• Imaging Science in Dentistry
• /
• v.48 no.3
• /
• pp.201-212
• /
• 2018

Purpose: The aim of this study was to compare cone-beam computed tomography (CBCT) and digital panoramic radiography (DPR) for the detection of pulp stones. Materials and Methods: DPR and CBCT images of 202 patients were randomly selected from the database of our department. All teeth were evaluated in sagittal, axial, and coronal sections in CBCT images. The systemic condition of patients, the presence of pulp stones, the location of the tooth, the group of teeth, and the presence and depth of caries and restorations were recorded. The presence of pulp stones in molar teeth was compared between DPR and CBCT images. Results: Pulp stones were identified in 105 (52.0%) of the 202 subjects and in 434 (7.7%) of the 5,656 teeth examined. The prevalence of pulp stones was similar between the sexes and across various tooth locations and groups of teeth (P>.05). A positive correlation was observed between age and the number of pulp stones(${\rho}=0.277$, P<.01). Pulp stones were found significantly more often in restored or carious teeth (P<.001). CBCT and DPR showed a significant difference in the detection of pulp stones(P<.001), which were seen more often on DPR than on CBCT. Conclusion: DPR, as a 2D imaging system, has inherent limitations leading to the misinterpretation of pulp stones. Restored and carious teeth should be carefully examined for the presence of pulp stones. CBCT imaging is recommended for a definitive assessment in cases where there is a suspicion of a pulp stone on DPR.

• Journal of Periodontal and Implant Science
• /
• v.32 no.1
• /
• pp.51-59
• /
• 2002

The aim of the present study was to investigate the distribution of periodontally hopeless teeth in patients who had not been treated. Five hundred nineteen teeth of 163 patients who had visited at the Department of Periodontology, Chonbuk National University Hospital during the period from January 1999 to July 2001 were selected as a periodontally hopeless tooth. Selection criteria were as follows: 1) probing pocket depth more than 8mm, 2) tooth mobility of degree III, 3) radiographic bone loss more than 75%. The contralateral tooth to a hopeless tooth (experimental tooth) was designated as a control tooth. Between the experimental and control tooth, differences in probing pocket depth, tooth mobility and amount of radiographic bone loss were examined as well as correlation. The results showed that hopeless teeth were most frequently found in the maxillary first molar position and least frequently in the maxillary canine position. Differences between experimental and control teeth were 2mm in probing depth, 1 degree in tooth mobility, and 20% in amount of bone loss (p<0.01). The periodontal conditions between the experimental and control teeth showed correlation in general, however, statistical significances were found in posterior teeth positions. Within limitations of this study, it can be concluded that local factors may play a role in deterioration of periodontal disease along with symmetrical character of periodontal disease.

• The korean journal of orthodontics
• /
• v.26 no.1 s.54
• /
• pp.105-111
• /
• 1996

Most of orthodontic cases are treated with extraction of certain teeth, which influence the pre-eruptive movement of the lower third molar The purpose of this study was to evaluate the positional change of lower third molar following orthodontic treatment. Pre- and post-treatment pantomograms of 163 orthodontic patients (77 nonextraction group, 78 first premolar- extraction group, 8 second molar- extraction group) were analyzed in terms of the mesiodistal and buccolingual angles of lower third molar. The results were as follows. 1. The change of the mesiodistal angle of lower third molar by orthodontic treatment was significant in second molar-extraction group. 2. The mesiodistal angle of lower third molar in pre-treatment was significantly correlated to the mesiodistal angle in post-treatment and/or the change of the mesiodistal angle by treatment. 3. The change of the buccolingual angle of lower third molar by orthodontic treatment was significant in non -extraction group or first premolar-extrction group. 4. The change of the buccolingual angle of lower third molar by treatment was significantly correlated to the mesiodistal angle in post-treatment, the change of the mesiodistal angle by treatment, the buccolingual angle in pre-treatment or the buccolingual angle in post-treatment.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.43 no.1
• /
• pp.1-7
• /
• 2016

The developmental age of permanent teeth was evaluated in children and adolescents according to age and gender using the Nolla Method. A retrospective study was performed on panoramic radiographs of 1,200 subjects aged 4-15 years, including 50 children for each age/gender group. Three well-trained examiners estimated the developmental stage of upper and lower permanent teeth using the Nolla Method. The inter-examiner reliability was excellent (intra-class correlation coefficient value = 0.973). The mean developmental age was calculated. In boys, Nolla stage 6, indicated by crown completion, was seen in the central incisor, lateral incisor, canine, first premolar, second premolar, first molar, and second molar at 5.4, 6.4, 6.7, 7.5, 7.8, 4.6, and 8.1 years, respectively, in the maxilla and at 4.8, 5.1, 6.0, 6.5, 7.2, 4.5, and 8.0 years, respectively, in the mandible. In girls, Nolla stage 6 was seen at 5.3, 6.0, 6.3, 7.3, 7.7, 4.8, and 8.1 years, respectively, in the maxilla and at 4.8, 5.1, 5.9, 6.5, 7.2, 5.0, and 7.9 years, respectively, in the mandible. In this study, the developmental age of permanent teeth was evaluated in Korean children and adolescents who visited Yonsei University Dental Hospital. This study may be helpful in diagnosis and treatment planning in the clinic.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.34 no.3
• /
• pp.186-199
• /
• 2012

Purpose: Single implants, of which screw loosening has been observed frequently, presents problems such as fixtures fractures, marginal bone loss, and inflammation of the soft tissue around the implant. However, the single implant is more conservative, cost effective, and predictable compared to the 3 unit bridge with respect to the long-term outcome. This study evaluated the survival rate as well as future methods aimed at increasing the survival rate in single implants in posterior teeth. Methods: Among the implants placed in the Dankook University Dental Hospital department of Oral & Maxillofacial surgery from January 2001 to June 2008, 599 implants placed in the maxillar and mandibular posterior were evaluated retrospectively. Survival rates were investigated according to implant location, cause of tooth loss, gender, age, general disease, fixture diameter and length, surface texture, implant type and shape, presence of bone graft, surgery stage, surgeons, bone quality and opposite teeth. Results: Out of 599 single implants in posterior teeth, 580 implants survived and the survival rate was 96.8%. The difference in survival rate was statistically significant according to the implant location. The survival rate was low (84.2%) in implants exhibiting a wide diameter (${\geq}5.1mm$) and the surface treated by the acid etching group demonstrated a significantly lower survival rate (91.1%). One stage surgical procedure, which implemented a relatively better bone quality survival rate (100%), was higher than the two stage surgical procedure (96.1%). The survival rate of type IV bone quality (75%) was significantly lower than the other bone quality. Conclusion: Single posterior teeth implant treatments should use an improved surface finishing fixture as well as careful and safe procedures when performing implant surgery in the maxilla premolar and molar regions since bone quality is poor.

• The korean journal of orthodontics
• /
• v.25 no.4
• /
• pp.447-451
• /
• 1995

The purpose of this study was to investigate the effects of cleft on mesiodistal dimensions of permanent teeth in unilateral cleft lip and palate patients. Mesiodistal dimensions of permanent teeth were measured to the nearest 0.01mm on plaster models of 50 subjects with unilateral complete cleft lip and palate, 10 siblings and 50 Controls. The results were as follows : 1. Tooth size discrepancy in the cleft group was significant in all regions except maxillary cuspid, mandibular cuspid and mandibular first premolar. 2. Some of the mesiodistal dimensions of the teeth on the cleft side were significantly smaller than those of their antimeres on the non-cleft side in the cleft group. 3. A comparison of mesiodistal dimensions of the teeth for the right and left sides of the control group showed no statisically significant differences excepts maxillary lateral incisor. 4. Asymmetries of mesiodistal dimensions of the teeth in the sibling group was not found except maxillary first molar.

• The Journal of the Korean dental association
• /
• v.11 no.12
• /
• pp.787-799
• /
• 1973

Surveying the calcification degree of permanent tooth crown in 719 Korean children (Male 387, female 332) from 2 to 10 years old by orthopantomograph, the author got the following results. 1. Female was earlier than male in calcification of permanent teeth. 2. The results of the complete calcification of the permanent tooth crown were as follows. 3. The completion of calcification in the mandibular crown was seen earlier than that of the maxilla. 4. The order of calcification in permanent tooth crowns was as follows : 1 st molar, central incisor, lateral incisor, canine, 1st premolar, 2nd premolar, and 2nd molar. 5. The completion of calcification of the permanent crowns in Korean children was slightly retarded comparing with the Japanese and the American children.

• The korean journal of orthodontics
• /
• v.17 no.2
• /
• pp.223-248
• /
• 1987

The early tissue reactions in the periodontal tissues of the tension zones following the application of force (30gm) to the maxillary first molar teeth of the albino rats were studied by the light microscopy and electron microscopy The increase of periodontal fibroblasts was evident, particularly in 1 day survival period. Osteoblast differentiation and new bone formation on the alveolar bone surface were occurred from 1 day survival period. Mononuclear phagocytes occurred consistently and in relatively high number adjacent to and at some distance from blood vessel Extensive breakdown of collagen fibers was observed. The increase of the phagocytosis of collagen by the active fibroblasts was evident Also, collagen fibrils were sparse or lost near the macrophage.

• The korean journal of orthodontics
• /
• v.6 no.1
• /
• pp.71-77
• /
• 1976

19 years old female had untreated Veau classification class II cleft palate with ectopic eruption of upper right lateral incisor and congenital missing of lower lateral incisors. Upper left lateral incisor, left first molar aid lower left first molar were root restswithperiapicalpathologiclesions. So all root rests were extracted and prosthodontic rehabilitation after orthodontic treatment was planned. She was treated by means of multibanded system with face bow. After 23 months all orthodontic correction were achieved and, as soos as debanding procedure was done she was referred to oral surgeon and prosthodontist for surgical operation and bridge construction.

• The Journal of the Korean dental association
• /
• v.37 no.2 s.357
• /
• pp.126-130
• /
• 1999

Forty healty patients (15 males and 25 females) between 19 and 45 years of age with mandibular impacted third molar were selected for this tudy. A visual analog scale from 0 to 100 was used on the day of the procedure and on the first postoperative day for patient pain assessment. 1. In comparative study according to anesthesia, preoperative medication, depth of impacted teeth and gender, there were a variable range of pain and no significant differences statistically. 2. Intraoperative pain was the highest in the 2nd decade and first postoperative pain was the highest in the 3rd decade (P=0.0398) 3. Intraoperative and postoperative pain of operative duration below 10 minutes were the lower than that between 11 to 20 minutes (P=0.0398)