Postoperative changes in the pharyngeal airway space through computed tomography evaluation after mandibular setback surgery in skeletal class III patients: 1-year follow-up / 대한악안면성형재건외과학회지

Background@#This study evaluated the pharyngeal airway space changes up to 1 year after bilateral sagittal split osteotomy mandibular setback surgery and bimaxillary surgery with maxillary posterior impaction through threedimensional computed tomography analysis. @*Methods@#A total of 37 patients diagnosed with skeletal class III malocclusion underwent bilateral sagittal split osteotomy setback surgery only (group 1, n = 23) or bimaxillary surgery with posterior impaction (group 2,n = 14).Cone-beam computed tomography scans were taken before surgery (T0), 2 months after surgery (T1), 6 months after surgery (T2), and 1 year after surgery (T3). The nasopharynx (Nph), oropharynx (Oph), hypopharynx (Hph) volume, and anteroposterior distance were measured through the InVivo Dental Application version 5. @*Results@#In group 1, Oph AP, Oph volume, Hph volume, and whole pharynx volume were significantly decreased after the surgery (T1) and maintained. In group 2, Oph volume and whole pharynx volume were decreased (T2) and relapsed at 1 year postoperatively (T3). @*Conclusion@#In class III malocclusion patients, mandibular setback surgery only showed a greater reduction in pharyngeal airway than bimaxillary surgery at 1 year postoperatively, and bimaxillary surgery was more stable in terms of airway. Therefore, it is important to evaluate the airway before surgery and include it in the surgical plan.

Regenerative effect of recombinant human bone morphogenetic protein-2/absorbable collagen sponge (rhBMP-2/ACS) after sequestrectomy of medication-related osteonecrosis of the jaw (MRONJ)

Objectives@#Beyond the original application approved by the U.S. Food and Drug Administration, recombinant human bone morphogenetic protein- 2 (rhBMP-2) is used for medication-related osteonecrosis of the jaw (MRONJ) treatment because of its bone remodeling enhancement properties. The purpose of the study was to investigate the bone formation effect of rhBMP-2/absorbable collagen sponge (ACS) in patients with MRONJ. @*Materials and Methods@#In this retrospective cohort study, 26 female patients diagnosed with MRONJ and who underwent mandibular sequestrectomy at Ajou University Dental Hospital from 2010 to 2018 were included. The experimental group was composed of 18 patients who received rhBMP-2/ACS after sequestrectomy, while the control group was composed of 8 patients who did not receive rhBMP-2/ACS after sequestrectomy. A total dose of 0.5 mg of rhBMP-2 was used in the experimental group at a concentration of 0.5 mg/mL. Follow-up panoramic X-rays were taken immediately after the surgery and more than 6 months after the surgery. Using those X-rays, a radiographic index of bone defect area was calculated using the modified Ihan Hren method, which measures radiographic density of the normal bone and the defect site. @*Results@#This study suggests that rhBMP-2 contributes to new bone formation. The mean radiographic index immediately after surgery and more than 6 months after the surgery for the experimental group was 68.4% and 79.8%, respectively. The mean radiographic index immediately after surgery and more than 6 months after the surgery for the control group was 73.4% and 76.7%, respectively (Wilcoxon signed rank test, P>0.05). The mean radiographic index increased 11.4% in the experimental group and 3.27% in the control group (Mann–Whitney U-test, P <0.05). @*Conclusion@#Based on the results, use of rhBMP-2/ACS on bone defect sites after sequestrectomy could be a successful strategy for treatment of MRONJ patients.

Dental Problems Related with Mastication and Swallowing / 대한연하장애학회지

Mastication and swallowing require the action of masticatory muscles, mandible, maxilla and teeth. Teeth play a significant role in pronunciation and aesthetics and form the occlusal surface, constituting the most important first step of the chewing function. In order for the tooth to withstand the masticatory function, the structure of the teeth must be strong, and the surrounding tissues such as the periodontal ligament and the alveolar bone should be maintained in a healthy state. The three major diseases of dentistry which are dental caries, periodontal disease and malocclusion: adversely affect the tooth and its surrounding tissues, and may cause masticatory and swallowing disorders. The purpose of this review is provide detailed information about dental problems and related mastication and swallowing problems.

Correlation between clinical symptoms and magnetic resonance imaging findings in patients with temporomandibular joint internal derangement

OBJECTIVES: The purpose of this study was to clarify which findings in magnetic resonance imaging (MRI) are good predicators of pain and mouth opening limitation in patients with temporomandibular joint (TMJ) internal derangement (ID). MATERIALS AND METHODS: Clinical examinations for pain and mouth opening limitation were conducted for suspected TMJ ID. MRI scans were taken within a week of clinical examinations. On the oblique-sagittal plane image, readings were obtained in terms of the functional aspect of disc position, degree of displacement, disc deformity, joint effusion, and osteoarthrosis. Multiple logistic regression analyses were conducted to identify the predictors of pain and mouth opening limitation. RESULTS: A total of 48 patients (96 TMJs) were studied, including 39 female patients and 9 male patients whose ages ranged from 10 to 65 years. The resultant data showed significant correlations between pain and the MR imaging of the degree of disc displacement (P<0.05). The probability of there being pain in moderate to significant cases was 9.69 times higher than in normal cases. No significant correlation was found between mouth opening limitation and MRI findings. CONCLUSION: We identified a significant correlation between clinical symptoms and MRI findings of ID. The degree of anterior disc displacement may be useful for predicting pain in patients with TMJ ID.

Retrospective study on change in pharyngeal airway space and hyoid bone position after mandibular setback surgery

OBJECTIVES: The purpose of this study was to evaluate changes in the pharyngeal airway space and hyoid bone position after mandibular setback surgery with bilateral sagittal split ramus osteotomy (BSSRO) and to analyze the correlation between the amount of mandibular setback and the amount of change in pharyngeal airway space or hyoid bone position. MATERIALS AND METHODS: From January 2010 to February 2013, a total of 30 patients who were diagnosed with skeletal class III malocclusion and underwent the same surgery (BSSRO) and fixation method in the Division of Oral and Maxillofacial Surgery, Department of Dentistry at the Ajou University School of Medicine (Suwon, Korea) were included in this study. Lateral cephalograms of the 30 patients were assessed preoperatively (T1), immediately postoperatively (T2), and 6 months postoperatively (T3) to investigate the significance of changes by time and the correlation between the amount of mandibular setback and the amount of change in the airway space and hyoid bone position. RESULTS: Three regions of the nasopharynx, oropharynx, and hypopharynx were measured and only the oropharynx showed a statistically significant decrease (P<0.01). A significant posterior and inferior displacement of the hyoid bone was found 6 months after surgery (P<0.01). Analysis of the correlation between the amount of mandibular setback and the amount of final change in the airway space and hyoid bone position with Pearson's correlation showed no significant correlation. CONCLUSION: In this study, the oropharynx significantly decreased after mandibular setback surgery, and changes in the surrounding structures were identified through posteroinferior movement of the hyoid bone during long-term follow-up. Therefore, postoperative obstructive sleep apnea should be considered in patients who plan to undergo mandibular setback surgery, and necessary modifications to the treatment plan should also be considered.

Influencing factor on the prognosis of arthrocentesis

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 or =40 mm), and pain relief was defined as when a group with TMJ pain with a visual analog scale (VAS) score of 4 or more (VAS > or =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.

Simultaneous Glossectomy with Orthognathic Surgery for Mandibular Prognathism / 대한악안면성형재건외과학회지

Macroglossia can create dental and skeletal instability after orthodontic treatment or orthognathic surgery for mandibular prognathism. In relevant literature, partial glossectomy is suggested for a good post-treatment prognosis. Most of the published partial glossectomy cases are two-staged surgery, because of concern about postoperative airway obstruction. As orthognathic surgical techniques and fixation method develop, however, concerns about postoperative airway obstruction have lessened. In this case, mandibular setback surgery and partial glossectomy were performed simultaneously, leading to stable recovery without any postoperative respiratory problems. After surgical technique to preserve the tongue tip, we achieved good outcomes without postoperative side effects of lingual hypoesthesia, pronunciation disorder and dyskinesia. We report this case with a literature review.

Anchor Plate Efficiency in Postoperative Orthodontic Treatment Following Orthognathic Surgery via Minimal Presurgical Orthodontic Treatment / 대한악안면성형재건외과학회지

PURPOSE: The efficiency of an anchor plate placed during orthognathic surgery via minimal presurgical orthodontic treatment was evaluated by analyzing the mandibular relapse rate and dental changes. METHODS: The subjects included nine patients with Class III malocclusion who had bilateral sagittal split osteotomy at the Division of Oral and Maxillofacial Surgery, Department of Dentistry in Ajou University Hospital, after minimal presurgical orthodontic treatment. During orthognathic surgery, anchor plates were placed at both maxillary buttresses. The anchor plates were used to move maxillary teeth backward and for maximum anchorage of Class III elastics to minimize mandibular relapse during the postoperative orthodontic treatment. The lateral cephalometric X-ray was taken preoperatively (T0), postoperatively (T1), and one year after the surgery (T2). Seven measurements (distance from Pogonion to line Nasion-Nasion perpendicular [Pog-N Per.], angle of line B point-Nasion and Nasion-Sella [SNB], angle of line maxilla 1 root-maxilla 1 crown and Nasion-Sella [U1 to SN], distance from maxilla 1 crown to line A point-Nasion [U1 to NA], overbite, overjet, and interincisal angle) were taken. Measurements at T0 to T1 and T1 to T2 were compared and differences tested by standard statistical methods. RESULTS: The mean skeletal change was posterior movement by 13.87+/-4.95 mm based on pogonion from T0 to T1, and anterior movement by 1.54+/-2.18 mm from T1 to T2, showing relapse of about 10.2%. There were significant changes from T0 to T1 for both Pog-N Per. and SNB (P<0.05). However, there were no statistically significant changes from T1 to T2 for both Pog-N Per. and SNB. U1 to NA that represents the anterior-posterior changes of maxillary incisor did not differ from T0 to T1, yet there was a significant change from T1 to T2 (P<0.05). CONCLUSION: This study found that the anchor plate minimizes mandibular relapse and moves the maxillary teeth backward during the postoperative orthodontic treatment. Thus, we conclude that the anchor plate is clinically very useful.

Drug holiday as a prognostic factor of medication-related osteonecrosis of the jaw

OBJECTIVES: To identify post-treatment prognostic factors for medication-related osteonecrosis of the jaw (MRONJ). MATERIALS AND METHODS: We evaluated 54 MRONJ patients who visited the Department of Dentistry, Ajou University Hospital, from May 2007 to March 2014. Twenty-one patients were surgically managed with debridement or sequestrectomy and 33 patients were conservatively managed using antibiotics. Correlations of age, sex, stage, bisphosphonate duration and type, and drug holiday with the prognosis of MRONJ were investigated. Correlations were verified by logistic regression analysis and t-tests with a significance level of 0.05. RESULTS: Clinical outcomes were evaluated on the basis of both clinical and radiographic findings. Twelve out of 21 surgically managed patients showed a favorable prognosis and nine patients relapsed. Thirty-one of the 33 conservatively managed patients showed no specific change in prognosis, and two patients worsened. Statistical analyses of the conservative management group did not reveal any correlation of the above factors with the prognosis of conservative management. Drug holiday was the only prognostic factor in the surgical management group (P=0.031 in logistic regression analysis, P=0.004 in t-test). CONCLUSION: Drug holiday is a prognostic factor in the surgical management of MRONJ. Because the drug holiday in the patients of the poor prognosis group occurred 1.5 to 4 months prior to surgical management, we recommend a drug holiday more than 4 months before surgery.

Open reduction and internal fixation of mandibular fracture in an 11-month-old infant: a case report

Mandibular fractures in infants are rare. This case report describes management of a mandibular fracture in an 11-month-old infant using a microplate and screws with open reduction. The surgical treatment was successful. Because the bone fragments were displaced and only the primary incisors had erupted, conservative treatment, such as an acrylic splint and circummandibular wiring, was not recommended. Nine weeks after surgery, the microplate was removed. The results showed complete clinical and radiological bone healing with normal eruption of deciduous teeth.

Comparative Study on Surgical and Conservative Management of Bisphosphonate-related Osteonecrosis of the Jaw (BRONJ) in Disease Stage 2

0.05).CONCLUSION: The results of the present study suggests that surgical intervention is good choice against the conservative treatment, after proper drug holidays period, while further investigation is needed for a definite solution to BRONJ.

Cephalometric Predisposing Factors of the Snoring and Obstructive Sleep Apnea

or =5) were diagnosed as OSA after the overnight PSG. To evaluate the hard and soft tissue profiles, the cephalometric radiograms were taken at the maximal intercuspation. The correlation between the patient's age, height, weight, body mass index (BMI) and AHI was inspected in the OSA and control group. The difference between the OSA and control group was evaluated (Mann-Whitney U Test). The cephalometric influencing factors to OSA were analyzed (Pearson's correlation coefficient) statistically using SPSS statistics.RESULTS: The OSA Group had a significantly higher BMI than the control group. The mean lower facial height (ANS-Me) was longer in the OSA group; however, statistically significant difference was not detected in the anteroposterior craniofacial measurements. The distance between mandibular plane and hyoid bone of the OSA group was significantly longer than that of the control group. The hyoid position (MP-Hyoid) had a positive correlation between AHI (P<0.001). However, the measurements of oropharyngeal airway were not different between the two groups. The hypothesis, that the antero-posteriorly narrow oropharyngeal airway may aggravate the airway resistance and give rise to a higher AHI, was rejected in the study.CONCLUSION: We suggest that the lateral cephalogram may be utilized as a useful method to evaluate OSA. The patients with a lower hyoid position can be expected to have higher risks of OSA. However, a comprehensive intraoral inspection, including the soft palate and tonsilar hypertrophy, is emphasized, as the lateral cepahlogram cannot visualize the oropharyngeal status completely.

Clinical Study on Outfracture Osteotomy Sinus Graft

Implant-supported overdenture with prefabricated bar attachment system in mandibular edentulous patient

Implant-supported overdenture is a reliable treatment option for the patients with edentulous mandible when they have difficulty in using complete dentures. Several options have been used for implant-supported overdenture attachments. Among these, bar attachment system has greater retention and better maintainability than others. SFI-Bar(R) is prefabricated and can be adjustable at chairside. Therefore, laboratory procedures such as soldering and welding are unnecessary, which leads to fewer errors and lower costs. A 67-year-old female patient presented, complaining of mobility of lower anterior teeth with old denture. She had been wearing complete denture in the maxilla and removable partial denture in the mandible with severe bone loss. After extracting the teeth, two implants were placed in front of mental foramen, and SFI-Bar(R) was connected. A tube bar was seated to two adapters through large ball joints and fixation screws, connecting each implant. The length of the tube bar was adjusted according to inter-implant distance. Then, a female part was attached to the bar beneath the new denture. This clinical report describes two-implant-supported overdenture using the SFI-Bar(R) system in a mandibular edentulous patient.

Comparison of the Clinical Characteristics of Bisphosphonate-associated Osteonecrosis of the Jaw with Inflammation-associated Osteonecrosis of the Jaw in Patients with Osteoporosis and Benign Diseases / 대한골다공증학회지

OBJECTIVES: Osteonecrosis of the jaw (ONJ) involving the use of bisphosphonates is referred to as bisphosphonate-associated ONJ (BONJ). Inflammation also can cause ONJ and it may be called inflammation-associated ONJ (IONJ). The aim of this study was to compare clinical characteristics between BONJ and IONJ. MATERIALS AND METHODS: Medical records at the Ajou University Hospital were reviewed using key words "osteonecrosis", "sequestrum", and "dead bone" of the mandible and maxilla. Eighteen patients diagnosed with ONJ were identified from January 2003 to December 2009. Using criteria from the American Association of Oral and Maxillofacial Surgeons, 12 cases were diagnosed as BONJ and six as IONJ. Clinical characteristics and treatment modalities, outcomes of two groups of patients were investigated. RESULTS: Patients of the BONJ group were older than those of IONJ group (median: 76.5 years vs. 60 years). In the BONJ group, mandible was more commonly involved sites and percentage of diabetic patients was higher. Three of 12 (25%) BONJ patients received oral glucocorticoids, while none of the IONJ patients. Ten (83.3%) of the BONJ cases and 2 (33.3%) of the IONJ cases were triggered by dental extractions. Though duration of ONJ treatment was longer in the BONJ group than the IONJ group (6.4+/-5.2 months vs. 2.9+/-1.9 months), both groups eventually showed good prognosis. CONCLUSIONS: ONJ may occur in the absence of bisphosphonate. BONJ occurred in older patients, and needed longer treatment duration compared to IONJ. Prognosis of ONJ was relatively good.

Infection of the temporomandibular joint: a report of three cases

An intracapsular and pericapsular infection of the temporomandibular joint (TMJ) is rare. The invasion of bacteria into the joint space can occur through several routes. Among them, hematogenous spread is most common. This report describes three cases of abscess formation in the TMJ (intracapsular and pericapsular infection). The patients were treated with supportive care and surgical intervention (incision and drainage) under hospitalization, and their symptoms had improved. Pain of the TMJ is a typical symptom of temporomandibular joint disorders (TMD). On the other hand, an infection of the TMJ can also cause pain on the affected side, and can be misdiagnosed as routine TMD. Therefore, the possibility of an infection of the TMJ cavity should be considered when treating TMD.

Effect of implant surface microtopography by hydroxyapatite grit-blasting on adhesion, proliferation, and differentiation of osteoblast-like cell line, MG-63

OBJECTIVE: This study examined the potential of the in vitro osteogenesis of microtopographically modified surfaces, RBM (resorbable blasting media) surfaces, which generate hydroxyapatite grit-blasting. METHODS: RBM surfaces were modified hydroxyapatite grit-blasting to produce microtopographically modified surfaces and the surface morphology, roughness or elements were examined. To investigate the potential of the in vitro osteogenesis, the osteoblastic cell adhesion, proliferation, and differentiation were examined using the human osteoblast-like cell line, MG-63 cells. Osteoblastic cell proliferation was examined as a function of time. In addition, osteoblastic cell differentiation was verified using four different methods of an ALP activity assay, a mineralization assay using alizarin red-s staining, and gene expression of osteoblastic differentiation marker using RT-PCR or ELISA. RESULTS: Osteoblastic cell adhesion, proliferation and ALP activity was elevated on the RBM surfaces compared to the machined group. The cells exhibited a high level of gene expression of the osteoblastic differentiation makers (osteonectin, type I collagen, Runx-2, osterix). imilar data was represented in the ELISA produced similar results in that the RBM surface increased the level of osteocalcin, osteopontin, TGF-beta1 and PGE2 secretion, which was known to stimulate the osteogenesis. Moreover, alizarin red-s staining revealed significantly more mineralized nodules on the RBM surfaces than the machined discs. CONCLUSION: RBM surfaces modified with hydroxyapatite grit-blasting stimulate the in vitro osteogenesis of MG-63 cells and may accelerate bone formation and increase bone-implant contact.

The conservative treatment of mandibular fracture in a child with circummandibular wiring: case report

Maxillofacial injuries are less common in children than in adolescents and adults. This lower incidence is a result of the relatively small size of mandible, the resilient nature of the bones, and a relatively protected environment, which distinguish the treatment principles of pediatric mandibular fractures from those of the adult. The bone of child is malleable, so pediatric fractures tend to be less displaced and rarely comminuted. Moreover, high regeneration potential of the wound allows more conservative treatment modalities for the pediatric mandibular fracture. High risk of damaging unerupted tooth bud renders many clinicians to resort to more conservative treatment modality for the reduction of displaced segments. This case report describes two successful treatment cases using the circummandibular wiring which was applicated to the fracture on parasymphysis of mandible. Circummandibular wiring can protect the tooth buds, and there is no need for intermaxillary fixation so that it prevents the possible complications of intermaxillary fixation such as the temporomandibular joint ankylosis and the facial growth disturbances. The acrylic splint was removed after 3 weeks, which showed clinically good union across the fracture line without complications. They showed complete clinical and radiological bone healing with an optimum occlusion.

COMPARISON OF RESONANCE FREQUENCY ANALYSIS BETWEEN VARIOUS SURFACE PROPERTIES

Clinical Study of Bisphosphonate-Induced Osteonecrosis of Mandibular and Maxillary Bone

Bisphosphonates are compounds widely used in the treatment of various metabolic and malignant bone disease. Recently, an association between bisphosphonate use and a rare dental condition termed 'osteonecrosis of the jaw(ONJ)' has been reported. Bisphosphonate-related osteonecrosis of the jaw(BRONJ) is rare, but serious, side effect of bisphosphonate therapy in affected patients. It is characterized by poor wound healing and spontaneous intra-oral soft tissue break down, which lead to exposure of necrotic maxillary and mandibular bone. We reviewed 11 patients of BRONJ visited Ajou University Hospital Dental clinic from May 2007 to November 2008. The management of the patients included cessation of bisphosphonate therapy and various surgical restorative procedures and conservative care there after. Aggressive debridement is contraindicated. A new complication of bisphosphonate therapy administration, osteonecrosis of jaws, seems to be developing. The improved results after cessation of the medication should make clinicians reconsider the merits of the rampant use of bisphosphonates, while further investigation is needed to completely elucidate this complication.