• The Journal of the Korean dental association
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• v.52 no.10
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• pp.623-632
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• 2014

The facial asymmetries include maxillary, mandibular, and chin asymmetries, although the most common deformity is primarily in the mandible. Common causes of this type of asymmetry can include asymmetric growth of the condyle or the mandible. In these patients, the location of the Me would be deviated to the shorter side because of the asymmetric growth of the mandible, and, commonly, the maxillary occlusal plane would be tilted toward the deviated side because the maxilla likely grows asymmetrically according to the pattern of asymmetric mandibular growth. Three-dimensional CT images are ideal for evaluating the size and location of anatomic structures, and such reconstructed images allow the use of software that can show anatomic structures from numerous angles, allowing actual measurements of distances and angles without problems of magnification, distortion, or superimposition caused by 2-dimensional imaging. In the present study using 3D-CT imaging, the 8 parameters, including measurements of the upper midline deviation, maxillary canting in the canine and first molar regions, width of the upper arch, width of the mandible at the Go, vertical length of the ramus, inclination of the ramus, and deviation of the Me were easily measured. The dentition should be orthodontically decompensated and dental midline should ensure incisor midlines positioned in the midline of each jaw before surgical correction. Surgical correction could be considered such as canting or yawing correction in the frontal or horizontal aspect, respectively.

• Journal of Technologic Dentistry
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• v.34 no.4
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• pp.353-359
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• 2012

Purpose: The aim of this study measured and compared the marginal and internal fit of metal cores with two base metal alloy (Ni-Cr alloy(non-beryllium), Co-Cr alloy). Methods: Maxillary right first molar abutment fabricated by titanium was prepared for this study. Impressions(10ea) were made from titanium model, and study models were poured with improved dental stone. Wax cores of twenty were prepared for burn-out and casting. Ten wax cores cast Ni-Cr alloy(non-Be), and finally ten cast Co-Cr alloy. Marginal and internal fit of cores was evaluated using silicone replica technique and digital microscope(x160). The data were statistically analyzed with the independent samples t-test (${\alpha}$ <.05). Results: Mean(standard deviation, SD) marginal and internal fit total size of Ni-Cr alloy(non-Be) group was $73.3(14.4){\mu}m$ and of Co-Cr alloy group $65.6(17.4){\mu}m$. The marginal and internal fit total size of Ni-Cr alloy group(non-Be) was statistically significantly greater than that of Co-Cr alloy group (P=.004). Conclusion: Co-Cr alloy cores in this study had a better marginal fit than Ni-Cr alloy(non-Be) cores.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.293-308
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• 1996

Recently, dental laser have been applied for removal of soft tissues, hemostasis and blood coagulation, removal of benign and malignant tumor, treatment of leukoplakia, aphthous ulcer and herpetic lesion, implant second surgery, removal of granulation tissue, frenectomy, clinical crown lengthening, gingivectomy, gingivoplasty, and treatment of dentin hypersensitivity. Even though the frequency of laser treatment is increasing, the research on the healing process after gingivectomy using pulsed Nd : YAG laser is very rare. The purpose of this study was to observe and compare the wound healing after gingivectomy using scalpel and pulsed Nd : YAG laser in the rat. Gingivectomy was performed using pulsed Nd : YAG laser(SUNRISE Technologies, U.S.A., 1.5 Watts, 10 pps) on the buccal gingiva of right maxillary first molar and using scalpel(No.12) on the contralateral side. Those sites treated by surgical scalpel were designated as the control, and by pulsed Nd : YAG laser as the experimental group. Animals were sacrificed at 1, 2, 3, 5, 7, 11 and 14 days postoperatively, and specimens were histologically observed under light microscope. The results were as follows : 1. Clinical observation Normal color and shape were observed at the 5th day ill the control group and the 7th day in the experimental group. 2. Histologic findings 1) In the control group, denser inflammatory infiltration was observed. 2) Epithelialization started at the 2nd day in the control group, similar to the experimental group, and completed at the 11th to the 14th day postoperatively. 3) In the experimental group, connective tissue showed the vacuole formation and degenerative change during early healing period. Healing of connective tissue was slower in the experimental group than in the control group by 2 days. 4) In the both groups, wound healing was completed at the 2nd week. From this study, gingivectomy using pulsed Nd : YAG laser seems to result in a little delayed wound healing process, compared to the gingivectomy using scalpel. Considering the clinical advantages of laser surgery, pulsed Nd : YAG laser might be useful device for gingivectomy.

• The Journal of Advanced Prosthodontics
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• v.12 no.5
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• pp.316-321
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• 2020

PURPOSE. The stress distribution and microgap formation on an implant abutment structure was evaluated to determine the relationship between the direction of the load and the stress value. MATERIALS AND METHODS. Two types of three-dimensional models for the mandibular first molar were designed: bone-level implant and tissue-level implant. Each group consisted of an implant, surrounding bone, abutment, screw, and crown. Static finite element analysis was simulated through 200 N of occlusal load and preload at five different load directions: 0, 15, 30, 45, and 60°. The von Mises stress of the abutment and implant was evaluated. Microgap formation on the implant-abutment interface was also analyzed. RESULTS. The stress values in the implant were as follows: 525, 322, 561, 778, and 1150 MPa in a bone level implant, and 254, 182, 259, 364, and 436 MPa in a tissue level implant at a load direction of 0, 15, 30, 45, and 60°, respectively. For microgap formation between the implant and abutment interface, three to seven-micron gaps were observed in the bone level implant under a load at 45 and 60°. In contrast, a three-micron gap was observed in the tissue level implant under a load at only 60°. CONCLUSION. The mean stress of bone-level implant showed 2.2 times higher than that of tissue-level implant. When considering the loading point of occlusal surface and the direction of load, higher stress was noted when the vector was from the center of rotation in the implant prostheses.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.667-673
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• 1996

The prevalence of class III malocclusion is approximately 5$\sim$9%, and about one fourth of this malocclusion is due to underdeveloped maxilla. Maxillary protraction appliance is an orthopedic device which promote the growth of a deficient maxilla by applying extraoral force to actively growing patients. The object of using maxillary protraction appliance is to guide a normal growth of maxilla and mandible and improve the occlusal relationship and also improve the facial profile. The author treated three patients whom were diagnosed as a class III malocclusion due to deficient maxilla using maxillary protraction appliance and the followings are the conclusions : 1. In these cases, anterior crossbite was corrected by anterior movement of maxilla and downward backward rotation of mandible and simultaneously, anterior facial height was increased. 2. The amount of dental change compare to skeletal change was greater as the patients got older. 3. When 500gm of force to each side was applied, the treatment period has been decreased. 4. As a result of applying the force between maxillary first primary molar and canine, there was a small degree of changes in palatal plane. So, it can be concluded that the maxillary protraction appliance is effective in treating growing patients with a deficient maxilla.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.688-696
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• 1996

Garre's osteomyelitis is a unique form of osteomyelitis characterized rediographically by localized thickening of the periosteum and deposition of laminated subperiosteal bone. The most common inciting factor is a mandibular infection in permanent first molar with necrotic pulp. This disease occurs primarily in children and to date in all instances it has occured only in mandible. It usually results in hard swelling over the jaws, producing facial asymmetry with little or no pain. The overlying skin is normal but can occasionally be inflammed mostly when pain is present. Palpation reveals a usually smooth, bone-hard lesion which feel like an inherent part of the mandible. Unlike other forms of osteomyelitis, there is no marked increase in fever, white bloods cell count, sedimentation rate or alkaline phosphatase value. The treatment of Garre's osteomyelitis usually consist of elimination of the sourses of infection, i.e., either extration of an offending infected teeth or root canal therapy. This treatment almost always results in resolution of the Garre's osteomyelitis. Resistant cases have involved secondary surgery, i.e., decortication and sequestrectomy. This report presents three cases of Garre's osteomyelitis resolved by endodontic treatment. Cliniqtl examination revealed swelling on the face with no tenderness. Periapical radiograph showed deep caries lesion extending into pulp chamber and periapical radiolucency. Occlusal radiograph showed an enlargement of bone and stretching the periosteum. A clinical diagnosis of the Garre's osteomyelitis was made. Endodontic treatment was accomplished with conventional method and restored facial symmetry. Long-term check-ups are necessary to evaluate the results of endodontic treatment.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.4
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• pp.341-351
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• 1991

Sixteen Holstein heifer calves were used in an 112-day trial to study the effects of probiotic supplementation on growth performance and rumen metabolism. Calves were divided into four groups of four calves each, with two groups receiving the probiotic supplement and two groups serving as controls. Calves were limited to 1.6 kg dry matter of a corn-barley based grain mix per day. Long-stem bromegrass hay was fed as forage the first 56 days and bromegrass silage the last 56 days of the trial. Probiotic (28 g/d/calf) was fed along with the grain mix twice daily. Data were analyzed for the entire trial and also for the separate hay and silage feeding periods. Total weight gain and average daily gain were not affected (p>.05) by probiotic supplementation. Dry matter intake was lower (p<.05) and feed efficiency (kg feed/kg weight gain) was improved slightly during the hay feeding period for the probiotic-supplemented calves. Wither height gain was greater (p<.05) during the hay period and lower (p<.05) during the silage period for probiotic-supplemented calves. Heart girth gain was improved (p<.07) by probiotic supplementation, particularly during the hay feeding period (p<.05). Total rumen volatile fatty acid (VFA) concentration was higher (p<.05) with the probiotic-supplemented calves. Molar proportions of individual VFA were not affected (p>.05). Rumen ammonia-N and plasma urea-N concentration were lower (p<.05) for probiotic-supplemented calves during the hay feeding period. Total tract nutrient digestibility was not affected (p>.05). Some improvements in animal performance and changes in rumen and blood metabolites were observed when calves were supplemented with probiotic. Effects due to probiotic supplementation were most pronounced during the hay feeding period.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.3
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• pp.255-261
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• 2007

Preface: Dental implant is important method that may solve the mastication, occlusion, esthetic, temporomandibular joint, and psychologic problem in oral and maxillofacial surgery. It is ideal that all of the implant are well positioned by adequate technique. By the way it‘s not always possible because of some anatomic, physiologic factor. In this case, If the implant can be moved to adequate position, it may be possible more esthetically and implanted patients more satisfied, but the majority of Implantists and orthodontists have thought that it is not possible. However, Implant, in fact, can be moved. and thus we can overcome the limit of implantation more. The aim of the present study was to evaluate the possibility of implant movement after corticotomy. Case report: Patient missed the upper right first molar. and implantation was done after completion of socket healing. We wait six months for osseointegration. Then, corticotomy was done under local anesthesia and close coil was used for orthodontic force. After traction during 3 weeks, we find the change of implant position at horizontal plane. we can not see the degenerative change on adjacent structure and tracted implant. there is a clinical mobility on upper right second premolar that used for anchorage but it subside spontaneously at the timing of prosthetic restoration without additional treatment. Discussion: As we could have some knowledge with this experiment, we report the case of implant movement after corticotomy and suggest a method about more esthetic implant treatment with a review of literature.

• The korean journal of orthodontics
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• v.23 no.2 s.41
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• pp.165-177
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• 1993

Upper canine is important because it protects and maintains the stability of the dental arch and also, joins the anterior with the posterior teeth. The incidence of impaction of upper canine is the second most frequent next to the third molar because it takes a long period of time to develop, and has a complicated path of eruption, and erupts lately. After the age of 10, clinical and radioglaphic examination can be used in revealing the possibility of impaction and efforts should be put to reduce the side effects. To prevent impaction, selective extraction of primary canine at the age of 8 to 9 could be considered and prolonged retention of primary canine in oral cavity should be avoided at this time. Once the impaction is iden, the first stage of the treatment is to lcocalize the lesion by radiographic examination and According to the severity, orthodontic traction or autotransplantation should be considered and comprehensive diagnosis and treatment plan of malocclusion should be established. Generally, labial impaction is due to arch length discrepancy and palatal impaction is due to malposition or morphologic pathosis of lateral incisors rather than arch length discrepancy. In surgical procedure, peridontal problems should be considered and the minimum amount of bone and soft tissue should be reduced and direct bonding method of many attachment methods should be recommended. Especially in traction of labially impacted canine, it should be guided to erupt through the keratinized zone and proper forced magnitude should be applied. The importance of periodontal condition should always be in mind following the patient education to mintain the good oral hygiene at each stage of treatment. Properly managed impacted canine can provide function and esthetic by proper diagnosis and treatment if extraction of canine is not indicated.

• Journal of Oral Medicine and Pain
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• v.24 no.1
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• pp.81-94
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• 1999

This study intends to find usefulness of the computer assisted dental identification in mass disaster. The variety of dental characteristics was investigated through the research of dental records of 508 adults. And a computer assisted simulation program was used to evaluate the selectivity of dental identification. Findings were as follows : 1. Combinations of dental characteristics were found 155 types. The most various dental characteristic was showed on the mandibular first molar. 99.0% of subjects had dental characteristics for dental identification. 2. The posterior teeth, in comparison with anterior teeth, showed higher selectivity in dental identification which was enhanced by information on the material, type and cavity of the restoration. 3. The variety of dental characteristics was mainly found on the combinations of missing tooth with the material, type and cavity of the restoration. 4. The computer assisted dental identification program, with informa- tion about one's tooth state, made individual identification possible when there was only a part of the teeth in a corpse. 5. The computer assisted dental identification had considerably high selectivity based on the variety of dental characteristics. And it was also performed faster and preciser than the existing identification methods. Based on the results of this study, there are various combinations of the feature of the tooth itself with dental characteristics caused by a certain type of treatment on the teeth. And using the computer assisted dental identification program based on this, dental identification can be more efficient economically and more useful than any other forensic identification methods.