• The Journal of the Korean dental association
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• v.57 no.12
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• pp.758-767
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• 2019

The classification of periodontal disease in 1999 has been widely used for determining a diagnosis, establishing a treatment plan, and evaluating the prognosis of the patient with periodontal disease. However, scientific evidence from many studies indicates the need for a new classification system for periodontal and peri-implant disease. Summary at 2017 world workshop as follows: 1) Periodontal health and peri-implant health was defined; 2) Chronic periodontitis and aggressive periodontitis were unified as periodontitis; 3) Periodontitis was further classified by staging and grading to reflect disease severity and management complexity, rate of disease progression, respectively; 4) Periodontal disease as manifestation of systemic disease is based on the International Statistical Classification of Diseases and Related Health Problems-10 (ICD-10) code; 5) Periodontal biotype and biologic width was replaced to periodontal phenotype and supracrestal tissue attachment, respectively; 6) The excessive occlusal force was replaced by a traumatic occlusal force; 7) ≥3 mm of radiographic bone loss, ≥6 mm of pocket probing depth and bleeding on probing indicates peri-implantitis in the absence of radiograph at final prosthesis delivery.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.305-312
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• 2008

Crown-root fractures occur throughout both crown and root, and are defined as fractures involving enamel, dentin and cementum. The fractures may be grouped according to pulpal involvement into complicated and uncomplicated one. Crown-root fractures often occur on maxillary anterior teeth and comprise 5% of injuries affecting the permanent dentition and 2% in the primary dentition. To restore crown-root fractured tooth, biologic width must be maintained. For maintaining biologic width, such methods as gingivectomy following osteoplasty or orthodontic extrusion or surgical extrusion are available. Surgical extrusion is a method that extracts the tooth and replants the fractured tooth supragingivally. It is indicated when the length of the crown fragment is less than half the length of the clinical root. In these cases, root canal treatment and crown restoration using light-cured composite resin were performed after surgical extrusion. In following periodic examinations, favorable outcome was observed.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.4
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• pp.262-271
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• 2020

To restore a tooth with a fracture line extending below the marginal bone level, a surgical crown lengthening procedure accompanied by ostectomy could be considered to expose the fracture line and reestablish the biologic width. However, this procedure could lead to esthetic failure, especially in the anterior teeth. Therefore, orthodontic extrusion, which elevates the fracture line from within the alveolar socket without sacrificing the supporting bone and gingiva, is recommended. This technique allows for the proper placement of the crown on a sound tooth structure, with the reestablishment of the biologic width. Alternatively, surgical extrusion is an one-step procedure that is simpler and less time-consuming than orthodontic extrusion; placing and adjusting the orthodontic appliance does not require multiple visits. This study presents successful restoration in 2 cases with a crown-tooth root fracture of the maxillary central incisor treated using a multidisciplinary approach through orthodontic extrusion or surgical extrusion followed by successful restoration.

• Restorative Dentistry and Endodontics
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• v.41 no.3
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• pp.210-217
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• 2016

Exposing sound structure of a subgingivally fractured tooth using orthodontic extrusion is considered to be a conservative way to re-establish biologic width without sacrificing esthetics or jeopardizing periodontal support of neighboring teeth. When a misaligned tooth is traumatically involved, a more comprehensive approach combining tooth extrusion and re-alignment may be necessary for a successful restorative outcome. This case report describes a successful esthetic management of a patient with complicated crown-root fracture on the maxillary right central incisor and pre-existing malocclusion in the maxillary anterior region. Forced eruption along with re-alignment of teeth by orthodontic movement seems to allow re-positioning of the fracture line to a favorable position and correction of crowding, providing a better esthetic result.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.3
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• pp.243-251
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• 2008

A subgingival crown-root fracture presents a restorative problem to the clinician because restoration is complicated by the need to maintain the sound tooth structures. Forced eruption offers a method of treatment of teeth fractured close to the alveolar crest. Extrusion of such teeth allows elevating the fracture line above the epitherial attachment and so the proper finishing margins can be prepared. The purpose of this case is to report successful tooth restoration using forced eruption in case of crown-root fractures.

• The korean journal of orthodontics
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• v.25 no.5 s.52
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• pp.593-604
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• 1995

Mandibular incisor crowding is one of the most common features of malocclusion and is interesting characteristic in view of relapse and stability after orthodontic treatment. There are many potential factors in the etiology of lower anterior crowding. The tooth size variation is one of them, but biologic significance for the faciolingual width of the teeth has been overlooked. Peck and Peck reported that persons with ideal mandibular incisor alignment were shown to have incisor with smaller mesiodistal and larger faciolingual dimensions than persons with incisor crowding. On the basis of these findings they suggested MD/FL index as a clinical guideline for the assessment for lower incisor crowding. The present study was undertaken to examine the relationship between mandibular incisor crowding and mandibular incisor dimension, and determine their correlation with arch length discrepancy. 154 dental casts of people from 11 to 17 years of age were made, and were divided into normal group with irregularity index less than of 1, and crowding group with irregularity index greater than 1.The casts were measured and analyzed statistically. The results were as follows. 1. The mean mesiodistal width for mandibular incisor was larger in crowding group, and has significant difference in central inciosr measurement. There are no significant differences in the faciolingul width and MD/FL index. 2. Irregularity index has significant correlation coefficients with mesiodistal width and MD/FL index for mandibular incisor in crowding group, but no correlation with faciolingual width. It also has correlation with maxillary and mandibular arch length discrepancy, total tooth material, mandibular intercanine width, and mandibular inter first premolar width. 3. Upper and lower arch length discrepancy have significant correlation with mesiodistal width of mandibular incisor and overbite, but have no correlation with faciolingual width. Lower arch lenth discrepancy has significant correlation with MD/FL index for mandibular incisor and upper arch length discrepancy has correlation with MD/FL index for mandibular lateral incisor. 4. Significant differences were observed between normal and crowding group for the mandibular arch length discrepancy and overbite.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.1
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• pp.21-28
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• 2012

Purpose: The purpose of this study was to investigate the effects of implant collar design on marginal bone change and soft tissue response by an animal test. Materials and methods: Two types of Implant (Neobiotech Co. Seoul, Korea) that only differs in collar design were planted on two healthy Beagle dogs. The implants were divided into two groups, the first group with a beveled collar (Bevel Group) and the second group with "S" shaped collar (Bioseal group). Standardized intraoral radiographs were used to investigate the mesio-distal change of the marginal bone. Histological analysis was done to evaluate the bucco-lingual marginal bone resorption and the soft tissue response adjacent to the implant. Mann-Whitney test was done to compare the mesio-distal marginal bone change at equivalent time for taking the radiographs and the tissue measurements between the groups. Results: Radiographic and histological analysis showed that there was no difference in marginal bone change between the two groups (P>.05). Histological analysis showed Bioseal group had more rigid connective tissue attachment than the Bevel group. There was no difference in biological width (P>.05). Bevel group showed significantly longer junctional epithelium attachment and Bioseal group showed longer connective tissue attachment (P<.05). Conclusion: For three months there were no differences in marginal bone change between the Bevel group and the Bioseal group. As for the soft tissue adjacent to the implant, Bioseal group showed longer connective tissue attachment while showing shorter junctional epithelium attachment. There were no differences in biologic width.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.1
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• pp.60-69
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• 2016

Complicated crown-root fracture of permanent incisors cause esthetic, functional, and psychological problems to patients. Therefore, treatment is important and multidisciplinary treatment is required. This case report describes the clinical procedures involved in the treatment of trauma-induced complicated crown-root fractures in the maxillary incisor of two young patients. Conventional root canal treatment and apexification were performed in each patient. To expose the fracture margins to the supragingival level and to reestablish the biologic width, orthodontic extrusions with fixed appliances were performed followed by a retention period. During the retention period, fiber-optic posts and cores were built up and provisional crowns were placed. Finally, ceramic crowns manufactured using a computer-aided design/computer-aided manufacturing (CAD/CAM) system were placed. In both patients, the teeth presented satisfactory functional and esthetic outcomes without relapse. The periodontal tissues were healthy.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.535-542
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• 2007

Background : Repeated dis/re-connection of implant abutment caused bone loss around implant fixtures due to the new formation of biologic width of the mucosal-implant barrier. The aim of this clinical study was to evaluate whether the repeated dis/re-connection of implant abutment cause bone loss clinically and the effect of cleansing methods on a bone loss during the early healing period. Methods : A total 50 implants were installed in 20 patients and repeated dis/re-connection of abutment was performed at the time of surgery and once per week for 12 weeks. 0.9% normal saline solution as group1 and 0.1% chlorhexidine solution as group 2 was used to clean abutments. All patients had radiographs taken at the placement of implant and 4, 8, and 12 weeks postoperatively. The data for bone loss around implant were analyzed. Results: The marginal bone loss at 12 weeks were $1.28{\pm}0.51mm$, $1,32{\pm}0,57mm$ in the mesial and distal sides in group1, $1.94{\pm}0.75mm$, $1.81{\pm}0.84mm$ in group 2, respectively. In view of marginal bone loss, there was not a significant statistical difference between groups. Conclusions : Repeated dis/re-connection of implant abutment may not cause marginal bone loss around implant fixture although limited samples and short-term observation period. In spite of more bone loss in group 2, there was no statistical significant difference between groups. In context of those results, the clinical significance of the repeated dis/re-connection of implant abutment and the cleansing method of abutments is debatable when it comes to marginal bone loss during early healing period.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.85-92
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• 2005

Reconstruction of defect in the anterior part of the maxilla to enable implant placement or prothesis is a complicated treatment due to the anatomical position and lack of soft tissues. Two cases are presented in which autogenous iliac PMCB(particulate marrow and cancellous bone) with titanium mesh were used for premaxilla reconstruction and alveolar bone repair of the anterior maxillas prior to denture and implants fixation respectively. Cancellous bone from the anterior iliac crest was compressed and placed against a titanium mesh fixed to the bone of palate in a patient with severe defect of the anterior maxilla. There were no problem in the healing, and the anterior maxillas of two patients had increased height and width during the initial healing and remodeling. The clinical reports describe the use of titanium mesh for reconstruction of premaxilla. Autogenous bone grafts were harvested from the iliac crest and were loaded on a titanium mesh that were left in the patient's maxilla for 6 months before they were removed respectively. The radiographic analysis demonstrated that a 10mm vertical ridge augmentation had been achieved. In guided bone regeneration, the quantity of bone regenerated under the barrier has been demonstrated to be directly related to the amount of the space under the membrane. This space can diminish as a result of membrane collapse. To avoid this problem which involved the use of a titanium mesh barrier to protect the regenerating tissues and to achieve a rigid fixation of the bone segments, were used in association with autologous bone in 2 cases. The aim of this study was to evaluate the capability of a configured titanium mesh to serve as a mechanical and biologic device for restoring a vertically defected premaxilla.