• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.11 no.2
• /
• pp.53-59
• /
• 1989

The ameloblastoma is the most common form of the odontogenic tumors exhibiting minimal inductive change in connective tissue, it comprising 1% of all tumor and cysts of the jaws. It is a true neoplasm, generally considered to be a benign but persistent or, locally malignant lesion. The tumor occurs most commonly in persons between the age of 20 and 50 years. 80% and 90% of all lesions are in the mandible. The presenting clinical signs and symptoms of the ameloblastoma very from patient to patient, but most common symptom was swelling, followed by pain, draining sinuses, and superficial ulcerations. It is slow-growing lesion, and the radiographic features of the ameloblastoma depend large one the nature and the local bone reaction to the particular tumor. Recurrence rate is about 33%, but this is probably due to incommplete initial removal of lesion. We had operated a patient ; 29-year-old female immediate reconstruction combined with autocompression plate and iliac bone graft and screw fixation after hemimandibulaectomy with recurred ameloblastoma involving from premolar to ascending ramus at right side mandible. We obtained favorable results of good function, short intermaxillary fixation periods and easy operation precedure than the other reconstruction methods.

• The korean journal of orthodontics
• /
• v.30 no.6 s.83
• /
• pp.699-712
• /
• 2000

Reduced nasal breathing can influence the growth at)d development of facial structures. It nay have many causes, and enlarged adenoid is the most frequent one. To investigate the effects of adenoids to jaw growth, we must first understand the normal growth of adenoids and jaws, and the relationship between size of adenoids and the values lot the jaw variables. The purpose of this study is to present a more objective standard of nasopharyngeal size and jaw dimension at each bone age, by using Cervical Vertebrae Maturation Index(CYMI) of Hassel, from normal occlusion children aged 6 to 17. The results of this study suggests as follows : 1. At same bone age, female's chronologic age was about 2 year older than male. 2. There was a growth peak of nasopharyngeal(NP) height and depth between CVMI 1 to 2 in male, hut in female NP height and depth gradually increase through CVMI 1 to 6. 3. Relative airway of nasopharynx increases the most between CVMI 1 to 2 period in both gender 4. Among adenoid measurements, Ad2-related variables and upper pharynx, and among dentofacial measurements inter canine width in both arch, maxillary intermolar width and palatal depth had high correlation coefficient with adenoid percentage.

• The korean journal of orthodontics
• /
• v.30 no.6 s.83
• /
• pp.687-698
• /
• 2000

The purpose of this study was to evaluate the changes of skeletodental patterns during Class II treatment and its retention period. Forty two patients of Class II malocclusion, which was treated with nonextraction or first premolar-extraction were selected and their lateral cephalograms were examined in this study. Various skeletodental changes in lateral cephalograms of pre-treatment, post-treatment and retention were measured by superimposition in reference to the cranial base for jaws, the palatal plane for maxillary teeth, and mandibular plane for mandibular teeth. The data were analyzed by paired t-test. In this study, occlusal plane showed the significant anterior downward steepening after active treatment, and remained during retention period. In the nonextraction group, maxillary incisors were retracted and extruded during treatment. Maxillary molars were extended, and mandibular molar were uprighted, with no mesial movement. In the extraction group, both maxillary and mandibular incisors were retracted and extruded. Maxillary molars were extruded and moved mesially, and mandibular molars were extruded and moved mesially with no mesial tilting. During retention period in both groups, there were tendencies of labial tipping of maxillary incisor, and mesial tipping of maxillary and mandibular molar. But the changes were not significant and most of teeth showed no change in vortical and horizontal direction.

• Journal of radiological science and technology
• /
• v.39 no.4
• /
• pp.571-575
• /
• 2016

Monte Carlo simulations are widely used as the most accurate technique for dose calculation in radiation therapy. In this paper, the GATE6(Geant4 Application for Tomographic Emission ver.6) code was employed to calculate the dosimetric performance of the photon beams from a linear accelerator(LINAC). The treatment head of a Varian 21EX Clinac was modeled including the major geometric structures within the beam path such as a target, a primary collimator, a flattening filter, a ion chamber, and jaws. The 6 MV photon spectra were characterized in a standard $10{\times}10cm^2$ field at 100 cm source-to-surface distance(SSD) and subsequent dose estimations were made in a water phantom. The measurements of percentage depth dose and dose profiles were performed with 3D water phantom and the simulated data was compared to measured reference data. The simulated results agreed very well with the measured data. It has been found that the GATE6 code is an effective tool for dose optimization in radiotherapy applications.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.37 no.3
• /
• pp.176-183
• /
• 2011

Introduction: Very high aggressiveness and recurrence are important clinical characteristics of ameloblastoma compared to the other benign tumors. Therefore, an accurate diagnosis and treatment plan is important. This study examined the association of the clinical findings and recurrence based on the radiological findings of ameloblastoma. In recurrent cases, these results are expected to help in the diagnosis and treatment of ameloblastoma to examine the relevance with the clinical characteristics and radiological features. Materials and Methods: For a clinical (gender, age) and radiological (location, internal pattern, size, perforation, border pattern, impacted tooth, root resorption) evaluation, this study examined 156 cases of 147 patients diagnosed with ameloblastoma, who had been treated and in most cases regularly checked at the department of oral and maxillofacial surgery, Kyungpook National University Hospital, between January 1993 and December 2009. For a recurrent rate evaluation, a more than 3 years follow-up period is needed. Accordingly, 116 patients diagnosed with ameloblastoma between January 1994 and December 2007 were investigated. Results: The recurrence rate in all cases was 6.1% but was 7.8% in cases with follow-up periods more than 3 years. The male-to-female ratio was 3:2, showing a slight male predilection. Ameloblastoma had a peak occurrence in the second decade of life followed by the fourth decade of life. The mandibular angle area is the most frequent site of ameloblastoma (50.8%) in the jaws. Six cases of unilocular (7.8%) and 3 cases of multilocular (7.7%) ameloblastomas recurred. Seven cases of smooth (10%) and 2 cases of irregular (4.3%) ameloblastomas recurred. No cases of ameloblastomas without perforation of the cortical bone (0%) and 9 cases with a perforation of cortical bone (11.1%) recurred. Four cases of the ameloblastomas with impacted teeth (11.4%) and 5 cases of ameloblastomas without impacted tooth (6.2%) recurred. Seven cases of ameloblastomas with root resorption (10.9%) and 2 cases of ameloblastomas without root resorption (3.8%) recurred. Conclusion: A multiple smooth margin, unilocular ameloblastoma with an impacted tooth, root resorption tends to recur more easily. Therefore, they need to be treated more carefully and require a a longer follow-up.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.35 no.3
• /
• pp.153-157
• /
• 2009

Recently, an increasing number of bisphosphonate related osteonecrosis of the jaw(BRONJ) is being reported. A guideline has been already established in the US, but it does not seem to be fully recognized by clinicians in Korea. Therefore, a survey study was done to inform and have clinicians realize the seriousness of BRONJ. 1,341 practitioners were randomly selected out of 13,405 practitioners(by Feb of 2008, KDA) in Korea. A questionnaire was given to them between May to July in 2008. Questions were designed to investigate each respondent's experience term years in the clinic, occupation, speciality, awareness on risk of bisphosphonate, experience on treating osteonecrosis patients, awareness about the guideline on BRONJ suggested by AAOMS and whether if they ask about bisphosphonate medication history to patients before invasive treatment. 45.1% of the clinicians have reported on experiencing delayed healing on bone exposed site after extraction both in the maxilla and the mandible. However, clinicians have asked the patients whether if they are on bisphosphonate or not in only 15.1% of these cases. 56.5% of the clinicians simply knew about BRONJ but only 28.9% of the clinicians were aware that bisphosphonate can cause osteonecrosis after invasive dental treatment. Only 19.3% knew about the contents of guideline on BRONJ and 57.2% were aware of the seriousness of BRONJ. Clinicians with shorter clinical experience term were more aware of BRONJ and the guideline on BRONJ than the experienced clinicians. But awareness of the possibility of BRONJ after invasive dental treatment were about the same regardless of their clinical experience. The results show that Korean clinicians need to be more aware about BRONJ. Data on BRONJ cases in Korea should be collected and provided with additional education to let Korean clinicians know and be more aware about BRONJ.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.2
• /
• pp.200-206
• /
• 2005

Cemento-ossifying fibroma of the jaws is well circumscribed, generally slow-growing, benign lesions which enlarge in an expansile manner. Clinically it presents as a slowly enlarging lesion commonly in the premolar-molar area of the mandible and only occasionally in the maxilla and other locations. It occurs twice as often in females and primarily in the 20 to 30 year age group. Differential diagnosis should be peformed, preferably with other fibro-osseous lesions such as fibrous dysplasia. A faster growing and more destructive variant of cemento-ossifying fibroma sometimes occurs in patients under age 15 and is termed juvenile (aggressive) ossifying fibroma. Treatment is surgical removal with the extent depending on the size and location of the individual lesion. Recurrence is considered rare. A case involving a 12-year-old male patient with delayed eruption of right mandibular canine is discussed. Following an incisional biopsy, the histopathologic diagnosis established was cemento-ossifying fibroma. After the surgical enucleation of the lesion, no sign of recurrence was detected.

• The korean journal of orthodontics
• /
• v.20 no.3 s.32
• /
• pp.447-462
• /
• 1990

The objective of this experiment is to observe structural differences in the othodontic movement of vital (control group) and devitalized (experimental group) teeth in the mongrel dogs. The 5 utilized dogs in this experiment were approximately 1 year of age and their average weight was about 12 Kg. Endodontic therapy was performed on the 2nd premolars in upper & lower jaws of each animal under the general anesthesia by intravascular injection of 25mg/kg of pentobarbital sodium. The canals of the teeth were obturated by using gutta percha in conjunction with root canal sealer (AH26 Densply). One of the roots in the 2nd premolars was hemisected to make an extraction space for the devitalized teeth to be moved. The edgewise technique was employed for the movement of the teeth. Orthodontic models and intraoral roentgenograms were taken before and after orthodontic tooth movement. The open coil springs (.010 x .040) were used at interbraket space in order to provide equal forces (75gm) between the teeth in each arch wire. After 13 weeks of active orthodontic tooth movement, dogs were sacrified and the experimental results w ere examined through the intraoral radiography, microscopic examination and scanning electromicroscopic examination at the root sulfate. From the results of the study, the following conclusions may be drawn: The root resolution and cemental deposition were observed within the pressure and tension site in both group. 2. The root resorbed lacunae were observed in the cementum and/or into the dentin in both group. 3. The prominent osteoblastic activities were observed on the alveolar margin in the tension site in both group. 4. A few of blood vessels were observed in the pressure site, but also lots of blood vessels were observed in the tension site especially in the periphery of the alveolar bone in both group. 5. In the pressure site, resorbed lacunae were formed with deep and narrow cavity in the control group; the shallow and wide cavity in the experimental group. 6. In the pressure site, the repaired cementum or cementoid tissue was lined on cementum in the experimental group, but not in the control group. 7. There was no significant difference between external root resolution of endodontically and vital teeth when both were subjected to orthodontic forces.

• The korean journal of orthodontics
• /
• v.26 no.2 s.55
• /
• pp.125-139
• /
• 1996

The author obtained some useful information for the class III treatment from long term observation on the growing patients with class III malocclusion. 8 patients were selected for this study and presentation. From these observation so far my conclusions might be as follows: First in the early correction of the anterior crossbite, considerable forward growth changes were observed in the maxilla Second, as for the growth modification of jaws by orthopedic treatment only limited effects were recognized from the long-term observation Thrid, at early age of patients with anterior crossbite, any data couldn't make me predict the stability after treatment on the long-term basis. Fortunately, however, genial angle showed a marginal possibility of it prediction. Fourth, at an advanced age/ retraction orthopedic force on the mandible and the rapid change in the mandibular position may cause some trouble in the T.M.joint. Finally, the followings are recommendable. As for the anterior crossbite, correct it early as possible, and use orthopedic force under the age of ten. Do not enter the phase II treatment directly. Just wait and observe until the growth were almost completed, focusiong on some important factors such as airway problem, tongue position, and third molar development. Of course, these factors may have some effects on the mandibular growth. for the female, at the age of around 14 years old and the male, around 17 years old, make a final decision whether the patients will continue to be treated orthodontically or surgically Thereby, (I think) the relapse and retreatment problem after treatemnt we have observed so far might be minimized. Furthermore, the active treatment time may be also reduced.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.25 no.2
• /
• pp.399-408
• /
• 1995

The purpose of this study was to obtain information on the clinical and radiographic features of the dentigerous cysts in the jaws. For this study, the authors examined and analysed the clinical records and radiographs of 233 patients who had lesions of dentigerous cyst diagnosed by clinical and radiographic or histopathological examinations. And the obtained results were as follows: 1. Dentigerous cysts occurred the most frequently in the 2nd decade(38.2％) and occurred more frequently in males(67.4％) than in females(32.6％). 2. The most common clinical symptom was swelling of the jaw(33.9％), and the lesions were treated by the method of surgical removal. 3. The type of lesions was mainly observed as central type(72.5％), and size of the lesion was most frequently observed 2 - 2.9cm in the widest length. 4. The lesions were most frequently observed well-defined outline with hyperostotic border(49.8％), and smooth margin(73.4％), and homogeneous lesional radiolucency(79.4％). 5. Cortical thinning and expansion of the lesions(82.0％) were observed, and their direction were most frequently observed toward buccal side(64.0％). 6. The effect on the causative tooth were observed as tooth displacement(41.2％) and delayed root development(l9.3％), and the distance between cemento-enamel junction and lesional wall attachment of the causative tooth was mainly observed as below 2mm(79.6％). 7. The effect on the adjacent tooth were observed as loss of lamina dura(66.8％), root resorption(33.9％), and tooth displacement(31.5％). 8. The effects on the adjacent anatomic structures were observed as displacement of the mandibular canal(46.5％) and maxillary sinus or nasal cavity(72.2％).