• Journal of Oral Medicine and Pain
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• v.33 no.1
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• pp.85-95
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• 2008

The purpose of this study was to evaluate the effects of oral habits on the muscles of mastication and facial expression by means of two parameters: muscle stiffness and elasticity. 10 healthy, fully-dentate male subjects in their twenties were selected for this study; all had normal Class I occlusal relationships. Muscle stiffness and elasticity were measured with a tactile sensor(Venustron, Axiom Co., JAPAN) while subjects were asked to relax and perform various parafunctional activities such unilateral clenching(biting the bite force recorder with a force of 50kg on each subject's preferred side), jaw thrusting and lip bracing. The following muscles were examined: temporalis anterior(Ta), masseter(Mm), frontalis(Fr), inferior orbicularis oculi(OOci), zygomaticus major(Zm), superior and inferior orbularis oris(OOrs and OOri) and mentalis(Mn). Paired t-test, Correlation Coefficients, ANOVA and Multiple Comparison t-tests were used for statistical analysis. Unilateral clenching was highly correlated with bilateral stiffness and elasticity of all the muscles tested. Mm was affected by all three oral habits; Ta was affected by unilateral clenching(p<0.05); Zm was affected by unilateral clenching and OOrs, OOri and Mn were most affected by lip bracing(p<0.05). This study indicates that not only the masticatory muscles but also the muscles of facial expression, mainly circumoral muscles, can be significantly influenced by parafunctional activities such as unilateral clenching and lip bracing.

• Journal of Periodontal and Implant Science
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• v.46 no.2
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• pp.96-106
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• 2016

Purpose: Stress distribution and mandible distortion during lateral movements are known to be closely linked to bruxism, dental implant placement, and temporomandibular joint disorder. The present study was performed to determine stress distribution and distortion patterns of the mandible during lateral movements in Class I, II, and III relationships. Methods: Five Korean volunteers (one normal, two Class II, and two Class III occlusion cases) were selected. Finite element (FE) modeling was performed using information from cone-beam computed tomographic (CBCT) scans of the subjects' skulls, scanned images of dental casts, and incisor movement captured by an optical motion-capture system. Results: In the Class I and II cases, maximum stress load occurred at the condyle of the balancing side, but, in the Class III cases, the maximum stress was loaded on the condyle of the working side. Maximum distortion was observed on the menton at the midline in every case, regardless of loading force. The distortion was greatest in Class III cases and smallest in Class II cases. Conclusions: The stress distribution along and accompanying distortion of a mandible seems to be affected by the anteroposterior position of the mandible. Additionally, 3-D modeling of the craniofacial skeleton using CBCT and an optical laser scanner and reproduction of mandibular movement by way of the optical motion-capture technique used in this study are reliable techniques for investigating the masticatory system.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.4
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• pp.372-380
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• 2005

Condylar process of mandible, has the specialized anatomic structure compared with any other body structure, acts directly in connection with mastication and speech and so on. In general, mandibular condyle fractures have been managed by two methods as open and closed reduction. But, there are no reasonable consensus about the proper management of this injury. This study was designed for analysis of the prognosis of two methods of treatment, open and closed reduction, with positional change of fractured condyle and complications within 6 months post-intermaxillary fixation period. We conducted a retrospective analysis of 154 patients whose unilateral mandibular condyle fractures were treated by open or closed reduction in our department. The horizontal, sagittal, and coronal change of the condyle was examined using modified Towne's and panoramic radiographs before intermaxillary fixation(IMF), immediately after IMF, and at 6 months after IMF. Patients, whose mandibular condyle fractures were treated by closed reduction, had significantly shorter ramus height on the side of injury(P<0.05). But, fractured condylar fragments were displaced insignificantly with aspect to sagittal and coronal plane(P>0.05). The level of the fracture influenced the ramus length and the degree of coronal change in the closed reduction group(P<0.05). There was no significant correlation among the level of the fracture, treatment methods and complications(P>0.05). From the results obtained in this study, fractured mandibular condyles, were treated by closed reduction, had a tendency that continuous condylar displacement was occurred with aspect to horozontal and coronal plane in treatment period including intermaxillary fixation. And then there was a correlation between the level of the fracture and the position change in close reduction group statistically. These result suggested that care must be taken in basing treatment decisions on the degree of displacement of the condyle and in treating the mandibular condyle fractures for a long time.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.3
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• pp.319-324
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• 2017

Patients with maxillectomy defects predisposed to not only difficulty in deglutition, mastication, speech but also psychological depression from impaired facial esthetics that affect life quality. Obturator prostheses play a important role in restoring the lost form, function and the quality of life for patients with maxillectomy defects. This clinical report presents the simplified approach to predict the degree of adequate facial support by Artificial palate which reflected from a maxillary interim obturator during the stabilization period after maxillectomy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.308-315
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• 1996

Osteoarthritis is a noninflammatory degenerative disease affecting the articular surfaces and is accompanied by remodeling of the underlying bone. The sympotms of osteoarthritis of the temporomandibular joint are pain in the joint and muscles of mastication, limitation. Osteoarthritis is generally accepted that several factors can contribute to the trauma, aging process, internal derangement and MPDS. Radiographic features of the osteoarthritis are seen flattening of joint, sclerosis on flattened area and osteophyte or anterior lipping. In the past, osteoarthritis was considered to self-limiting disease. Currently, synovial chondromembrane is part of the process of osteoarthritis secondary to trauma. Synovial chondromatosis is an uncommon disease of cartilaginous transformation of synovial membrane with formation of loose bodies within the joint space. The pathogenesis is more an active metaplastic than a neoplastic process. The cause of synovial chondromatosis is unknown. Although trauma and inflammation have all been cited as possible factors in tis pathogenesis. The clinical sign and symptoms are unilateral swelling of the joint region, pain in the joint area and crepitus seem to be the most reliable signs and symptoms. Radiographic evidence of loose bodies may or may not be present. This is a case report of 66 year old female with synovial chondromatosis, that is advanced disease of the osteoarthrits. We treated patient with surgical excision of lose bodies, diskectomy and synovectomy. The defected articular fossa area was reconstructed with temporalis fascia flap. The result was satisfactory.

• 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 Periodontal and Implant Science
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• v.23 no.2
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• pp.352-357
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• 1993

The purpose of the present study was to evaluate and compare the periodontal conditions of distally extending cantilever bridges(CB) and removable patial dentures(RPD). 78 patients treated with removable partial dentures were divided into 2 groups; bilateral free-ending (type 1) and unilateral free-ending(type 2). 43 patients treated with distally extending cantilever bridges were divided into 4 groups according to position of missing molars and number of including abutment tooth (or teeth) (type 1-4). Prosthodontic status of the abutment teeth were assessed; overcontoured crown, overhanged margin, embrasure closure, and others. Their Periodonted status were assessed with Plaque Index Gingial Index(GI) Sulcus bleedy Index (SBI), Tooth mobility(TM) & Posher depth(PPD). 35.9% of RPD group and 38.1 of CB grouphad disconfort on mastication with prosthetics. 16.7% of RPD group and 6.1% of CB group showed on opposing sites. Overhanged margins were 58.3% for RPD group and 86.6% for GB group. 45.5% of RPD group and 72% of CB group had embrasure closure on the abutment teeth. 30.5% of GB group had oversized pontic. Gb group showed much higher clinical parameters than RPD groups, but statistically not significant. Type 2 of RPD group showed lower GI and SBI, but statistically not significant. Type 3 of CB group showed the highest GI and SBI and type 2 showed the highest tooth mobility, but there is no differences between the same type of groups. In conclusion, only minor differences in periodontal conditions were recorded in RPD and CB group.

• Journal of Oral Medicine and Pain
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• v.34 no.3
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• pp.317-324
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• 2009

This study aimed to assess stiffness and elasticity of the masticatory muscle in the patients with the masticatory muscle pain using a tactile sensor and to investigate whether the masticatory muscle pain affects the facial expression muscles. From those who visited Department of Oral Medicine in Dankook University Dental Hospital, 27 patients presenting with unilateral muscle pain and tenderness in the masseter muscle (Ms) were selected (mean age: $36.4{\pm}13.8$ years). Exclusion criterion was those who also had temporomandibular joint (TMJ) disorders or any neurological pain. Muscle stiffness and elasticity for the muscles of mastication and facial expression was investigated with the tactile sensor (Venustron, Axiom Co., JAPAN) and the muscles measured were the Ms, anterior temporal muscle (Ta), frontalis (Fr), inferior orbicularis oculi (Ooci), zygomaticus major (Zm), superior and inferior orbicularis oris (Oors, Oori) and mentalis (Mn). t-tests was used to compare side difference in muscle stiffness and elasticity. Side differences were also compared between diagnostic groups (local muscle soreness (LMS) vs myofascial pain syndrome (MPS) and between acute (< 6M) and chronic ($\geq$ 6M) groups. This study showed that Ms and Zm at affected side exhibited significantly increased stiffness and decreased elasticity as compared to the unaffected side.(p<0.05) There was no significant difference between local muscle soreness and myofascial pain syndrome groups and between acute and chronic groups. The results of this study suggests that masticatory muscle pain in Ms can affect muscle stiffness and elasticity not only for Ms but also for Zm, the facial expression muscle.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.88-94
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• 2011

Ranula is a mucosal cyst that occurs in the mouth floor. This is a pseudo cyst caused by mucous retention within the tissue due to the rupture of catheter in the salivary gland. Ranula occurs mainly in a unilateral form and is characterized by painless bluish transparent swelling, with a increasing mass size. If the size is large, it can cause discomfort during swallowing, pronounciation, and mastication, but external swelling and infection is rare. Treatments include observation for spontaneous resolution, simple incision and drainage, marsupialization and excision. Marsupialization done by removing parts of the cyst wall and connecting it to the oral mucosa. It is a conservative procedure and recommended for children. It has advantages such as maintaining outline of oral tissue and less risk of damaging anatomic structure. Recurrence is common, mostly occurring within 4 months after surgery. This case is about a eight-year-old girl with ranula on the right mouth floor. This patient was treated with marsupialization that is one of treatment for ranula, and recurrence was not observed.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.1
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• pp.19-28
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• 2022

In removable partial dentures, abutment teeth are essential for support, maintenance, and stability of partial dentures, and are an important factor in the fabrication of functional dentures. If the number of periodontally sound abutments is sufficient and they are located on both sides, it will be easy to manufacture functional dentures with good support, maintenance, and stability. But on the contrary, if the number of teeth is insufficient or if they are located on one side, it is biomechanically disadvantageous and relatively difficult to make functional denture. On the other hand, recently, implant-supported removable dentures, which reinforce the three elements of maintenance, support, and stability by using implant surveyed crown, have been frequently selected as treatment plans. In particular, by adding an implant surveyed crown when only a small number of residual teeth remain, mastication efficiency, esthetics, patient comfort, and pronunciation can be improved. In this case, bilateral posterior extension partial denture was fabricated using implant surveyed crown as abutments by placing implants in the premolars area opposite to the residual tooth unilaterally in the mandible. As a result, the asymmetry of the abutment was resolved, and the maintenance and stability of the denture was achieved.