• Imaging Science in Dentistry
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• v.53 no.4
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• pp.303-312
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• 2023

Purpose: This study investigated the prevalence of developmental and acquired pathologic conditions associated with impacted third molars (3Ms) in a Southern Brazilian population and evaluated whether demographic and tooth characteristics were correlated with the presence of bone or tooth lesions. Materials and Methods: Panoramic radiographs were assessed for developmental (bone-related) or acquired (tooth-related) pathoses associated with impacted upper or lower 3Ms. Data on tooth positioning, tooth development, and patient demographics were collected. A trained, calibrated postgraduate student evaluated all images. Binary and multivariate logistic regression models were used to assess associations between outcomes and the demographic and radiographic variables. The threshold for statistical significance was set at 5% (P<0.05). Results: The sample comprised panoramic radiographs from 2054 patients, predominantly female (59.2%), with a mean age of 27.2±11.5 years. Overall, 4066 impacted 3Ms were evaluated, revealing 471 (11.6%) developmental and 710 (17.5%) acquired pathoses. Among the developmental pathoses, 460 (95.2%) were indicative of dentigerous cysts. Male sex, lower 3M location, vertical or distoangular positioning, and incomplete root formation were associated with an elevated likelihood of developmental pathology. Lower tooth position, complete root formation, and partial eruption were linked to an increased probability of an acquired pathology in the third or second molar. Conclusion: The prevalence of pathologic conditions associated with impacted 3Ms was low. Male sex, lower 3M placement, horizontal or distoangular positioning, and incomplete root formation were associated with developmental pathoses, while lower tooth position, complete root formation, and partial eruption were related to acquired pathoses.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.41-57
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• 1997

The present study investigated the effects of hyperbaric oxygen therapy on periodontal wound healing of replanted rat tooth. 80 rats (Sprague-Dawley strain) weighting $130{\pm}5gm$ were selected and divided into experimental and control group, each group consisting of 40 rats. Rats were administered 0.4% ${\beta}$-aminoproprionitrile for 5 days to achieve gentle tooth extraction. The maxillary first molars were extracted under anesthesia with pentobarbital, washed in sterile distilled water, treated with bacterial collagenase to remove collagen fibers on the root surfaces. After washing in water overnight, the mesial root surface were demineralized by application of citric acid, washed, dried and stored at $4^{\circ}C$. Immediately after tooth extraction and bleeding control, the treated molars extracted previously from other rats were replanted. The experimental group was exposed to hyperbaric oxygen at 2.5 atm. for 2 hrs. a day during experimental period. Eight animals of each group were sacrificed 1, 3, 6, 8, 10 days after reimplantation of teeth by intracardiac perfusion with 4% paraformaldehyde. The replanted molars and surrounding tissues were cut, demineralized, dehydrated and embedded in paraffin. Sections were stained with azan, toluidine blue and hematoxylin. Some other sections were stained by means of immunostaining achieved by the avidinbiotin complex method. The results as follows; 1. Experimental group showed fast healing of gingival epithelium. 2. Macrophage and newly formed blood vessels appeared early in the gingival connective tissue of experimental group. 3. Experimental group showed fast, abundant fibroblast proliferation and regularity of collagen fiber. 4. In both group, collagen was distributed along the collagen fiber. The distribution was strong and regular in the experimental group. 5. In the regenerated periodontal ligament of experimental group, fibers showed regular arrangement and invaded root surface fast.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.1
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• pp.9-17
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• 2020

Background: This study aimed to compare the pain levels during anesthesia and the efficacy of the QuickSleeper intraosseous (IO) injection system and conventional inferior alveolar nerve block (IANB) in impacted mandibular third molar surgery. Methods: This prospective randomized clinical trial included 30 patients (16 women, 14 men) with bilateral symmetrical impacted mandibular third molars. Thirty subjects randomly received either the IO injection or conventional IANB at two successive appointments. A split-mouth design was used in which each patient underwent treatment of a tooth with one of the techniques and treatment of the homologous contralateral tooth with the other technique. The subjects received 1.8 mL of 2% articaine. Subjects' demographic data, pain levels during anesthesia induction, tooth extractions, and mouth opening on postoperative first, third, and seventh days were recorded. Pain assessment ratings were recorded using the 100-mm visual analog scale. The latency and duration of the anesthetic effect, complications, and operation duration were also analyzed in this study. The duration of anesthetic effect was considered using an electric pulp test and by probing the soft tissue with an explorer. Results: Thirty patients aged between 18 and 47 years (mean age, 25 years) were included in this study. The IO injection was significantly less painful with lesser soft tissue numbness and quicker onset of anesthesia and lingual mucosa anesthesia with single needle penetration than conventional IANB. Moreover, 19 out of 30 patients (63%) preferred transcortical anesthesia. Mouth opening on postoperative first day was significantly better with intraosseous injection than with conventional IANB (P = 0.013). Conclusion: The IO anesthetic system is a good alternative to IANB for extraction of the third molar with less pain during anesthesia induction and sufficient depth of anesthesia for the surgical procedure.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.759-772
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• 1994

Orthodontists have experienced the treatment of cases with three lower incisors. Occasionally a lower incisor was either congenitally missing or so seriously damaged by injury or disease that its removal presented the best prospect for the patient. Sometimes the intentional extraction of a lower incisor is needed to produce enhanced functional and esthetic results with minimal orthodontic manipulation. Such cases have unfavorable anterior tooth size discrepancies and present difficulties in achieving good occlusal results. However such difficulties can be overcome by the sensible diagnosis and treatment plan. Three different cases are presented and the conclusions are listed. 1. It is important for orthodontist who tries to treat three lower incisor cases to measure and calculate accurately the degree of deviation of tooth size and morphology and the anterior tooth size ratio. 2. A diagnostic setup model should be made to determine whether the incisor extraction is appropriate and space closure is needed or not. It is the best way to be sure that the occlusal results, including overbite and overjet, will be acceptable and how far the degree of midline deviation is. It also shows the amount of interproximal reduction to achieve an acceptable occlusal result. 3. The class I relationship between the upper canine and the lower one must be obtained to establish the canine rise during eccentric movement by the concept of mutually protective occlusion. It also helps to maintain the stable occlusal result.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.475-480
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• 2009

An infraoccluded tooth is a tooth that has failed to erupt to be in line with adjacent teeth in the vertical plane of occlusion. Multiple complications can occur as a result of an infraoccluded tooth. Tipping of neighboring teeth, loss of space opposing teeth elongation, increased susceptibility to dental caries and abnormal eruption path, impaction and rotation of permanent successor are the consequences of infraocclusion of primary molar. Therefore, early diagnosis and treatment is the key to prevent the complications. Treatment options can be periodic follow-up, temporary restoration or extraction of the infraoccluded tooth depending on the presence of the successor, the extent of infraocclusion and the extent of tilting of the neighboring teeth. The infraoccluded primary molars with permanent successors present tend to exfoliate normally. However, failure to do periodic check up of the infraoccluded teeth may lead to serious complications. In these cases, surgical extractions are often necessary after space regaining and space maintainers should be placed until the eruption of the permanent successors are completed.

• The korean journal of orthodontics
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• v.50 no.3
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• pp.188-196
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• 2020

Objective: Preservation of the periodontal ligament (PDL) is vital to the success of tooth autotransplantation (TAT). Increased PDL volumes and facilitated tooth extraction have been observed upon orthodontic preloading. However, it is unclear whether any changes occur in the expressions of bone biomolecules in the increased PDL volumes. This study aimed to determine the expressions of runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) in PDL upon preloading. Methods: Seventy-two premolars from 18 patients were randomly assigned to experimental groups that received a leveling force for 1, 2, or 4 weeks or to a control unloaded group. Following extraction, PDL volumes from 32 premolars of eight patients (21.0 ± 3.8 years) were evaluated using toluidine blue staining. The expressions of the biomolecules in the PDL from 40 premolars of ten patients (21.4 ± 4.0 years) were analyzed via immunoblotting. Results: The median percentage of stained PDL was significantly higher at 2 and 4 weeks after preloading than in the unloaded condition (p < 0.05). The median RUNX2 and ALP expression levels were significantly higher at 2 and 4 weeks after preloading than in the unloaded condition (p < 0.05), whereas the median RANKL/OPG ratios were significantly higher at 1 and 4 weeks after preloading (p < 0.05). Conclusions: Orthodontic preloading for 4 weeks enhances PDL volumes as well as the expressions of RUNX2, ALP and the RANKL/OPG ratio in the PDL, suggesting this loading period is suitable for successful TAT.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.4
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• pp.301-307
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• 2006

The subgingival fracture near the alveolar bone is difficult to treat. This fractured tooth will be treated by many methods. First approach is to preserve the fractured tooth. Periodontal surgery has been used to lengthen the clinical crown, thereby allowing the tooth to be restored. Another method is erupting the tooth with orthodontic eruption (forced eruption) or surgical extrusion. Second approach is the restoration after extraction of the subgingivally fractured tooth. This is restorative with conventional fixed partial denture or implant. This article presents the variable restorative approach of subgingivally fractured upper incisor.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.1
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• pp.55-59
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• 2013

In the oral and maxillofacial area, bone defects are created by various reasons and demand for bone grafts, while dental implant implantation has been increased consistently. To solve these problems, there has been development of autogenous tooth-bone graft material (AutoBT$^{(R)}$, Korea Tooth Bank Co., Korea), and we have collected ground reasons to substitute free autobone graft with this material in clinical use. This autogenous tooth-bone graft material is produced in powder type and block type. Block type is useful in esthetic reconstruction of the defect site and vertical and horizontal augmentation of alveolar bone because this type has high strength value, well maintained shape and is less absorbed. Therefore, the author of this study gained favorable result by grafting the block type autogenous tooth-bone graft material after dental implant implantation on the bone defects of the mandibular molar extraction site. Moreover, the author represents this case with literature review after confirming bone remodeling on the computed tomography image and by histological analysis.

• Journal of Korean Dental Science
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• v.16 no.2
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• pp.115-127
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• 2023

The demand for orthodontic clear aligner therapy (CAT) has increased significantly over the last decade, offering advantages over the fixed appliances (FA) including enhanced aesthetics, better hygiene and comfort, along with minimal restrictions on the patient's diet. Moreover, a marked improvement in the efficacy of tooth movement using aligners has been documented. On the contrary, there have been known limitations of CAT including the compliances issues and the apparent lack of efficacy for certain types of tooth movement such as closure of extraction space compared to FA. Thus, evidence-based evaluation of the accuracy of prediction of tooth movement with clear aligners and their ability to effectively perform major tooth and root movements compared to FA are crucial. Although several systematic reviews have investigated various aspects of the effectiveness of CAT, we are yet to obtain a rather conclusive answer to this question. The current review attempted to summarize the evidence-based findings of most systematic reviews about CAT available to date. Major issues regarding the predictability of tooth movement, the role of attachments and auxiliaries in improving the effectiveness of CAT, and the treatment outcomes in comparison to FA were investigated. Clinical recommendation have been also elaborated based on the interpretation of the findings of all systematic reviews included in this study.

• Journal of Periodontal and Implant Science
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• v.29 no.4
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• pp.893-914
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• 1999

Tooth mobility may be the decisive factor that determines whether dental treatment of any kind is undertaken. Although tooth mobility in isolation says little in itself, the finding of increased tooth mobility is of both diagnostic and prognostic importance. Only the detection of an increase or decrease in mobility makes an evaluation possible. Thus prior to treatment, we must understand the pathologic process causing the observed the tooth mobility and decide whether the pattern and degree of observed tooth mobility is reversible or irreversible. And then it must be decided whether retention and treatment or extraction and replacement. The purpose of this study was to compare tooth mobility at different time period during root planing and flap operation and to relate changes in mobility to each treatment method. Twenty-one patients (287 teeth) with chronic adult periodontitis were treated with root planing(control group) and flap operation(experimental group), and each group was divided 3 subgroups based upon initial probing pocket depth (1-3mm, 4-6mm, 7mm and more). Tooth mobility was measured with $Periotest^{(R)}$ at the day of operation, 4 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 8 weeks, 12 weeks after each treatment. Tooth mobility, attachment loss, radiographic bone loss, and bleeding on probing were measured at the day of operation, 4 weeks, 8 weeks and 12 weeks after treatment. 1. In group initial probing depth was 1-3mm, tooth mobility had no significant difference after root planing and flap operation. 2 . In group initial probing depth was 4-6mm, 7mm and more, tooth mobility had decreased in 12 weeks after root planing(p<0.01). And the mobility had increased after flap operation(p<0.01) and was at peak in 1 week, and decreased at initial level in 4 weeks, below the initial level in 12 weeks(p<0.01). 3. In 1 week, significant difference in tooth mobility between control and experimental group was found(p<0.01) but, in 12 weeks no difference between two groups was found. 4. Change of immediate tooth mobility after treatment was more larger in deep pocket than in shallow one. In group with the same probing pocket depth, the change of tooth mobility in molar group was greater than that of premolar group. 5. Tooth mobility before treatment was more strongly correlated with radiographic bone loss (r=0.5325) than probing depth, attachment loss and bleeding on probing, in 12 weeks after treatment, was more strongly correlated with attachment loss($r^2$=0.4761) than probing depth and bleeding on probing. Evaluation of the treatment effect and the prognosis after root planing and flap operation were meaningful on tooth initial probing depth 4mm and more. After flap operation, evaluation of the prognosis should be performed at least in 4 weeks and in 12 weeks after treatment, no difference in tooth mobility between two groups was observed. Radiographic bone loss and attachment loss were good clinical indicators to evaluate tooth mobility.