• Journal of TMJ Balancing Medicine
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• v.8 no.1
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• pp.6-10
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• 2018

In order to propose a fundamental and appliable theories for balancing therapy of temporomandibular joint (TMBT), evolutionary proofs and up-down theories in evolutionary biology and Korean medicine were investigated. Balancing therapy of temporomandibular joint treats disorder and diseases of the whole body through straightening of the abnormal linking between temporomandibular joint and axis. Although the mechanism of this therapy contains many merits like multicellular integrity and coadjustment, ease of balance and alert forward mobility by the bipedal stepping and evolution to Homo sapiens, increasing disadvantages of balancing pressure of right and left in the lengthened perpendicular axis and the balancing load of temporomandibular joint and axis following the reactional change of dental occlusion are deeply related and considered in this therapy. As for up-down theory, crossing of heavenly qi and earth qi centering on cervical joint is presented as the first mechanism for TMBT, and the other ones like in-out and up-down qi activity of tripple energizer, up-down of essence-qi-spirit in the three backbone barrier and three cinnabar field, up-down of yin-yang-water-fire of viscera and bowels can be related too.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.37.1-37.13
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• 2020

Background: The human mandible is variable in shape, size and position and any deviation from normal can affect the facial appearance and dental occlusion. Objectives: The objectives of this study were to determine whether the Sassouni cephalometric analysis could help predict two-dimensional mandibular shape in humans using cephalometric planes and landmarks. Materials and methods: A retrospective computerised analysis of 100 lateral cephalometric radiographs taken at Kingston Hospital Orthodontic Department was carried out. Results: Results showed that the Euclidean straight-line mean difference between the estimated position of gonion and traced position of gonion was 7.89 mm and the Euclidean straight-line mean difference between the estimated position of pogonion and the traced position of pogonion was 11.15 mm. The length of the anterior cranial base as measured by sella-nasion was positively correlated with the length of the mandibular body gonion-menton, r = 0.381 and regression analysis showed the length of the anterior cranial base sella-nasion could be predictive of the length of the mandibular body gonion-menton by the equation 22.65 + 0.5426x, where x = length of the anterior cranial base (SN). There was a significant association with convex shaped palates and oblique shaped mandibles, p = 0.0004. Conclusions: The method described in this study can be used to help estimate the position of cephalometric points gonion and pogonion and thereby sagittal mandibular length. This method is more accurate in skeletal class I cases and therefore has potential applications in craniofacial anthropology and the 'missing mandible' problem in forensic and archaeological reconstruction.

• 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 Journal of Korean Academy of Prosthodontics
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• v.54 no.1
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• pp.28-34
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• 2016

Implant has been an effective treatment option for the patients with oligodontia. However, it still remains unclear when the implant should be placed. Skeletal growth that can appear even after the growth period can lead to infraocclusion of the implant which can cause functional or esthetic complications. In order to minimize these problems, definitive restorations should be placed after the functional and esthetic rehabilitation is achieved through the use of provisional restorations. Definitive restorations made with monolithic zirconia were created by replicating provisional restorations by using the latest CAD/CAM technology. These definitive restorations were delivered to the patient and clinical observation after the treatment showed satisfactory result.

• Korean Journal of Cleft Lip And Palate
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• v.12 no.2
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• pp.73-84
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• 2009

The treatment of cleft lip and palate must be based on a complete knowledge of the anatomy, physiology and growth of the involved deformity, because of not only the appearance but also impaired functions such as phonation, mastication, respiration and lingual posture of the maxillomandibular complex. Delaire has long studied all these aspects, and has published many numbers of articles and constructed a philosophy concerning the significance and interrelationship of the various structures. The results obtained from its application seem to be particularly valid from a clinical point of view, although it has not all been scientifically supported by experimental data. For these reasons, Delaire's primary unilateral and bilateral cheilorhinoplasty procedures are particulary good, as is his secondary gingivoalveoloplsty procedure during the course of the surgical repair of the hard palate. In order to understand Delaire's philosophy, it is necessary to consider the normal and pathologic anatomy of the structures involved in the deformity, the role of some structures, such as nasal septum, musculature, and tongue, and some functions, such as dental occlusion or nasal respiration, which play important roles in maxillary and particularly premaxillary growth. Despite of important concept and meanings, Delaire's philosophy has not been introduced widely to our Korean cleft surgeons yet. So authors will summarize the basic concepts of Delaire's philosophy according to already published literatures and lectures based on our previous treatment outcomes.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.1
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• pp.33-48
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• 2005

Differential diagnosis of articulation and resonance problems in the cleft lip and palate speech is required for evaluating various factors contribute to speech problems such as VPI, dental occlusion, palatal fistulae, learning. However, validity of speech stimuli is current issue to evaluate accurately each problem in cleft speech. This study was conducted to investigate speech stimuli using in the clinical setting and review the literatures and articles published 1990 to 2005 for helping develop standardized speech samples. The results were recommendation to evaluate properly velopharyngeal function when conducting a diagnostic evaluation as follows : 1) In identification hypernasality, the speech stimuli should be included low pressure consonants to eliminate effects of nasal emission, compensatory articulation. 2) Speech stimuli should be consist of visual, front sounds to eliminate compensatory articulation and to stimulate easily. 3) Regarding early diagnosis and treatment, speech stimuli need to develop for infants and preschooler. 4) Stimulus length on nasalance scores should be at least 6 syllables. 5) In phonetic context on nasalance scores, /i/ vowel should be take into consideration excluding paragraph. 6) Connected speech stimuli should be developed for evaluating intelligibility and VP function.

• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.9.1-9.6
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• 2018

The objective of this case report is to introduce a simple technique for simultaneously taking a closed-mouth impression and functionally generated path (FGP) for a full coverage crown restoration. A monolithic zirconia crown was the restoration of choice. An alginate impression of the abutment tooth was taken to fabricate a custom-made closed-mouth impression tray covering the abutment tooth and the adjacent teeth. The tray had an FGP table and an abutment tray in cameo and intaglio surfaces, respectively. The impression was taken with silicone impression material after adjusting the abutment tray and inscribing the FGP using self-curing acrylic resins. Plaster casts were made from the impression, and a zirconia crown was fabricated. The crown was cemented to the abutment tooth with minimal adjustments. This simple technique resulted in a well-fitting crown that accounted for mandibular movements. Using the custom closed-mouth impression tray incorporating an FGP table simultaneously aids in fabricating an accurately fitting restoration that incorporates harmonious mandibular movements using a single impression capture.

• Journal of Periodontal and Implant Science
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• v.48 no.2
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• pp.124-134
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• 2018

Purpose: Clinicians must examine tooth wear to make a proper diagnosis. However, qualitative methosds of measuring tooth wear have many disadvantages. Therefore, this study aimed to develop and evaluate quantitative parameters using the cusp area and volume of virtual dental models. Methods: The subjects of this study were the same virtual models that were used in our former study. The same age group classification and new tooth wear index (NTWI) scoring system were also reused. A virtual occlusal plane was generated with the highest cusp points and lowered vertically from 0.2 to 0.8 mm to create offset planes. The area and volume of each cusp was then measured and added together. In addition to the former analysis, the differential features of each cusp were analyzed. Results: The scores of the new parameters differentiated the age and NTWI groups better than those analyzed in the former study. The Spearman ${\rho}$ coefficients between the total area and the area of each cusp also showed higher scores at the levels of 0.6 mm (0.6A) and 0.8A. The mesiolingual cusp (MLC) showed a statistically significant difference (P<0.01) from the other cusps in the paired t-test. Additionally, the MLC exhibited the highest percentage of change at 0.6A in some age and NTWI groups. Regarding the age groups, the MLC showed the highest score in groups 1 and 2. For the NTWI groups, the MLC was not significantly different in groups 3 and 4. These results support the proposal that the lingual cusp exhibits rapid wear because it serves as a functional cusp. Conclusions: Although this study has limitations due to its cross-sectional nature, it suggests better quantitative parameters and analytical tools for the characteristics of cusp wear.

• Archives of Craniofacial Surgery
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• v.9 no.2
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• pp.105-109
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• 2008

Temporomandibular joint(TMJ) and dental occlusion are important in functional aspect as well as in cosmetic aspect for craniofacial surgery such as orthognathic and traumatic surgery. During these operations, appropriate maxillomandibular fixation(MMF) is especially necessary to conserve or reconstruct, dynamic TMJ and functional occlusion. Arch bar is one of the most popular method to gain proper MMF. Seventeen patients including 5 patients with mandibular fracture, 12 patients with orthognathic surgery(6 patients had relatively normal occlusion, however 6 patients had facial anomalies such as hemifacial microsomia with irregular occlusal plane.) were joined in this study. Arch bar was contoured on the dental cast, which was prepared for model surgery, prior to apply it on the facial anomaly patient. On using pre-contoured arch bar, patients felt better during the procedure and surgeons saved time. Moreover, well-contoured arch bar promises precise transmission of force on the bone, which implies surgeons do not need to worry about the occlusion while fixing bony structures. Authors suggest how to apply arch bar to satisfy basic theories about dental row and occlusion based on the experience. In addition, it is proposed to contour arch bar on the dental impression prior to apply it on the patient who has irregular and complex occlusal plane.

• Journal of Oral Medicine and Pain
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• v.20 no.1
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• pp.195-204
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• 1995

The purpose of this study was to evaluate effect of head posture change on initial occlusal contacts through measuring the distances between initial occlusal contacts and maximum intercuspal position at different head posture. Two special devices were designed and constructed. Mandibular movement replicator was used to assess reliability of the K6 diagnostic system(MKG; Myo-tronic Inc, Seatle, USA) and head posture calibrator was used to maintain the constant head posture during experiment. We measured difference of distance between initial occlusal contact and maximum intercuspal position with MKG in upright, supine, 45 degrees extension, 30 degrees flexion, 30 degrees right and left bending postion of the head. The Frankfurt horizontal plane was used as a reference plane. 21 adults aged from 23 to 25 were selected, who have normal or class I molar relationship, and have no symptoms on TMJ and masticatory muscles, and have restorations less than 3 surfaces on each tooth, and have no other prosthetic restoration. The obtained results were as follows : The mean absolute distances between initial occlusal contact and maximum intercuspal postion were 0.39(0.18mm in the upright position, 0.65(0.37mm in the supine position, 0.59(0.33mm in the 45 degree extension, 0.70(0.53mm in the 30 degrees flexion, 1.12(1.10mm in the 30 degrees right bending and 1.94(0.67mm in the 30 degrees left bending of the head. The positions of the initial occlusal contacts have a tendency to locate anterior, left and inferior to maximal intercuspal position in upright position, posterior and inferior in supine position and 45 degrees extension, anterior and inferior in 30 degrees flexion, right and inferior in 30 degrees right bending, and left and inferior in 30 degrees left bending of the head. There were significant differences among the initial occlusal contacts in each head postures(P<0.0001). Therefore, we need to check initial occlusal contacts in the altered head posture during occlusal analysis and adjustment of occlusal appliance and dental occlusion for diagnosis and treatment of temporomandibular disorder.