• 대한소아치과학회지
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• 제48권3호
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• pp.255-268
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• 2021

이 연구의 목적은 한국 아동의 골 성숙 단계와 여러 치아들의 석회화 단계 간의 상관관계를 알아보고자 하는 것이다. 만 6 - 14세의 남아 359명, 여아 384명의 수완부 방사선사진, 측방두부규격 방사선사진, 파노라마 방사선사진을 분석하여 평가하였다. 하악 좌측의 7개 영구치의 치아 석회화 단계는 Demirjian이 제시한 방법에 의해 평가되었다. 골 성숙도 단계를 평가하기 위하여 수완부 방사선 사진은 Fishman이 제시한 skeletal maturity indicators(SMI)에 따라 평가되었고, 측방두부규격 방사선사진은 Baccetti가 제시한 cervical vertebral maturation(CVM) 방법에 따라 평가되었다. Spearman의 순위상관분석을 시행한 결과 치아 석회화 단계와 골 성숙도 간에 유의미하게 높은 상관관계가 나타났다(r = 0.40-0.84, p < 0.001). 7개의 영구치 중에서 하악 제2대구치가 골 성숙도와 가장 높은 상관관계를 보인 반면 중절치가 가장 낮은 상관관계를 나타내었다. 남녀 모두에서 하악 견치의 stage G와 하악 제2대구치의 stage F가 SMI 6단계와 CS 3단계에서 나타날 확률이 가장 높았다. 이 연구의 결과에 따르면 치아 성숙도와 골 성숙도 사이에 높은 상관관계가 있으므로, 파노라마 방사선사진에서의 치아 성숙도 평가는 성장기 아동의 골 성숙도를 평가하는 보조적 수단으로 활용될 수 있다.

• 대한치과교정학회지
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• 제48권1호
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• pp.30-38
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• 2018

Objective: The purpose of this study was to investigate factors influencing the success rate of orthodontic microimplants (OMIs) using panoramic radiographs (PRs). Methods: We examined 160 OMIs inserted bilaterally in the maxillary buccal alveolar bone between the second premolars and first molars of 80 patients (51 women, 29 men; mean age, $18.0{\pm}6.1years$) undergoing treatment for malocclusion. The angulation and position of OMIs, as well as other parameters, were measured on PRs. The correlation between each measurement and the OMI success rate was then evaluated. Results: The overall success rate was 85.0% (136/160). Age was found to be a significant predictor of implant success (p < 0.05), while sex, side of placement, extraction, and position of the OMI tip were not significant predictors (p > 0.05). The highest success rate was observed for OMIs with tips positioned on the interradicular midline (IRML; central position). Univariate analyses revealed that the OMI success rate significantly increased with an increase in the OMI length and placement height of OMI (p = 0.001). However, in simultaneous analyses, only length remained significant (p = 0.027). Root proximity, distance between the OMI tip and IRML, interradicular distance, alveolar crest width, distance between the OMI head and IRML, and placement angle were not factors for success. Correlations between the placement angle and all other measurements except root proximity were statistically significant (p < 0.05). Conclusions: Our findings suggest that OMIs positioned more apically with a lesser angulation, as observed on PRs, exhibit high success rates.

• Imaging Science in Dentistry
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• 제46권1호
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• pp.1-7
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• 2016

Purpose: This study assessed the accuracy of age estimates produced by a regression equation derived from lower third molar development in a Thai population. Materials and Methods: The first part of this study relied on measurements taken from panoramic radiographs of 614 Thai patients aged from 9 to 20. The stage of lower left and right third molar development was observed in each radiograph and a modified Gat score was assigned. Linear regression on this data produced the following equation: Y=9.309+1.673 mG+0.303S (Y=age; mG=modified Gat score; S=sex). In the second part of this study, the predictive accuracy of this equation was evaluated using data from a second set of panoramic radiographs (539 Thai subjects, 9 to 24 years old). Each subject's age was estimated using the above equation and compared against age calculated from a provided date of birth. Estimated and known age data were analyzed using the Pearson correlation coefficient and descriptive statistics. Results: Ages estimated from lower left and lower right third molar development stage were significantly correlated with the known ages (r=0.818, 0.808, respectively, $P{\leq}0.01$). 50% of age estimates in the second part of the study fell within a range of error of ${\pm}1year$, while 75% fell within a range of error of ${\pm}2years$. The study found that the equation tends to estimate age accurately when individuals are 9 to 20 years of age. Conclusion: The equation can be used for age estimation for Thai populations when the individuals are 9 to 20 years of age.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.6.1-6.10
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• 2019

Background: Osteomyelitis is an intraosseous inflammatory disease characterized by progressive inflammatory osteoclasia and ossification. The use of quantitative analysis to assist interpretation of osteomyelitis is increasingly being considered. The objective of this study was to perform early diagnosis of osteomyelitis on digital panoramic radiographs using basic functions provided by picture archiving and communication system (PACS), a program used to show radiographic images. Methods: This study targeted a total of 95 patients whose symptoms were confirmed as osteomyelitis under clinical, radiologic, pathological diagnosis over 11 years from 2008 to 2017. Five categorized patients were osteoradionecrosis, bisphosphonate-related osteonecrosis of jaw (BRONJ, suppurative and sclerosing type), and bacterial osteomyelitis (suppurative and sclerosing type), and the control group was 117 randomly sampled. The photographic density in a certain area of the digital panoramic radiograph was determined and compared using the "measure area rectangle," one of the basic PACS functions in INFINITT PACS^® (INFINITT Healthcare, Seoul, South Korea). A conditional inference tree, one type of decision making tree, was generated with the program R for statistical analysis with SPSS^®. Results: In the conditional inference tree generated from the obtained data, cases where the difference in average value exceeded 54.49 and the difference in minimum value was less than 54.49 and greater than 12.81 and the difference in minimum value exceeded 39 were considered suspicious of osteomyelitis. From these results, the disease could be correctly classified with a probability of 88.1%. There was no difference in photographic density value of BRONJ and bacterial osteomyelitis; therefore, it was not possible to classify BRONJ and bacterial osteomyelitis by quantitative analysis of panoramic radiographs based on existing research. Conclusions: This study demonstrates that it is feasible to measure photographic density using a basic function in PACS and apply the data to assist in the diagnosis of osteomyelitis.

• Imaging Science in Dentistry
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• 제45권2호
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• pp.109-115
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• 2015

Central odontogenic fibroma (COF) is a rare benign tumor that accounts for 0.1% of all odontogenic tumors. A case of COF (simple type) of the mandible in a four-year-old boy is described in this report. The patient showed asymptomatic swelling in the right inferior border of the lower jaw for one week. A panoramic radiograph showed a poorly-defined destructive unilocular radiolucent area. Cone-beam computed tomography showed expansion and perforation of the adjacent cortical bone plates. A periosteal reaction with the Codman triangle pattern was clearly visible in the buccal cortex. Since the tumor had destroyed a considerable amount of bone, surgical resection was performed. No recurrence was noted.

• Imaging Science in Dentistry
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• 제42권1호
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• pp.35-39
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• 2012

A 9-year-old girl visited our hospital, complaining of a rapid-growing and rigid swelling on the left posterior mandibular area. Panoramic radiograph showed a moderately defined multilocular honeycomb appearance involving the left mandibular body. CT scan revealed an expansile, multilocular osteolytic lesion and multiple fluid levels within cystic spaces. Bone scan demonstrated increased radiotracer uptake and angiography showed a highly vascularized lesion. The lesion was suspected as aneurysmal bone cyst (ABC) and preoperative embolization was performed, which minimize the extent of operation and the surgical complication. The lesion was treated by surgical curettage and lateral decortication with repositioning. No additional treatment such as a surgical reconstruction or bone graft was needed. Early diagnosis of ABC is very important and appropriate treatment should be performed considering several factors such as age, surgical complication, and possibility of recurrence.

• 치과방사선
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• 제21권1호
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• pp.137-143
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• 1991

In the study of the focal trough of panoramic radiograph using Panoura Eight-S (the Yoshida company), a series of 63 X-ray films were taken with the 8-19 metal pins placed in the holes of the plastic model plate and evaluated by 4 observers. The author analized the focal trough defined by the sharpness criteria and calculated dimension of focal trough in the horizontal plane. The results were as follows; 1. Focal trough was not continued in the anterior region within a very high degree of sharpness. 2. With optional sharpness, the width of anterior and posterior focal trough was approximately l3㎜ and 60㎜ respectively. 3. The focal trough was narrow in the anterior region and was flared laterally with symmetry in posterior region. 4. Sharp image began to show at the position of 18㎜ posteriorly from the most anterior position of chin rest.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권5호
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• pp.278-280
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• 2015

Migration of dental implants into the maxillary sinus is uncommon. However, poor bone quality and quantity in the posterior maxilla can increase the potential for this complication to arise during implant placement procedures. The aim of this report is to present a dental implant that migrated into the maxillary sinus and disappeared. A 53-year-old male patient was referred to us by his dentist after a dental implant migrated into his maxillary sinus. The displaced implant was discovered on a panoramic radiograph taken five days before his referral. Using computed tomography, we determined that the displaced dental implant was not in the antrum. There was also no sign of oroantral fistula. Because of the small size of the displaced implant, we think that the implant may have left the maxillary sinus via the ostium.

• Imaging Science in Dentistry
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• 제44권2호
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• pp.171-175
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• 2014

One of the most common oral surgical procedures is the extraction of the lower third molar (LTM). Postoperative complications such as paresthesia due to inferior alveolar nerve (IAN) injury are commonly observed in cases of horizontal and vertical impaction. The present report discusses a case of a vertically impacted LTM associated with a dentigerous cyst. An intimate contact between the LTM roots and the mandibular canal was observed on a panoramic radiograph and confirmed with cone-beam computed tomographic (CBCT) cross-sectional cuts. An orthodontic miniscrew was then used to extrude the LTM prior to its surgical removal in order to avoid the risk of inferior alveolar nerve injury. CBCT imaging follow-up confirmed the success of the LTM orthodontic extrusion.

• Imaging Science in Dentistry
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• 제35권4호
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• pp.215-219
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• 2005

Hepatocellular carcinoma is one of the most common cancer worldwide, primarily affecting those in regions with a high prevalence of viral hepatitis. However, the metastasis of hepatocellular carcinoma to the oral cavity is a rare phenomenon. This report presents a case of metastatic hepatocellular carcinoma in the left mandibular angle and ramus region of a 62-year-old man. Panoramic radiograph revealed an ill-defined radiolucent lesion extending from the retained root of the mandibular left second molar into the ascending ramus. The lesion had irregular and ill-defined margins.