• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.149-159
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• 2000

Occlusal disease is comparable to periodontitis in that it is generally not reversible. Occlusal disease, however, like periodontitis, often maintainable. It does itself to treatment and when restorative dentistry is utilized it becomes, in that sense, reversible. Moreover, a systematized and integrated approach will lead to a prognosis that is favorable and predictable. This approach facilitates development of optimum oral function, comfort, and esthetics, resulting in a satisfied patient. Such a systematized approach consists of four logical phase : (1) patient evaluation, (2) comprehensive analysis and treatment planning, (3) integrated and systematic reconstruction, and (4) postoperative maintenance. An integrated treatment plan is first developed on one set of diagnostic casts, properly mounted on a semiadjustable articulator using jaw relationship records. This is accomplished by using wax to make reconstructive modifications to the casts. These modified casts become the blueprint for planned occlusal changes and the fabrication of provisional restorations. The treatment goals are : (1) comfortably functioning temporomandibular joints and stomatognathic musculature, (2) adherence to the basic principle of occlusion advocated by Schuyler, (3) anterior guidance that is in harmony with the envelope of function, (4) restorations that will not violate the patient's neutral zone. This report shows the treatment procedures for a patient whose mandibular position has been altered due to posterior bite collapse. Migration of the maxillary anterior teeth had occurred, and the posterior occlusal contacts showed pathologic interference. Precise diagnosis using mounted casts was executed and prosthodontic reconstruction by the aid of an unconventional orthodontic correction on maxillary flaring was planned. An unconventional orthodontic correction can be accomplished by using preexisting natural teeth, which can be modified for use in active tooth movement or splinted together for orthodontic anchorage. This technique has an advantage over conventional fixed appliance orthodontic therapy because it can accomplish tooth movement concurrently with restorative and periodontal therapy. On occasion, minor tooth movement can be necessary to achieve the optimum occlusal scheme, crown form, and tooth position for the forces of occlusion to be displaced down the long axis of the periodontally compromised teeth. Once the occlusion, periodontal health, and crown contours for the provisional splinted restoration are acceptable, the final splinted restoration can be similarly fabricated, and it becomes an excellent orthodontic retainer.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.651-657
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• 2007

Odontomas are the common type of odontogenic tumors and generally are asymptomatic and frequently lead to impaction or delayed eruption of permanent teeth. They are composed of enamel, dentin, cementum and pulp tissue and are divided into compound and complex according to the morphology of the hard tissues. Compound odontomas consist of varying numbers of small toothlike structure and have a predilection for the maxillary anterior regions. Complex odontomas consist of an unorganized mass of odontogenic tissues and comprise approximately 25 percent of all odontomas and have a predilection for the mandibular posterior regions. The etiology of odontomas is uncertain but hypothesized to involve local trauma, infection and genetic factors. Treatment of odontoma is conservative surgical removal and are little probability of recurrence. These two cases were about the patients with delayed eruption of mandibular first molar and mandibular lateral incisor. We surgically removed odontoma, exposed impacted tooth and guided impacted tooth into normal position by orthodontic traction. At the completion of traction, the mandibular first molar and mandibular lateral incisor was positioned fairly within the arch and complications such as root resorption were not observed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.1
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• pp.1-9
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• 2007

Purpose: To evaluate the effect of compression on the distracted area in new bone formation during mandibular distraction osteogenesis in rabbits. Materials and method: Sixteen rabbits, weighing approximately 2 Kg, and the prefabricated distraction device were used. With the rabbits under general anesthesia, we performed vertical osteotomies between the anterior and posterior mandibular teeth and then placed the distraction device. After a 5 -day latency period, the mandible was distracted to a length of 10.0 mm at a rate of 1 mm/day and then immediately compressed 4 mm in the experimental group (n=8). In the control group (n=8), the mandible was distracted to a length of 6.0 mm at a rate of 1 mm/day. Rabbits in the control group were killed at 2 and 8 weeks during the consolidation period. The specimens were evaluated with light microscope after H & E stain. Histomorphometric analysis was done at 8 week specimens. Results: All experimental animals showed mandibular elongation on the macroscopical and radiographic evaluations. At 2 week, immature bone formation was observed from the surface of the host bone margins with collagen fibers arranged parallel to the direction of distraction in the control group; in the experimental group, immature bone formation was observed adjacent to the host bone, and the collagen fibers were not arranged uniformly. At 8 week, spindle-shaped new bone formation was seen in the direction of distraction in distracted area of the control group, while in the experimental group, the newly formed bone was arranged in a multidirectional manner, like the pattern of trabeculae. In the histomorphometric analysis of 8 weeks, the area of bone deposition was $2.12{\pm}\;0.75\;inch^2$ in the experimental group and $0.87{\pm}0.51\;inch^2$ in the control group (p<0.01). The bone deposition ratio was $29.60{\pm}10.50%$ in the experimental group and $12.10{\pm}7.17%$ in the control group (p<0.01). Conclusion: These results suggest that compression after over-distraction during the mandibular distraction osteogenesis is an effective method of increasing the amount of newly formed bone in distracted area.

• The korean journal of orthodontics
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• v.25 no.5 s.52
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• pp.593-604
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• 1995

Mandibular incisor crowding is one of the most common features of malocclusion and is interesting characteristic in view of relapse and stability after orthodontic treatment. There are many potential factors in the etiology of lower anterior crowding. The tooth size variation is one of them, but biologic significance for the faciolingual width of the teeth has been overlooked. Peck and Peck reported that persons with ideal mandibular incisor alignment were shown to have incisor with smaller mesiodistal and larger faciolingual dimensions than persons with incisor crowding. On the basis of these findings they suggested MD/FL index as a clinical guideline for the assessment for lower incisor crowding. The present study was undertaken to examine the relationship between mandibular incisor crowding and mandibular incisor dimension, and determine their correlation with arch length discrepancy. 154 dental casts of people from 11 to 17 years of age were made, and were divided into normal group with irregularity index less than of 1, and crowding group with irregularity index greater than 1.The casts were measured and analyzed statistically. The results were as follows. 1. The mean mesiodistal width for mandibular incisor was larger in crowding group, and has significant difference in central inciosr measurement. There are no significant differences in the faciolingul width and MD/FL index. 2. Irregularity index has significant correlation coefficients with mesiodistal width and MD/FL index for mandibular incisor in crowding group, but no correlation with faciolingual width. It also has correlation with maxillary and mandibular arch length discrepancy, total tooth material, mandibular intercanine width, and mandibular inter first premolar width. 3. Upper and lower arch length discrepancy have significant correlation with mesiodistal width of mandibular incisor and overbite, but have no correlation with faciolingual width. Lower arch lenth discrepancy has significant correlation with MD/FL index for mandibular incisor and upper arch length discrepancy has correlation with MD/FL index for mandibular lateral incisor. 4. Significant differences were observed between normal and crowding group for the mandibular arch length discrepancy and overbite.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.169-179
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• 2004

The purpose of this study was to discriminate clinically and radiographically among the three groups of dentigerous cysts studied. First, Group I, involved area of dentigerous cyst was successive permanent tooth area beneath deciduous tooth. Second, Group II, involved permanent molar area, and the last, Group III involved maxillary anterior supernumerary tooth area. The author observed and compared the clinico-radiographic features of 49 cases of Group I, 36 cases of Group II, and 15 cases of Group III of dentigerous cyst and this observation and comparison had been done by based on the charts and panoramic films. The obtained results were as follows: 1. The cases of Group I were 29 cases and, those of Group II were 36 and those of Group III were 15. 2. The incidence of dentigerous cyst is high in first decade. In Group I, before first decade and early first decade was 87.8%, in Group II and Group III, was discovered more lately. 3. The frequency of dentigerous cyst is 2.5 times higher in male than in female. 4. The sequence of chief complaint was swelling(50%), routine examination(32%), and pain(9%). 5. When considering the type of the cyst, lateral type is many most in Group I (71.4%) and central type is many most in Group II (94.4%) and Group III (100%). 6. The most size of dentigerous cyst was 2 crown size in Group I, 1 crown size in Group II, above of 4 crown size in Group III. 7. Almost involved teeth showed displacement and some tooth of displaced teeth showed delayed root development and dilaceration of root. 8. The most many response of alveolar bone was buccal bone expansion in Group I (67.3%), no bone expansion in Group II(66.7%) and palatal bone expansion in Group III (60.0%). 9. The percentage of involved teeth were as follows : The mandibular third molar was 31% and many most. The mandibular second premolar was 30%. Mesiodens of maxillary anterior area was 15%. The maxillary canine was 8%. The mandibular first premolar was 5%. 10. In the Group I, causes suggesting of dentigeous cyst are pulpotomized deciduous tooth(59.2%), severe dental caries of deciduous tooth, untreated traumatic history on the deciduous tooth etc. 11. The treatment method of dentigerous was marsupialization in 61.2% of cases of Group I and that was enucleation in 61.1% of cases of Group II and in 80.0% of cases of Group III.

• The Journal of Korean Academy of Prosthodontics
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• v.22 no.1
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• pp.72-78
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• 1984

The notion that the axis of the shaft of the articulator must coincide the patient's mandibular transverse axis tells us the importance of locating the axis precisely. When using kinematic axis to transfer a cast to an articulator, the anatomic asymmetry of the contralateral points will result in certain distortion when the axis transferred to an articulator where the mechanical axis produces symmetry. In this study, after locating the true hinge axis point with Denar hinge axis locator, the discrepancies between true hinge axis point and arbitrary hinge axis point that was 13mm anterior from the posterior margin of center of trangus to the outer canthus of eye were measured. And the discrepancies between left and right true hinge axis point in the superoinferior and anteroposterior directions were measured. For this study, 20 dental students who have no missing teeth and no difficulties of mandibular movement were selected. Upper and lower cast of subjects were mounted on Denar Mark II articulator uisng Denar Slidematic face-bow and centric relation record for the measurement of discrepancies between left and right true hinge axis points. The results obtained as follows. 1. The mean distance from the arbitrary hinge axis point to the true hinge axis point was as follows. Right: horizontal distance; 1.99mm, vertical distance; 2.12mm, linear distance; 3.36 mm. Left: horizontal distance; 1.39mm, vertical distance; 2.06mm, linear distance; 2.09mm. Total: horizontal distance; 1.69mm, vertical distance; 2.09mm linear distance; 3.06 mm. 2. The 87.5% of true hinge axis points were within 5mm of the arbitrary hinge axis point. 3. The mean discrepancies between the right and left hinge axis point were 2.92mm in superoinferior direction and 4.74mm in anteroposterior direction. 4. When transferring the axis to the articulator, anatomic asymmetry between right: and left axis point produces in dislocation of cast on the articulator, and undesirable shift in esthetic tooth position will be resulted.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.119-135
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• 1987

For the determination of instantaneous centre of rotation in the mandibular movement, the habitual opening path was recorded on the sagittal tracing plate by a Gnathorecorder attached on the lower anterior teeth which was designed for this study. The opening path was demonstrated mathematically and the instantaneous centre of rotation in the opening path were calculated and plotted by computer programs, and then a computer graphic movement of the mandible was obtained according to the opening path. The hinge path of posterior border movement was graphied by the Gnathorecorder as well and demonstated mathematically. This hinge path was compared with the same obtained by Visitrainer to prove a reliability of the Gnathorecorder. The results obtained from this study were as follows. 1. The habitual opening path and hinge path obtained from the Gnathorecorder movement were expressed mathematically as follows: $y=0.11x^2-0.66x+3.09$ (equation of opening path), $y=0.04x^2+0.21x+3.71$ (equation of hinge path), and a kinematic hinge axis was not shown in the equation of kings path. 2. The early habitual opening movement of the mandible demonstrated almost a straight opening path or an arc motion with the larger radius and it's centre of rotation moved parallelly in the more rear and lower position than a kinematic hinge axis. 3. Instantaneous centre of rotation occured along with the translation of the condyle, and mandible was rotated around an axis in the close to the maximum opening and then moved toward the forward and upward position. 4. There were some similarities between the articular eminence and the movement pattern of a special point which was the kinematic hinge axis.

• The korean journal of orthodontics
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• v.12 no.1
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• pp.21-26
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• 1982

This study was undertaken to document relations between facial skeletal pattern and dental occlusion. The data in .this study were collected from pretreatment cephalometric radiographs and study models of patients' records present in the files of Orthodontic Department, Seoul National University Hospital. Patients were selected on the basis of a mandibular plane-sella nasion angle equal to or greater than $38^{\circ}$ (high SN-MP angle) or equal to or less than $26^{\circ}$ (low SN-MP angle). Patients in the mixed dentition and with missing permanent teeth were excluded for ease of assessing tooth size / arch circumference relationships and then 30 high SN-MP and 11 low SN-MP patients were selected among them. The mean age of these two groups of patients was high SN-MP, $12.8{\pm}1.23$ years and low SN-MP, $13.0{\pm}1.48$ years. The following conclusions were obtained. 1. In the maxilla and mandible the mean tooth size of high SN-MP patients was nearlly identical to the low SN-MP patients. 2. The mean maxillary arch circumference was increased in low SN-MP group compared with high SN-MP group and a smilar, but smaller, mean increase was present in mandible. 3. The difference between the mean maxillary circumference required and the mean maillary circumference present ranged from -4.8mm in the high SN-MP group to -1.3mm in the low SN-MP group. A small range of means occurred in the mandible (high SN-MP: -4.0mm to low SN-MP: -1.8mm). 4. In the maxilla and mandible the mean arch length was nearly identical in the high and low SN-MP groups. 5. The mean incisor inclination was increased as the SN-MP angle decreased in the maxilla and mandible. 6. The men distance of the maxillary first molar from anterior border of the pterygomaxillary fissure was nearly similar between high and low groups. 7. The mean mandibular intermolar width was increased from high SN-MP to low SN-MP patients.

• Imaging Science in Dentistry
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• v.43 no.2
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• pp.129-134
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• 2013

Turner syndrome (TS) is one of the most common chromosomal abnormalities, with an estimated frequency among female live births of 1/2,000-3,000. The syndrome is characterized by the partial or complete absence of one X chromosome (45,X karyotype). We reported a unique case of a 40-year-old woman with TS accompanying unexpected elongated styloid process specific to Eagle syndrome (ES) and followed up-prolactinoma. The present article is the first report to define the cone-beam computed tomographic (CBCT) features of TS accompanying ES. Patients with TS carry various risks that make treatment more complicated; thus advanced imaging techniques for proper treatment and follow-up are extremely important. In the light of CBCT examination, craniofacial abnormalities specific to TS and accompanying syndromes such as the crowding of teeth especially in the maxillary anterior region caused by maxillary narrowness, micrognatic maxilla and mandible, relative mandibular retrusion, malocclusion, open-bite, and an elongated styloid process (length of 32.7 mm) on the right side were illustrated in detail.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.1
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• pp.109-118
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• 1991

The author studied the age distribution, etiology, affected site and several radiographic features of periapical granulomas, cysts, and abscesses. The material consisted of 928 films obtained from the patients who were diagnosed and treated under the diagnosis of periapical granulomas, cysts, and abscesses during the past 8 years (1979-1986) at the Infirmary of Dental School, Chosun University. The obtained results were as follows: 1. The order of incidence was as follows: periapical abscess (67.2%), granuloma, and cyst. 2. The age distribution revealed the highest incidence around the age of 30 and relatively higher incidence over the age of 60 in the case of periapical abscess and granuloma. 3. In the frequency of location: Periapical abscesses occured most frequently in the mandibular molars. Granulomas showed relatively higher incidence in maxilla than in mandible. Cysts were most common in the maxillary anterior teeth. 4. The mean diameter of dental granuloma was 5.9㎜, however, all dental granulomas were less than 9.3㎜ in diameter. The mean diameter of periapical cyst was l3.8㎜. 5. Periapical cyst revealed well circumscribed radiolucent lesions and 77.8% of the lesion showed white line. 86.0% of dental granuloma showed well circumscribed border, 54.5% sclerosis on surrounding bone and 38.5% partial white line. Periapical abscess revealed diffuse radiolucent lesion, 89.6% of the lesions had sclerosis on surrounding bone, and 38.0% sinus tract.