Seoul National University Dental Hospital Research Articles

A Comparative Study on the Voxel Values in Alveolar Bones Acquired by MDCT and Newly Developed Dental Dual-Energy CBCT.

The purpose of this study was to analyze the effectiveness of newly developed dental dual-energy (DE) cone-beam computed tomography (CBCT) to compare both the voxel values in hard bone tissue of DE-CBCT and multidetector computed tomography (MDCT) images, collected in a clinical trial conducted at Seoul National University Dental Hospital. A software implemented as a scripted module of a three-dimensional (3D) slicer was developed to register the volume data from the MDCT space to DE-CBCT, locate the same 3D regions of interest (ROIs) in each image space, and extract the statistics of the ROIs. The mean values were paired and used as representative values of the ROIs. A scatter plot with the line of equality and Bland–Altman (BA) plot of difference for a pair of measured means were used for statistical analysis. Of the ROI pairs, 96% were within ±15% from the identity line, and more than 95% of the measured ROI pairs were within the limits of agreement of the 95% confidence intervals (CIs), with the CI of the limits in BA plots. The newly developed dental DE-CBCT showed a level of voxel value accuracy similar to that of MDCT.

Characterization of Treatment Modalities for Patients With Syndromic Craniosynostosis in Relation to Degree of Midface Hypoplasia and Patient's Age Using Longitudinal Follow-Up Data.

The purpose of this study was to investigate the type and frequency of use of treatment modalities (Tx-Mods) in patients with syndromic craniosynostosis (SC) using longitudinal follow-up data. A total of 28 patients with SC (24 Crouzon, 2 Apert, and 2 Antley-Bixler syndromes), who were treated at the Department of Orthodontics, Seoul National University Dental Hospital, Seoul, South Korea between 1998 and 2020, was included. According to the degree of midface hypoplasia (MH) at the initial visit (T1), the patients were divided into the mild-MH (78°≤SNA < 80°, n = 8), moderate-MH (76≤SNA < 78°, n = 7), and severe-MH (SNA < 76°, n = 13) groups. T1-age and Tx-Mods, including cal-varial surgery (CALS), orthopedic treatment (OPT), fixed orthodontic treatment, and midface advancement surgery in childhood (MAS-child) and adulthood (MAS-adult), were investigated. Complexity of MAS-adult was graded as follows: 0, no surgery; 1, orthognathic surgery; 2, distraction osteogenesis (DOG); 3, combination of distraction osteogenesis and orthognathic surgery. Then, statistical analysis was performed. Percentage distribution of Tx-Mods was 71.4% in CALS, 21.4% in MAS-child, 42.9% in OPT, 100% in fixed orthodontic treatment, and 89.3% in MAS-adult. 92.9% of patients underwent MAS more than once. The number of MAS increased according to the severity of MH ( P < 0.05). The complexity of MAS-adult increased as T1-age and severity of MH increased (all P < 0.05); whereas it decreased when CALS and OPT were performed (all P < 0.05). However, MAS in childhood did not guarantee the avoidance of additional MAS in adulthood ( P > 0.05). These findings may be used as basic guidelines for successful treatment planning and prognosis prediction in patients with SC.

Characterization of phenotypes and predominant skeletodental patterns in pre-adolescent patients with Pierre-Robin sequence.

ObjectiveTo investigate the phenotypes and predominant skeletodental pattern in pre-adolescent patients with Pierre–Robin sequence (PRS).MethodsThe samples consisted of 26 Korean pre-adolescent PRS patients (11 boys and 15 girls; mean age at the investigation, 9.20 years) treated at the Department of Orthodontics, Seoul National University Dental Hospital between 1998 and 2019. Dental phenotypes, oral manifestation, cephalometric variables, and associated anomalies were investigated and statistically analyzed.ResultsCongenitally missing teeth (CMT) were found in 34.6% of the patients (n = 9/26, 20 teeth, 2.22 teeth per patient) with 55.5% (n = 5/9) exhibiting bilaterally symmetric missing pattern. The mandibular incisors were the most common CMT (n = 11/20). Predominant skeletodental patterns included Class II relationship (57.7%), posteriorly positioned maxilla (76.9%) and mandible (92.3%), hyper-divergent pattern (92.3%), high gonial angle (65.4%), small mandibular body length to anterior cranial base ratio (65.4%), linguoversion of the maxillary incisors (76.9%), and linguoversion of the mandibular incisors (80.8%). Incomplete cleft palate (CP) of hard palate with complete CP of soft palate (61.5%) was the most frequently observed, followed by complete CP of hard and soft palate (19.2%) and CP of soft palate (19.2%) (p < 0.05). However, CP severity did not show a significant correlation with any cephalometric variables except incisor mandibular plane angle (p < 0.05). Five craniofacial and 15 extra-craniofacial anomalies were observed (53.8% patients); this implicated the need of routine screening.ConclusionsThe results might provide primary data for individualized diagnosis and treatment planning for pre-adolescent PRS patients despite a single institution-based data.

Characterization of Phenotypes and Treatment Modalities in Patients With Treacher-Collins Syndrome.

The purpose of this study was to investigate the phenotypes and treatment modalities (Tx-Mod) in patients with Treacher-Collins syndrome (TCS) using a TCS severity index (TSI). The sample consisted of 14 Korean TCS patients treated at the Department of Orthodontics, Seoul National University Dental Hospital during 1998 to 2019. The TSI was calculated by adding the scores from the number of deformity-involved midface structures (eye, ear, zygoma) and the degree of mandibular hypoplasia (Pruzansky-Kaban type, gonial angle, Sella-Nasion-B point angle). The deformity-involved midface structure, degree of mandibular hypoplasia, oral manifestations, dental phenotypes, and Tx-Mod types were investigated using descriptive statistics. The TSI classified the subjects into 2 mild, 6 moderate, and 6 severe cases. The severity of ear and zygoma deformities, degree of condylar hypoplasia (Pruzansky-Kaban type), clockwise-rotated morphology (gonial angle) and retrusive position (Sella-Nasion-B point angle) of the mandible, and frequency of oral/craniofacial cleft, openbite, congenitally missing tooth and impacted tooth showed a tendency of increase from mild to severe TCS cases. After growth observation (78.6%), diverse combinations of Tx-Mods were applied except for functional appliance therapy. Surgical procedures for eye, ear, and zygoma reconstruction were performed on all patients (100%), whereas fixed orthodontic treatment, mandibular distraction osteogenesis, and orthognathic surgery were performed on 50% of patients. Surgical procedure for hearing improvement was the most frequent Tx-Mod (78.6%). The main desires of TCS patients were to obtain the facial esthetics in the midface and to improve hearing function. The TSI might provide a primary data for individualized diagnosis and treatment planning.

Distribution of Pediatric Malocclusion Patients in Seoul National University Dental Hospital

A total of 580 patients, who visited and received an orthodontic diagnosis in the Department of Pediatric Dentistry, Seoul National University Dental Hospital from 2017 to 2019, were investigated in this study. The aim of this study was to evaluate skeletal patterns of pediatric orthodontic patients determined with lateral cephalometric analysis and to analyze the relationship between skeletal pattern and probable associated clinical features. Also, the modality of orthodontic treatment for each skeletal classification was investigated to aid in therapeutic decisions.&lt;br/&gt;Patients aged 7 year accounted for the largest age group; 54.2% of patients showed a skeletal class I pattern, 22.2% showed a skeletal class II pattern, and 23.6% showed a skeletal class III pattern. Bi-maxillary retrusion for skeletal class I, retruded mandible with normal positioning of the maxilla for skeletal class II, and retrusion of the maxilla with protrusion of the mandible for skeletal class III were the largest subgroups by skeletal pattern. Brachyfacial type accounted for 55.0% of patients, followed by 31.9% of mesofacial type and 13.1% of dolichofacial type. The prevalence of anterior crossbite in the study was 43.3%, higher than that in previous studies.

Diagnostic and prognostic ability of salivary MMP-9 for oral squamous cell carcinoma: A pre-/post-surgery case and matched control study.

Over 90% of oral cancers are oral squamous cell carcinoma (OSCC). Hitherto, early detection marker for OSCC has not been available. Hence, this study aimed to evaluate the diagnostic and prognostic ability of salivary matrix-metalloproteinase-9 (MMP-9) and 8-hydroxydeoxyguanosine (8-OHdG) for OSCC. Total of 318 participants with 106 cases and 212 controls were included: OSCC cases were from Seoul National University Dental Hospital and age, sex, and smoking matched controls were from Yangpyeong cohort. Unstimulated saliva was collected to determine MMP-9 and 8-OHdG using sensitive enzyme-linked immunosorbent assay. Multivariable linear regression and analysis of covariance (ANCOVA) were applied to evaluate the adjusted association of markers with OSCC. Wilcoxon sign rank sum test and Friedman test for median were applied to evaluate follow-up level of MMP-9 after surgery. Receiver operating characteristic curve was obtained for diagnostic ability. Salivary MMP-9 was associated with OSCC (ANCOVA and multivariable linear regression, p<0.05), while 8-OHdG was not. The diagnostic ability of MMP-9 was area under curve of 0.96 (100% specificity and 89.6% sensitivity, p<0.001). MMP-9 decreased dramatically after tumor surgery (p<0.05). Salivary MMP-9 could be a critical diagnostic and prognostic marker for OSCC.

Factors Affecting Functional Sensory Recovery After Inferior Alveolar Nerve Repair Using the Nerve Sliding Technique

The nerve sliding technique (NST) was introduced for repairing inferior alveolar nerve (IAN) defect and overcoming the disadvantages of conventional surgical treatment methods such as nerve graft. This study was conducted to identify factors associated with functional sensory recovery (FSR) following inferior alveolar nerve repair using the NST. This was a retrospective cohort study including all patients who underwent IAN repair using the NST at Seoul National University Dental Hospital, Department of Oral and Maxillofacial Surgery from February 2009 to March 2020. The damaged part of the IAN was excised, and the incisive branch was transected intentionally to perform direct anastomosis without tension. Cox proportional hazard analysis was utilized to determine the relationships between predictor variables (age, gender, chief complaints, preoperative sensory results, duration from injury to repair, length of nerve tissue resected during the procedure, and neuroma formation) and outcome variable (time to FSR). The sample was composed of 16 patients with a mean age of 56.1±10.1years, 25% were males and 75% were females. The mean nerve gap deficit was 7.69mm (3-15mm). Ten patients (62.5%) achieved FSR with a median time from operative treatment to FSR of 84.5days. Dental implant placement was found as the main cause for IAN injury (93.8%) and 56.2% of patients complained of hypoesthesia and dysesthesia. Factors associated with time to FSR at 1year were age, chief complaint, and early repair. Younger patients (P=.041) and patients without dysesthesia (P=.019) were more likely to achieve FSR. Higher proportion of early repair group achieved FSR, although not statistically significant (P=.068). The use of NST in repair of IAN defects up to 15mm achieved 62.5% FSR. Younger age and absence of dysesthesia were associated with higher FSR.

Retrospective study on three-dimensional characteristics of mesiodens using CBCT in pediatric dentistry

The purpose of this study was to investigate the three-dimensional characteristics of mesiodens using Cone-beam Computed Tomography(CBCT) and analyze the factors affecting complications and anesthetic methods of extraction. This study evaluated 602 mesiodens of 452 patients who underwent extraction of mesiodens at the department of Pediatric Dentistry in Seoul National University Dental Hospital between 2017 and 2019. The ratio of mesiodens patients over total patient per year was gradually increased over the past 20 years. Mesiodens with labio-palatally horizontal direction while root directing labial were the most common among the mesiodens with horizontal direction. Mesiodens were the most common at the cervical side of the adjacent teeth(37.0%) and mesiodens located in the near-palatal side were observed about 3.83 times higher than the far-palatal side. Most of the mesiodens(82.1%) were in contact with adjacent permanent teeth on all three sides of the CBCT and 46.2% of mesiodens had curved roots. The patient’s age, vertical position, presence of complications, and proximity showed a significant difference in the selection of general anesthesia among anesthetic methods. The direction and vertical position of mesiodens had a significant effect on complications. These results provide a better understanding of mesiodens for establishing an accurate diagnosis and treatment plan.

Predictors of Red Blood Cell Transfusion in Bimaxillary Orthognathic Surgery: A Retrospective Study.

Background: Orthognathic surgery requires red blood cell (RBC) transfusions more frequently than other oral and maxillofacial surgeries. The purpose of this study was to identify reliable predictors for RBC transfusion during bimaxillary orthognathic surgery (BOS).Methods: This retrospective study reviewed 1,616 electronic medical records of patients who underwent BOS during a 5-year period at Seoul National University Dental Hospital. The perioperative variable data were collected from electronic medical records and analyzed by dividing patients into the two groups (non-transfusion and transfusion group).Results: Of the 1,616 patients, 1,311 patients were excluded. The remaining 305 patients were divided into non-transfusion (NTF, n = 256) and transfusion (TF, n = 49) groups. Univariate logistic regression analysis revealed that age, body mass index, the presence of several adjunctive surgeries (including genioplasty, extraction, and mandibular angle reduction), preoperative hemoglobin (Hb) and prothrombin time, surgical time, amount of fluid infusion and blood loss, and mean pulse rate during surgery were significant factors predicting RBC transfusion. Multivariate logistic regression analysis revealed that preoperative Hb and blood loss amount during surgery were significantly related to RBC transfusion in BOS patients.Conclusion: Since blood loss amounts could not be measured preoperatively, we found that the independent predictor associated with RBC transfusion during BOS was a low preoperative Hb level.

Radiographic features of cleidocranial dysplasia on panoramic radiographs.

PurposeThis study aimed to investigate the panoramic imaging features of cleidocranial dysplasia (CCD) with a relatively large sample.Materials and MethodsThe panoramic radiographs of 40 CCD patients who visited Seoul National University Dental Hospital between 2004 and 2018 were analyzed. Imaging features were recorded based on the consensus of 2 radiologists according to the following criteria: the number of supernumerary teeth and impacted teeth; the shape of the ascending ramus, condyle, coronoid process, sigmoid notch, antegonial notch, and hard palate; the mandibular midline suture; and the gonial angle.ResultsThe mean number of supernumerary teeth and impacted teeth were 6.1 and 8.3, respectively, and the supernumerary teeth and impacted teeth were concentrated in the anterior and premolar regions. Ramus parallelism was dominant (32 patients, 80.0%) and 5 patients (12.5%) showed a mandibular midline suture. The majority of mandibular condyles showed a rounded shape (61.2%), and most coronoid processes were triangular (43.8%) or round (37.5%). The mean gonial angle measured on panoramic radiographs was 122.6°.ConclusionPanoramic radiographs were valuable for identifying the features of CCD and confirming the diagnosis. The presence of numerous supernumerary teeth and impacted teeth, especially in the anterior and premolar regions, and the characteristic shapes of the ramus, condyle, and coronoid process on panoramic radiographs may help to diagnose CCD.

Distribution, side involvement, phenotype and associated anomalies of Korean patients with craniofacial clefts from single university hospitalbased data obtained during 1998-2018.

ObjectiveTo investigate the distribution, side involvement, phenotype, and associated anomalies of Korean patients with craniofacial clefts (CFC).MethodsThe samples consisted of 38 CFC patients, who were treated at Seoul National University Dental Hospital during 1998–2018. The Tessier cleft type, sex, side involvement, phenotype, and associated anomalies were investigated using non-parametric statistical analysis.ResultsThe three most common types were #7 cleft, followed by #0 cleft and #14 cleft. There was no difference between the frequency of male and female. Patients with #0 cleft exhibited nasal deformity, bony defect, and missing teeth in the premaxilla, midline cleft lip, and eye problems. A patient with #3 cleft (unilateral type) exhibited bilateral cleft lip and alveolus. All patients with #4 cleft were the bilateral type, including a combination of #3 and #4 clefts, and had multiple missing teeth. A patient with #5 cleft (unilateral type) had a posterior openbite. In patients with #7 cleft, the unilateral type was more prevalent than the bilateral type (87.0% vs. 13.0%, p < 0.001). Sixteen patients showed hemifacial microsomia (HFM), Goldenhar syndrome, and unilateral cleft lip and palate (UCLP). There was a significant match in the side involvement of #7 cleft and HFM (87.5%, p < 0.01). Patients with #14 cleft had plagiocephaly, UCLP, or hyperterorbitism. A patient with #30 cleft exhibited tongue tie and missing tooth.ConclusionsDue to the diverse associated craniofacial anomalies in patients with CFC, a multidisciplinary approach involving a well-experienced cooperative team is mandatory for these patients.

Characterization of dental phenotypes and treatment modalities in Korean patients with Parry-Romberg syndrome.

ObjectiveTo investigate the dental phenotypes and treatment modalities (Tx-Mod) in Korean patients with Parry–Romberg syndrome (PRS) using longitudinal data.MethodsThe samples consisted of 10 PRS patients, who were treated and/or followed-up at Seoul National University Dental Hospital between 1998 and 2019. Using a novel PRS severity index based on the numbers of the atrophy-involved area and asymmetry-involved item, we classified them into mild (n = 3), moderate (n = 2), and severe (n = 5). Dental phenotypes, including congenitally missing tooth (Con-Missing-Tooth), microdontia, tooth with short root (Short-Root), tooth with dilacerated root, and delayed eruption/impacted tooth, were investigated along with Tx-Mod.ResultsThe side of occurrence of all dental phenotypes showed 100% concordance with the side of PRS involvement. The most two common dental phenotypes were Con-Missing-Tooth and Short-Root (n = 29 and n = 17 in six patients). The sums of the average number of Con-Missing-Tooth and Short-Root increased from mild PRS to moderate PRS and severe PRS cases (1.0, 6.0, and 6.2). In terms of Tx-Mod, growth observation due to mild atrophy, fixed orthodontic treatment, and grafting were used for mild PRS cases. Tx-Mod for moderate PRS cases involved growth observation for surgery due to an early age at the initial visit. For severe PRS cases, diverse Tx-Mod combinations including unilateral functional appliance, fixed orthodontic treatment, growth observation, grafting, and orthognathic surgery were used.ConclusionsThe novel PRS severity index may be useful to provide primary data for individualized diagnosis and treatment planning for PRS patients.

Prevention of COVID-19 in Dental Hospitals: Literature Review and Countermeasures

The outbreak of COVID-19, caused by SARS-CoV-2 infection, has spread worldwide and resulted in a pandemic for health systems. The disease is transmitted via respiration as droplets or aerosol. Due to the nature of dental treatment, aerosols, including body fluid, blood, and saliva, are frequently produced in dental hospitals. The present study investigated the potential risk of nosocomial infection of COVID-19 in dental hospitals to provide recommendations in clinical situations. The Seoul National University Dental Hospital in Korea established a countermeasure to cope with the clinical situation based on The Guidelines of Korean Centers for Disease Control &amp; Prevention (KCDC) for dental practitioners and the available literature. Notably, numerous considerations for patient reservation and schedule management are required for space separation in the hospital, including infection control. Experiences in dental hospitals in Korea would be referable for other dental hospitals facing this infectious respiratory disease.

Leiomyosarcoma of the jaw: case series.

ObjectivesLeiomyosarcoma is a malignant neoplasm that affects smooth muscle tissue and it is very rare in the field of oral and maxillofcial surgery. The purpose of this study was to obtain information on diagnosis of and treatment methods for leiomyosarcoma by retrospectively reviewing of the cases.Patients and MethodsThe study included nine patients who were diagnosed with leiomyosarcoma in the Department of Oral and Maxillofacial Surgery at Seoul National University Dental Hospital. The subjects were analyzed with respect to sex, age, clinical features, primary site of disease, treatment method, recurrence, and metastasis.ResultsParticular clinical features included pain, edema, mouth-opening limitations, dysesthesia, and enlarged lymph nodes. All cases except one were surgically treated, and recurrence was found in two cases. Four of nine patients were followed up without recurrence and one patient underwent additional surgery due to recurrence.ConclusionIn our case series, notable symptoms included pain, edema, mouth-opening limitations, and dysesthesia; however, it was difficult to label these as specific symptoms of leiomyosarcoma. Considering the aggressive characteristics of the disease and poor prognosis, surgical treatment is necessary with careful consideration of postoperative radiotherapy and chemotherapy.

Implant-supported fixed and removable prostheses in the fibular mandible

BackgroundTo restore the health-related quality of life (HRQoL) of patients who underwent jaw resection and reconstruction surgery, dental rehabilitation is an essential procedure and also one of the most challenging for oral and maxillofacial surgeons. Even though recent studies have reported the possibility and reliability of dental implant rehabilitation with the fibula free flap (FFF), clinical reports of long-term follow-up cases are scarce. We herein reported seven cases of FFF reconstruction and implant rehabilitation. We also discussed implant planning strategy and surgical techniques.MethodsFrom 2012 to 2019, seven patients were treated with FFF reconstructive jaw surgery combined with dental implant installation and fabrication of implant-supported prostheses at Seoul National University Dental Hospital, Seoul, Korea. Patient characteristics and FFF treatment results were collected. Records of dental implants were analyzed clinically and radiologically.ResultsAmong the seven patients in this report, there were three males and four females, with an average age of 54.4 years. A total of 39 implants were placed in the fibular bone. The mean follow-up period after implant installation was 24 months. Five implants failed and were removed 3 months after installation. The implant success rate was 87.2%. Marginal bone loss at 12 months after loading was 0.23 ± 0.18 mm on the mesial side and 0.25 ± 0.26 mm on the distal side.ConclusionWith the challenges present in FFF-reconstructed patients, an implant-supported prosthesis is a reliable option for stable and functional oral rehabilitation. The implant-supported prosthesis on the FFF has great results regarding restoration of function (mastication, swallowing, and speaking), appearance, and overall HRQoL. Collaboration between surgeons and prosthodontists is essential for a satisfying outcome.

Clinical feasibility and benefits of a tapered, sand-blasted, and acid-etched surfaced tissue-level dental implant

BackgroundIt has been 50 years since Brånemark first introduced the concept of osseointegration. Since then, numerous ongoing research, developments, and optimization of implant properties have been conducted. Despite the high survival and success rates of dental implants, failures still occur in a small number of patients that are being rehabilitated by implants. The purpose of this study was to evaluate the survival and success rate of the Stella® implants that incorporate sand-blasted and acid-etched (S&E) surface treatment and tapered body design to confirm their clinical feasibility and benefits after placement.MethodsWe reviewed 61 partially and fully edentulous patients who underwent a tapered, S&E surfaced tissue-level implant placement between May 2013 and February 2016 in the Department of Oral and Maxillofacial Surgery in the Seoul National University Dental Hospital. Patient characteristics and treatment results were collected, and records of dental implants were analyzed clinically and radiologically.ResultsA total of 105 implant fixtures were placed in these patients. The mean age at the time of the surgery was 63.7 years with a range of 31 to 88 years. In total, 4.0-mm and 4.5-mm diameter implants were the most frequently used dental implants (40%, 49%) in this study. Implants 8.5 mm in length were predominantly used (60%). Seventy dental implants were placed in the mandible (70%), and only one dental implant was placed in the maxillary anterior region. At the end of the 5-year observation period, the success rate of the Stella® implants was 98.1%. Among the 105 implants placed, 2 were considered to be failures. Summarizing the clinical and radiographic results, the remaining 103 implants were considered successfully integrated.ConclusionThe overall success rate was 98.1%. The tapered, S&E surfaced tissue-level implant system exhibited great performance in a variety of clinical situations including failed implant sites that enabled predictable and successful treatment outcomes. The effectives of a tapered design of tissue level, not a parallel design, are shown in this clinical report.

Survival of oral mucosal melanoma according to treatment, tumour resection margin, and metastases.

Because of the poor prognosis and of oral mucosal melanoma, and patients' short survival, large, randomised, clinical studies are difficult. We have investigated its demographic characteristics and analysed the effect of treatment, resection margins, and metastases on survival. We recorded age, sex, site of primary tumour, and types of treatment, survival, and metastases in 74 patients treated at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Survival was analysed based on bony invasion, depth of invasion, and resection margins, and we found that it varied depending on the primary site (p=0.002), and declined with liver (p=0.001) or brain (p=0.033) metastases. The two-year survival according to the primary site was as follows: palate 85% (n=32), anterior maxillary gingiva 53% (n=13), mandible 58% (n=13), and posterior maxillary gingival 74% (n=10) and buccal mucosa 50% (n=4). The two-year survival was 34% (n=8) in patients with liver metastases and 23% (n=7) in patients with brain metastases. In cases of bony invasion (p=0.005), depth of invasion (p=0.042), unclear resection margin (p=0.023), or higher T stages (p=0.009), the survival declined considerably. Neck dissection did not affect survival (p=0.343). Survival of the patients given chemotherapy was significantly lower (p=0.013) and the two-year survival was 54.0%. The patients given radiotherapy showed no significant difference in survival compared with those not given radiotherapy (p=0.107). In conclusion, primary site, bony invasion, resection margins, depth of invasion and systemic metastases were critical to predict prognosis and selection of treatment of oral mucosal melanoma.

Association between Developmental Anomalies of Permanent Lateral Incisors and Tooth Eruption Disturbances

The purpose of this study was to examine the prevalence of developmental anomalies of permanent lateral incisor and eruption disturbances and analyze the association between two components. Panoramic radiographs of 3984 patients (aged 5 to 13 years) who visited the Department of Pediatric Dentistry of Seoul National University Dental Hospital between November 2016 and October 2017 were screened.&lt;br/&gt;The prevalence of developmental anomalies of permanent lateral incisors was 10.2%. The most common developmental anomalies were congenitally missing teeth(66.1%), followed by peg lateralis(33.5%). The prevalence of eruption disturbances was 16.5%. Among the patient with developmental anomalies of permanent lateral incisors, associated eruption disturbances were appeared on 31.1% of patients. Peg lateralis(&lt;i&gt;p&lt;/i&gt; &lt; 0.001), underdeveloped lateral incisors(&lt;i&gt;p&lt;/i&gt; &lt; 0.001) and dens invaginatus(&lt;i&gt;p&lt;/i&gt; = 0.004) were associated significantly with eruption disturbance of permanent teeth. Eruption disturbance in patients with peg lateralis and dens invaginatus was most prevalent in maxillary canine. For patients with underdeveloped lateral incisor, eruption disturbance of maxillary central incisor was most frequent.&lt;br/&gt;It is important for patients with developmental anomalies of lateral incisors to detect associated eruption disturbance early through regular checkup. Diagnosis and treatment plan in view of such relationships is important in order to treat appropriately at the optimal time.

The effects of pentoxifylline and tocopherol in jaw osteomyelitis.

ObjectivesPentoxifylline (PTX) is a methylxanthine derivative that has been implicated in the pathogenesis of peripheral vessel disease and intermittent lameness. The purpose of this study was to investigate the effect of PTX and tocopherol in patients diagnosed with osteoradionecrosis (ORN), bisphosphonate-related osteonecrosis of the jaw (BRONJ), and chronic osteomyelitis using digital panoramic radiographs.Materials and MethodsThis study was performed in 25 patients who were prescribed PTX and tocopherol for treatment of ORN, BRONJ, and chronic osteomyelitis between January 2014 and May 2018 in Seoul National University Dental Hospital. Radiographic densities of the dental panorama were compared prior to starting PTX and tocopherol, at 3 months, and at 6 months after prescription. Radiographic densities were measured using Adobe Photoshop CS6 (Adobe System Inc., USA). Blood sample tests showing the degree of inflammation at the initial visit were considered the baseline and compared with results after 3 to 6 months. Statistical analysis was performed using the Mann–Whitney test and repeated measurement ANOVA using IBM SPSS 23.0 (IBM Corp., USA).ResultsEight patients were diagnosed with ORN, nine patients with BRONJ, and the other 8 patients with chronic osteomyelitis. Ten of the 25 patients were men, average age was 66.32±14.39 years, and average duration of medication was 151.8±80.65 days (range, 56–315 days). Statistically significant increases were observed in the changes between 3 and 6 months after prescription (P<0.05). There was no significant difference between ORN, BRONJ, and chronic osteomyelitis. Only erythrocyte sedimentation rate (ESR) was statistically significantly lower than before treatment (P<0.05) among the white blood cell (WBC), ESR, and absolute neutrophil count (ANC).ConclusionLong-term use of PTX and tocopherol can be an auxiliary method in the treatment of ORN, BRONJ, or chronic osteomyelitis in jaw.

Distribution and phenotypes of hemifacial microsomia and its association with other anomalies.

ObjectiveTo investigate the distribution and phenotypes of hemifacial microsomia (HFM) and its association with other anomalies.MethodsThis study included 249 Korean patients with HFM, whose charts, photographs, radiographs, and/or computed tomography scans acquired during 1998–2018 were available from Seoul National University Hospital and Dental Hospital. Prevalence according to sex, side involvement, degree of mandibular deformity, compensatory growth of the mandibular body, and Angle's classification, and its association with other anomalies were statistically analyzed.ResultsPrevalence was not different between male and female patients (55.0% vs. 45.0%, p > 0.05). Unilateral HFM (UHFM) was more prevalent than bilateral HFM (BHFM) (86.3% vs. 13.7%, p < 0.001). Although distribution of the Pruzansky–Kaban types differed significantly in patients with UHFM (I, 53.0%; IIa, 18.6%; IIb, 24.7%; III, 3.7%; p < 0.001), no difference was observed in occurrence between the right and left sides (52.6% vs. 47.4%, p > 0.05). Among patients with BHFM, prevalence of different Pruzansky–Kaban types on the right and left sides was greater than that of the same type on both sides (67.6% vs. 32.4%, p < 0.05). Despite hypoplasia of the condyle/ramus complex, compensatory growth of the mandibular body on the ipsilateral side occurred in 35 patients (14.1%). Class I and II molar relationships were more prevalent than Class III molar relationships (93.2% vs. 6.8%, p < 0.001). Forty-eight patients (19.3%) had other anomalies, with 50.0% and 14.4% in the BHFM and UHFM groups (p < 0.001).ConclusionsPatients with HFM require individualized diagnosis and treatment planning because of diverse phenotypes and associations with other anomalies.