• The korean journal of orthodontics
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• v.47 no.1
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• pp.21-30
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• 2017

Objective: The aim of this study was to investigate the three-dimensional (3D) position of the center of resistance of 4 mandibular anterior teeth, 6 mandibular anterior teeth, and the complete mandibular dentition by using 3D finite-element analysis. Methods: Finite-element models included the complete mandibular dentition, periodontal ligament, and alveolar bone. The crowns of teeth in each group were fixed with buccal and lingual arch wires and lingual splint wires to minimize individual tooth movement and to evenly disperse the forces onto the teeth. Each group of teeth was subdivided into 0.5-mm intervals horizontally and vertically, and a force of 200 g was applied on each group. The center of resistance was defined as the point where the applied force induced parallel movement. Results: The center of resistance of the 4 mandibular anterior teeth group was 13.0 mm apical and 6.0 mm posterior, that of the 6 mandibular anterior teeth group was 13.5 mm apical and 8.5 mm posterior, and that of the complete mandibular dentition group was 13.5 mm apical and 25.0 mm posterior to the incisal edge of the mandibular central incisors. Conclusions: Finite-element analysis was useful in determining the 3D position of the center of resistance of the 4 mandibular anterior teeth group, 6 mandibular anterior teeth group, and complete mandibular dentition group.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.498-505
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• 2007

Management options for impacted maxillary canines can include (1) continued observation, (2) extraction of the primary canine to aid spontaneous eruption, (3) uncovering and bonding of the impacted tooth and its eruption using orthodontic traction, (4) autotransplantation, and (5) extraction followed by prosthetic replacement. Autotransplantation should be considered when the degree of malposition is too severe to correct by orthodontic alignment. The present report describes the management of an ectopic eruption of the left maxillary canine in an 10-year-old girl. The treatment included the extraction of primary maxillary left canine and the autotransplantation using a Rapid Prototyping model. By using RP model to contour the recipient bone and check for fitting in the prepared socket, the extra-oral time can reduce. The autotransplanted canine showed mobility within normal limit, negative response to percussion and positive to electric pulp test after 6 months.

• Korean Journal of Community Nutrition
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• v.13 no.5
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• pp.620-629
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• 2008

The purpose of this study was to assess dietary habits and seasonal variation and diversity of food intakes of elderly women living alone as compared to those of elderly women living with family in a rural area. Forty nine elderly women living alone and forty one elderly women living with family who reside in Goryeong-gun, Gyeongbuk, were interviewed using questionnaires in summer 2005, and their food intakes were assessed secondly in winter and thirdly in spring 2006. The average ages were 74.7 years for elderly living alone and 72.8 years for elderly living with family. Tooth status and bone fracture experience were similar between the groups. The prevalence of musculoskeletal disease was 61.2% and that of circulatory disease was 32.7% of the subjects. Average of total score of mental depression of the subjects was 5.94 out of 12 points, and it was not significantly different between the two groups. Skipping meals was more frequent and mealtime was more irregular in the elderly women living alone as compared with the elderly women living with family. Consumption of dietary supplements was also less in the elderly women living alone. Food intakes by the elderly women living alone tended to be lower than those by the elderly women living with family. Dietary diversity score was significantly lower with the elderly women living alone as compared with the elderly women living with family only in summer (p < 0.01). Percentages of the subjects who have taken meat group and vegetable group were significantly lower in the elderly living alone compared with the elderly living with family during summer. Therefore, it is necessary to develop food assistance or supporting program suited for the season within a community for elderly women living alone.

• Restorative Dentistry and Endodontics
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• v.36 no.3
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• pp.238-242
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• 2011

Objectives: Palatogingival groove is a developmental anomaly that starts near the cingulum of the tooth and runs down the cementoenamel junction in apical direction, terminating at various depths along the roots. While frequently associated with periodontal pockets and bone loss, pulpal necrosis of these teeth may precipitate a combined endodontic-periodontal lesion. This case presents a case of a lateral incisor anatomically complicated with palatogingival groove. Methods: Two patients with lesion associated with the palatogingival groove were chosen for this report. Palatogingival grooves were treated with different restoration materials with endodontic treatment. Conclusions: Maxillary lateral incisor with a palatogingival groove may occur the periodontal disease with pulpal involvement. Elimination of groove may facilitate the periodontal re-attachment and prevent the recurrence.

• The korean journal of orthodontics
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• v.17 no.1
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• pp.135-148
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• 1987

To investigate the relationship between craniofacial growth and bone maturity of the hand wrist in normal occlusion, the author took cephalogram and handwrist radiogram of 391 students (male 192, female 199) and assessed the measurements of cephalogram according to skeletal maturity stages of the hand and wrist. In this study, four skeketal stages and 36 linear, angular measurements of the cephalometrics were selected. In hand-wrist X-ray the bones used to determine skeletal maturity were the middle phalanges of the third finger, and distal epiphysis of the radius. In cephalogram, the landmark used to measure the angle and length were N, S, Po., Ar., Go., Me., Gn., Pog., Point B, Point A, ANS, PNS, Or., U1, L1, U6, L6 etc.. The results were as follows, 1. The table of mean, standard deviation, p-value from measurements were made in each group and both sex. 2. The increased measurements according to skeletal maturity were anterior cranial bese length, posterior cranial base length, ramus height, anterior facial height, posterior facial height, L1 to mandibular plane (mm), facial plane angle. In contrast to, decreased measurements were genial angle, facial cnvexity and facial plane angle. 3. Denture pattern measurements (IMPA, FMIA, occlusal plane to Go-Gn, interincisal angle, U1 to SN plane, U1 to SN plane, U1 to facial plane, L1 to facial plane etc.) .had nothing to do with skeletal maturity. 4. Skeletal maturity had close relationship with craniofacial growth, but had little to do with tooth development.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.367-375
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• 2004

As the periodontal ligament cells show similar phenotype with osteoblasts, periodontal ligament cells are thought to play an important role in alveolar bone remodeling. According to recent studies, receptor activation of nuclear factor $^{\kappa}B$ ligand (RANKL) and osteoprotegerin (OPG) are expressed in periodontal ligament cells during tooth movement. Also periodontal ligament cells is known to play an important role in the progression of periodontal disease. This study was designed how the expression of RANKL and OPG in periodontal ligament cells was regulated by IL-1 ${\beta}in$ the concentration of $0.01{\sim}10$ ng/ml. The results are as follows; 1. Periodontal ligament cells which stimulated by 1L-1 ${\beta}$ increased soluble RANKL synthesis by dose-dependent pattern in the concentration of $0.01{\sim}10$ ng/ml. 2. 1L-1 ${\beta}$ induced mRANKL expression in dose-dependent manner in the concentration of $0.01{\sim}5$ ng/ml. 3. mOPG expression was not to be influenced by 1L-1 ${\beta}$. These results suggested that rat periodontal ligament cells could regulate osteoclastogenesis by stimulation of production of RANKL.

• The Journal of Advanced Prosthodontics
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• v.5 no.3
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• pp.351-358
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• 2013

PURPOSE. This retrospective study analyzed the distribution of the dental implants with regards to age and gender of the patients and type of indication for the implant therapy, as well as the location, dimension and type of the implants. MATERIALS AND METHODS. The data of demographics (age and gender), type of indication for implant therapy, anatomical location, dimensions (length and diameter) and type (bone and tissue level) of 1616 implants were recorded from patient charts between January 2000 and January 2010. Descriptive statistics were analyzed using a chi-squared test for demographic parameters, type of indication, tooth position, anatomical location, implant dimensions and type (${\alpha}$=.05). RESULTS. The patient pool comprised of 350 women and 266 men, with a mean age of $52.12{\pm}13.79$ years. The difference in n% of the implants of the age groups was statistically significant between the types of indications. The difference in the position of the implants was statistically significant between the n% of the implants of all age groups. Gender did not significantly vary, except that the diameter of the implants was significantly higher for the standard diameter implants in males. The difference between the implant positions was statistically significant when considered according to indication. The relationship between implant length and anatomical location was statistically significant. CONCLUSION. The indication for dental implant use is age dependent and the type and size of the implant seems to be strongly related to the location of the implant.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.1
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• pp.49-57
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• 2006

Mandibular fractures have higher incidence rate compared to facial bone fractures because of relatively prominent form. Specially, mandibular angle fractures were known as common fracture site because of morphological anatomic structure. The mandibular third molar appears to be the most frequent impacted tooth. The mandibular third molar have influence on mandibular angle fractures according to it's eruption state. Also, the mandibular angle fracture including the third molar may influence on post operative infection whether the third molar is in impacted or extracted state when reduction of fracture site is operated. The presence or absence and degree of impaction of the mandibular third molar were assessed for each patient and were related to the occurrence of the mandibular angle fracture. The extraction or non extraction of the mandibular third molar were related to the occurrence of the post operative infection in the reduction of mandibular angle fractures. In the presence of mandibular third molar, the possibility of mandibular angle fractures were relatively common. When viewing the mandibular third molar at occlusal plane, the possibility of mandibular angle fractures were high in the class C group. The possibility of mandibular angle fractures were high in the mesial angulation and partial impaction. There was a statistically significant difference(P<0.05). In complete erupted mandibular third molar, the possibility of post operative infection occurs quite often, but there was no statistical significant difference(P>0.05). In the extracted or non extracted of mandibular third molar, the post operative infection showed no statistical significant difference(P>0.05). With the results mentioned above, mandibular third molar was significantly more susceptible to mandibular angle fracture. In the reduction of mandibular angle fracture, it was recommended that mandibular third molar should be extracted especially in case of pericoronitis, periodontitis and other infections.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.3
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• pp.236-241
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• 2010

Purpose: The purpose of this retrospective clinical study was to monitor the outcomes of periapical surgery in periapically infected tooth with or without retrograde filling materials (MTA or IRM). Patients and Methods: A total of 85 teeth in 63 patients were included in the study between November 2004 and August 2008. Randomly, MTA or IRM was used as a retrograde filling material or only apical resection without retrograde filling. Teeth with advanced periodontal bone loss or presence of root fracture were excluded from the study. The patients were subjected to a minimum follow-up period of 12 months, with a mean of 17.1 months. Results: Successful healing was observed in 83.3% of the MTA-treated teeth, 80% of the IRM-treated teeth and 75% of the teeth which was not retrograde filling. Doubtful healing was seen 9.3% (MTA), 13.3% (IRM), 12.5% (no retro-filling). The success rate of upper incisors (92%) was higher than lower lincisor and molars (66.7% and 50%, respectively). Conclusion: In this study, periapical surgery including retrograde filling improves the prognosis. And, no statistically significant differences were found between retrograde filling materials (MTA or IRM).

• Journal of the Korean Academy of Esthetic Dentistry
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• v.10 no.1
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• pp.30-45
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• 2001

In recent years, clinicians' and dentists' esthetic demands in dentistry have increased rapidly. The ultimate goal in modern restorative dentistry is to achieve "white" and "pink" esthetics in the esthetically important zones. Therefore, modern esthetic dentistry involves not only the restoration of lost teeth and their associated hard tissues, but increasingly the management and reconstruction of the encasing gingiva with adequate surgical techniques. Interdental space are filled by interdental papilla in the healthy gingiva, preventing plaque deposition and protecting periodontal tissue from infection. This also inhibits impaction of food remnants and whistling through the teeth during speech. These functional aspects are obviously important, but esthetic aspects are important as well. Complete and predictable restoration of lost interdental papillae remains one of the biggest challenges in periodontal reconstructive surgery. One of the most challenging and least predictable problems is the reconstruction of the lost interdental papilla. The interdental papilla, as a structure with minor blood supply, was left more or less untouched by clinicians. Most of the reconstructive techniques to rebuild lost interdental papillae focus on the maxillary anterior region, where esthetic defects appear interproximally as "black triangle". Causes for interdental tissue loss are, for example, commom periodontal diseases, tooth extraction, excessive surgical periodontal treatment, and localized progressive gingiva and periodontal diseases. If an interdental papilla is absent because of a diastema, orthodontic closure is the treatment of choice. "Creeping" papilla formation has been described by closing the interdental space and creating a contact area. In certain cases this formation can also be achieved with appropriate restorative techniques and alteration of the mesial contours of the adjacent teeth. The presence of an interdental papilla depends on the distance between the crest of bone and the interproximal contact point, allowing it to fill interdental spaces with soft tissue by altering the mesial contours of the adjacent teeth and positioning the contact point more apically. The interdental tissue can also be conditioned with the use of provisional crowns prior to the definitive restoration. If all other procedures are contraindicated or fail, prosthetic solutions have to be considered as the last possibility to rebuild lost interdental papillae. Interdental spaces can be filled using pink-colored resin or porcelain, and the use of a removable gingival mask might be the last opportunity to hide severe tissue defects.