calculated regression formulae from data of Korean population groups and develop a subsidiarily applicable method to the existing method. Methods: Ratio of pulp cavity to dental crown was calculated by measuring the height and width of dental crowns and pulp cavities at the cervical line from 4,034 first and second upper molars, first and second upper premolars, first and second lower molars and first and second lower premolars on both left and right sides of 400 patients who had been treated in Dental Hospital of Yonsei University College of Dentistry, and regression equations were derived from the values of the ratio. Results: The equation with correlation coefficients the highest among females was as follows: age=$107.96-75.684{\times}{\sharp}17$ TCHI-$53.741{\times}{\sharp}26$ TCVI-$40.664{\times}{\sharp}45$ TCVI-$56.307{\times}{\sharp}46$ TCVI. Randomized anohter Korean female subjects (n=20) are applicated to the new equation. Mean of error of estimate is 10.322 years, standard deviation is 12.852 years. Minimum of error of estimate is 1.018 years, maximum is 21.365 years Conclusions: The error range of age estimation was found to be slightly wider when the existing regression formulae of Drusini were applied to Korean population groups. Also age estimation in females using the ratio of pulp cavity to dental crown measured with the length and width of dental crowns and pulp cavities from maxillomandibular molars was observed to have the highest reliability in the research. However, we consider that advanced equations of regression are needed to apply to both molars and premolars of males and females in the future.