• Journal of Periodontal and Implant Science
• /
• 제34권1호
• /
• pp.101-112
• /
• 2004

Osseointegrated implnats have proven to be successful in both full and partial edentulous patients since the 1960s and recently have shown successful results when used to restore single tooth missing. However, in most studies reporting the success of single implants, single implants replacing anterior teeth are more frequently mentioned than posterior single implants. Moreover, in studies regarding posterior single implants, the replaced region seemed to be variable; the maxilla, mandible and areas from the first premolar to the second molar were mentioned. However, considering the difference in bone quality in the mandible and maxilla, and the increased occlusal force in the posterior region, the success rates in each region may be different. In this study, the cumulative success rates and amount of bone loss of single implants replacing the mandibular first and second molar, respectively, were compared and analyzed to come to the following conclusion. 1. The 20 (20 persons) single implants that were placed in the mandibular first molar region were all successful and showed a 100% 5 year cumulative success rate. Among the 27 (24 persons) single implants replacing the mandibular second molar, 8 failed (27.63%) showing a 5 year cumulative success rate of 70.37%. 2. Among the 8 failed implants, one showed symptoms of postoperative infection and one complained of parenthesia. 6 implants failed after functional loading; 5 showed mobility and one resulted in fixture fracture. 3. After the attachment of the prosthesis, there was no significant statistical difference regarding the marginal bone loss in group 1 and group 2 during the checkup period (P>0.05). In conclusion, restoration of the mandibular first molar using single implants was found to be an excellent treatment modality, and when replacing mandibular second molars with single implants, poor bone quality and risk of overloading must be considered.

• Journal of Oral Medicine and Pain
• /
• 제34권3호
• /
• pp.333-340
• /
• 2009

골수염은 골수의 염증을 의미하며 임상적으로는 골을 구성하고 있는 조직등의 염증을 포함한다. 일반적으로 골수에서 시작되어 수질내로 확장되며 피질골, 골막등에 이환되어 골 전반에 걸친 골괴사를 야기시킨다. 원인은 일반적으로 세균에 의한 감염으로 여겨지며 항생제의 발달로 그 유병율이 감소하였으나 여전히 외상, 매독, 만성 신질환, 알코올 중독, 영양결핍, 방사선 조사나 화학적 항암요법은 골의 감염을 위험하는 인자로 알려져 있다. 골수염의 치료는 비교적 까다로우며 난치성으로 진행될 가능성이 있다. 특히 소아에서는 하악구조가 성숙이 덜되어 있어 염증이 쉽고 빠르게 퍼진다. 따라서 소아에서는 골수염을 조기에 발견하고 치료하는 것이 중요하다. 또한 소아는 성장중이므로 악골의 성장 또한 고려해야 하므로 조기발견이 더욱 중요하다고 볼 수 있다. 특히 하악골중에서 하악과두는 하악골 성장의 중요한 곳으로 하악과두의 질환발생시 하악성장율감소, 안면비대칭과 같은 큰 문제를 야기할 수 있어 주의가 요구된다. 하악과두의 골수염은 대부분 치성감염이나 하악골절후의 감염으로 발생한다. 단, 소아의 경우에는 특별한 감염원인 없이 하악의 골수염이 발생했다는 보고도 있다. 이에 저자는 9세의 소아에서 뚜렷한 원인을 찾기 어려운 하악과두의 골수염을 경험하였기에 증례보고와 함께 문헌고찰을 하고자 한다.

• Journal of Periodontal and Implant Science
• /
• 제34권2호
• /
• pp.281-292
• /
• 2004

Periodontal defects of the furcation are characterized by several inherent anatomic factors that can make successful periodontal therapy difficult and results unpredictable. The severity and rate of occurrence of periodontal disease are directly related to the location of the furcation relative to the cementa-enamel junction and anatomical form of the root by limiting the accessibility and effectiveness of the periodontal instrumentation. This study investigated the reliability and accuracy of panoramic radiograph diagnoses of the periodontal state of mandibular molars, particularly regarding the diagnosis of furcation area periodontal defects, treatment planning, and prognosis prediction. This study examined a total of 110 teeth belonging to 33 subjects (19 male, 14 female) presenting with incipient to moderate periodontitis 4-7mmpocket depth. The alveolar bone level, length and width of the root trunk, and root separation angle were measured using the panoramic radiograph and compared to the results taken directly by retracting a full-thickness flap. The results of the study are as follows: 1. Data regarding the alveolar bone level of the mandibular first molar showed that the directly taken surgical measurements resulted in $5.1{\pm}0.9mm$ that was slightly deeper than the corresponding panoramic measurement resulted in $4.8{\pm}0.8mm$, but these differences were statistically insignificant (p>0.05). 2. The data of the directly taken surgical measurement of the mandibular second molar $(5.1{\pm}1.1mm)$ was slightly deeper than the corresponding panoramic measurement $(4.7{\pm}1.2mm)$, but these differences were statistically insignificant (p>0.05). 3. The measured values of the length and width of the mandibular first molar root trunks were determined to be $4.1{\pm}0.6mm$ and $7.3{\pm}0.9mm$, respectively, while the values of the mandibular second molar root trunks were determined to be $4.6{\pm}1.3mm$ and $7.6{\pm}0.9mm$ respectively. The differences between these values were found to be statistically significant (p<0.01). 4. The measured values of the root separation angle showed that the mandibular first molars averaged $34.5{\pm}4.4^{\circ}$, while the mandibular second molars averaged $23.0{\pm}10.0^{\circ}$. The differences between these values were found to be statistically significant (p<0.01).

• 대한치과교정학회지
• /
• 제34권2호
• /
• pp.143-152
• /
• 2004

하악과두 연골이 발생하고 분화하는 과정에서 나타내는 특성을 규명하기 위하여, 발생 16, 18일과 출생 1일, 5일, 10일, 20일 및 30일 후의 ICR생쥐의 하악과두를 형태학적으로 분석하고, 생쥐 I형, II형, X형 교원질, Indian hedgehog (IHH) 및 BMP-4 등의 mRNA 발현을 in-situ hybridization 방법으로 연구하였다. 1. 생쥐 I형 및 II형 교원질 mRNA는 하악과두의 발생 및 성장과정에서 모두 발현되었다. I형 교원질 mRNA는 휴지층과 증식층의 상부에서 관찰된 반면 II형 교원질은 휴지층과 증식층 그리고 비대연골층의 상부에서 관찰되었다. 2. 하악과두 연골은 성장에 따라 비대연골층이 계속 증가하는 소견을 보였으며, 비대 연골층의 세포들은 특징적으로 X형 교원질 mRNA의 발현을 보였다. 3. BMP-4 mRNA는 하악과두 연골 원기와 골화중인 하악골체에서 모두 발현되었다. 4. IHH mRNA는 하악과두의 발생과정에서 증식 연골층의 하부와 비대연골층의 상부에서 선택적으로 관찰되었다.

• Journal of Periodontal and Implant Science
• /
• 제25권2호
• /
• pp.301-320
• /
• 1995

The purpose of this study was to evaluate a new biodegradable membrane - atelocollagen as a guided tissue regeneration barrier on the dehiscence defects adjacent to the dental implants. 3 beagle dogs were selected for this study and all the mandibular premolars($P_1,P_2,P_3&P_4$) were extracted. Twelve weeks after the extraction, the edentulous ridges were formed to be placed the titanium plasma-sprayed IMZ implants. Four implant osteotomies were performed on each side of the mandible. The osteotomies were placed facially in the edentulous ridges to approximate an actual dehiscence defect as closely as possible, The standardized dehiscence defects were created 3 mm in width and 4 mm in height by osteotomy. A total 24 implants were placed. e-PTFE, ateloco11agen and $Collatape^{(R)}$ were placed to cover the defects and the one defect served as a control, not covered any membrane. By random selection, three dogs were sacrificed at 2 weeks, 4weeks and 8 weeks after fixation with 3% glutaraldehyde. A week before sacrificing, 8-week dog was infused intravenously with oxy-tetracycline 30mg/kg. The left mandibular blocks were used for full decalcified histologic preparation and the right mandibular blocks were selected for undeca1cified preparation, At 2 weeks, the regenerated bone of e-PTFE and atelocollagen groups appeared to be more dense than other groups and the percentage of bone defect fill was highest for e-PTFE and follwed by ateloco1lagen group. However, the $Collatape^{(R)}$ and control groups showed a little new bone formation. $Collatape^{(R)}$ was almost degraded within 2 weeks. At 4 weeks, the regenerated new bone were much greater and denser than at 2 weeks for e-PTFE and ateloco11agen group. Although a part of atelocollagen bagan to be degraded at the margin and surrounded by foreign body giant cells related to foreign body reaction, it was generally intact and the regenerated new bone was shown much more than at 2 weeks. The amount of new bone in $Collatape^{(R)}$ and control groups at 4 weeks were similar to that of 2 weeks group. At 8 weeks, the regenerated bone was matured and observed along the implant fixture. Direct new bone formation and calcium deposits beneath the e-PTFE were observed. No further bone growth was seen in the $Collatape^{(R)}$ and control groups. In reflected fluoromicrcocopic observation, the osteogenic activity was pronounced between e-PTFE membrane and the old bone. High osteogenic activity was also observed in atelocol1agen group. This study suggested that the ateloco11agen as well as e-PTFE could be used for guided tissue regeneration on dehiscence defects adjacent to the dental implants. But the $Collatape^{(R)}$ was completely resorbed within 2 weeks and was not a suitable membrane for guided bone regeneration.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제35권5호
• /
• pp.294-301
• /
• 2013

Purpose: The purpose of this study is to assess the effectiveness of beta-tricalciumphosphate (${\beta}$-TCP) as a bone graft material on new bone formation and regeneration of mandible bone defect around dental implants. Methods: Both mandibular sites of ten rabbits were exposed. The experimental subjects were divided into two groups. Rabbits in the control group (right site of the mandible) had dental implants around cortical bone defects, without treatment, while, in the experimental group (left site of the mandible), ${\beta}$-TCP was grafted into the bone defect around the implant. Rabbits were sacrificed after one, two, three, four, and eight weeks, and histomorphometric evaluation and analysis of the bone implant contact rate were performed using an optical microscope. Results: Bone formation rates in the experimental group were greater than those in the control group from one to eight weeks, and percentages of implant surface contacted to bone were greater in the experimental group than in the control group from three weeks after implantation. Conclusion: These results suggest that the bone formation activity around dental implants was increased by osteoconduction activity of ${\beta}$-TCP.

• 치과방사선
• /
• 제26권2호
• /
• pp.33-44
• /
• 1996

This study was for comparing healing patterns and effects between with odontogenic and nonodontogenic tissues on the defected mandible. Experimental bone defects that measured 3 mm in diameter were created on the mandibular body of guinea pig by removal of bone with the use of trephine burs and bone defects were grafted with Biogran(Orthovita Co., U.S.A.) and covered with Dura Mata(Pfrimmer-Viggo GmbH Co., Germany). Guinea pigs were serially terminated by fours on the 3 days, the 1 week, the 2 weeks, the 3 weeks, the 4 weeks, and the 5 weeks after experiment, and the mandibular body was removed and fixed with 10％ neutral formalin. They were decalcified and embedded in paraffin as using the usual methods. The specimen sectioned and stained with hematoxylin and eosin and toluidine blue. They were observed with a light microscope and a polarizing microscope. The obtained results were as follows : 1. Defected bone was healed fast from the odontogenic tissues in early stage of the experiment. 2. The arrangement of the bone matrix was relatively regular in the bone from the nonodontogenic tissues, but irregular in the bone from the odontogenic tissues. 3. Compact bone has started to be resorbed and changed to the pattern of matrix bone tissue from 3 weeks after experiment.

• Imaging Science in Dentistry
• /
• 제35권4호
• /
• pp.221-223
• /
• 2005

A case of osteoporotic bone marrow defect, which appeared as a well-defined multilocular radiolucency overlapping the roots of mandibular right second molar, was reported. On periapical radiograph, a daughter cyst-like radiolucency was seen at the anterior margin of the lesion making it difficult to rule out odontogenic keratocyst.

• Journal of Oral Medicine and Pain
• /
• 제13권1호
• /
• pp.13-21
• /
• 1988

The author studied the vertical height of tooth crown and the amounts of alveolar bone resorption with age. All 84 subjects(44 male, 40female) who visited Dental hospital of Wonkwang University with no history of sever periodontal disease and no experience of periodontal surgery. 84 subject were divided into 3 groups by age, that is, group I(28-32yrs), group II(38-42yrs), and group III(48-52yrs). Informal radiogram with bite wing film(horizontal angulation : $0^{\circ}$, vertical angulation : $+5^{\circ}~+10^{\circ}$) were taken on premolar and molar area. The distances from cusp tip to cementoenamel junction (vertical height of tooth crown) and from cementoenamel junction alveolar crest(amount of alveolar bone resorption) were measured, and then recorded data from 946 teeth were statistically analysed. This study was undertaken to obtain the data for age estimation by the changes of tooth crown height and alveolar bone resorption in the point of forensic odontology. The obtained results were as follows : 1. The average crown height of mandibular right 1st. molar was 7.1mm in group I, 6.7mm in group II, and 6.6mm group III, and the average amount of alveolar bone resorption on mandibular right 1st. molar were 1.8mm in group I, 2.5mm in group II, and 3.0mm in group III. Ratio of tooth crown height to amount of alveolar bone resorption was 4.0:1 in groupI, 2.7:1 in group II, and 2.2:1 in group III, the ratio was decreased with age. 2. In comparison with upper teeth and lower teeth in ipsilateral side, the average value of tooth crown height and amount of alveolar bone resorption were slightly higher in upper arch than those in lower arch, but there was not a statistically significant difference. 3. The ratio of height of tooth crown to amount of alveolar bone resorption was decreased with age, and which depended mainly upon the change of amount of alveolar bone resorption rather than the change of tooth crown height.

• Imaging Science in Dentistry
• /
• 제49권1호
• /
• pp.9-17
• /
• 2019

Purpose: This study aimed to introduce a novel method to evaluate the alveolar bone and interdental septum in the anterior mandible using cone-beam computed tomography (CBCT). Materials and Methods: Fifty-six CBCT scans from adult patients were selected. The CBCT scans were obtained before and after orthodontic treatment. The following measurements were taken: width of the alveolar bone and the interdental septum, height of the interdental septum, height of the bone plates, distance between the cementoenamel junction and marginal bone crests, and vertical positioning of the mandibular incisor, using the lingual plane as a reference. To test the reproducibility and the stability of the lingual plane, a triangle was traced in the anterior mandible. The intra-class correlation coefficient(ICC) was used to determine intra- and inter-examiner agreement. The paired Student t-test was used to evaluate the area of the triangle and the reproducibility of all measurements. Results: The ICC was excellent for the alveolar bone and dental measurements (0.9989 and 0.9977, respectively), as well as for the interdental septum (0.9987 and 0.9961, respectively). The area of the triangles showed stability in the lingual plane (P>0.05). For the alveolar bone, mandibular incisor, and interdental septum measurements, no statistically significant differences were found between the 2 examiners(P>0.05), confirming the technical reliability of the measurements. Conclusion: The method used in this study provides a valid and reproducible assessment of alveolar bone dimensions in the anterior mandible measured on CBCT images.