• Imaging Science in Dentistry
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• v.48 no.3
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• pp.213-221
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• 2018

Purpose: The purpose of this study was to evaluate the relationship between masseter muscle thickness, facial morphology, and mandibular morphology in Korean adults using ultrasonography. Materials and Methods: Ultrasonography was used to measure the masseter muscle thickness bilaterally of 40 adults(20 males, 20 females) and was performed in the relaxed and contracted states. Facial photos and panoramic radiography were used for morphological analyses and evaluated for correlations with masseter muscle thickness. We also evaluated the correlations of age, body weight, stature, and body constitution with masseter muscle thickness. Results: In the relaxing, the masseter was $9.8{\pm}1.3mm$ in females and $11.3{\pm}1.2mm$ in males. In the contracted state, it was $12.4{\pm}1.4mm$ in females and $14.7{\pm}1.4mm$ in males. Facial photography showed that bizygomatic facial width over facial height was correlated with masseter muscle thickness in both sexes in the relaxed state, and was statistically significantly correlated with masseter muscle thickness in males in the contracted state. In panoramic radiography, correlations were found between anterior angle length and posterior angle length and masseter muscle thickness in females, and between body length and posterior angle length, between anterior angle length and body length, between ramal length and body length, and between body length and condyle length in males. Conclusion: Masseter muscle thickness was associated with facial and mandibular morphology in both sexes, and with age in males. Ultrasonography can be used effectively to measure masseter muscle thickness.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.6
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• pp.545-551
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• 2005

Purpose: The effect of orthognathic surgery on the temporomandibular dysfunction has been controversial. The purpose of this study is to prove statistically that early removal of fixation plate at postoperative 2 weeks with active exercise of mouth opening could relieve preoperative temporomandibular dysfunction and reposition of temporomandibular joint. Patients and Methods: All 28 subject patients underwent mandibular setback with BSSRO in Kyunghee medical center by one surgeon. The fixation plates used for rigid fixation were removed at postoperative 2 weeks and we had the patients excercise active mouth opening with intermaxillary rubber rings for the guiding proper postoperative occlusion. Temporomandibular symptoms were checked and radiographs were taken before surgery, within a month after surgery, six to twelve months after surgery respectively. Results: The temporomandibular dysfunction symptoms were relieved after the surgery and the condyle was displaced inferior-posteriorly immediate after surgery and repositioned toward its original position during follow-up periods. Conculusion: Orthognathic surgery may benefit temporomandibular joint dysfunction by obtaining a postoperative stable occlusion and more physiologic neuromuscular function. The early removal of fixation plates after BSSRO could reposition the temporomandibular joint to physiologic position and relieve the symptoms of temporomandibular dysfunction by permitting movement of proximal segment.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.4
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• pp.386-394
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• 2008

Osteosarcoma of the jaw is a rare malignant bone tumor which usually leads to a poor prognosis. It commonly occurs in young patients, especially in male. The tumor can involve mandible or maxilla with same frequency. The swelling in the involved area and facial deformity are common clinical findings. The pain and sensory changes are also complained by the patients. Although radical surgery plays an important role in the management of this tumor, the adjuvant chemotherapy or radiotherapy is used to enhance local control and to prevent distant metastases. We treated a 22-year-old male patient who had osteosarcoma in the left condylar region. The radical surgery which consisted of hemimandibulectomy and total parotidectomy, was done and an immediate mandibular reconstruction was performed with a vascularized free iliac osteomuscular flap. The obtained results, both esthetic and functional, were satisfactory. The patient was received postoperative chemotherapy. This is a case with reviews of the literatures.

• Imaging Science in Dentistry
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• v.37 no.2
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• pp.83-86
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• 2007

Purpose : To evaluate the efficacy of panoramic radiography by comparing the results of clinical examination with radiographic findings. Materials and Methods: We studied 190 patients (20 men and 170 women; mean age, 40 years; range, 22 to 68 years) who visited the health promotion center of Korea Medical Science Institute and were examined both clinically and by panoramic radiography. We compared results from both examinations. Treatment options by clinical examination were described as "no treatment indicated", "treatment of dental caries", "removal of calculus", "treatment of periodontal disease", "prothodontic treatment" and "extraction of the third molar". Findings taken from the panoramic radiography were: dental caries, periapical lesion, alveolar bone loss, calculus deposition, retained root, impaction of the third molar, disease of maxillary sinus, bony change of mandibular condyle, etc. Results: The prevalence of panoramic findings were: 37.9% of dental caries, 17.4% of periapical lesions, 44.7% of alveolar bone losses, 62.6% of calculi deposition, 7.9% of retained roots, 26.8% of third molar impactions, 6.3% of diseases of maxillary sinus, 2.1 % of bony changes of mandibular condlye and 35.8% of miscellaneous lesions. Abnormal conditions revealed by panoramic radiography which had not been discovered on clinical examination were: 24.2% of the patients had dental caries, 17.4% had periapical lesions, 7.4% had calculi deposition, 5.3% had retained roots, 15.3% had third molar impactions. The opposite cases were: 5.2% had dental caries, 12.6% had calculi deposition, and 9.5% had third molar impactions. Conclusion: The use of panoramic radiography as a supplement to the clinical examination might be a valuable screening technique.

• The korean journal of orthodontics
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• v.43 no.2
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• pp.74-82
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• 2013

Objective: The purpose of this study was to evaluate displacement of the mandibular condyle after orthognathic surgery using a condylar-repositioning device. Methods: The patient group comprised 20 adults who underwent bimaxillary surgery between August 2008 and July 2011. The degree of condylar displacement was measured by pre- and postoperative tomographic analysis using centric relation bite and a wire during surgery. A sur vey assessing temporomandibular joint (TMJ) sound, pain, and locking was performed. The 20 tomographs and surveys were analyzed using the Wilcoxon signed-rank test and McNemar's test, respectively. Results: No significant changes were observed in the anterior, superior, or posterior joint space of the TMJ (p > 0.05). In addition, no significant change was observed in TMJ sound (p > 0.05). However, TMJ pain and locking both decreased significantly after surgery (p < 0.05). Conclusions: Due to its simplicity, this method may be fea sible and useful for repositioning condyles.

• Imaging Science in Dentistry
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• v.47 no.2
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• pp.93-97
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• 2017

Purpose: The purpose of this study was to evaluate the accuracy of panoramic imaging in measuring the right and left gonial angles by comparing the measured angles with the angles determined using a lateral cephalogram of adult patients with class I malocclusion. Materials and Methods: The gonial angles of 50 class I malocclusion patients (25 males and 25 females; mean age: 23 years) were measured using both a lateral cephalogram and a panoramic radiograph. In the lateral cephalograms, the gonial angle was measured at the point of intersection of the ramus plane and the mandibular plane. In the panoramic radiographs, the gonial angle was measured by drawing a line tangent to the lower border of the mandible and another line tangent to the distal border of the ascending ramus and the condyle on both sides. The data obtained from both radiographs were statistically compared. Results: No statistically significant difference was observed between the gonial angle measured using the lateral cephalograms and that determined using the panoramic radiographs. Further, there was no statistically significant difference in the measured gonial angle with respect to gender. The results also showed a statistically insignificant difference in the mean of the right and the left gonial angles measured using the panoramic radiographs. Conclusion: As the gonial angle measurements using panoramic radiographs and lateral cephalograms showed no statistically significant difference, panoramic radiography can be considered in orthodontics for measuring the gonial angle without any interference due to superimposed images.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.44-52
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• 1999

The purpose of this study was to investigate the distribution of CGRP immunoreactive nerve fibers in rat squamosomandibular joint with postnatal development. Squamosomandibular joint with adjacent tissue of 8 groups of rats(1, 5, 10, 15, 20, 25, 35-postnatal day and adult groups) were removed on bloc and processed for immunohistochemistry and were subjected to light microscopic examination. The results obtained were as follows; 1. The anterior portion of the articular disk was most densely innervated, followed by the posterior, lateral, and medial portions in each group. 2. Increase of CGRP immunoreactive nerve fibers was evident in 10, 15, 20 postnatal day groups. 3. Almost no CGRP immunoreactive nerve fibers were observed in articular surface of disk proper, mandibular fossa and condyle head of each group. These result suggest that CGRP immunoreactive nerve fibers increased in synovial membrane and peripheral portion of articular disk during 10-20 postnatal day may play a important role in squamosomandibular joint function after weaning period.

• The Journal of Korean Academy of Prosthodontics
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• v.26 no.1
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• pp.113-131
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• 1988

Although TMJ sound is common, its relationship to subjective and objective evaluation and the magnitude and the position of the sound during the mandibular movement is not fully understood. So, the purpose of this investigation was to provide further insight into the characteristics of the TMJ sounds. Twelve subjects (9 men and 3 women) with TMJ sounds were selected from students at Chosun University, School of Dentistry. Condylar movements and TMJ sounds of each subject were recorded and analyzed using a simplified condylar path recorder and a sound checker. Although specific conclusions were difficult to make from this study, the finding suggested the followings. 1. The position of TMJ sounds were visually observed and marked on the condylar tracings during maximum opening and closing, protrusive and retrusive and right and left lateral movements. 2. Information about the size, location and number of condylar deviations and the translation freedom of the condyle was recorded and analyzed objectively. 3. The most obvious characteristic of TMJ sounds was their variability. 4. TMJ sounds were categorized into one of four groups (soft click, hard click, soft crepitus, hard crepitus) by the quality and quantity of the duration and amplitude components.

• Journal of Oral Medicine and Pain
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• v.39 no.4
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• pp.156-162
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• 2014

Dislocation of temporomandibular joint (TMJ) is troublesome condition which was most commonly shown far anteriorly displaced mandibular condyle to the articular eminence, thereby make it impossible to close one's mouth. It is often referred to as 'open lock' in clinically. Although anatomical modification of the articular eminence through eminectomy has been considered most satisfactory and efffective treatment for managing the recurrent dislocation, it seldom performs clinically due to its invasiveness and patient's reluctance. We thought a shortterm intermaxillary fixation could be of benefit to the patient suffering from recurrent dislocation. A 21-year-old male patient with recurrent TMJ dislocation which had developed after excessive mouth opening, was successfully treated with intermaxillay fixation using microimplant for 2 months. It is more conservative and less complicated method than eminectomy in treating recurrent TMJ dislocation. Transient intermaxillary fixation using microimplant and elastics could be one of treatment options for recurrent TMJ dislocation.

• Imaging Science in Dentistry
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• v.32 no.2
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• pp.113-118
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• 2002

Ankylosis of joint is defined as limited movement due to infection, trauma, or surgical procedure. A 59-year-old female with a chief complaint of limited movements during mouth opening had a positive history of trauma to her right TMJ area about 5 years ago. From that time, progressive mouth opening limitation and intermittent pain have occurred. At the time of admission the patient showed mandibular deviation to the right side during mouth opening, with a maximum opening limited to 5 mm. On plain radiographs, right condylar enlargement and joint space reduction by newly formed bony tissues were observed. CT scans showed right condylar enlargement, cortical sclerosis, and thickening of the condyle, articular fossa and articular eminence.