Yookyeong Sim - Academia.edu (original) (raw)

Papers by Yookyeong Sim

Journal of The Korean Association of Oral and Maxillofacial Surgeons, 2019

Objectives: This study evaluated the predictive factors for survival of patients with oral squamo... more Objectives: This study evaluated the predictive factors for survival of patients with oral squamous cell carcinoma (OSCC) and investigated the overall and disease-specific survival (DSS) outcomes. Materials and Methods: A total of 67 consecutive patients who underwent surgery for OSCC from January 2006 to November 2014 were included in this study. Patients were classified according to age, sex, pTNM stages, primary sites, smoking and alcohol drinking habits, depth of invasion, perineural and lymphovascular invasion, cell differentiation and postoperative radiotherapy. Kaplan-Meier methods were used to estimate the survival categorized by patient groups. Cox regression methods were used to investigate the main independent predictors of survival. Results: Nineteen patients died of OSCC during follow-up periods. Another five patients died of other diseases including lung adenocarcinoma (n=1), cerebral infarction (n=1), general weakness (n=2), and pneumonia (n=1). The tongue (n=16) was the most common site for primary origin, followed by buccal mucosa (n=15), mandibular gingiva (n=15), maxillary gingiva (n=9), floor of mouth (n=9), retromolar trigone (n=2), and palate (n=1). Eleven patients had pTNM stage I disease, followed by stage II (n=22) and stage IV (n=34). No patients had pTNM stage III disease in this study. The overall survival of all patients was 64.2% and the DSS was 71.6%. DSS of patients with stage I and II disease was 100%. Stepwise Cox regression showed the two predictors for DSS were pTNM stage (P<0.0001, odds ratio=19.633) and presence of metastatic lymph nodes (P=0.0004, odds ratio=0.1039). Conclusion: OSCC has been associated with poor prognosis; however, there were improved survival outcomes compared with past studies. Advanced-stage disease and presence of metastatic lymph nodes were associated with poorer survival compared with early-stage OSCC and absence of neck node metastasis. Stage I and II OSCC were associated with excellent survival results in this study.

Current Applied Physics, Sep 1, 2009

The accurate terahertz (THz) electrical and optical properties of biomaterials are required as th... more The accurate terahertz (THz) electrical and optical properties of biomaterials are required as the biological applications of THz electromagnetic waves were recently increased. The frequency-dependent characteristics of enamel and dentin of human tooth were measured in this study through THz time-domain spectroscopy. The power absorptions of enamel and dentin were found to be similar while the index of refraction of

Journal of Craniofacial Surgery, May 1, 2018

The purpose of this study was to report clinical characteristics, surgical results, and new PTCH1... more The purpose of this study was to report clinical characteristics, surgical results, and new PTCH1 gene mutations in nevoid basal cell carcinoma syndrome (NBCCS). Five patients were referred to the Department of Oral and Maxillofacial Surgery from local dental clinics between 2006 and 2016 to treat multiple keratocystic odontogenic tumors (KOTs). The cystic lesions were enucleated and peripheral ostectomy was performed to obtain safety margin. Recurrence and/or de novo development of KOT were assessed. Gene analysis using peripheral blood was performed in all patients to identify the mutation of PTCH1 gene. Three patients showed familial history of first-degree relatives. Of the major criteria, all patients presented KOT but only 1 patient had basal cell carcinoma. Of the minor criteria, 4 of the 5 patients presented macrocephaly and hypertelorism. During follow-up periods, all patients showed recurrence and/or de novo development of KOT in the jaw bone. Mutation analysis of PTCH1 gene showed 3 frameshifts (c.817_818ins(T), c.1226_1227ins(A), and c.2748del(C)), 1 splicing (c.1504-2A>T), and 1 missense (c.385T>C) mutation. Mutations were found in exon 1, 6, 9, 17, and intron 10. Regular follow-up is necessary because recurrence rate of KOT was very high. To help early diagnosis, it is essential to routinely perform genetic testing to detect PTCH1 gene mutations among patients with NBCCS.

Clinical Implant Dentistry and Related Research, Jun 13, 2013

Migration of a dental implant into the paranasal sinuses may be the result of sinus membrane perf... more Migration of a dental implant into the paranasal sinuses may be the result of sinus membrane perforation, loss of osseointegration, and lack of initial stability. The majority of displaced implants migrate into the maxillary sinus, which may cause sinusitis. The purpose of this study is to report an extremely rare ethmoid sinus migration of a dental implant after crestal approach in a resorbed posterior maxilla. A 60-year old Korean male with a noncontributory medical history was referred from a local clinic to remove the migrated dental implant in the right ethmoid sinus. The patient had symptoms of mild sinusitis. The implant had been placed 6 months earlier through the bone-added transalveolar approach in a severely resorbed maxilla. The displaced implant was removed through the intraoral approach. A lateral window was made and an endoscopic surgery was performed to remove the implant. Healing was uneventful, and sinusitis symptom had ceased. The crestal approach for severely resorbed posterior maxillae should be performed when there is a potential for primary stability. If bone quality is poor and initial stability cannot be achieved, lateral window sinus elevation procedure is a better option for successful implant placement. Migrated implant may be removed with antrostomy and endoscopic surgery.

IEEE Transactions on Terahertz Science and Technology, Jul 1, 2013

Biomedical Optics Express, Jul 23, 2013

The feasibility of terahertz (THz) imaging at frozen temperature for the clinical application of ... more The feasibility of terahertz (THz) imaging at frozen temperature for the clinical application of oral cancer detection was investigated by analyzing seven oral tissues resected from four patients. The size, shape, and internal position of the oral cancers were mapped by THz radiation in the frequency range of 0.2-1.2 THz at 20 °C and 20 °C, and compared with those identified in the histological examination. THz imaging of frozen tissue was found to offer greater sensitivity in distinguishing cancerous areas from surrounding tissue and a larger THz-frequency spectral difference between the oral cancer and normal mucosa than roomtemperature THz imaging. A cancerous tumor hidden inside tissue was also detected using this method by observing the THz temporal domain waveform. The histological analysis showed that these findings resulted from cell structure deformations involving the invasion of oral tumor and neoplastic transformations of mucous cells. Therefore, a cytological approach using THz radiation at a frozen temperature might be applied to detect oral cancer.

Terahertz (THz) electromagnetic waves occupy the frequency region between 0.1 and 10 THz. They sh... more Terahertz (THz) electromagnetic waves occupy the frequency region between 0.1 and 10 THz. They show promising application potential. THz waves have many advantages for biomaterial applications due to their nonionizing properties. One advantage is the non-destructive image obtained for pharmaceutical inspection and medical diagnosis. We measured the frequency-dependent electrical constants of enamel and dentin in the human tooth using THz time-domain spectroscopy in the frequency range of 0.1-1 THz. The index of refraction of enamel was larger than that of dentin. The power absorptions of enamel and dentin were similar. We compared power absorptions of enamel and dentin with wet samples, which were observed to be greater than that of dry samples.

Oral Surgery, Jan 7, 2014

The objective of this study is to present a hereditary pattern of florid cemento-osseous dysplasi... more The objective of this study is to present a hereditary pattern of florid cemento-osseous dysplasia. A 49-year-old female was diagnosed with familial florid cemento-osseous dysplasia in 2008. Her identical twin daughters were referred for evaluation of mixed radio-opaque/lucent lesions in both maxilla and mandible in 2009. Based on radiographic and histopathological findings, the lesions of the identical twins were diagnosed as early-stage familial florid cemento-osseous dysplasia. Microscopically, the tissue showed a mixture of woven trabeculae and cementum-like calcification in the fibrous stroma. This study reports the first familial florid cemento-osseous dysplasia in a mother and her identical twin daughters. Long-term follow-up is required to observe the progression of this disease. Clinical relevance The distinction between familial florid cementoosseous dysplasia (FFCOD) and familial gigantiform cementoma is quite challenging because of their histopathological and radiological similarity. The initial phase of these two diseases involves an osteolytic pattern mixed with partial radiopaque bone formation. Only four cases of FFCOD are reported in the English literature. This report is the first case of FFCOD found in a mother and her identical twins.

Journal of Craniofacial Surgery

Journal of the Korean Association of Oral and Maxillofacial Surgeons

J Korean Assoc Oral Maxillofac Surg 2019;45:83-90)

AIP Conference Proceedings, 2009

Terahertz (THz) electromagnetic waves occupy the frequency region between 0.1 and 10 THz. They sh... more Terahertz (THz) electromagnetic waves occupy the frequency region between 0.1 and 10 THz. They show promising application potential. THz waves have many advantages for biomaterial applications due to their nonionizing properties. One advantage is the non-destructive image obtained for pharmaceutical inspection and medical diagnosis. We measured the frequency-dependent electrical constants of enamel and dentin in the human tooth using THz time-domain spectroscopy in the frequency range of 0.1-1 THz. The index of refraction of enamel was larger than that of dentin. The power absorptions of enamel and dentin were similar. We compared power absorptions of enamel and dentin with wet samples, which were observed to be greater than that of dry samples.

IEEE Transactions on Terahertz Science and Technology, 2013

We imaged a single case of oral malignant melanoma using terahertz (THz) reflection imaging at ro... more We imaged a single case of oral malignant melanoma using terahertz (THz) reflection imaging at room temperature (20 °C) and below freezing (-20 °C). A malignant nodule beneath the oral tissue surface was visualized using 2-D and B-scan THz imaging techniques. The THz images were well correlated with the histological findings. The nodule was found to have lower water content than that of normal cells, and this water effect may have influenced the THz refractive index and absorption coefficient at 20 °C. The THz spectroscopic image of the frozen tissue at -20 °C showed better contrast because of the lack of liquid water; this implies that there are significant structural differences between malignant oral melanoma cells and normal mucosal cells. The better contrast in the frozen tissue images was due to the greater penetration of THz radiation into the sample. This temperature-dependent THz imaging approach demonstrated the feasibility of accurate imaging of the oral tumor tissue.

Biomedical Optics Express, 2013

The feasibility of terahertz (THz) imaging at frozen temperature for the clinical application of ... more The feasibility of terahertz (THz) imaging at frozen temperature for the clinical application of oral cancer detection was investigated by analyzing seven oral tissues resected from four patients. The size, shape, and internal position of the oral cancers were mapped by THz radiation in the frequency range of 0.2-1.2 THz at 20 °C and 20 °C, and compared with those identified in the histological examination. THz imaging of frozen tissue was found to offer greater sensitivity in distinguishing cancerous areas from surrounding tissue and a larger THz-frequency spectral difference between the oral cancer and normal mucosa than roomtemperature THz imaging. A cancerous tumor hidden inside tissue was also detected using this method by observing the THz temporal domain waveform. The histological analysis showed that these findings resulted from cell structure deformations involving the invasion of oral tumor and neoplastic transformations of mucous cells. Therefore, a cytological approach using THz radiation at a frozen temperature might be applied to detect oral cancer.

Oral Surgery, 2014

ABSTRACT The objective of this study is to present a hereditary pattern of florid cemento-osseous... more ABSTRACT The objective of this study is to present a hereditary pattern of florid cemento-osseous dysplasia. A 49-year-old female was diagnosed with familial florid cemento-osseous dysplasia in 2008. Her identical twin daughters were referred for evaluation of mixed radio-opaque/lucent lesions in both maxilla and mandible in 2009. Based on radiographic and histopathological findings, the lesions of the identical twins were diagnosed as early-stage familial florid cemento-osseous dysplasia. Microscopically, the tissue showed a mixture of woven trabeculae and cementum-like calcification in the fibrous stroma. This study reports the first familial florid cemento-osseous dysplasia in a mother and her identical twin daughters. Long-term follow-up is required to observe the progression of this disease.

Current Applied Physics, 2009

The accurate terahertz (THz) electrical and optical properties of biomaterials are required as th... more The accurate terahertz (THz) electrical and optical properties of biomaterials are required as the biological applications of THz electromagnetic waves were recently increased. The frequency-dependent characteristics of enamel and dentin of human tooth were measured in this study through THz time-domain spectroscopy. The power absorptions of enamel and dentin were found to be similar while the index of refraction of

Clinical Implant Dentistry and Related Research, 2013

Migration of a dental implant into the paranasal sinuses may be the result of sinus membrane perf... more Migration of a dental implant into the paranasal sinuses may be the result of sinus membrane perforation, loss of osseointegration, and lack of initial stability. The majority of displaced implants migrate into the maxillary sinus, which may cause sinusitis. The purpose of this study is to report an extremely rare ethmoid sinus migration of a dental implant after crestal approach in a resorbed posterior maxilla. A 60-year old Korean male with a noncontributory medical history was referred from a local clinic to remove the migrated dental implant in the right ethmoid sinus. The patient had symptoms of mild sinusitis. The implant had been placed 6 months earlier through the bone-added transalveolar approach in a severely resorbed maxilla. The displaced implant was removed through the intraoral approach. A lateral window was made and an endoscopic surgery was performed to remove the implant. Healing was uneventful, and sinusitis symptom had ceased. The crestal approach for severely resorbed posterior maxillae should be performed when there is a potential for primary stability. If bone quality is poor and initial stability cannot be achieved, lateral window sinus elevation procedure is a better option for successful implant placement. Migrated implant may be removed with antrostomy and endoscopic surgery.

Current Applied Physics, 2009

The accurate terahertz (THz) electrical and optical properties of biomaterials are required as th... more The accurate terahertz (THz) electrical and optical properties of biomaterials are required as the biological applications of THz electromagnetic waves were recently increased. The frequency-dependent characteristics of enamel and dentin of human tooth were measured in this study through THz time-domain spectroscopy. The power absorptions of enamel and dentin were found to be similar while the index of refraction of

Journal of The Korean Association of Oral and Maxillofacial Surgeons, 2019

Objectives: This study evaluated the predictive factors for survival of patients with oral squamo... more Objectives: This study evaluated the predictive factors for survival of patients with oral squamous cell carcinoma (OSCC) and investigated the overall and disease-specific survival (DSS) outcomes. Materials and Methods: A total of 67 consecutive patients who underwent surgery for OSCC from January 2006 to November 2014 were included in this study. Patients were classified according to age, sex, pTNM stages, primary sites, smoking and alcohol drinking habits, depth of invasion, perineural and lymphovascular invasion, cell differentiation and postoperative radiotherapy. Kaplan-Meier methods were used to estimate the survival categorized by patient groups. Cox regression methods were used to investigate the main independent predictors of survival. Results: Nineteen patients died of OSCC during follow-up periods. Another five patients died of other diseases including lung adenocarcinoma (n=1), cerebral infarction (n=1), general weakness (n=2), and pneumonia (n=1). The tongue (n=16) was the most common site for primary origin, followed by buccal mucosa (n=15), mandibular gingiva (n=15), maxillary gingiva (n=9), floor of mouth (n=9), retromolar trigone (n=2), and palate (n=1). Eleven patients had pTNM stage I disease, followed by stage II (n=22) and stage IV (n=34). No patients had pTNM stage III disease in this study. The overall survival of all patients was 64.2% and the DSS was 71.6%. DSS of patients with stage I and II disease was 100%. Stepwise Cox regression showed the two predictors for DSS were pTNM stage (P<0.0001, odds ratio=19.633) and presence of metastatic lymph nodes (P=0.0004, odds ratio=0.1039). Conclusion: OSCC has been associated with poor prognosis; however, there were improved survival outcomes compared with past studies. Advanced-stage disease and presence of metastatic lymph nodes were associated with poorer survival compared with early-stage OSCC and absence of neck node metastasis. Stage I and II OSCC were associated with excellent survival results in this study.

Current Applied Physics, Sep 1, 2009

The accurate terahertz (THz) electrical and optical properties of biomaterials are required as th... more The accurate terahertz (THz) electrical and optical properties of biomaterials are required as the biological applications of THz electromagnetic waves were recently increased. The frequency-dependent characteristics of enamel and dentin of human tooth were measured in this study through THz time-domain spectroscopy. The power absorptions of enamel and dentin were found to be similar while the index of refraction of

Journal of Craniofacial Surgery, May 1, 2018

The purpose of this study was to report clinical characteristics, surgical results, and new PTCH1... more The purpose of this study was to report clinical characteristics, surgical results, and new PTCH1 gene mutations in nevoid basal cell carcinoma syndrome (NBCCS). Five patients were referred to the Department of Oral and Maxillofacial Surgery from local dental clinics between 2006 and 2016 to treat multiple keratocystic odontogenic tumors (KOTs). The cystic lesions were enucleated and peripheral ostectomy was performed to obtain safety margin. Recurrence and/or de novo development of KOT were assessed. Gene analysis using peripheral blood was performed in all patients to identify the mutation of PTCH1 gene. Three patients showed familial history of first-degree relatives. Of the major criteria, all patients presented KOT but only 1 patient had basal cell carcinoma. Of the minor criteria, 4 of the 5 patients presented macrocephaly and hypertelorism. During follow-up periods, all patients showed recurrence and/or de novo development of KOT in the jaw bone. Mutation analysis of PTCH1 gene showed 3 frameshifts (c.817_818ins(T), c.1226_1227ins(A), and c.2748del(C)), 1 splicing (c.1504-2A>T), and 1 missense (c.385T>C) mutation. Mutations were found in exon 1, 6, 9, 17, and intron 10. Regular follow-up is necessary because recurrence rate of KOT was very high. To help early diagnosis, it is essential to routinely perform genetic testing to detect PTCH1 gene mutations among patients with NBCCS.

Clinical Implant Dentistry and Related Research, Jun 13, 2013

Migration of a dental implant into the paranasal sinuses may be the result of sinus membrane perf... more Migration of a dental implant into the paranasal sinuses may be the result of sinus membrane perforation, loss of osseointegration, and lack of initial stability. The majority of displaced implants migrate into the maxillary sinus, which may cause sinusitis. The purpose of this study is to report an extremely rare ethmoid sinus migration of a dental implant after crestal approach in a resorbed posterior maxilla. A 60-year old Korean male with a noncontributory medical history was referred from a local clinic to remove the migrated dental implant in the right ethmoid sinus. The patient had symptoms of mild sinusitis. The implant had been placed 6 months earlier through the bone-added transalveolar approach in a severely resorbed maxilla. The displaced implant was removed through the intraoral approach. A lateral window was made and an endoscopic surgery was performed to remove the implant. Healing was uneventful, and sinusitis symptom had ceased. The crestal approach for severely resorbed posterior maxillae should be performed when there is a potential for primary stability. If bone quality is poor and initial stability cannot be achieved, lateral window sinus elevation procedure is a better option for successful implant placement. Migrated implant may be removed with antrostomy and endoscopic surgery.

IEEE Transactions on Terahertz Science and Technology, Jul 1, 2013

Biomedical Optics Express, Jul 23, 2013

The feasibility of terahertz (THz) imaging at frozen temperature for the clinical application of ... more The feasibility of terahertz (THz) imaging at frozen temperature for the clinical application of oral cancer detection was investigated by analyzing seven oral tissues resected from four patients. The size, shape, and internal position of the oral cancers were mapped by THz radiation in the frequency range of 0.2-1.2 THz at 20 °C and 20 °C, and compared with those identified in the histological examination. THz imaging of frozen tissue was found to offer greater sensitivity in distinguishing cancerous areas from surrounding tissue and a larger THz-frequency spectral difference between the oral cancer and normal mucosa than roomtemperature THz imaging. A cancerous tumor hidden inside tissue was also detected using this method by observing the THz temporal domain waveform. The histological analysis showed that these findings resulted from cell structure deformations involving the invasion of oral tumor and neoplastic transformations of mucous cells. Therefore, a cytological approach using THz radiation at a frozen temperature might be applied to detect oral cancer.

Terahertz (THz) electromagnetic waves occupy the frequency region between 0.1 and 10 THz. They sh... more Terahertz (THz) electromagnetic waves occupy the frequency region between 0.1 and 10 THz. They show promising application potential. THz waves have many advantages for biomaterial applications due to their nonionizing properties. One advantage is the non-destructive image obtained for pharmaceutical inspection and medical diagnosis. We measured the frequency-dependent electrical constants of enamel and dentin in the human tooth using THz time-domain spectroscopy in the frequency range of 0.1-1 THz. The index of refraction of enamel was larger than that of dentin. The power absorptions of enamel and dentin were similar. We compared power absorptions of enamel and dentin with wet samples, which were observed to be greater than that of dry samples.

Oral Surgery, Jan 7, 2014

The objective of this study is to present a hereditary pattern of florid cemento-osseous dysplasi... more The objective of this study is to present a hereditary pattern of florid cemento-osseous dysplasia. A 49-year-old female was diagnosed with familial florid cemento-osseous dysplasia in 2008. Her identical twin daughters were referred for evaluation of mixed radio-opaque/lucent lesions in both maxilla and mandible in 2009. Based on radiographic and histopathological findings, the lesions of the identical twins were diagnosed as early-stage familial florid cemento-osseous dysplasia. Microscopically, the tissue showed a mixture of woven trabeculae and cementum-like calcification in the fibrous stroma. This study reports the first familial florid cemento-osseous dysplasia in a mother and her identical twin daughters. Long-term follow-up is required to observe the progression of this disease. Clinical relevance The distinction between familial florid cementoosseous dysplasia (FFCOD) and familial gigantiform cementoma is quite challenging because of their histopathological and radiological similarity. The initial phase of these two diseases involves an osteolytic pattern mixed with partial radiopaque bone formation. Only four cases of FFCOD are reported in the English literature. This report is the first case of FFCOD found in a mother and her identical twins.

Journal of Craniofacial Surgery

Journal of the Korean Association of Oral and Maxillofacial Surgeons

J Korean Assoc Oral Maxillofac Surg 2019;45:83-90)

AIP Conference Proceedings, 2009

Terahertz (THz) electromagnetic waves occupy the frequency region between 0.1 and 10 THz. They sh... more Terahertz (THz) electromagnetic waves occupy the frequency region between 0.1 and 10 THz. They show promising application potential. THz waves have many advantages for biomaterial applications due to their nonionizing properties. One advantage is the non-destructive image obtained for pharmaceutical inspection and medical diagnosis. We measured the frequency-dependent electrical constants of enamel and dentin in the human tooth using THz time-domain spectroscopy in the frequency range of 0.1-1 THz. The index of refraction of enamel was larger than that of dentin. The power absorptions of enamel and dentin were similar. We compared power absorptions of enamel and dentin with wet samples, which were observed to be greater than that of dry samples.

IEEE Transactions on Terahertz Science and Technology, 2013

We imaged a single case of oral malignant melanoma using terahertz (THz) reflection imaging at ro... more We imaged a single case of oral malignant melanoma using terahertz (THz) reflection imaging at room temperature (20 °C) and below freezing (-20 °C). A malignant nodule beneath the oral tissue surface was visualized using 2-D and B-scan THz imaging techniques. The THz images were well correlated with the histological findings. The nodule was found to have lower water content than that of normal cells, and this water effect may have influenced the THz refractive index and absorption coefficient at 20 °C. The THz spectroscopic image of the frozen tissue at -20 °C showed better contrast because of the lack of liquid water; this implies that there are significant structural differences between malignant oral melanoma cells and normal mucosal cells. The better contrast in the frozen tissue images was due to the greater penetration of THz radiation into the sample. This temperature-dependent THz imaging approach demonstrated the feasibility of accurate imaging of the oral tumor tissue.

Biomedical Optics Express, 2013

The feasibility of terahertz (THz) imaging at frozen temperature for the clinical application of ... more The feasibility of terahertz (THz) imaging at frozen temperature for the clinical application of oral cancer detection was investigated by analyzing seven oral tissues resected from four patients. The size, shape, and internal position of the oral cancers were mapped by THz radiation in the frequency range of 0.2-1.2 THz at 20 °C and 20 °C, and compared with those identified in the histological examination. THz imaging of frozen tissue was found to offer greater sensitivity in distinguishing cancerous areas from surrounding tissue and a larger THz-frequency spectral difference between the oral cancer and normal mucosa than roomtemperature THz imaging. A cancerous tumor hidden inside tissue was also detected using this method by observing the THz temporal domain waveform. The histological analysis showed that these findings resulted from cell structure deformations involving the invasion of oral tumor and neoplastic transformations of mucous cells. Therefore, a cytological approach using THz radiation at a frozen temperature might be applied to detect oral cancer.

Oral Surgery, 2014

ABSTRACT The objective of this study is to present a hereditary pattern of florid cemento-osseous... more ABSTRACT The objective of this study is to present a hereditary pattern of florid cemento-osseous dysplasia. A 49-year-old female was diagnosed with familial florid cemento-osseous dysplasia in 2008. Her identical twin daughters were referred for evaluation of mixed radio-opaque/lucent lesions in both maxilla and mandible in 2009. Based on radiographic and histopathological findings, the lesions of the identical twins were diagnosed as early-stage familial florid cemento-osseous dysplasia. Microscopically, the tissue showed a mixture of woven trabeculae and cementum-like calcification in the fibrous stroma. This study reports the first familial florid cemento-osseous dysplasia in a mother and her identical twin daughters. Long-term follow-up is required to observe the progression of this disease.

Current Applied Physics, 2009

The accurate terahertz (THz) electrical and optical properties of biomaterials are required as th... more The accurate terahertz (THz) electrical and optical properties of biomaterials are required as the biological applications of THz electromagnetic waves were recently increased. The frequency-dependent characteristics of enamel and dentin of human tooth were measured in this study through THz time-domain spectroscopy. The power absorptions of enamel and dentin were found to be similar while the index of refraction of

Clinical Implant Dentistry and Related Research, 2013

Migration of a dental implant into the paranasal sinuses may be the result of sinus membrane perf... more Migration of a dental implant into the paranasal sinuses may be the result of sinus membrane perforation, loss of osseointegration, and lack of initial stability. The majority of displaced implants migrate into the maxillary sinus, which may cause sinusitis. The purpose of this study is to report an extremely rare ethmoid sinus migration of a dental implant after crestal approach in a resorbed posterior maxilla. A 60-year old Korean male with a noncontributory medical history was referred from a local clinic to remove the migrated dental implant in the right ethmoid sinus. The patient had symptoms of mild sinusitis. The implant had been placed 6 months earlier through the bone-added transalveolar approach in a severely resorbed maxilla. The displaced implant was removed through the intraoral approach. A lateral window was made and an endoscopic surgery was performed to remove the implant. Healing was uneventful, and sinusitis symptom had ceased. The crestal approach for severely resorbed posterior maxillae should be performed when there is a potential for primary stability. If bone quality is poor and initial stability cannot be achieved, lateral window sinus elevation procedure is a better option for successful implant placement. Migrated implant may be removed with antrostomy and endoscopic surgery.

Current Applied Physics, 2009

The accurate terahertz (THz) electrical and optical properties of biomaterials are required as th... more The accurate terahertz (THz) electrical and optical properties of biomaterials are required as the biological applications of THz electromagnetic waves were recently increased. The frequency-dependent characteristics of enamel and dentin of human tooth were measured in this study through THz time-domain spectroscopy. The power absorptions of enamel and dentin were found to be similar while the index of refraction of