Reliability of a chairside CAD-CAM surgical guide for dental implant surgery on the anterior maxilla: An in vitro study

PURPOSE@#. This study evaluated the reliability of the chair-side CAD-CAM surgical guide (CSG) in the anterior maxilla by comparing its accuracy with the laboratory 3D-printed surgical guide (3DSG) and manual surgical guide (MSG) concerning different levels of dentists' surgical experience. @*MATERIALS AND METHODS@#. Ten surgical guides of each type (MSG, 3DSG, and CSG) were fabricated on a control study model with missing right and left central incisors. Sixty implants were placed in 30 study models by two dentists (one inexperienced and one experienced) using three different types of surgical guides. Horizontal deviations at shoulder and at apex, vertical, and angular deviations were measured after superimposing the planned and placed implant positions in the software. Kruskal-Wallis and Mann-Whitney U tests were used to compare the accuracy of three types of surgical guides in each dentist group and the accuracy of each surgical guide between two dentists (α = .05). @*RESULTS@#. There were no significant differences in any deviations between CSG and 3DSG, apart from angular deviation, for both dentists’ groups. Moreover, both CSG and 3DSG showed no significant differences in accuracy between the two dentists (P > .05). In contrast, MSG demonstrated significant differences from CSG and 3DSG and a significant difference in accuracy between the two dentists (P < .05). @*CONCLUSION@#. CSG provides superior accuracy to MSG in implant placement in the maxillary anterior region and is comparable to 3DSG at different levels of surgical experience, while offering the benefits of shorter manufacturing time and reduced patient visits.

Extraction of mandibular third molars: relationship of preoperative anxiety with body mass index, serum high-sensitivity C-reactive protein levels, and visual analog scale scores and predictors of postoperative complications

Objectives@#Patients undergoing oral surgery exhibit high anxiety, which may elevate their cortisol levels and affect postoperative recovery. Overweight patients are often encountered in the dental clinic due to the increasing prevalence of overweight. We aimed to investigate the relationships between preoperatively assessed body mass index (BMI), serum cortisol and high-sensitivity C-reactive protein (hs-CRP) levels, and visual analog scale (VAS) scores and preoperative anxiety in patients undergoing mandibular third molar (MM3) extraction and to identify predictors of postoperative complications. @*Patients and Methods@#We analyzed 43 patients (age, 20-42 years) undergoing MM3 extraction. At the first visit, patients completed the Modified Dental Anxiety Scale (MDAS) and Amsterdam Preoperative Anxiety and Information Scale (APAIS) questionnaires. Their BMI and VAS scores were also calculated. The participants underwent blood tests 1 hour before MM3 extraction. On the first postoperative day, the participants’ VAS scores and serum hs-CRP levels were reevaluated. @*Results@#We found that BMI was significantly correlated with preoperative VAS scores. Further, BMI and preoperative hs-CRP levels were significantly correlated among women and patients undergoing extractions of fully impacted MM3s. No correlations were found between serum cortisol and other variables. The preoperative MDAS and VAS scores were significantly positively correlated, especially among patients undergoing extractions of fully impacted MM3s. Multiple linear regression showed that BMI and the eruption status of the MM3 were significant predictors of postoperative hsCRP levels and VAS scores, respectively. @*Conclusion@#In MM3 removals, patients with higher BMI showed elevated hs-CRP and higher VAS scores before surgery. Patients with higher anxiety among those undergoing extractions of fully impacted MM3s showed higher preoperative VAS scores. The two main predictors of postoperative complications were BMI and MM3 eruption status.

The double-barrier technique using platelet-rich fibrin for closure of oroantral fistulas

An oroantral fistula (OAF) or oroantral communication (OAC) is an opening between the oral cavity and the maxillary sinus. If left untreated, these openings may cause chronic maxillary sinusitis. Although small defects (diameter <5 mm) may close spontaneously, larger communications require surgical intervention. Various studies have been conducted on OAC closure using a platelet-rich fibrin (PRF) membrane; most of these prior studies have involved simple direct application of PRF clots. This study introduces a new “double-barrier technique” using PRF for closure of an OAF involving sinus mucosal lifting and closure. The PRF material is inserted into the prepared maxillary sinus space, and the buccal advancement flap covers the oral side. This technique was successfully used to treat two patients with chronic OAF in the posterior maxillary region after implant removal or tooth extraction. The use of a PRF membrane in a double-barrier technique may have advantages in soft-tissue healing and could enable easy closure of chronic OAF with minimal trauma.

The use of a pedicled buccal fat pad for reconstruction of posterior mandibular defects / 대한악안면성형재건외과학회지

Background@#The pedicled buccal fat pad has been used for a long time to reconstruct oral defects due to its ease of flap formation and few complications. Many cases related to reconstruction of defects in the maxilla, such as closing the oroantral fistula, have been reported, but cases related to the reconstruction of defects in the mandible are limited. Under adequate anterior traction, pedicled buccal fat pad can be a reliable and effective method for reconstruction of surgical defects in the posterior mandible.Case presentation: This study describes two cases of reconstruction of surgical oral defects in the posterior mandible, all of which were covered by a pedicled buccal fat pad. The size of the flap was sufficient to perfectly close the defect without any tension. Photographic and radiologic imaging showed successful closure of the defects and no problems were noted in the treated area. @*Conclusion@#In conclusion, the pedicled buccal fat pad graft is a convenient and reliable method for the reconstruction of surgical defects on the posterior mandible.

A large invasive chondroblastoma on the temporomandibular joint and external auditory canal: a case report and literature review / 대한악안면성형재건외과학회지

Background@#Chondroblastomas, which account for approximately 1% of all bone tumors, typically occur in long bones, such as the femur, humerus, and tibia. However, in extremely rare cases, they may also occur in the craniofacial region where the tumor is often found in the squamous portion of the temporomandibular joint (TMJ) and in the temporal bone.Case presentation: This case report describes a large chondroblastoma (diameter, approximately 37 mm) that occurred in the TMJ. The tumor was sufficiently aggressive to destroy the TMJ, mandibular condyle neck, external auditory canal (EAC), mandibular fossa of the temporal bone, and facial nerve. The tumor was completely excised using a pre-auricular approach. The EAC and surgical defect were successfully reconstructed using a temporoparietal fascia flap (TPFF) and an inguinal free fat graft. There was no local tumor recurrence at the 18-month follow-up visits. However, the patient developed sensory neural hearing loss, and his eyebrow paralysis worsened, eventually requiring plastic surgery. @*Conclusion@#Large, invasive chondroblastomas of the TMJ can be completely removed through a pre-auricular approach, and the resulting surgical defect can be reconstructed using TPFF and free fat grafts. However, preoperative evaluation of the facial nerve and auditory function is necessary. Therefore, a multidisciplinary approach is essential.

Main results of the Korea National Hospital Discharge In-depth Injury Survey, 2004-2016 / 한국역학회지

OBJECTIVES@#The purpose of this study was to estimate the incidence of injuries and to identify their causes by classifying injuries according to various categories including age, sex, mechanism of injury, body parts injured, and place of injury. @*METHODS@#This study used data from the Korea National Hospital Discharge In-depth Injury Survey (KNHDIS) from 2004 to 2016. The KNHDIS is conducted annually by the Korea Centers for Disease Control and Prevention, and its survey population includes all hospitalized patients discharged from medical institutions that have 100 or more beds, such as hospitals, general hospitals, and secondary community health centers. The number of injured cases is weighted and estimated using the mid-year estimated population of each year. @*RESULTS@#The injury discharge rate steadily increased since 2004 (1,505 per 100,000 population in 2004, 2,007 per 100,000 population in 2016) and most injuries were unintentional (annual average of 94.7%). On average, during the 13-year study period, the injury rate for males was 1.5 times as high as for females. The 2 main causes of injury were consistently traffic accidents and falls. Notably, the rate of injuries resulting from falls rose by 1.7-fold from 463 to 792 per 100,000 people, and exceeded the rate of traffic accidents in 2016. @*CONCLUSIONS@#The incidence of injuries steadily increased after the survey was first conducted, whereas mortality resulting from injuries mostly remained unchanged. This suggests that effective strategies and interventions should be reinforced to reduce unintentional injuries.

Main results of the Korea National Hospital Discharge In-depth Injury Survey, 2004-2016 / 한국역학회지

OBJECTIVES@#The purpose of this study was to estimate the incidence of injuries and to identify their causes by classifying injuries according to various categories including age, sex, mechanism of injury, body parts injured, and place of injury. @*METHODS@#This study used data from the Korea National Hospital Discharge In-depth Injury Survey (KNHDIS) from 2004 to 2016. The KNHDIS is conducted annually by the Korea Centers for Disease Control and Prevention, and its survey population includes all hospitalized patients discharged from medical institutions that have 100 or more beds, such as hospitals, general hospitals, and secondary community health centers. The number of injured cases is weighted and estimated using the mid-year estimated population of each year. @*RESULTS@#The injury discharge rate steadily increased since 2004 (1,505 per 100,000 population in 2004, 2,007 per 100,000 population in 2016) and most injuries were unintentional (annual average of 94.7%). On average, during the 13-year study period, the injury rate for males was 1.5 times as high as for females. The 2 main causes of injury were consistently traffic accidents and falls. Notably, the rate of injuries resulting from falls rose by 1.7-fold from 463 to 792 per 100,000 people, and exceeded the rate of traffic accidents in 2016. @*CONCLUSIONS@#The incidence of injuries steadily increased after the survey was first conducted, whereas mortality resulting from injuries mostly remained unchanged. This suggests that effective strategies and interventions should be reinforced to reduce unintentional injuries.

Rapid Collection of Opinions from Healthcare Professionals in Multiple Institutions Using Short Message Service and Google Forms / 대한의료정보학회지

No abstract available.

Application of Monitored Anesthesia Care Using Dexmedetomidine to Common Oral and Maxillofacial Trauma Cases

Oral and maxillofacial surgery (OMFS) trauma cases are commonly treated under general anesthesia. The purpose of this case report is to introduce an alternative method of anesthesia in patients who refuse general anesthesia. A combination of dexmedetomidine and ketamine for sedation anesthesia in 3 frequent fracture types in the field of OMFS—Le Fort I fracture, mandibular fracture, and alveolar bone fracture—was used. Dexmedetomidine as the single agent has not shown stable success rates for invasive procedures. To overcome some of the pitfalls with dexmedetomidine, combination sedation using ketamine was performed. Visual analogue scale scores were recorded postoperatively. Dexmedetomidine combined with ketamine administration provided safe and effective sedation and anxiolysis for surgical reduction and internal fixation of OMFS fractures. It showed advantages of decreased admission time, reduced expenses, minimal pain, and reduced anesthetic burden for the patient thus ultimately increasing overall satisfaction.

Novel approach to the maxillary sinusitis after sinus graft / 대한악안면성형재건외과학회지

BACKGROUND: Postoperative infection occurs when bone graft material is dislodged into the maxillary sinus cavity and most of the patients are often uncomfortable with the drainage and irrigation procedures to eradicate the infection. In this case report, we share a technique in treating patients with such condition. MATERIAL AND METHODS: A 47-year-old patient was referred after sinus elevation using the crestal socket osteotome, bone graft, and implant insertion at a local clinic. Clinical and radiographic findings confirmed the diagnosis of right maxillary sinusitis. A surgical and medical treatment regimen was applied. RESULTS: By using this technique for irrigation, we were able to achieve successful results, and the patient was satisfied due to less discomfort during the irrigation process. CONCLUSION: This method is a patient-friendly technique for sinus irrigation. It is not only limited to sinus grafted patients, but also maxillary sinusitis patients in any other type of odontogenic infection.

Hypoglossal nerve stimulation for treatment of obstructive sleep apnea (OSA): a primer for oral and maxillofacial surgeons / 대한악안면성형재건외과학회지

The prevalence of obstructive sleep apnea (OSA) is estimated to be 1–5% of the adult population world-wide, and in Korea, it is reported at 4.5% of men and 3.2% of women (Age 40 to 69 years old). Active treatment of OSA is associated with decrease in insulin resistance, cardiovascular disease, psychosocial problems, and mortality. Surgical treatment of OSA has evolved in the era of neuromodulation with the advent of hypoglossal nerve stimulation (HGNS). We share this review of HGNS with our maxillofacial surgical colleagues to expand the scope of surgical care for OSA.

Healing outcomes of root canal treatment for C-shaped mandibular second molars: a retrospective analysis

OBJECTIVES: This study aimed to evaluate the healing rate of non-surgical endodontic treatment between C-shaped and non-C-shaped mandibular second molars. MATERIALS AND METHODS: Clinical records and radiological images of patients who had undergone endodontic treatment on mandibular second molars between 2007 and 2014 were screened. The periapical index scoring system was applied to compare healing outcomes. Information about preoperative and postoperative factors as well as the demographic data of the patients was acquired and evaluated using chi-square and multinomial logistic regression tests. RESULTS: The total healing rate was 68.4%. Healing rates for the mandibular second molar were 70.9% in C-shaped canals (n = 79) and 66.6% in non-C-shaped ones (n = 117). The difference was not statistically significant. CONCLUSIONS: The presence of a C-shaped canal in the mandibular second molar did not have a significantly negative effect on healing after treatment. Instead, proper pulpal diagnosis and final restoration were indicated as having significantly greater influence on the healing outcomes of C-shaped and non-C-shaped canals, respectively.

The Factors Influencing Neurological Outcome of Out-of-hospital Cardiac Arrest with Cardiac Etiology

PURPOSE: The purpose of this study is to examine the factors associated with neurological outcome and to provide ideas for improving the operation of the emergency medical system in Korea. METHODS: A total of 95,911 out-of-hospital cardiac arrests (OHCAs) with cardiac etiology who were transported by 119 EMS ambulances for seven years from 2006 to 2012 in Korea were analyzed. According to these data there is a multilevel structure, so that patient's neurological outcome in the same region is not independent but interrelated, therefore two-level (patient-region) logistic regression analysis was applied to adjust this correlation. RESULTS: The adjusted odds ratio (OR) in the group in which Cardiopulmonary Resuscitation (CPR) was performed by a bystander was 1.27 for good neurological outcome. The adjusted OR in the group with implementation of an automated external defibrillator (AED) before arrival at the hospital was 4.11 for good neurological outcome. The adjusted OR in the numbers of emergency physicians compared with <3 was 2.76 (3-4), 4.24 (≥5) and the adjusted OR in OHCAs volume of each hospital compared with <50 was 2.31 (50-64), 2.51 (65-102), and 2.94 (≥103). The adjusted OR in deprivation level compared with <2 was 0.72 (≥2). CONCLUSION: The neurological outcome was significantly better in the group in which CPR was performed by a bystander and AED was applied early. The neurological outcome tended to be significantly better in hospitals with higher numbers of emergency physicians and higher volume of OHCAs, in less deprived districts.

Finite element analysis on stress distribution of maxillary implant-retained overdentures depending on the Bar attachment design and palatal coverage

PURPOSE: The purpose of this study was to determine the effect of anchorage systems and palatal coverage of denture base on load transfer in maxillary implant-retained overdenture. MATERIALS AND METHODS: Maxillary implant-retained overdentures with 4 implants placed in the anterior region of edentulous maxilla were converted into a 3-D numerical model, and stress distribution patterns in implant supporting bone in the case of unilateral vertical loading on maxillary right first molar were compared with each other depending on various types of anchorage system and palatal coverage extent of denture base using three-dimensional finite element analysis. RESULTS: In all experimental models, the highest stress was concentrated on the most distal implant and implant supporting bone on loaded side. The stress at the most distal implant-supporting bone was concentrated on the cortical bone. In all anchorage system without palatal coverage of denture base, higher stresses were concentrated on the most distal implant and implant supporting bone on loaded side. CONCLUSION: It could be suggested that when making maxillary implant retained overdenture, using Hader bar instead of milled bar and full palatal coverage rather than partial palatal coverage are more beneficial in distributing the stress that is applied on implant supporting bone.

Magnesium vs. machined surfaced titanium - osteoblast and osteoclast differentiation

PURPOSE: This study focused on in vitro cell differentiation and surface characteristics in a magnesium coated titanium surface implanted on using a plasma ion source. MATERIALS AND METHODS: 40 commercially made pure titanium discs were prepared to produce Ti oxide machined surface (M) and Mg-incorporated Ti oxide machined surface (MM). Surface properties were analyzed using a scanning electron microscopy (SEM). On each surface, alkaline phosphatase (ALP) activity, alizarin red S staining for mineralization of MC3T3-E1 cells, and quantitative analysis of osteoblastic gene expression, were evaluated. Actin ring formation assay and gene expression analysis of TRAP and GAPDH performing RT-PCR were performed to characterize osteoclast differentiation on mouse bone marrow-derived macrophages (BMMs). RESULTS: MM showed similar surface morphology and surface roughness with M, but was slightly smoother after ion implantation at the micron scale. M was more hydrophobic than MM. No significant difference between surfaces on ALP activity at 7 and 14 days were observed. Real-time PCR analyses showed similar levels of mRNA expression of the osteoblast phenotype genes; osteopontin (OPN), osteocalcin (OCN), bone sialoprotein (BSP), and collagen 1 (Col 1) in cell grown on MM at 7, 14 and 21 days. Alizarin red S staining at 21 days showed no significant difference. BMMs differentiation increased in M and MM. Actin ring formation assay and gene expression analysis of TRAP showed osteoclast differentiation to be more active on MM. CONCLUSION: Both M and MM have a good effect on osteoblastic cell differentiation, but MM may speed the bone remodeling process by activating on osteoclast differentiation.

Healing after horizontal root fractures: 3 cases with 2-year follow-up

Among dental traumas, horizontal root fractures are relatively uncommon injuries. Proper initial management and periodical evaluation is essential for the successful treatment of a root-fractured tooth. If pulpal necrosis develops, endodontic treatment is indicated, exclusively for the coronal fragment. Fragment diastases exert a great influence on healing at the fracture line and on pulpal necrosis. An adequately treated root-fractured tooth has a good prognosis. This case report describes the treatment and 2-yr follow up of 3 maxillary central incisors, first with horizontal root fracture, second with horizontal root fracture and avulsion, and third with horizontal root fracture and lateral luxation. All three cases were treated with mineral trioxide aggregate (ProRoot, Dentsply). During 2 yr of follow-up evaluation, the root-fractured teeth of the present patients were well retained in the arch, showing periodontal healing, even after endodontic treatment.

A Case Report of Temporomandibular Bilateral Osseous Ankylosis Treated by Total Joint Replacement in Ankylosing Spondylitis

Polymorphous Low-grade Adenocarcinoma of the Palate: Case Report

Power density of various light curing units through resin inlays with modified layer thickness

OBJECTIVES: The purpose of this study was to enhance curing light penetration through resin inlays by modifying the thicknesses of the dentin, enamel, and translucent layers. MATERIALS AND METHODS: To investigate the layer dominantly affecting the power density of light curing units, resin wafers of each layer with 0.5 mm thickness were prepared and power density through resin wafers was measured with a dental radiometer (Cure Rite, Kerr). The dentin layer, which had the dominant effect on power density reduction, was decreased in thickness from 0.5 to 0.1 mm while thickness of the enamel layer was kept unchanged at 0.5 mm and thickness of the translucent layer was increased from 0.5 to 0.9 mm and vice versa, in order to maintain the total thickness of 1.5 mm of the resin inlay. Power density of various light curing units through resin inlays was measured. RESULTS: Power density measured through 0.5 mm resin wafers decreased more significantly with the dentin layer than with the enamel and translucent layers (p < 0.05). Power density through 1.5 mm resin inlays increased when the dentin layer thickness was reduced and the enamel or translucent layer thickness was increased. The highest power density was recorded with dentin layer thickness of 0.1 mm and increased translucent layer thickness in all light curing units. CONCLUSIONS: To enhance the power density through resin inlays, reducing the dentin layer thickness and increasing the translucent layer thickness would be recommendable when fabricating resin inlays.

Endodontic management of a C-shaped maxillary first molar with three independent buccal root canals by using cone-beam computed tomography

The aim of this study was to present a method for endodontic management of a maxillary first molar with unusual C-shaped morphology of the buccal root verified by cone-beam computed tomography (CBCT) images. This rare anatomical variation was confirmed using CBCT, and nonsurgical endodontic treatment was performed by meticulous evaluation of the pulpal floor. Posttreatment image revealed 3 independent canals in the buccal root obturated efficiently to the accepted lengths in all 3 canals. Our study describes a unique C-shaped variation of the root canal system in a maxillary first molar, involving the 3 buccal canals. In addition, our study highlights the usefulness of CBCT imaging for accurate diagnosis and management of this unusual canal morphology.