• Journal of Periodontal and Implant Science
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• v.44 no.5
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• pp.216-221
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• 2014

Purpose: This retrospective study compares the amount of bone resorption around implants between an autogenous tooth bone graft (AutoBT) and a synthetic bone graft after a bone-added crestally approached sinus lift with simultaneous implant placements. Methods: In all, 37 patients participated in this study. Seventeen patients were grouped as group I and underwent an AutoBT-added sinus lift using the crestal approach. The remaining 20 patients were grouped as group II and underwent synthetic bone grafting. Both groups received the implant placements simultaneously. Of the 37 participating patients, only 22 patients were included in the final results: Eleven patients of group I and 11 patients of group II. Before the surgery, the distance from the alveolar crest to the sinus floor was measured using panoramic radiography. After the surgery, the distance was measured again from the neck of the implant thread to the most superior border of the added graft materials. Then, the amount of sinus lift was calculated by comparing the two panoramic radiographs. After a year, a panoramic radiograph was taken to calculate the resorption of the bone graft material from the radiograph that was taken after the surgery. The significance of the resorption amount between the two types of graft materials was statistically analyzed. Results: The bone height was increased to an average of 4.89 mm in group I and 6.22 mm in group II. The analysis of panoramic radiographs 1 year after the surgery showed an average bone resorption of 0.76 mm and 0.53 mm, respectively. However, the degree of lifting (P=0.460) and the amount of bone-grafted material resorption (P=0.570) showed no statistically significant difference. Conclusions: Based on this limited study, AutoBT can be considered a good alternative bone graft to a synthetic bone graft in a bone-added sinus lift, when extraction is necessary prior to the surgery.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.147-154
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• 2006

Surgical intervention in the posterior maxillary region requires detailed knowledge of maxillary sinus anatomy and the possible anatomical variations. This study evaluated the incidence, location of maxillary sinus septa by using radiographic (panoramic radiography and computed tomography) findings and comparison of panoramic radography with CT in antral anatomical variation. This study was based on data from 70 sinuses in partial dentate maxilla. The sample consisted of 61 patients(25 women and 36 men, with ages ranging between 19 and 77 years and a mean age of $49.4{\pm}11.3$ years) who were being treatment-planned to receive implant-supported restorations. First, the panoramic images were examined for the presence of antral septa by radiologist and examiner who don't know about CT findings. And incidence of antral septa was evaluated using an axial plane of CT image. The incidence of septa was compared between panoramic radiography and CT. The accuracy of the incidence was compared between radiologists and dentists. A total of 20 septa were found in 70 sinuses on CT image and the prevalence of one or more septa per sinus was found to be 28.6%. The assumed incidence of septa on panoramic radiography was $27.6%{\pm}2.2%$ in radiologist and $31.9%{\pm}5.8%$ in dentists. Erroneous diagnosis rate was 11.42% in radiologist and 15.96% in dentists. 40% of antral septa were located in the anterior(premolar) region, 30% of septa were located in the middle(first molar) and posterior(second molar) region separately. Prior to implant placement, it seems appropriate to consider panoramic radiography as a standard radiographic examination and periapical radiographs may be used to complete the findings in regions not sharply depicted in the panoramic radiograph. And cross-sectional imaging should be used in sites with severe bone loss and close proximity of the maxillary sinus.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.2
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• pp.121-130
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• 2004

The purpose of this study was the long-term clinical and radiological evaluation of conservatively treated condylar fractures in children. This study was therefore undertaken to analyze the long-term effects of treating condylar fractures in children with conservative therapy in order to resolve the controversial question of whether complete remodeling occurs in this age or, if not, whether it is more likely to be associated with certain types of fracture or with other factors. This study was based on a series of 11 consecutive children and adolescents, aged between 3 and 15 years, with fractures of the condylar process who had been treated with conservative therapy at the Department of Oral & Maxillofacial surgery, Inha University Hospital, Inchon, Korea. All patients underwent a clinical investigation with special emphasis on Temporomandibular joint function and facial asymmetry. The patients also underwent a radiologic investigation, focusing on fracture remodeling and symmetry of mandible. It consists of panoramic radiograph, PA & lateral cephalogram and 3-D CT. No patient described impaired temporomandibular joint(TMJ) function or pain on the affected side. 2 of 8 (25%) unilateral and 1 bilateral fractures show slight facial asymmetry. Despite apparently excellent recovery of function, there were marked remodeling changes evident on the CT scan. Such changes are not usually evident on panoramic radiograph. Radiologic investigation showed incomplete remodelling(54.5%) and asymmetry of the mandible (27.3%) in some patients. Conservative treatment of condyle fracture in children results in satisfactory long-term outcome of jaw function despite a relative high frequency of radiologically noted aberrations.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.2
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• pp.120-127
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• 2021

Primary intraosseous squamous cell carcinoma (PIOSCC) is very rare type of squamous cell carcinoma (SCC) that occurs within the jaw and arises from remnants of odontogenic epithelium with no connection to the oral mucosa. This study reports two cases of PIOSCC of the mandible. Reported in this article are two cases of PIOSCC of the mandible that were treated with resection and reconstruction using a fibular free flap. The first case was a 36-year-old male patient who complained of right mandibular pain. Computed tomography (CT) and panoramic radiograph revealed a large radiolucency in the mandibular ramus area. At first, an odontogenic keratocyst was tentatively diagnosed, and an excision procedure was carried out at another clinic. A final biopsy after cyst enucleation revealed well-differentiated SCC, so we proceeded with segmental mandibulectomy and reconstruction using a fibular free flap. The second case was a 48-year-old male patient with left mandibular pain. CT and panoramic radiograph revealed irregular radiolucency in the mandibular angle area near tooth #38. At first, osteomyelitis was tentatively diagnosed, and a curettage was carried out. A later biopsy revealed well-differentiated SCC, so segmental mandibulectomy and reconstruction with a fibular free flap were secondarily performed. Our two cases have had no recurrence. The facial appearance of both patients is satisfactory, and the neo-mandibular body created using a fibular bone transfer displays adequate bony volume.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.47-58
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• 1998

The purpose of this study was to investigate an influence of the change of central panoramic curves on the image reconstruction in the dental implant CT. The author designed three experimental groups according to the location of central panoramic curve. In group A, central panoramic curve was determined as the curve connecting the center of roots from the first premolar to the first molar. In group B, central panoramic curve was determined as the line connecting the lingual cortical plate at the level of the mesial aspect of the first premolar with the buccal cortical plate at the level of the mesial aspect of the first molar. In Group C, central panoramic curve was determined as the line connecting the buccal cortical plate at the level of the mesial aspect of the first premolar with the lingual cortical plate at the level of the mesial aspect of the first molar. Twenty four reformatted CT images was acquired from four mandibles embedded in the resin block and twenty four contact radiographs of dog specimens were acquired. Each Image was processed under Adobe Photoshop program analysed by MSPA(mandible/maxilla shape pattern analysis) variables such as MXVD, MXHD, UHD, MHD, and LHD. The obtained results were as follows ; 1. The mean of MXVD variable was 19.9, 20.2, and 20.0 in group A, B, and C, respectively, which were smaller than actual value 20.5. But, there was no significant difference among 3 groups (p>0.05). 2. The mean of MXHD, UHD, MHD, and LHD variables in group A, B, and C was 11.9, 12.2, and 12.3; 9.3, 9.5, and 9.6; 10.0, 10.3, and 10.3; 9.2, 9.3, and 9.4 respectively which were equal to or greater than the actual value 11.8, 9.3, 10.0, and 9.2. But, there was no significant difference among 3 groups (p>0.05). 3. The number of noneffective observations with difference over or under 1 mm with comparison to the actual value was 24(20％), 58(48.3％), and 52(43.3％), respectively, in group A, B, and C. 4. In group A, the number of observations over 1 mm and under 1 mm was 9 and 15, respectively, but in group Band C, the number of observations over 1 mm was more than under 1 mm.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.545-548
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• 1998

Sialolithiasis is the formation of calcareous concretions within ductal system of a major or minor salivary gland. They are formed by deposition of calcium salts around a central nidus which may consist of desquamated epithelial cells, bacteria, foreign bodies, or products of bacterial decomposition. An 11-year-old boy complained of pain during meals and intermittent mild swelling in the right submandibular region. Although it was not detected in true occlusal radiograph, panoramic radiograph showed a round radiopaque mass 3mm in diameter. Computed tomography(CT) was taken for locating the stone and 3-dimensional reconstruction was performed. Under general anesthesia, sialoadenectomy was done through extraoral approach. Diagnosis of submandibular sialolithiasis using high-resolution CT with reconstructions was helpful for surgical decisions, namely radical removal of the submandibular gland and its duct.

• The Journal of the Korean dental association
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• v.52 no.1
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• pp.8-16
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• 2014

The introduction of cone-beam computed tomography(CBCT) and computer software in orthodontics has allowed orthodontists to provide more accurate diagnosis and treatment. The most common use of CBCT imaging allows orthodontists to visualize the precise position of supernumerary or impacted teeth, especially impacted canines. In doing so, the exact angulation of impaction and proximity of adjacent roots can be evaluated by orthodontists, allowing them to choose vector forces for tooth movement while minimizing root resorption. Even though 2-dimensional panoramic images can be used to view the position of the impacted canines, they have limitations because it is not possible to evaluate the impacted tooth position 3-dimensionally. An accurate knowledge of root position improves the determination of success in orthodontic treatment. Nowadays, considering the fast pace of technological development, a combination of intraoral scanning, digital setups, custommade brackets and wires, and indirect bonding may soon become the orthodontic standard. In this paper, this will be discussed along with the digital models.

• Imaging Science in Dentistry
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• v.43 no.3
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• pp.201-207
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• 2013

A 40-year-old man suffered from a repeatedly recurrent desmoplastic ameloblastoma in the right maxillary anterior and premolar regions. During the first visit, the patient was provisionally histopathologically diagnosed with a developmental cyst, and it was confirmed to be unicystic ameloblastoma and resected. Four years later, the lesion recurred, and was diagnosed as a desmoplastic type of ameloblastoma and removed again. Then, 5 years after the second surgery, the lesion recurred again, and was diagnosed as a type containing a follicular pattern, recurrent ameloblastoma. A panoramic radiograph showed a multilocular and mixed radiolucent/radiopaque expansile lesion at the first visit, a unilocular cystic lesion confined to the premolar area at the second visit, and a small soap bubble appearance in the molar area in the final visit. Cone-beam computed tomographic images of the final recurrence of the tumor revealed multiple small cyst-like structures in the right maxillary anterior and posterior regions.

• Imaging Science in Dentistry
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• v.36 no.1
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• pp.55-62
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• 2006

Purpose : To find the cause of root curvature by use of panoramic and lateral cephalometric radiograph. Materials and Methods : Twenty six 1st graders whose mandibular 1st molars .just emerged into the mouth were selected. Panoramic and lateral cephalometric radiograph were taken at grade 1 and 6, longitudinally. In cephalometric radio graph, mandibular plane angle, ramus-occlusal plane angle, gonial angle, and gonion-gnathion distance (Go-Gn distance) were measured. In panoramic radio graph, elongated root length and root angle were measured by means of digital subtraction radiography. Occlusal plane-tooth axis angle was measured, too. Pearson correlations were used to evaluate the relationships between root curvature and elongated length and longitudinal variations of all variables. Multiple regression equation using related variables was computed. Results : The Pearson correlation coefficient between curved angle and longitudinal variations of occlusal plane-tooth axis angle and ramus-occlusal plane angle was 0.350 and 0.401, respectively (p<0.05). There was no significant correlation between elongated root length and longitudinal variations of all variables. The resulting regression equation was $Y=10.209+0.208X_1+0.745X_2$ (Y: root angle, $X_1$: variation of occlusal plane-tooth axis angle, $X_2$: variation of ramus-occlusal plane angle). Conclusion : It was suspected that the reasons of root curvature were change of tooth axis caused by contact with 2nd deciduous tooth and amount of mesial and superior movement related to change of occlusal plane.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.4.1-4.10
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• 2019

Background: The mandibular third molar (M3) is typically the last permanent tooth to erupt because of insufficient space and thick soft tissues covering its surface. Problems such as alveolar bone loss, development of a periodontal pocket, exposure of cementum, gingival recession, and dental caries can be found in the adjacent second molars (M2) following M3 extraction. The specific aims of the study were to assess the amount and rate of bone regeneration on the distal surface of M2 and to evaluate the aspects of bone regeneration in terms of varying degree of impaction. Methods: Four series of panoramic radiographic images were obtained from the selected cases, including images from the first visit, immediately after extraction, 6 weeks, and 6 months after extraction. ImageJ software^® (NIH, USA) was used to measure linear distance from the region of interest to the distal root of the adjacent M2. Radiographic infrabony defect (RID) values were calculated from the measured radiographic bone height and cementoenamel junction with distortion compensation. Repeated measures of analysis of variance and one-way analysis of variance were conducted to analyze the statistical significant difference between RID and time, and a Spearman correlation test was conducted to assess the relationship between Pederson's difficulty index (DI) and RID. Results: A large RID (> 6 mm) can be reduced gradually and consistently over time. More than half of the samples recovered nearly to their normal healthy condition (RID ≤ 3 mm) by the 6-month follow-up. DI affected the first 6 weeks of post-extraction period and only showed a significant positive correlation with respect to the difference between baseline and final RID. Conclusions: Additional treatments on M2 for a minimum of 6 months after an M3 extraction could be recommended. Although DI may affect bone regeneration during the early healing period, further study is required to elucidate any possible factors associated with the healing process. The DI does not cause any long-term adverse effects on bone regeneration after surgical extraction.