• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.2
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• pp.185-187
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• 2010

Most studies of the black soldier fly, Hermitia illucens, widely distributed throughout Southeast Asia and America focused on the use of larvae for recycling various organic materials and feed for fish and livestock. To recognize the instars of the soldier fly's larvae, we examined the number of exuviae originated from each larva from 1st instar to pupa. The weight and the head capsule width of the black soldier fly larvae also confirmed that the black soldier fly was passed through 6th instars. In addition, we found that the black soldier fly larvae had a well developed mandibular-maxillary complex, similar to those reported from the larvae of scavengers including Odontomyia cincta, Neopachygaster maculicornis, Ptecticus brunettii and Stratiomys ruficornis.

• Imaging Science in Dentistry
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• v.37 no.1
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• pp.19-26
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• 2007

Purpose : To examine whether the maxillofacial skeletal morphology correlates with the condylar position and the anatomic characteristics of articular eminence using measurements of lateral cephalometric radiographs and individualized sagittal temporomandibular joint (TMJ) tomographs. Materials and Methods : I compared measurements of 202 TMJs of 101 orthodontic patients of Kangnung National University Dental Hospital. 1 used Pearson's correlation for comparison of the measuring values in lateral cephalometric radiographs and individualized sagittal TMJ tomographs. Results : Large occlusal plane angle tendency showed decreased width of posterior eminence slope, decreased depth of articular fossa and decreased posterior slope angle of eminence. Large mandibular plane angle tendency showed decreased superior joint space, decreased depth of articular fossa and decreased posterior slope angle of eminence. Large genial angle tendency showed decreased depth of articular fossa, decreased posterior slope angle of eminence and anterior position of condylar head. Large anterior facial height and large posterior facial height tendency showed increased width of posterior slope of eminence, increased depth of articular fossa, increased posterior slope angle of eminence and posterior position of condylar head. Conclusion : Maxillofacial skeletal morphology has correlation with the anatomic characteristics of TMJ. Individualized sagittal TMJ tomographs can provide useful information for anatomical analysis of TMJ.

• The korean journal of orthodontics
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• v.37 no.3 s.122
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• pp.192-203
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• 2007

Objective: The aim of this study was assessment of the relationship between airway space and facial morphology in Class III children with nasal obstruction. Methods: For this study, 100 Class III children (50 boys and 50 girls) were chosen. All subjects were refered to ENT, due to nasal obstruction. Airway space measurements and facial morphology measurements were measured on lateral cephalometric radiograph. Pearson correlation analysis was used to assess the relationship between airway space and facial morphology Results: Ramal height, SNA, SNB, PFH, FHR and facial plane angle were positively related to upper PAS, and sum of saddle angle, articular angle, and genial angle, SN-GoGn, Y-axis to SN and FMA negatively related to upper PAS. Genial angle, FMA were positively related to lower PAS, and articular angle, facial depth, PFH and FHR negatively related to lower PAS. PCBL, ramal height, Mn. body length, Mn. body length to ACBL, facial depth, facial length, PFH and AFH were positively related to tonsil size. Sum of saddle angle, articular angle, genial angle, facial length, AFH, FMA and LFH were positively related to tongue gap, and IMPA and overbite was negatively related to tongue gap. Upper PAS, related to size of adenoid tissue, was mainly related to posterior facial dimension following a vertical growth pattern of face and mandibular rotation. Lower PAS and tonsil size, related to anterior-posterior tongue base position, were significantly related to each other. Lower PAS was related to growth pattern of mandible, and tonsil size was related to size of mandible and horizontal growth pattern of face. Tongue gap was related to anterior facial dimension following a vertical growth pattern of face. Conclusion: Significant relationship exists between airway space and facial morphology.

• Imaging Science in Dentistry
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• v.44 no.3
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• pp.221-227
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• 2014

Purpose: This study aimed to investigate the clinical anatomy of lower premolar roots in a Spanish population by using cone-beam computed tomography (CBCT), correlating findings with patient gender and tooth type. Materials and Methods: Using 70 CBCT images, we evaluated 126 healthy, untreated, well-developed lower premolars. The number and morphology of roots and root canals, and the foramina number were assessed. Results for gender and tooth type were compared using the chi-squared and ANOVA tests. Results: The average length of teeth and roots was significantly higher in men (p=0.00). All 126 premolars had a single root. One canal was found in 83.3% of the premolars, with no gender or tooth type differences; Vertucci configuration types I and V were the most prevalent. The first premolars showed significantly greater variability than the second premolars (p=0.03). A single apical foramen was found in 89.7% of the premolars, with no differences by tooth type. Women had a significantly higher prevalence of two apical foramina than men (p=0.04). Some degree of curvature was observed in 65% of the premolars, with no differences by gender or tooth type. A root angle of more than $20^{\circ}$ was found in 12.98% of the premolars, without any differences by gender or tooth. Conclusion: All premolars were single-rooted. One canal had the most prevalent morphology. More variability in canal anatomy was found in the first premolars. Curvatures greater than $20^{\circ}$ were found at less than 5 mm from the apex.

• The Journal of Advanced Prosthodontics
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• v.7 no.6
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• pp.431-436
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• 2015

PURPOSE. The aim of this study was to evaluate occlusal contacts generated by 3 different biogeneric design modes (individual (BI), copy (BC), reference (BR)) of CEREC software and to assess the designs subjectively. MATERIALS AND METHODS. Ten pairs of maxillary and mandibular casts were obtained from full dentate individuals. Gypsum cast contacts were quantified with articulating paper and digital impressions were taken. Then, all ceramic crown preparation was performed on the left first molar teeth and digital impressions of prepared teeth were made. BI, BC, and BR crowns were designed. Occlusal images of designs including occlusal contacts were superimposed on the gypsum cast images and corresponding contacts were determined. Three designs were evaluated by the students. RESULTS. The results of the study revealed that there was significant difference among the number of contacts of gypsum cast and digital models (P<.05). The comparison of the percentage of virtual contacts of three crown designs which were identical to the contacts of original gypsum cast revealed that BI and BR designs showed significantly higher percentages of identical contacts compared with BC design (P<.05). Subjective assessment revealed that students generally found BI designs and BR designs natural regarding naturalness of fissure morphology and cusp shape and cusp tip position. For general occlusal morphology, student groups generally found BI design "too strong" or "perfect", BC design "too weak", and BR design "perfect". CONCLUSION. On a prepared tooth, three different biogeneric design modes of a CAD/CAM software reveals different crown designs regarding occlusal contacts and morphology.

• The korean journal of orthodontics
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• v.51 no.2
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• pp.126-134
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• 2021

Objective: This study aimed to evaluate the following null hypothesis: there are no differences in the morphology of the temporomandibular joint (TMJ) structures in relation to vertical and sagittal cephalometric patterns. Methods: This retrospective study was performed with 131 participants showing no TMJ symptoms. The participants were divided into Class I, II, and III groups on the basis of their sagittal cephalometric relationships and into hyperdivergent, normodivergent, and hypodivergent groups on the basis of their vertical cephalometric relationships. The following measurements were performed using cone-beam computed tomography images and compared among the groups: condylar volume, condylar size (width, length, and height), fossa size (length and height), and condyle-to-fossa joint spaces at the anterior, superior, and posterior condylar poles. Results: The null hypothesis was rejected. The Class III group showed larger values for condylar width, condylar height, and fossa height than the Class II group (p < 0.05). Condylar volume and superior joint space in the hyperdivergent group were significantly smaller than those in the other two vertical groups (p < 0.001), whereas fossa length and height were significantly larger in the hyperdivergent group than in the other groups (p < 0.01). The hypodivergent group showed a greater condylar width than the hyperdivergent group (p < 0.01). The sagittal and vertical cephalometric patterns showed statistically significant interactions for fossa length and height. Conclusions: TMJ morphology differed across diverse skeletal cephalometric patterns. The fossa length and height were affected by the interactions of the vertical and sagittal skeletal patterns.

• Restorative Dentistry and Endodontics
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• v.32 no.1
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• pp.37-46
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• 2007

The C-shaped canal system is an anatomical variation mostly seen in mandibular second molars, although it can also occur in maxillary and other mandibular molars. The main anatomical feature of C-shaped canals is the presence of fins or web connecting the individual root canals. The complexity of C-shaped canals prevents these canals from being cleaned, shaped, and obturated effectively during root canal therapy, and sometimes it leads to an iatrogenic perforation from the extravagant preparation. The purpose of this study was to provide further knowledge of the anatomical configuration and the minimal thickness of dentinal wall according to the level of the root. Thirty extracted mandibular second molars with fused roots and longitudinal grooves on lingual or buccal surface of the root were collected from a native Korean population. The photo images and radiographs from buccal, lingual, apical direction were taken. After access cavity was prepared, teeth were placed in 5.25% sodium hypochlorite solution for 2 hours to dissolve the organic tissue of the root surface and from the root canal system. After bench dried and all the teeth were embedded in a self-curing resin. Each block was sectioned using a microtome (Accutom-50, Struers, Denmark) at interval of 1 mm. The sectioned surface photograph was taken using a digital camera (Coolpix 995, Nikon, Japan) connected to the microscope. 197 images were evaluated for canal configurations and the minimal thickness of dentinal wall between canal and external wall using 'Root Thickness Gauge Program' designed with Visual Basic. The results were as follows : 1. At the orifice level of all teeth, the most frequent observed configuration was Melton's Type C I (73%), however the patterns were changed to type C II and C III when the sections were observed at the apical third. On the other hand, the type C III was observed at the orifice level of only 2 teeth but this type could be seen at apical region of the rest of the teeth. 2. The C-shaped canal showed continuous and semi-colon shape at the orifice level, but at the apical portion of the canal there was high possibility of having 2 or 3 canals 3. Lingual wall was thinner than buccal wall at coronal, middle, apical thirds of root but there was no statistical differences.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.43-52
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• 2000

Hemifacial microsomia ( HFM ) is the second most common craniofacial abnormalies. HFM represnted a spectrum of clinical findings such as hypoplasia of the mandibular ramus and condyle, confinement of maxilla growth, external and/or middle ear defects, involvement of some cranial suture, buccal soft tissue, facial nerve, and muscles in the affected side. HFM often showed progressive facial asymmetry and occlusal plane slanting to the affected side with growth. There were several reports about asymmetry of tooth maturation, hypodontia, delayed eruption, enamel hypoplasia in HFM. Since teeth develope in close association with size and morphology of the maxillary and the mandible, it is highly likely that dental changes will be present in HFM. So the Purpose of this study was to investigate the differences of the primary and the permanent teeth dimensions in the maxillary and the mandibular dentition between the affected and the non-affected side of HFM.. The sample of this study consisted of 34 unilateral HFM Patients (18 males and 16 females, average age : 5 year 11 months old). The authors examined the mesiodistal and the faciolingual dimensions of the primary and the permanent teeth and performed statistical study by using paired t-test. The results were as follows 1. The mesiodistal dimensions of the mandibular second primary molar and the mandibular first permanent molar in the affected side of HFM were significantly smaller than those of non-affected side. But there were no significant differences in the anterior teeth and the mandibular first primary molar. It means that a gradient of severity from anterior teeth to posterior teeth was found in the mandibular dentition. 2. Although there were no significant differences in the faciolingual dimensions of the primary and the permanent teeth in the maxillary and the mandibular dentition between the affected and non-affected side of HFM, there were general trend of compensatory increase in faciolingual dimension of the mandibular primary and the permanent teeth in the affected side Therefore these results showed that HFM might affect on the abnormality of tooth dimension, especially the most posterior teeth, in the affected side of the mandible.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.2
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• pp.203-220
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• 1991

The purpose of this study was to investigate the changes of morphology and structure of bone tissue, caused by administration of high-dose hydrocortisone, elcatonin and cyclophosphamide. In order to carry out experiment, 60 four-week old Sprague-Dawley strain rats weighing about 107 gms were selected and divided into experimental group and control group. The experimental group was subdivided into three groups, assigned fifteen rats for each group, by the different drugs administered. Each experimental group was then categorized as follows: hydrocortisone 30㎎/㎏ b.w. with daily subcutaneous injection, elcatonin 20U/㎏ b.w. with daily subcutaneous injection, and cyclophosphamide 100㎎/㎏ b.w. with a single intraperitoneal injection. Fifteen rats were injected daily with 5㎖/㎏ b.w. of normal saline solution subcutaneously in control group. Rats in control group and experimental group were serially sacrificed on the 6th, the 15th and the 22nd day after injection of normal saline, hydrocortisone, elcatonin and cyclophosphamide, respectively. Being sacrificed, both sides of mandibular condyles were removed and fixed with 10% neutral formaline. The one side of mandibular condyles was radiographed with soft X-ray apparatus. Thereafter, the obtained radiographs were observed, and the bone density of condylar head and condylar neck regions was measured by use of transferring video-based digital radiograph. The other side was further decalcified and embedded in paraffin as usual manner, then sectioned and stained with hematoxylin and eosin, observed by light microscope. The obtained results were as follows: 1. Sclerotic changes with regularly increased trabecular pattern were seen throughout experimental periods in hydrocortisone group. Increased the number of trabecular pattern with irregularity and periodic striation on the periphery of condylar head region were appeared with lapse of time in elcatonin group. In cyclophosphamide group, irregular trabecular pattern and stippled radiopacities on mandibular condyle were observed with lapse of time. 2. The bone density of condylar head region was increased in hydrocortisone group, decreased in elcatonin group, and tended to be decreased in cyclophosphamide group, compared with that of control group according to the experimental periods. 3. The bone density of condylar neck region tended to be rather increased in hydrocortisone group, elcatonin group and cyclophosphamide group, depending on the experimental periods. 4. In microscopic studies, there were irregular trabecular bonds and osteoblastic activity in hydrocortisone group and elcatonin group throughout experimental periods, degenerative cartilage and trabecular bones in the 6th day and densely calcified trabecular bones in the 22nd day in cyclophosphamide group.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.386-392
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• 2018

Turner syndrome (TS) is a chromosomal disorder caused by monosomy of the X chromosome, with complete or partial absence of the second sex chromosome. Anomalies of root morphology have been found to occur more often in patients with TS, which make endodontic treatment challenging and requires special handling. The patients with TS may also have systematic problems such as cardiac or renal malformations, so in treating these patients it is important for clinicians not only to be aware of the characteristic intraoral findings, but also to make the patients have regular dental check-ups to prevent oral complications in advance. An 12-year-old girl who had been diagnosed with TS at the age of 10 years was referred due to discomfort in the bilateral mandibular premolar regions. Dens evaginatus and taurodontism were detected in all the mandibular premolars characteristically. The bilateral mandibular first premolars had three roots and the bilateral mandibular second premolars had periapical lesion with two roots. Due to the complexity of the root canal anatomy, root canal treatment were completed with a dental microscope to ensure adequate visualization. After 2 years of regular follow-up examinations, there were no clinical sign or symptom associated with the teeth, and no periapical lesion, was found. This case report describes the characteristic oral features and dental management of TS patients.