• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권3호
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• pp.123-129
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• 2014

Objectives: The aim of this study was to verify the concordance of the measurement values when the same cephalometric analysis method was used for two-dimensional (2D) cephalometric radiography and three-dimensional computed tomography (3D CT), and to identify which 3D Frankfort horizontal (FH) plane was the most concordant with FH plane used for cephalometric radiography. Materials and Methods: Reference horizontal plane was FH plane. Palatal angle and occlusal plane angle was evaluated with FH plane. Gonial angle (GA), palatal angle, upper occlusal plane angle (UOPA), mandibular plane angle (MPA), U1 to occlusal plane angle, U1 to FH plane angle, SNA and SNB were obtained on 2D cephalmetries and reconstructed 3D CT. The values measured eight angles in 2D lateral cephalometry and reconstructed 3D CT were evaluated by intraclass correlation coefficiency (ICC). It also was evaluated to identify 3D FH plane with high degree of concordance to 2D one by studying which one in four FH planes shows the highest degree of concordance with 2D FH plane. Results: ICCs of MPA (0.752), UOPA (0.745), SNA (0.798) and SNB (0.869) were high. On the other hand, ICCs of gonial angle (0.583), palatal angle (0.287), U1 to occlusal plane (0.404), U1 to FH plane (0.617) were low respectively. Additionally GA and MPA acquired from 2D were bigger than those on 3D in all 20 patients included in this study. Concordance between one UOPA from 2D and four UOPAs from 3D CT were evaluated by ICC values. Results showed no significant difference among four FH planes defined on 3D CT. Conclusion: FH plane that can be set on 3D CT does not have difference in concordance from FH plane on lateral cephalometry. However, it is desirable to define FH plane on 3D CT with two orbitales and one porion considering the reproduction of orbitale itself.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권3호
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• pp.103-110
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• 2014

Objectives: In this study, we assessed soft tissue asymmetry that occurred after open reduction of unilateral zygomaticomaxillary complex (ZMC) fractures. We proposed a simple method to assess soft tissue asymmetry after reduction surgery by evaluating the symmetry between the affected and the unaffected sides. The factors affecting soft tissue contour after surgery were also analyzed. Materials and Methods: Subjects included patients admitted to Wonkwang University Dental Hospital from 2008 to 2013. Cone-beam computed tomography (CBCT) images of asymmetric patients who underwent open reduction at least 3 months prior were compared with healthy patients. Results: The degree of asymmetry was measured in both the open reduction and control groups. Landmarks that showed a statistically significant difference between the two groups were zygion ($1.73{\pm}0.24mm$), bucclae ($1.08{\pm}0.26mm$), point of cheek ($2.05{\pm}0.33mm$) and frontozygomatic point ($1.30{\pm}0.31mm$). Conclusion: When compared with the normal group, asymmetry can occur in the affected side, which usually shows depression of overlying soft tissue and is statistically significantly different. Evaluation of soft tissue asymmetry with CBCT images after open reduction of ZMC fracture is useful.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권3호
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• pp.140-146
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• 2014

Pigmented villonodular synovitis (PVNS) is a benign but locally aggressive and destructive disease originating in the synovial membranes. It is a proliferative disorder of unknown etiology. Involvement of the temporomandibular joint (TMJ) is very rare. Computed tomography clearly reveals areas of lytic bone erosion and sclerosis, and also clearly defines the extent of the tumor which is the focal areas of hyperdensity within the soft-tissue mass. Magnetic resonance images invariably show profound hypointensity on both T1- and T2-weighted sequences due to hemosiderin pigmentation. Additionally, high signal intensity on T2-weighted images may indicate cystic loculation of the joint fluid. This case study describes a rare case of PVNS of the TMJ with bone destruction of the mandibular condyle. Complete surgical excision of the lesion was performed through a preauricular approach with temporal extension. During the 10-year follow-up, two more operations were performed due to local recurrence and the fracture of the reconstruction plate. Total joint reconstruction with Biomet was finally performed, and the absence of disease was confirmed with a biopsy report showing fibrosis with hyalinization and mild inflammation of the excised soft tissue from the old lesion.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권3호
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• pp.135-139
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• 2014

This following case report describes the open reduction, internal fixation and the reconstruction of an extensive comminuted mandibular fracture with bilateral condylar fractures in a 19-year-old male patient with an intellectual disability and autistic disorder. He suffered fall trauma, resulting in shattered bony fragments of the alveolus and mandibular body between both mandibular rami, the fracture of both condyles and the avulsion or dislocation of every posterior tooth of the mandible. The patient underwent open reduction and internal fixation between both mandibular rami using a reconstruction plate, open reduction and internal fixation of the shattered fragments using miniplates and screws, and the closed reduction of the bilateral condylar fractures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권4호
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• pp.181-187
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• 2014

Objectives: The purpose of this preliminary study is to evaluate the effectiveness of a customized, three-dimensional, preformed titanium mesh as a barrier membrane for peri-implant alveolar bone regeneration. Materials and Methods: Ten patients were recruited for this study. At the time of implant placement, all patients had fenestration or a dehiscence defect around the implant fixture. A mixture of particulate intraoral autologous bone and freeze-dried bone allograft was applied to the defect in a 1 : 1 volume ratio and covered by the preformed titanium mesh. A core biopsy specimen was taken from the regenerated bone four months postoperatively. Patients were followed for 12 months after the definitive prosthesis was placed. Results: Satisfactory bone regeneration with limited fibrous tissue was detected beneath the preformed titanium mesh. Histologic findings revealed that newly formed bones were well-incorporated into the allografts and connective tissue. New growth was composed of approximately 80% vital bone, 5% fibrous marrow tissue, and 15% remaining allograft. All implants were functional without any significant complications. Conclusion: The use of preformed titanium mesh may support bone regeneration by maintaining space for new bone growth through its macro-pores. This preliminary study presents the efficacy of a preformed titanium mesh as a ready-to-use barrier membrane around peri-implant alveolar bone defect. This preformed mesh is also convenient to apply and to remove.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권4호
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• pp.173-180
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• 2014

Objectives: The purpose of this study was to investigate the neurogenic differentiation of human dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), and stem cells from apical papilla (SCAP). Materials and Methods: After induction of neurogenic differentiation using commercial differentiation medium, expression levels of neural markers, microtubule-associated protein 2 (MAP2), class III ${\beta}$-tubulin, and glial fibrillary acidic protein (GFAP) were identified using reverse transcriptase polymerase chain reaction (PCR), real-time PCR, and immunocytochemistry. Results: The induced cells showed neuron-like morphologies, similar to axons, dendrites, and perikaryons, which are composed of neurons in DPSCs, PDLSCs, and SCAP. The mRNA levels of neuronal markers tended to increase in differentiated cells. The expression of MAP2 and ${\beta}$-tubulin III also increased at the protein level in differentiation groups, even though GFAP was not detected via immunocytochemistry. Conclusion: Human dental stem cells including DPSCs, PDLSCs, and SCAP may have neurogenic differentiation capability in vitro. The presented data support the use of human dental stem cells as a possible alternative source of stem cells for therapeutic utility in the treatment of neurological diseases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권4호
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• pp.160-168
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• 2014

Objectives: The purpose of this study was to evaluate the condylar position in relation to the glenoid fossa before and after orthodontic-orthognathic surgical treatment and to investigate the relationship with skeletal relapse. Materials and Methods: Lateral cephalograms and temporomandibular joint tomograms from 19 patients with mandibular prognathism who received orthodontic-orthognathic surgery were included in this study. Samples were divided into two groups based on skeletal change during the retention period. The relapse group consisted of 7 patients (3 females and 4 males; mean age, 21.9 years) whose pogonion or menton displaced more than 1 mm during the retention period and the stable group consisted of 12 patients (5 females and 7 males; mean age, 21.7 years). Anterior joint space, posterior joint space, superior joint space, and anteroposterior index were measured on tomograms at pretreatment and posttreatment timepoints. Condyle position and frequency of the positional change were compared between both groups. Results: In the relapse group and stable group, 42.9% and 45.8% of the condyles, respectively, showed forward or backward displacement at posttreatment. However, the changes were small and the mean anterior, posterior, superior joint spaces and frequencies of the positional changes did not differ statistically between both groups. Conclusion: Our results suggest that small positional changes of the condyle, which may occur after orthodontic-orthognathic surgery treatment, may not be related to skeletal relapse after removal of the orthodontic appliances.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권4호
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• pp.155-159
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• 2014

Objectives: The purpose of this article is to evaluate factors influencing prognosis of arthrocentesis in patients with temporomandibular joint (TMJ) disorder. Materials and Methods: The subjects included 145 patients treated with arthrocentesis at the Dental Center of Ajou University Hospital from 2011 to 2013 for the purpose of recovering mouth opening limitation (MOL) and pain relief. Prognosis of arthrocentesis was evaluated 1 month after the operation. Improvement on MOL was defined as an increase from below 30 mm (MOL ${\leq}30mm$) to above 40 mm (MOL ${\geq}40mm$), and pain relief was defined as when a group with TMJ pain with a visual analog scale (VAS) score of 4 or more (VAS ${\geq}4$) decreased to a score of 3 or more. The success of arthrocentesis was determined when either mouth opening improved or pain relief was fulfilled. To determine the factors influencing the success of arthrocentesis, the patients were classified by age, gender, diagnosis group (the anterior disc displacement without reduction group, the anterior disc displacement with reduction group, or other TMJ disorders group), time of onset and oral habits (clenching, bruxism) to investigate the correlations between these factors and prognosis. Results: One hundred twenty out of 145 patients who underwent arthrocentesis (83.4%) were found to be successful. Among the influencing factors mentioned above, age, diagnosis and time of onset had no statistically significant correlation with the success of arthrocentesis. However, a group of patients in their fifties showed a lower success rate (ANOVA P=0.053) and the success rate of the group with oral habits was 71% (Pearson's chi-square test P=0.035). Conclusion: From this study, we find that factors influencing the success of arthrocentesis include age and oral habits. We also conclude that arthrocentesis is effective in treating mouth opening symptoms and for pain relief.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권1호
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• pp.14-20
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• 2013

Objectives: This study sought to evaluate the effect of simultaneous application of arthrocentesis and occlusal splint. Materials and Methods: A retrospective study of 43 patients (3 males, 40 females) whose symptoms had improved was conducted at the Department of Oral and Maxillofacial Surgery, Dong-A University Hospital between 2008 and 2010. Subjects were divided into three groups: Group A (17 patients with arthrocentesis and occlusal splints simultaneously applied), Group B (13 patients whose symptoms did not improve with occlusal splints, undergoing arthrocentesis after occlusal splint use for 8 weeks), and Group C (13 patients that only used occlusal splints). We compared these groups in maximum comfortable opening (MCO) and the visual analogue scale of pain and noise. Follow-up was performed at 1 week, 1 month, 3 months, and 6 months. Results: The improvement of symptoms was noted in all three groups, but Group A had a quicker improvement than the other groups, in terms of pain reduction and MCO increases. Conclusion: The simultaneous application of arthrocentesis and occlusal splints can reduce patient discomfort more quickly.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권4호
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• pp.161-167
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• 2013

Objectives: The objective of this study is compare the rate of marginal bone resorption around hydroxyapatite-coated implants given different loading times in order to evaluate their stability. Materials and Methods: The study was conducted retrospectively for one year, targeting 41 patients whose treatment areas were the posterior maxilla and the mandible. Osstem TS III HA (Osstem Implant Co., Busan, Korea) and Zimmer TSV-HA (Zimmer Dental, Carlsbad, CA, USA), which employ the new hydroxyapatite coating technique, were used. The patients were divided into two groups - immediate and delayed loading - and the bone level at the time of loading commencement and after one year of loading was measured using periapical radiography. Differences between the groups were evaluated using Mann-Whitney (${\alpha}$=0.05). Results: For all patients as a single group, the survival rate of the implants was 100%, and the mean marginal bone loss was $0.26{\pm}0.59mm$. In comparison of the differences by loading, mean marginal bone loss of $0.32{\pm}0.69mm$ was recorded for the immediate loading group whereas the delayed loading group had mean marginal bone loss of $0.16{\pm}0.42mm$. However, the difference was not significant (P>0.05). Conclusion: Within the limited observation period of one year, predictable survival rates can be expected when using immediately loaded hydroxyapatite-coated implants.