Assessment of bone density changes following two-jaw surgery using multidetector computed tomography: A pilot study / 대한치과교정학회지

Objective@#The aim of this retrospective study was to evaluate the pre- and postsurgical bone densities at alveolar and extra-alveolar sites following twojaw orthognathic surgery. @*Methods@#The sample consisted of 10 patients (mean age, 23.2 years; range, 18.0–27.8 years; 8 males, 2 females) who underwent two-jaw orthognathic surgery. A three-dimensional imaging program (Invivo 5) was used with multidetector computed tomography images taken preand postoperatively (obtained 32.3 ± 6.0 days before surgery and 5.8 ± 2.6 days after surgery, respectively) for the measurement of bone densities at the following sites: (1) alveolar bone in the maxilla and mandible, (2) extra-alveolar sites, such as the top of the head, menton (Me), condyle, and the fourth cervical vertebrae (C4). @*Results@#When pre- and postsurgical bone densities were compared, an overall tendency of decrease in bone density was noted. Statistically significant reductions were observed in the densities of cancellous bone at several areas of the maxillary alveolar bone; cortical and cancellous bone in most areas of the mandibular alveolar bone; cortical bone in Me; and cancellous bone in C4. There was no statistically significant difference in bone density in relation to the depth of the alveolar bone. In a comparison of the bone densities between groups with and without genioplasty, there was almost no statistically significant difference. @*Conclusions@#Accelerated tooth movement following orthognathic surgery may be confirmed with reduced bone density. In addition, this study could offer insights into bone metabolism changes following orthognathic surgery, providing direction for further investigations in this field.

Giant complex odontoma in the posterior mandible: A case report and literature review

Odontomas are considered a type of odontogenic hamartoma, and are generally reported not to exceed 3 cm in diameter. Some authors have referred to odontomas with a diameter exceeding 3 cm as giant odontomas. As hamartomas, giant odontomas generally show no signs or symptoms, but if they perforate the mucosa to become exposed in the oral cavity, oral and maxillofacial infections can result. Surgical removal and a histopathological examination may also be required to differentiate them from osteomas, cemento-osseous dysplasia, or mixed odontogenic tumors. This report presents the case of a 28-year-old woman with a giant odontoma in the right mandibular third molar area. Based on a review of the literature published since 2010, only 11 cases of “giant” or “large” odontomas have been reported, most of which were of the complex odontoma type. It was confirmed that they tend to occur in the right posterior mandible.

Characteristics of temporomandibular joint structures after mandibular condyle fractures revealed by magnetic resonance imaging / 대한악안면성형재건외과학회지

BACKGROUND: This study aimed to evaluate the structural changes of temporomandibular joint immediately after condylar fractures with magnetic resonance imaging (MRI). METHOD: We evaluated 34 subjects of condylar fractures with MRI. The position, shape, and signal intensity of the condyle, disc, and retrodiscal tissue were analyzed with MR images. RESULTS: Immediately after trauma, the disc was displaced with the fractured segment in almost all cases. And, the changes of signal intensity at the retrodiscal tissue were found but less related to the degree of fracture displacement. And, the high signals were observed almost at all fractured joint spaces and even at some contralateral joints. CONCLUSIONS: The displaced disc as well as the increased signal intensity of the joint space, condylar head, and retrodiscal tissue demands more attention to prevent the possible sequela of joint.

Three-dimensional functional unit analysis of hemifacial microsomia mandible-a preliminary report / 대한악안면성형재건외과학회지

BACKGROUND: The aim of this study was to present three-dimensional (3D) structural characteristics of the mandible in the hemifacial microsomia. The mandible has six distinct functional units, and its architecture is the sum of balanced growth of each functional unit and surrounding matrix. METHODS: In order to characterize the mandibular 3D architecture of hemifacial microsomia, we analyzed the mandibular functional units of four hemifacial microsomia patients using the 3D reconstructed computed tomography (CT) images. And we compared the functional unit size between affected and non-affected side. RESULTS: The length of condyle and angle showed significant differences between affected and non-affected sides. However, the length of mandibular body showed insignificant differences. The size differences between affected and non-affected side were observed at the condyle, angle, and body in descending order. CONCLUSIONS: This preliminary study suggests that the main etiopathogenic units are condyle and angle in the hemifacial microsomia mandible. Further investigation with the increased number of subjects will be helpful to establish treatment modality by etiopathogenic targeting of hemifacial microsomia.

Percutaneous self-injury to the femoral region caused by bur breakage during surgical extraction of a patient's impacted third molar

Extraction of an impacted third molar is one of the most frequently performed techniques in oral and maxillofacial surgery. Surgeons can suffer numerous external injuries while extracting a tooth, with percutaneous injuries to the hand being the most commonly reported. In this article, we present a case involving a percutaneous injury of the surgeon's femoral region caused by breakage of the fissure bur connected to the handpiece during extraction of the third molar. We also propose precautions to prevent such injuries and steps to be undertaken when they occur.

Reduction of superior-lateral intact mandibular condyle dislocation with bone traction hook

Lateral and superior-lateral dislocations of the intact condyle are a rare complication, following traumatic insult to the mandible. We report an unusual case of a 54-year-old male patient who experienced both types of dislocations of the intact condyles with symphysis fracture following a road-traffic accident. Under general anesthesia, conventional manipulation was unsuccessful in relocating the condyles into the glenoid fossa. After applying a percutaneous traction force, using a bone traction hook placed at the sigmoid notch, the displaced intact mandibular condyles were repositioned, and the symphyseal fracture was finally reduced and fixed. The mouth opening was within normal limits, and favorable occlusion was confirmed one month postoperatively. To our knowledge, this is the first case of dislocation of both intact condyles--associated with symphysis fracture--being reduced with bone traction hook.

Use of the pedicled buccal fat pad in the reconstruction of intraoral defects: a report of five cases

The buccal fat pad is specialized fat tissue located anterior to the masseter muscle and deep to the buccinator muscle. Possessing a central body and four processes it provides separation allowing gliding motion between muscles, protects the neurovascular bundles from injuries, and maintains facial convexity. Because of its many advantageous functions, the use of the buccal fat pad during oral and maxillofacial procedures is promoted for the reconstruction of defects secondary to tumor resection, and those defects resulting from oroantral fistula caused by dento-alveolar surgery or trauma. We used the pedicled buccal fat pad in the reconstruction of intraoral defects such as oroantral fistula, maxillary posterior bone loss, or defects resulting from tumor resection. Epithelization of the fat tissue began 1 week after the surgery and demonstrated stable healing without complications over a long-term period. Thus, we highly recommend the use of this procedure.

Surgical management of edentulous/atrophic mandibular fracture: a report of two cases

According to Luhr's classification, a fracture in the mandible with a width of less than 15-20 mm is considered to be an atrophic mandibular fracture and its incidence is very rare. Because of the reduced cross-sectional area and smaller contact area of the fractured ends as well as the poorly vascularized bony structure and delayed bone healing, an atrophic mandibular fracture is a great challenge for oral and maxillofacial surgeons. Surgeons tend to perform closed reduction, because open reduction is considered a non-life-saving surgery among elderly patients. Thus, most of them have limited experience in surgical management. According to recent reports, open reduction yields a good result, and the Association for Osteosynthesis (AO) group has recommended open reduction. This is a case report of our two experiences of open reduction and rigid fixation of atrophic mandibular fractures by the AO principle. Articles were also reviewed here.

Calcifying epithelial odontogenic tumor associated with the left mandibular first premolar: a case report and literature review

Calcifying epithelial odontogenic tumor (CEOT) is a rarely reported benign tumor, accounting for 0.4-3% of all odontogenic tumors. Approximately 150 cases have been reported in the literature between 1958 and 2003. The age range of CEOT varies from 8 to 92 years with mean of 36.9 years, and the occurrence of the lesion in both genders is almost equal. It has 2 clinico-topographic variants: the intraosseous (94%) and the extraosseous (6%) type. The intraosseous type has a predilection for mandible (maxilla : mandible ratio of 1 : 2). The intraosseous CEOT commonly associated with non-erupted teeth accounts for more than half (52%) of the cases and usually appears as painless swelling that causes bony expansion. The location of diffused round-shaped calcifying material is inside the connective tissue stroma and epithelial islands. The tumors tend to be located toward the tooth crown, which usually has a unilocular radiolucent region containing variant radiopaque materials radiologically. In this paper, we report a case of CEOT occurring in the left mandibular first premolar of a 23-year-old female and present a brief review of the literature.

Alveolar bone necrosis and spontaneous tooth exfoliation associated with trigeminal herpes zoster: a report of three cases

Herpes zoster is a viral infection caused by the reactivation of the varicella zoster virus, an infection most commonly affecting the thoracolumbar trunk. Herpes Zoster Infection (HZI) may affect the cranial nerves, most frequently the trigeminal. HZI of the trigeminal nerve distribution network manifests as multiple, painful vesicular eruptions of the skin and mucosa which are innervated by the infected nerves. Oral vesicles usually appear after the skin manifestations. The vesicles rupture and coalesce, leaving mucosal erosions without subsequent scarring in most cases. The worst complication of HZI is post-herpetic neuralgia; other complications include facial scarring, motor nerve palsy and optic neuropathy. Osteonecrosis with spontaneous exfoliation of the teeth is an uncommon complication associated with HZI of the trigeminal nerve. We report several cases of osteomyelitis appearing on the mandible, caused by HZI, and triggering osteonecrosis or spontaneous tooth exfoliation.

Reconsideration of decision making for third molar extraction

INTRODUCTION: Third molar extraction is one of the most common procedures in oral and maxillofacial surgery. The impacted third molar causes many pathological conditions, such as pericoronitis, caries, periodontitis, resorption of adjacent teeth, and cyst or tumors associated with impacted teeth. Extraction is often considered the treatment of choice for impacted lower third molars. On the other hand, imprudent extraction of deeply impacted third molars can cause permanent complications, such as inferior alveolar nerve damage. Therefore, guidelines for the extraction of lower third molars should be set to prevent embarrassing complications. This study examined the indication and current trends of the extracted lower third molars in the dental hospital of a dental college. MATERIALS AND METHODS: 557 extracted third molars were evaluated at the department of oral and maxillofacial surgery of Yonsei University. The chief complaint, diagnosis, age and degree of impaction were analyzed to determine the tendency for the extraction of asymptomatic lower third molars. RESULTS: The percentage of asymptomatic third molars was 40.8%. In cases of full impacted tooth or full erupted tooth, the percentage of asymptomatic teeth was more than 50% (52.4% and 54.3, respectively). Among those partially impacted teeth, 73.1% of them showed symptoms, such as pain, tenderness and swelling. In terms of age, pericoronitis was evident at a younger age, and dental caries/periodontitis was the main cause of removal in those aged over 50. Twenty nine cases (1.6%) had teeth associated with pathological changes. CONCLUSION: The incidence of pathological changes to the lower third molar was relatively low. Surgical extraction is recommended in cases of partially impacted teeth. In Korea, the incidence of asymptomatic third molar extraction was relatively higher than in European countries. More careful attention would be desirable to consider the risks and benefits of lower third molar extraction.

Image fusion accuracy for the integration of digital dental model and 3D CT images by the point-based surface best fit algorithm

PURPOSE: The goal of this study was to develop a technique for creating a computerized composite maxillofacial-dental model, based on point-based surface best fit algorithm and to test its accuracy. The computerized composite maxillofacial-dental model was made by the three dimensional combination of a 3-dimensional (3D) computed tomography (CT) bone model with digital dental model. MATERIALS AND METHODS: This integration procedure mainly consists of following steps : 1) a reconstruction of a virtual skull and digital dental model from CT and laser scanned dental model ; 2) an incorporation of dental model into virtual maxillofacial-dental model by point-based surface best fit algorithm; 3) an assessment of the accuracy of incorporation. To test this system, CTs and dental models from 3 volunteers with cranio-maxillofacial deformities were obtained. And the registration accuracy was determined by the root mean squared distance between the corresponding reference points in a set of 2 images. RESULTS AND CONCLUSIONS: Fusion error for the maxillofacial 3D CT model with the digital dental model ranged between 0.1 and 0.3 mm with mean of 0.2 mm. The range of errors were similar to those reported elsewhere with the fiducial markers. So this study confirmed the feasibility and accuracy of combining digital dental model and 3D CT maxillofacial model. And this technique seemed to be easier for us that its clinical applicability can good in the field of digital cranio-maxillofacial surgery.

Stability of maxillary position after lefort i osteotomy using biodegradable plates and screws

INTRODUCTION: In orthognathic surgery, internal fixation has been usually done with titanium plates and screws. Recently, Biodegradable plates and screws have been frequently used but the reports of long term results of postoperative stability are rare, especially after maxillary reposition in orthognathic surgery. OBJECTIVE: In order to clarify the clinical utility of self-reinforced bioresorbable poly-70L / 30DL-Lactide miniplates & screws in maxillary fixation after LeFort I osteotomy, this study examined the postsurgical changes in maxilla and complications of biodegradable plates and screws. STUDY DESIGN: Nineteen patients who had undergone maxillary internal fixation using biodegradable plates and screws were evaluated radiographically and clinically. A comparison study of the changes in maxilla position after surgery in all 19 patients was performed with 1-week, 1-month, 3-months, 6-months and/or 1-year postoperative lateral cephalograms by tracing. Complication of the biodegradable plates and screws was evaluated by follow-up roentgenograms and clinical observation. And one-way ANOVA test was used for statistical analysis. RESULTS: The position of the maxillary bone was stable after surgery and was not changed significantly from 1 week to 1 year after operation. And we could not find any complication of biodegradable plates and screws. CONCLUSIONS: Internal fixation of the maxilla after LeFort I osteotomy using self-reinforced biodegradable plates and screws is a reliable method for maintaining postoperative position of the maxilla after LeFort I osteotomy.

Accuracy of digital model surgery for orthognathic surgery: a preclinical evaluation

Annual Report on External Quality Assessment of Clinical Microbiology Laboratory in Korea (2005) / 임상검사와정도관리

Two trials of external quality assessment for clinical microbiology laboratory were performed in 2005. A total of 12 specimens were distributed. Six specimens were distributed to 308 laboratories with 272 (88.3%) returns in Trial I and 276 (89.6%) returns in Trial II. The acceptable percentages of Gram-stain were relatively good. The acceptable percentages of bacterial identification on Acinetobacter baumannii, Staphylococcus aureus, Streptococcus pyogenes, Aeromonas hydrophila, Enterococcus casseliflavus, Brucella species (Trial I) were 80.1%, 98.3%, 87.6%, 81.3%, 55.5%, 38.1%, respectively. The acceptable percentages of bacterial identification on Klebsiella pneumoniae, Enterococcus faecalis, Brahamella catarrhalis, Burkholderia cepacia, Campylobacter fetus, Rhodoccus equi (Trial II) were 97.5%, 85.9%, 71.0%, 85.9%, 8.3%, 51.0%, respectively. The acceptable percentages for antimicrobial susceptibility tests on Acinetobacter baumannii, Staphylococcus aureus and Klebsiella pneumoniae were relatively high, but those on Klebsiella pneumoniae for ESBL and Enterococcus faecalis for vancomycin-resistance were not high. In conclusion, the acceptable percentages of bacterial stain and identification were relatively good except C. fetus. However, it is necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.

Annual Report on External Quality Assessment of Clinical Microbiology Laboratory in Korea (2004) / 임상검사와정도관리

Two trials of external quality assessment for clinical microbiology laboratory were performed in 2004. A total of 12 specimens were distributed. Six specimens were distributed to 293 laboratories with 277 returns in Trial I and six specimens to 293 laboratories with 274 returns in Trial II. The acceptable percentages of Gram-stain on Streptococcus pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Enterococcus faecalis were 96.0%, 98.5%, 97.4% and 98.2%, respectively. The acceptable percentages of bacterial identification on Streptococcus pneumoniae, Escherichia coli, Enterococcus faecalis, Staphylococcus saprophyticus, Shigella flexneri, Gemella spp., Pseudomonas aeruginosa, Enterococcus faecalis (Trial II), Streptococcus agalactiae, Listeria monocytogenes, Erysipelothrix rhusiopathiae, and Eikenella corrodens were 97.5% (including 33.7% of no growth), 99.6%, 93.2%, 82.3%, 95.4%, 50.7%, 98.4%, 92.3%, 87.0%, 78.9%, 92.5% (including 53.4% of no growth), respectively. The acceptable percentages for antimicrobial susceptibility tests on Escherichia coli and Pseudomonas aeruginosa were relatively high, but those on Streptococcus pneumoniae and Enterococcus faecalis were not high. In conclusion, the acceptable percentages of bacterial stain and identification were relatively good. However, it is necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests on Streptococcus pneumoniae and Enterococcus faecalis, and the selection of the most appropriate antimicrobial agents to test should be also considered.

Annual Report on External Quality Assessment of Clinical Microbiology Laboratory in Korea (2003) / 임상검사와정도관리

Three trials of external quality assessment for clinical microbiology laboratory and two workshops were performed in 2003. A total of 19 specimens were distributed. Six specimens were distributed to 241 laboratories with 231 returns in Trial I, Five specimens to 241 laboratories with 225 returns in Trial II, and seven specimens to 245 laboratories with 220 returns in Trial III. The percentages of fully correct results of E. coli, E. faecalis, S. aureus, P. aeruginosa, K. pneumoniae, Candida albicans, P. aeruginosa, S. aureus, E. faecalis, K. pneumoniae, E. coli, and Candida tropicalis were 99%, 83%, 99%, 89%, 97%, 92%, 90%, 98%, 83%, 90%, 99%, and 63%, respectively. The standard deviation (SD) of inhibition zone diameter against each antibiotic was calculated. The within-one-SD percentages on disk diffusion test against ciprofloxacin, imipenem, ampicillin, cefotaxime, and cephalothin of E. coli (M0301) were 86%, 78%, 86%, 91%, and 76%, respectively. Those against vancomycin and teicoplanin of E. faecalis (M0302) were 77% and 95%, respectively. Those against vancomycin, oxacillin, penicillin G, clindamycin, erythromycin, ciprofloxacin, gentamicin and teicoplanin of S. aureus (M0303) were 82%, 80%, 81%, 81%, 79%, 80%, 88%, and 90%, respectively. Those against ciprofloxacin, gentamicin, imipenem, ceftazidime, and piperacillin of P. aeruginosa (M0304) were 73%, 88%, 85%, 83%, and 78%, respectively. Those against ciprofloxacin, imipenem, ampicillin, cefotaxime, and cephalothin of K. pneumoniae (M0305) were 89%, 89%, 87%, 81% and 86%, respectively. Thirty-five laboratories on Trial I and Trial II had reported the both results of disk diffusion and MIC methods. Seven laboratories use disk diffusion method or MIC method according to the bacterial species. The performance on the automated or E-test susceptibility tests was generally good. In conclusion, it is necessary that the quality assurance of the individual laboratories should be improved in the identification of Candida tropicalis and Enterococcus spp., and in susceptibility tests against oxacillin, erythromycin and ciprofloxacin of S. aureus, and cephalothin and imipenem of E. coli and vancomycin of E. faecalis in case of disk diffusion method.

Onychomycosis and Trichosporon beigelii / 대한피부과학회지

BACKGROUND: Onychomycosis is a common superficial fungal infection. Causative organisms in onychomycosis have been extensively studied, but the role of non-dermatophytes is controversial. Trichosporon beigelii are soil and water inhabiting yeasts, occasionally found in flora normally associated with human skin, mouth, and nails. Several reports in the literature have suggested that T. beigelii is one of the pathogens in onychomycosis. OBJECTIVE: We performed mycologic studies to investigate the causative organisms of onychomycosis and to confirm the pathogenic role of T. beigeliis in onychomycosis. METHODS: We performed a survey of the mycologic labaratory records of patients clinically suspected of onychomycosis from July 1996 to December 1998. RESULTS: 1) Out of a total of 1934 nail samples examined, 928(48.0%) of these were culture positive, including 192(10.8%)cases with T. beigelii. 2) The overall positive rate for the KOH mount examination was 59% and in the cases with T. beigelii was 89.1%. 3) Among the age groups, the incidence rate was highest in the fifth decade(26.6%). 4) The monthly prevalence of onychomycosis was highest in July(10.6%), the distribution of T. beigelii was high in July and August. 5) The most common causative organism of onychomycosis was Trichophyton rubrum(62.0%), and the others in decreasing frequency were T. beigelii(20.7%), Candida spp.(7.2%), Trichophyton mentagrophytes(4.0%) and mixed infection(2.2%). 6) T. beigelii was repeatedly isolated in the successive nail cultures from 10 out of 20 patients with T. beigelii nail infection. CONCLUSION: T. beigelii was the second commonly isolated fungus in onychomycosis had the high positive rate of the which KOH mount examination on nails and successive repeated cultures. We suggest that T. beigelii might be a pathogen of onychomycosis.

A Case of Rieger's Syndrome Associated with Controlled Glaucoma

Rieger's syndrome is a rare autosomal dominant developmental anomaly characterized by ocular and systemic abnomalities. These disorders are typically bilateral and usually diagnosed at birth or in the childhood. The most common ocular defects are hypoplasia of the iris, a prominent Schwalbe's line with iris strands and corectopia. A large number of patients have glaucoma due to devel-opmental defects of the anterior chamber angle structure. The authors experienced a case of Rieger's syndrome which was found in 31-year-old female, who had characteristic ocular and other systemic abnormalities. Associated glaucoma was well controlled by filtering surgery.

Comparison of antimicrobial susceptibility of nosocomial and community-acquired pathogens / 감염

No abstract available.