• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.5
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• pp.417-421
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• 2005

This study was to analyze the changes of levels of alkaline phosphatase before and after enucleation of jaw cysts combined with bone grafting, and to evaluate biochemically the effectiveness of the early detection of bone healing and infection as a prognostic marker. Eighteen patients (13 males, 5 females) with cystic lesions of the jaws were divided into two groups. The bone graft group underwent enucleation and bone graft. The control group underwent only enucleation. Both groups were measured levels of ALP before surgery, and plus-minus 4 weeks postoperatively. The more discriminating results were obtained in the bone graft group. The results were as follows : 1. Levels of ALP after enucleation of jaw cysts were decreased in all patients with and without bone graft. 2. The bone graft group showed more marked decrease in variation of levels of ALP than the control group.(p=0.008) This should be considered as a result of increased osteoblastic activity and new bone formation. 3. Such variation could be used as a prognostic marker for bone healing after cyst operation. In the cost/benefit ratio, measurement of ALP activity could be useful as a convenient procedure in routine clinical practice.

• The korean journal of orthodontics
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• v.52 no.4
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• pp.287-297
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• 2022

Objective: To investigate the pattern of accuracy change in artificial intelligence-assisted landmark identification (LI) using a convolutional neural network (CNN) algorithm in serial lateral cephalograms (Lat-cephs) of Class III (C-III) patients who underwent two-jaw orthognathic surgery. Methods: A total of 3,188 Lat-cephs of C-III patients were allocated into the training and validation sets (3,004 Lat-cephs of 751 patients) and test set (184 Lat-cephs of 46 patients; subdivided into the genioplasty and non-genioplasty groups, n = 23 per group) for LI. Each C-III patient in the test set had four Lat-cephs: initial (T0), pre-surgery (T1, presence of orthodontic brackets [OBs]), post-surgery (T2, presence of OBs and surgical plates and screws [S-PS]), and debonding (T3, presence of S-PS and fixed retainers [FR]). After mean errors of 20 landmarks between human gold standard and the CNN model were calculated, statistical analysis was performed. Results: The total mean error was 1.17 mm without significant difference among the four time-points (T0, 1.20 mm; T1, 1.14 mm; T2, 1.18 mm; T3, 1.15 mm). In comparison of two time-points ([T0, T1] vs. [T2, T3]), ANS, A point, and B point showed an increase in error (p < 0.01, 0.05, 0.01, respectively), while Mx6D and Md6D showeda decrease in error (all p < 0.01). No difference in errors existed at B point, Pogonion, Menton, Md1C, and Md1R between the genioplasty and non-genioplasty groups. Conclusions: The CNN model can be used for LI in serial Lat-cephs despite the presence of OB, S-PS, FR, genioplasty, and bone remodeling.

• Journal of Korean Dental Science
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• v.7 no.1
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• pp.16-24
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• 2014

Purpose: This study was planned to clarify a negative view of chewing gum due to the concern that continuous gum chewing might cause a change in the gonial angle and make the lower facial appearance look square. Materials and Methods: We had 25 adults (13 males and 12 females, with an average of 27.3 years) chew 6 g of gum (spearmint) evenly with both right and left posterior teeth for one hour per day for three months. We then measured their gonial angle, the inclination of occlusal plane, facial height, bone marrow density, and masticatory force before chewing, 1, 2, and 3 month after chewing to verify its significance statistically. Result: The results showed that the gonial angle increased from $122.7^{\circ}$ to $123.3^{\circ}$ (P>0.05), and thus the jaws became slightly slimmer. There was no change in the occlusal plane inclination and facial height. Meanwhile bone marrow density in the mandibular angle and ascending ramus increased from $0.285g/cm^2$ to $0.290g/cm^2$ (P<0.05), and masticatory force also increased by 0.5 kg on the right side and 0.8 kg on the left side (P<0.05). Conclusion: Continuous chewing of gum gives an appropriate exercise effect to the stomatognathic system. As chewing gum has effect on increase bone marrow density without changing the mandibular angle and facial appearance the claim that jaw bone changes to a square jaw through chewing gum is regarded to be groundless.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.4
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• pp.317-321
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• 1993

Two patients with maxillary developmental deficiency who have previously undergone cheiloplasty and palatoplasty were operated on by simultaneous two jaw surgery and maxillary advancement surgery respectively. And the following results were obtained. 1. After the operation, maxilla shifted superiorly, and then inferiorly without noticible posterior relapse. 2. Postoperative mandibular relapse to the anterior direction was evident in both cases. 3. It is highly suggested that definitive measures to enhance postoperative stability in orthognathic surgery on the cleft lip and palate patients be developed.

• Journal of Oral Medicine and Pain
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• v.38 no.3
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• pp.275-289
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• 2013

This study was conducted to investigate and analyze the dental patients' awareness and understanding about TMDs. Among the total number of 243 patients who had visited the department of dentistry of Busan Paik Hospital, Inje University or Hanvit dental hospital in Ulsan metropolitan city and participated in the survey, 195 patients who filled in all parts of the questionnaire were selected as the subjects. The results were as follows. 1. The subjects who were aware of the term, "TMDs" were 17.4%. The group with total education period of 12 years and over was significantly more aware of "TMD"(82.4%, p<0.01) than the other group. The subjects who were aware of the term, "jaw joint disease" were 81.0%. 30 to 49 age group(45.6%, p<0.05) and the group with total education period of 12 years and over(60.1%, p<0.01) were significantly more aware of "jaw joint disease" than other groups. 2. More than half of the subjects chose "overuse of the jaws" as the concept of jaw joint disease(50.6%). 3. TV, radio(41.4%) was the most frequent source of awareness about jaw joint disease followed by family and friends(20.2%), hospitals and health professionals(18.2%), internet(15.7%) and newspapers, magazines(4.5%). Among the respondents who were aware of jaw joint disease through TV, radio, 30 to 49 age group showed significantly higher percentage(52.4%, p<0.05) than other age groups. Among the respondents who were aware of jaw joint disease through internet, 18 to 29 age group showed significantly higher percentage(61.3%, p<0.01) than other age groups. Among the respondents who were aware of jaw joint disease from hospitals and health professionals, the group with total education period of 12 years and over showed significantly higher percentage(75.0%, p<0.05) than the other group. 4. Noise during mouth opening and closing(26.9%), mouth opening difficulty(25.1%) and jaw pain(13.7%) were the most frequently responded sign and symptoms of jaw joint disease. For the causes of jaw joint disease, enjoying hard food chewing(19.5%), occlusal discrepancy(19.0%) and chewing with one side only(18.5%) were responded in sequence. TMJ surgery(28%) was the most frequently responded treatment method for jaw joint disease, followed by occlusal appliance therapy(23.9%) and physical therapy(14.6%). For preventive method of jaw joint disease, avoid eating hard food(21.1%), avoid opening mouth wide(17.0%) and simultaneous using of molar of both side when chewing food(15.4%) were chosen frequently.

• Archives of Craniofacial Surgery
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• v.16 no.2
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• pp.96-98
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• 2015

Maxillomandibular fractures usually require intermaxillary fixation as a means to immobilize and stabilize the fracture and to re-establish proper occlusion. Arch bars or intermaxillary fixation screws cannot be used for edentulous patients or for patients who have poor dental health. Here, we present a case of repeated intermaxillary fixation failure in a patient weak alveolar rigidity secondary to multiple dental implants. Because single-point fixation screws were not strong enough to maintain proper occlusion, we have used Y-shaped plates to provide more rigid anchoring points for the intermaxillary wires. We suggest that this method should be considered for patients in whom conventional fixation methods are inappropriate or have failed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.2
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• pp.94-99
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• 2017

Objectives: Idiopathic bone cavity (IBC) is an uncommon intra-osseous cavity of unknown etiology. Clinical features of IBC are not well known and treatment modalities of IBC are controversial. The purpose of this study was to investigate the clinical characteristics of 27 IBC patients who underwent surgical exploration. Materials and Methods: A total of 27 consecutive patients who underwent surgery due to a jaw bone cavity from April 2006 to February 2016 were included in this study. Nine male and 18 female patients were enrolled. Patients were examined retrospectively regarding primary site, history of trauma, graft material, radiographic size of the lesion, presence of interdental scalloping, erosion of the inferior border of the mandible, complications, results of bone graft, and recurrence. Results: Female dominance was found. Maxillary lesion was found in one patient, and bilateral posterior mandibular lesions were found in two patients. The other patients showed a single mandibular lesion. The posterior mandible (24 cases) was the most common site of IBC, followed by the anterior mandible (5 cases). Two patients with anterior mandibular lesion reported history of trauma due to car accident, while the others denied any trauma history. Radiographic cystic cavity length over 30 mm was found in 10 patients. Seven patients showed erosion of the mandibular inferior border. The operations performed were surgical exploration, curettage, and bone or collagen graft. One bilateral IBC patient showed recurrence of the lesion during follow-up. Grafted bone was integrated into the native mandibular bone without infection. One patient reported necrosis of the mandibular incisor pulp after operation. Conclusion: Differential diagnosis of IBC is difficult, and IBC is often confused with periapical cyst. Surgical exploration and bone graft are recommended for treating IBC. Endodontic treatment of involved teeth should be evaluated before operation. Bone graft is recommended to reduce the healing period.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.5
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• pp.428-436
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• 2008

For Longevity of implant, considerations of biomechanical and microbiological aspects must be done. Recently, due to the remarkable development of bone grafting procedure. Implant has been implanted into the more favorable sites but peri-implantitis resulted from periodontal bacteria may obscure the long-term prognosis. Although many different modalities have been introduced to treat the failed implant. Implant's surface and irreversible bony destruction around the implant prevents good result. After Er,Cr:YSGG (waterlase) laser using the wave-length of 2780nm has been introduced to dental field, good results have been reported. Because waterlase uses the hydrokinetic force of water. It is excellent device to detoxify the implant surface mechanically without the heat generation and damage to the implant surface. We designed to evaluate waterlase effect on the peri-implantitis has been occurred after implantation. Four beagle dogs were involved. We have made four premolar extraction in each right and left side of the lower jaw and placed two implants in the anterior of the jaw as a control and six implant were placed posterior in each socket after extraction immediately as an experimental group. We tied floss-silk in each implant to make peri-implantitis intentionally. After three months, we explored peri-implant sites on each experimental fixtures. Using waterlase laser irradiation was performed on that implantitis sites under 3W, air 30% and water 20% intensity for 2 minutes. In control group, we repositioned the flap to cover the exposed fixture without any supportive care. Three months later, we sacrificed experimental animals and extracted and preparated bone blocks with Donath and Breuner (982), Donath (988)'s methods and examined under microscope. We have obtained good re-osseointegration around fixtures after treating with waterlaser irradiation. But it was shown fibroosseointegration in the control group.

• The Journal of the Korean dental association
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• v.57 no.2
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• pp.100-104
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• 2019

Orthognathic surgery is designed to correct problems of the jaw and face and restore facial harmony. The limitations of orthognathic surgery occur at all steps of the surgical workflow: preoperative planning, simulation, and operation. Many studies have shown the accuracy and advantages of 3 dimensional computer-assisted program for orthognathic surgery. The purpose of this paper is to introduce the accuracy of the maxillary repositioning in patients who underwent orthognathic surgery using a 3 dimensional computer assisted surgery program. The reliability of computer guided orthognathic surgery using splint and surgical guide need to be improved further. The 3 dimensional computer assisted analysis seems to be more precise to interpret than two-dimensional analysis. High-precision planning of orthognathic surgery has predictable results. Three-dimensional computer assisted orthognathic surgery has the following advantages : planned surgical movement is possible, splints guide with CAD/CAM technology; and increase predictable results .Computer assisted simulation surgery ensures accuracy during surgery, thereby facilitating predictable results. It may provide solution that enables surgeon to perform planned surgery more accurately.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.2
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• pp.150-160
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• 2005

Background: For normalization of displaced anatomical structure by large cyst, two-step procedure (decompression and enucleation afterward) has been recommended. However, the histological transformation after cystotomy for decompression was shown frequently in secondary enucleation. Therefore, analyses about effects and histological changes after decompression have been necessary. Methods: 48 cases diagnosed as large odontogenic cyst in the jaw and treated by decompression and secondary enucleation were retrospectively analyzed in clinical, rediographical, and histological aspects. Results: In dentigerous cyst, decompression was much useful. Impacted permanent teeth were erupted and reduction rate was higher than that of odontogenic keratocyst (OKC) and apical periodontal cyst. In OKC, among the 29 cases, 11 cases showed no-keratosis, proliferation and rete-ridge elongation after decompression. 4 cases showed no-keratosis, only. 7 cases showed orthokeratosis and rete-ridge elongation and 6 cases showed reteridge elongation, only. 1 case had no change. And the recurrence rate for OKCs was 10.3%. For all odontogenic cysts in this study, dysplasia was not found in cystic lining after decompression. Conclusions: This study implied that decompression for large odontogenic cyst was useful treatment modality because it was conservative treatment and recurrence rate was low although long treatment period was required.