Factors influencing the successful eruption of the maxillary third molar after extraction of the maxillary second molar.

INTRODUCTION: This study evaluated the occlusal status of the maxillary third molars that erupted spontaneously after extraction of the maxillary second molars and investigated the factors that influenced the occlusal status of the maxillary third molars. METHODS: We assessed 136 maxillary third molars in 87 patients. Alignment, marginal ridge discrepancy, occlusal contact, interproximal contact, and buccal overjet were used to score the occlusal status. Occlusal status was classified as good (G group), acceptable (A group), and poor (P group) for the maxillary third molar at its full eruption (T1). The Nolla's stage, long axis angle, the vertical and horizontal position of the maxillary third molar, and the maxillary tuberosity space were assessed at the time of maxillary second molar extraction (T0) and T1 to identify factors influencing the eruption of the maxillary third molar. RESULTS: G, A, and P groups comprised 47.8%, 17.6,% and 34.6% of the sample, respectively. Age was the lowest in the G group at both T0 and T1. The maxillary tuberosity space at T1 and the amount of the change of maxillary tuberosity space were the largest in the G group. There was a significant difference in the distribution of the Nolla's stage at T0. The proportions of the G group were 60.0% in stage 4, 46.8% in stages 5 and 6, 70.4% in stage 7, and 15.0% in stages 8-10. According to multiple logistic regression analysis, stages 8-10 for the maxillary third molar at T0 and the amount of the change of maxillary tuberosity were negatively associated with the G group. CONCLUSIONS: Good-to-acceptable occlusion was seen in 65.4% of the maxillary third molars after maxillary second molar extraction. Insufficient increase in the maxillary tuberosity space and Nolla stage 8 or higher at T0 negatively influenced the maxillary third molar eruption.

Three-dimensional soft tissue landmark detection with marching cube algorithm.

Current method of analyzing three-dimensional soft tissue data, especially in the frontal view, is subjective and has poor reliability. To overcome this limitation, the present study aimed to introduce a new method of analyzing soft tissue data reconstructed by marching cube algorithm (Program S) and compare it with a commercially available program (Program A). Cone-beam computed tomography images of 42 patients were included. Two orthodontists digitized six landmarks (pronasale, columella, upper and lower lip, right and left cheek) twice using both programs in two-week intervals, and the reliability was compared. Furthermore, computer-calculated point (CC point) was developed to evaluate whether human error could be reduced. The results showed that the intra- and inter-examiner reliability of Program S (99.7-100% and 99.9-100%, respectively) were higher than that of Program A (64.0-99.9% and 76.1-99.9%, respectively). Moreover, the inter-examiner difference of coordinate values and distances for all six landmarks in Program S was lower than Program A. Lastly, CC point was provided as a consistent single point. Therefore, it was validated that this new methodology can increase the intra- and inter-examiner reliability of soft tissue landmark digitation and CC point can be used as a landmark to reduce human error.

Evaluation of the dimensional alternation of the alveolar bone in patients with a congenitally missing mandibular lateral incisor using cone-beam computed tomography.

INTRODUCTION: The alveolar bone is an essential consideration when planning treatment for patients with tooth agenesis. This study evaluated the changes in the alveolar bone and adjacent teeth in patients with a congenitally missing mandibular lateral incisor using cone-beam computed tomography. METHODS: Twenty-three nonorthodontically treated adults with a unilateral congenitally missing mandibular lateral incisor were the missing group (M group). The control group (C group) consisted of 23 nonorthodontically treated adults with normal occlusion and no missing teeth. First, the difference in the arch perimeter between the groups was compared at the cementoenamel junction (CEJ) level and the root apex (RA) level. Next, the root divergence of the anterior teeth in the M group was observed. Finally, the alveolar bone thickness ratio was compared between the M and C groups at different vertical levels. RESULTS: The arch perimeter was significantly decreased in the M group at the CEJ and RA levels (P <0.05). Root divergence was observed adjacent to the missing site (P <0.0001). There were a reduction in total and cancellous cortical alveolar bone thickness (ABT) ratios at the 3-, 6-, and 9-mm positions (P <0.05). The buccal cortical ABT ratios decreased at the 3-and 6-mm positions. The lingual ABT ratio increased at the 9-mm position (P <0.05). CONCLUSIONS: The congenitally missing mandibular lateral incisor caused a reduction in the arch perimeter in the CEJ area and the RA area. The root divergences were observed in the teeth adjacent to the missing areas. A significant decrease in the buccal cortical bone and cancellous bone was observed in the missing area.

Incidence and clinical risk factors associated with the development of labial protuberances after orthodontic treatment.

INTRODUCTION: Distinct, irregular, and hard, nodular labial protuberances (LPs) that were due to differential alveolar bone modeling can be noted on the labial gingival surface of the incisors after orthodontic treatment. Clinically, LPs cause patient discomfort and esthetic issues, but information on this phenomenon is limited. This study aimed to evaluate the incidence of LPs and demonstrate the etiology and clinical risk factors associated with this phenomenon. METHODS: Differential alveolar bone modeling was defined as present (+) when ≥1 distinct LPs (diameter >1 mm) developed after orthodontic treatment by comparing pretreatment and posttreatment intraoral photographs and casts of an orthodontic patient cohort treated with fixed appliances (n = 872). The incidence rate, affected sites, and their association with age, sex, and orthodontic treatment modalities were evaluated. RESULTS: The incidence rate of differential alveolar bone modeling among orthodontic patients was 3.2% (28 out of 872). The maxillary lateral incisor region was the most frequently affected site. Males (vs females) (odds ratio, 2.56 [95% confidence interval, 1.155-5.604]), adults (aged ≥ 20 years) (vs teens) (12.84 [3.003-54.866]), and those who had orthodontic extraction (vs nonextraction) (11.60 [3.434-39.156]) demonstrated significantly higher odds of developing LPs after orthodontic treatment (P <0.05). CONCLUSIONS: The incidence rate of the development of notable LPs after orthodontic treatment was 3.2%. Adult males and those who undergo orthodontic extraction have a higher risk of developing LPs. Clinicians should be aware that distinct LPs may develop when large amounts of incisal retraction are planned in adults.

Long-term follow-up of a patient with deepbite and severely resorbed maxillary central incisors treated by maxillary premolar and mandibular incisor extraction.

Deepbite is a common type of malocclusion, but it leads to difficulties in treatment and retention. We report the treatment of an adult patient with deepbite and severe crowding of teeth. Several teeth had to be restored, and the maxillary central incisors had short roots. Various treatment plans were considered, and extraction of the maxillary right and left first premolars, and mandibular right central incisor was planned. Successful treatment results were obtained with long-term retention.

Comparison of the bite force and occlusal contact area of the deviated and non-deviated sides after intraoral vertical ramus osteotomy in skeletal Class III patients with mandibular asymmetry: Two-year follow-up.

Objective: The objectives of this study were to compare the time-dependent changes in occlusal contact area (OCA) and bite force (BF) of the deviated and non-deviated sides in mandibular prognathic patients with mandibular asymmetry before and after orthognathic surgery and investigate the factors associated with the changes in OCA and BF on each side. Methods: The sample consisted of 67 patients (33 men and 34 women; age range 15-36 years) with facial asymmetry who underwent 2-jaw orthognathic surgery. OCA and BF were taken before presurgical orthodontic treatment, within 1 month before surgery, and 1 month, 3 months, 6 months, 1 year, and 2 years after surgery. OCA and BF were measured using the Dental Prescale System. Results: The OCA and BF decreased gradually before surgery and increased after surgery on both sides. The OCA and BF were significantly greater on the deviated side than on the non-deviated side before surgery, and there was no difference after surgery. According to the linear mixed-effect model, only the changes in the mandibular plane angle had a significant effect on BF (p < 0.05). Conclusions: There was a difference in the amount of the OCA and BF between the deviated and non-deviated sides before surgery. The change in mandibular plane angle affects the change, especially on the non-deviated side, during the observation period.

Nonsurgical maxillary expansion in a 60-year-old patient with gingival recession and crowding.

Maxillary transverse deficiency often manifests as a posterior crossbite or edge-to-edge bite and anterior crowding. However, arbitrary arch expansion in mature patients has been considered to be challenging due to the possible periodontal adverse effects such as alveolar bone dehiscence and gingival recession. To overcome these limitations, nonsurgical maxillary expansion of the basal bone has been demonstrated in young adults. However, the age range for successful orthopedic expansion has remained a topic of debate, possibly due to the underlying individual variations in suture maturity. This case report illustrates nonsurgical, miniscrew-assisted rapid palatal expansion (MARPE) in a 60-year-old patient with maxillary transverse deficiency accompanied by anterior and posterior crossbites, crowding, and gingival recession. The use of MARPE allowed relief of crowding and correction of the crossbite without causing significant periodontal adverse effects.

Early replacement of ankylosed first molar via mesial root movement facilitates bone formation and normal eruption of the third molar.

Ankylosis of a molar during active growth leads to a significant vertical bone defect, extrusion of the opposing molar, and inclination of adjacent teeth. Treatment timing is an essential factor for the patient's quality of life. Early extraction of the ankylosed molar and protraction of the second molar is challenging because of the difficulty of tooth movement and the uncertainty of the normal eruption of the third molar. In view of the uncertainty of eruption of the mandibular third molar, it is essential to assess the potential for eruption according to the developmental stage of the third molar and to secure sufficient space for eruption. In this case report, a girl with an ankylosed right mandibular first molar and an advanced vertical bone defect was treated via early extraction of the ankylosed molar along with the intrusion of the maxillary molar and mesial root movement of the second molar before the initiation of third molar root formation. Restoration of the vertical bone defect was noted at the end of treatment. In addition, spontaneous eruption of the third molar was observed, which was in contrast to the mesioangular impaction of the contralateral third molar. This case emphasizes the importance of treatment timing to increase the chance of utilization of the third molar.

Cortical correlates of creative thinking assessed by the figural Torrance Test of Creative Thinking.

Torrance Test of Creative Thinking is the most widely used form of creativity test. Although creativity assessed using the figural form of Torrance Test of Creative Thinking has been considered non-unidimensional, the structural correlates for each separable dimension have yet to be explored. The present study investigated the underlying cortical structure of separable dimensions for creativity using the figural Torrance Test of Creative Thinking. To this end, we recruited healthy young adults and conducted a regression analysis of the figural Torrance Test of Creative Thinking scores of gray matter volume after factorizing the five subscales using exploratory factor analysis. As a result, two factors of the figural Torrance Test of Creative Thinking were identified: (1) 'FO' factor consisting of fluency and originality and (2) 'RAS' factor consisting resistance to premature closure, abstractness of titles, and sophistication/elaboration. Subsequently, the FO factor showed a positive association with cerebral volumes in the parieto-temporal regions of the left angular gyrus and the right inferior parietal lobule, inferior and middle temporal, and parahippocampal gyri, which overlapped the default network. The RAS factor showed a positive correlation with the fronto-temporal regions including the bilateral temporal area, the left inferior parietal, and the right dorsolateral prefrontal regions representing the semantic control network. Our findings revealed the morphological substrates for the figural Torrance Test of Creative Thinking depending on two creative dimensions. The implications of the results are discussed.

Clinical features and outcomes of community-acquired late-onset sepsis: Focusing on group B Streptococcus and Escherichia coli.

BACKGROUND: Group B Streptococcus (GBS) and Escherichia coli are leading causes of late-onset sepsis (LOS) and bacterial meningitis in neonates and infants. This study aimed to describe clinical characteristics and outcomes of community-acquired (CA) LOS caused by GBS and E. coli. METHODS: A retrospective observational study was performed in three university hospitals in Korea. All infants aged <90 days who were diagnosed with GBS or E coli CA-LOS from 2011 to 2017 were enrolled. Data on the clinical characteristics and outcomes of GBS and E. coli CA-LOS were compared. RESULTS: Forty GBS and 43 E. coli CA-LOS cases were identified, which mostly (82/83) included term or near-term infants. Meningitis was identified in 54.1% of GBS CA-LOS cases and in 30.3% of E. coli CA-LOS cases, and 88.4% of E. coli CA-LOS cases involved urosepsis. Ten percent each of GBS and non-uropathogenic E. coli (non-UPEC) meningitis cases and all uropathogenic E. coli (UPEC) meningitis cases were diagnosed by pleocytosis without bacterial growth in the cerebrospinal fluid (CSF). Patients with non-culture-proven meningitis had lower CSF pleocytosis and protein levels and higher CSF/serum glucose ratios than patients with culture-proven meningitis (P < 0.05 for all). One patient died of CA-LOS, which was accompanied by meningitis with extended-spectrum ß-lactamase-producing non-UPEC. Neurological complications developed in 22.5% of GBS CA-LOS cases and in 2.3% of E. coli CA-LOS cases. CONCLUSIONS: Neurological complications were frequently observed in GBS CA-LOS cases, although no mortality was observed. Escherichia coli CA-LOS generally developed as urosepsis, which caused non-culture-proven meningitis and had a favorable outcome.

Brain Areas Subserving Torrance Tests of Creative Thinking: An Functional Magnetic Resonance Imaging Study.

BACKGROUND AND PURPOSE: Torrance Tests of Creative Thinking (TTCT) is a well-known and commonly used measure of creativity. However, the TTCT-induced creative hemodynamic brain activity is rarely revealed. The purpose of this study is to elucidate the neural correlates of creative thinking in the setting of a modified version of the figural TTCT adapted for an functional magnetic resonance imaging (fMRI) experiment. METHODS: We designed a blocked fMRI experiment. Twenty-five participants (11 males, 14 females, mean age 19.9±1.8) were asked to complete the partially presented line drawing of the figural TTCT (creative drawing imagery; creative). As a control condition, subjects were asked to keep tracking the line on the screen (line tracking; control). RESULTS: Compared to the control condition, creative condition revealed greater activation in the distributed and bilateral brain regions including the left anterior cingulate, bilateral frontal, parietal, temporal and occipital regions as shown in the previous creativity studies. CONCLUSIONS: The present revealed the neural basis underlying the figural TTCT using fMRI, providing an evidence of brain areas encompassing the figural TTCT. Considering the significance of a creativity test for dementia patients, the neural correlates of TTCT elucidated by this study may be valuable to evaluate the brain function of patients in the clinical field.

Neuro-Scientific Studies of Creativity.

Creativity has historically been investigated in psychological and educational aspects, and developed by psychologists and educationists. Recent progress of computational and cognitive science has opened new horizons in the neuro-scientific approach, bridging the concept of creativity and specialized brain function. This review discusses the psychological and educational theories of creativity, and focuses on the recent works in neuroscience dealing with creativity in view of divergent thinking. We also summarize the brain areas and their networks found by the neuroimaging studies, especially functional magnetic resonance imaging.

The functionality of facial appearance and its importance to a korean population.

BACKGROUND: Many people have an interest in the correction of facial scars or deformities caused by trauma. The increasing ability to correct such flaws has been one of the reasons for the increase in the popularity of facial plastic surgery. In addition to its roles in communication, breathing, eating, olfaction and vision, the appearance of the face also plays an important role in human interactions, including during social activities. However, studies on the importance of the functional role of facial appearance. As a function of the face are scare. Therefore, in the present study, we evaluated the importance of the functions of the face in Korea. METHODS: We conducted an online panel survey of 300 participants (age range, 20-70 years). Each respondent was administered the demographic data form, Facial Function Assessment Scale, Rosenberg Self-Esteem Scale, and standard gamble questionnaires. RESULTS: In the evaluation on the importance of facial functions, a normal appearance was considered as important as communication, breathing, speech, and vision. Of the 300 participants, 85% stated that a normal appearance is important in social activities. CONCLUSIONS: The results of this survey involving a cross-section of the Korean population indicated that a normal appearance was considered one of the principal facial functions. A normal appearance was considered more important than the functions of olfaction and expression. Moreover, a normal appearance was determined to be an important facial function for leading a normal life in Korea.

Analysis of the effects of breast reconstruction in breast cancer patients receiving radiotherapy after mastectomy.

BACKGROUND: Immediate breast reconstruction after mastectomy and delayed breast reconstruction with post-supplementary treatment are the two types of breast reconstruction currently performed when treating breast cancer. Post-mastectomy radiation therapy (PMRT) not only reduces local recurrence but also improves overall survival. However, the complications and survival rates associated with PMRT need to be clear when determining the timing of breast reconstruction. Accordingly, we investigated the optimal timing of breast reconstruction by observing patients who underwent mastectomy followed by PMRT, based on their overall health and aesthetic satisfaction. METHODS: We retrospectively reviewed 21 patients who underwent breast reconstruction with PMRT between November 2004 and November 2010. We collected data regarding the various methods of mastectomy, and the modality of adjuvant therapy, such as chemotherapy, hormone therapy, and radiotherapy. Telephone interviews were conducted to study the general and aesthetic satisfaction. RESULTS: Patients who received PMRT after breast reconstruction showed a greater complication rate than those undergoing breast reconstruction after PMRT (P=0.02). Aesthetic satisfaction was significantly higher in the groups undergoing breast reconstruction after PMRT (P=0.03). Patients who underwent breast reconstruction before PMRT developed complications more frequently, but they expressed greater aesthetic satisfaction with the treatment. CONCLUSIONS: It is recommended that the complication rates and aesthetic satisfaction after breast reconstruction be carefully considered when determining the optimal timing for radiotherapy.

Palatal bone density in adult subjects: implications for mini-implant placement.

OBJECTIVES: To evaluate palatal bone density to allow for better selection of palatal implant anchorage sites. MATERIALS AND METHODS: Computed tomographic (CT) images were obtained from 15 males and 15 females (mean age, 27 years; range, 23-35 years). Bone density was measured in Hounsfield units (HU) at 80 coordinates at regular mediolateral and anteroposterior intervals along the midpalatal suture. RESULTS: Bone densities ranged from 805 to 1247 HU. A significant difference between male and female groups was noted, although no difference was found between left and right sides of individual palates. Palatal bone densities showed a tendency to decrease laterally and posteriorly. The midpalatal area within 3 mm of the midsagittal suture had the densest bone in the entire palate. CONCLUSION: Results suggest that mini-implants for orthodontic anchorage may be effectively placed in most areas with bone density equivalent to the palatal area if they are placed from 3 mm posterior to the incisive foramen and 1 to 5 mm to the paramedian side.

Nasal changes after surgical correction of skeletal Class III malocclusion in Koreans.

OBJECTIVE: To quantify the changes in the nose after bimaxillary surgery to correct skeletal Class III malocclusion and to test the hypothesis that there is no change in the nasal width following bimaxillary surgical correction of skeletal Class III when a nasal cinch is properly used. MATERIALS AND METHODS: Sixty-five adult Korean skeletal Class III patients who had received maxillary advancement/impaction and mandibular set-back surgery in conjunction with an alar base cinch suture were evaluated. The anthropometric variables of the nasal region were measured directly on the soft-tissue surface before and 6 months after surgery. RESULTS: After surgery, the alar width and alar base width had increased significantly (P < .001), while the nasal tip projection decreased (P < .001). The nostril morphology also showed widening (P < .001). There was a trend for females with a narrow alar width presurgically to have a larger amount of nasal widening compared with those with a broader alar width (P < .05). CONCLUSION: There is a high probability of nasal and nostril widening after bimaxillary surgery for skeletal Class III malocclusion in Koreans despite the careful performance of alar cinch suture. Nevertheless, the authors believe that alar cinch suture was positive in limiting the nasal widening to the minimum and would consider routine application during bimaxillary surgery for skeletal Class III especially for female patients with a narrow nose who are susceptible to these changes.