Journal of the Korean Association of Oral and Maxillofacial Surgeons

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Abstract

Objectives: Although nerve growth factor (NGF) could promote the functional regeneration of an injured peripheral nerve, it is very difficult for NGF to sustain the therapeutic dose in the defect due to its short half-life. In this study, we loaded the NGF-bound heparin-conjugated fibrin (HCF) gel in the NGF-delivering implants and analyzed the time-dependent release of NGF and its bioactivity to evaluate the clinical effectiveness. Materials and Methods: NGF solution was made of 1.0 mg of NGF and 1.0 mL of phosphate buffered saline (PBS). Experimental group A consisted of three implants, in which 0.25 μL of NGF solution, 0.75 μL of HCF, 1.0 μL of fibrinogen and 2.0 μL of thrombin was injected via apex hole with micropipette and gelated, were put into the centrifuge tube. Three implants of experimental group B were prepared with the mixture of 0.5 μL of NGF solution, 0.5 μL HCF, 1.0 μL of fibrinogen and 2.0 μL of thrombin. These six centrifuge tubes were filled with 1.0 mL of PBS and stirred in the water-filled beaker at 50 rpm. At 1, 3, 5, 7, 10, and 14 days, 1.0 mL of solution in each tubes was collected and preserved at -20oC with adding same amount of fresh PBS. Enzyme-linked immunosorbent assay (ELISA) was done to determine in vitro release profile of NGF and its bioactivity was evaluated with neural differentiation of pheochromocytoma (PC12) cells. Results: The average concentration of released NGF in the group A and B increased for the first 5 days and then gradually decreased. Almost all of NGF was released during 10 days. Released NGF from two groups could promote neural differentiation and neurite outgrowth of PC12 cells and these bioactivity was maintained over 14 days. Conclusion: Controlled release system using NGF-HCF gel via NGF-delivering implant could be an another vehicle of delivering NGF to promote the nerve regeneration of dental implant related nerve damage.

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Objectives: The aim of this study was to evaluate the pattern of lingual split line when performing a bilateral sagittal split osteotomy (BSSO) for asymmetric prognathism. This was accomplished with the use of cone-beam computed tomography (CBCT) and three-dimensional (3D) software program. Materials and Methods: The study group was comprised of 40 patients (20 males and 20 females) with asymmetric prognathism, who underwent BSSO (80 splits; n=80) from January 2012 through June 2013. We observed the pattern of lingual split line using CBCT data and image analysis program. The deviated side was compared to the contralateral side in each patient. To analyze the contributing factors to the split pattern, we observed the position of the lateral cortical bone cut end and measured the thickness of the ramus that surrounds the mandibular lingula. Results: The lingual split patterns were classified into five types. The true “Hunsuck” line was 60.00% (n=48), and the bad split was 7.50% (n=6). Ramal thickness surrounding the lingual was 5.55±1.07 mm (deviated) and 5.66±1.34 mm (contralateral) (P=0.409). The position of the lateral cortical bone cut end was classified into three types: A, lingual; B, inferior; C, buccal. Type A comprised 66.25% (n=53), Type B comprised 22.50% (n=18), and Type C comprised 11.25% (n=9). Conclusion: In asymmetric prognathism patients, there were no differences in the ramal thickness between the deviated side and the contralateral side. Furthermore, no differences were found in the lingual split pattern. The lingual split pattern correlated with the position of the lateral cortical bone cut end. In addition, the 3D-CT reformation was a useful tool for evaluating the surgical results of BSSO of the mandible.

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Objectives: The aim of this study was to retrospectively evaluate the clinical survival rate of Astra Tech implants in the maxillary molar region performed with sinus lift and bone graft. Materials and Methods: Ninety-nine Astra Tech implants (Osseospeed) placed in the maxillary molar region using sinus lift from September 2009 to February 2012 were selected with a minimum follow-up period of 1 year. The height of alveolar bone, sinus approach technique, bone material and implant survival rate were evaluated. Results: Of the 99 implants, the survival rate was 90.9%; 8 implants failed within 1 year after implant placement, and 1 implant failed 1 year after implant loading. All failed implants were placed with sinus lift simultaneously. The average height of alveolar bone before implant placement was 6.9 mm, while the height of alveolar bone of failed implants was 2.1 mm, on average. Conclusion: Astra Tech implants placed in the maxillary molar region had generally good survival rates, but the relationship between reduced pre-implant alveolar bone height and implant failure requires further attention.

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Objectives: The purpose of this article is to analyze the incidence, demographic distribution, type, and etiology of mandible fractures that were treated by the Department of Oral and Maxillofacial Surgery in Kyung Hee University Dental Hospital from January 2002 to December 2012. Materials and Methods: This was a descriptive and analytic retrospective study that evaluated 735 patients that were treated for mandible fracture. Results: This study included 1,172 fractures in 735 patients. The ratio of male to female patients was 5.45 : 1; the maximum value was in patients between 20 and 29 years (38.1%) and the minimum in patients over 70 years old. The monthly distribution of facial fractures peaked in the fall and was lower during winter. No specific correlation was identified based on the annual fracture distribution. Among the 735 fracture patients, 1.59 fracture lines were observed per patient. The most frequent site was the symphysis, which accounted for a total of 431 fractures, followed by the angle (348), condyle (279), and body (95). The symphysis with angle was the most common site identified in combination with fracture and accounted for 22.4%, followed by symphysis with condyle (19.8%). The angle was the most frequent site of single fractures (20.8%). The major cause of injury was accidental trauma (43.4%), which was followed by other causes such as violence (33.9%), sports-related accidents (10.5%), and traffic accidents (10.1%). Fracture incidents correlated with alcohol consumption were reported between 10.0%-26.9% annually. Conclusion: Although mandible fracture pattern is similar to the previous researches, there is some changes in the etiologic factors.

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Various surgical techniques, such as endoscopic surgery and robotic surgery, are developed to optimize the esthetic outcome even in operations for malignancy. A modified face-lift or retroauricular approach are used to minimize postoperative scarring. Recently, robot-assisted surgery is being done in various fields and considered as favorable treatment method by many surgeons. However its high cost is a nonnegligible fraction for many patients. On the other hand, endoscopic surgery, which is cheaper than robotic surgery, is minimally invasive with contentable neck dissection. Although it is a difficult technique for a beginner surgeon due to its limited operation view, we suppose it as an alternative method for robotic surgery. Herein, we report two cases of endoscopic neck dissection via retroauricular incision with a discussion regarding the pros and cons of endoscopic neck dissection.

Abstract

Preoperative surgical simulation in orthognathic surgery has progressed in recent years; the movement of the mandible can be anticipated through three-dimensional (3D) simulation surgery before the actual procedure. In this case report, the mandible was moved to the intended postoperative occlusion through preoperative surgical 3D simulation. Right-side condylar movement change was very slight in the surgical simulation, suggesting the possibility of mandibular surgery that included only left-side ramal osteotomy. This case report describes a patient with a mild asymmetric facial profile in which the mandibular menton had been deviated to the right and the lips canted down to the left. Before surgery, three-dimensional surgical simulation was used to evaluate and confirm a position for the condyle as well as the symmetrical postoperative state of the face. Facial asymmetry was resolved with minimal surgical treatment through unilateral intraoral vertical ramus osteotomy on the left side of the mandible. It would be a valuable complement for the reduction of the surgical treatment if one could decide with good predictability when an isolated intraoral vertical ramus osteotomy can be done without a compensatory osteotomy on the contralateral side.

Abstract

Recently, clinical application of autogenous tooth bone-graft materials has been reported. Autogenous tooth bone graft has been used in implant surgery. Familial tooth bone graft is a more advanced procedure than autogenous teeth bone graft in that extracted teeth can be used for bone graft materials of implant and teeth donation between siblings is possible. We used autogenous tooth and familial tooth bone-graft materials for ridge augmentation and sinus bone graft and obtained satisfactory results. The cases are presented herein.

Abstract

Eagle’s syndrome is a disease caused by an elongated styloid process or calcified stylohyoid ligament. Eagle defined the disorder in 1937 by describing clinical findings related to an elongated styloid process, which is one of the numerous causes of pain in the craniofacial and cervical region. The prevalence of individuals with this anatomic abnormality in the adult population is estimated to be 4% with 0.16% of these individuals reported to be symptomatic. Eagle’s syndrome is usually characterized by neck, throat, or ear pain; pharyngeal foreign body sensation; dysphagia; pain upon head movement; and headache. The diagnosis of Eagle’s syndrome must be made in association with data from the clinical history, physical examination, and imaging studies. Patients with increased symptom severity require surgical excision of the styloid process, which can be performed through an intraoral or an extraoral approach. Here, we report a rare case of stylohyoid ligament bilaterally elongated to more than 60 mm in a 51-year-old female. We did a surgery by extraoral approach and patient’s symptom was improved.