Publications by authors named "Seung Hak Baek"

Objective: To investigate which types of environmental exposure during pregnancy are risk and protective factors for cleft lip with or without cleft palate (CL/P).

Methods: This case-control study included 278 orthodontic patients with CL/P (CL/P group) and 51 without CL/P (non-CL/P group). Demographic and environmental exposure data were collected using questionnaires completed by the parents.

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Objective: This retrospective study investigated the influence of palatal fistula (PF) formation after double opposing Z-plasty (DOZ) on speech outcomes in patients with cleft palate (CP), focusing on cleft width and palatal length as predictors of velopharyngeal insufficiency (VPI).

Methods: This study included 1117 patients with CP (579 males, 538 females) who underwent DOZ, performed by a single surgeon, between 1988 and 2017. Demographic characteristics, cleft dimensions, history of PF formation, and speech outcomes were investigated.

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Article Synopsis
  • * Results showed significant over-transmission of specific gene variants in both Korean families and larger datasets from Asian and European populations, highlighting four variants with strong associations to NSCL/P.
  • * The analysis also indicated that certain alleles were more likely to be passed from mothers, suggesting a potential maternal influence in the genetic transmission of the condition; further research is needed to explore how these findings could be applied clinically.
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The purpose of this study was to compare speech outcomes in patients with submucous cleft palate (SMCP) between speech therapy alone and double-opposing Z-plasty (DOZ) combined with speech therapy. The subjects were 67 patients with SMCP (overt type, 45 males, 22 females), who were divided into the observation group (n=18), the speech therapy group (n=24; duration, 17.8 mo), and the DOZ and speech therapy (DOZ-speech therapy) group (n=25; median age at DOZ, 5.

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Objective: To investigate the growth patterns of the maxillomandibular complex in preadolescent patients with Pierre-Robin sequence (PRS).

Methods: The samples consisted of 20 preadolescent PRS patients who had cleft palate and did not undergo growth-modification therapy or surgical intervention [6 boys and 14 girls; mean age of lateral cephalograms taken, 8.8 y (T1) and 13.

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Article Synopsis
  • This study provides a comprehensive analysis of cranial growth patterns in a large sample of 1009 Korean children and adolescents, focusing on age- and sex-specific measurements.
  • Using thin-slice CT scans, researchers established key cranial parameters and created logarithmic curves for intracranial volume and other measurements, demonstrating that males generally have larger cranial dimensions than females.
  • The findings indicate that cranial measurements rapidly increase in the first few years of life and establish reference data that can aid in treating conditions like craniosynostosis in pediatric patients.
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Objective: : To quantify the effects of midline-related landmark identification on midline deviation measurements in posteroanterior (PA) cephalograms using a cascaded convolutional neural network (CNN).

Methods: : A total of 2,903 PA cephalogram images obtained from 9 university hospitals were divided into training, internal validation, and test sets (n = 2,150, 376, and 377). As the gold standard, 2 orthodontic professors marked the bilateral landmarks, including the frontozygomatic suture point and latero-orbitale (LO), and the midline landmarks, including the crista galli, anterior nasal spine (ANS), upper dental midpoint (UDM), lower dental midpoint (LDM), and menton (Me).

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Contouring surgery is an operation that makes a smooth, oval-shaped face by removing protruding parts of the face. In particular, mandibuloplasty is a procedure that softens the shape of the mandible and is a popular procedure among Asians with a dominant mesocephalic profile. In this study, we tried to discuss the considerations before surgery by dividing the mandibular shape into morphologic aspects in the lateral and frontal views and anatomic considerations.

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Article Synopsis
  • The study focused on how the spheno-occipital synchondrosis fusion (SOSF) develops from preadolescence to young adulthood in a sample of 630 Korean subjects, categorized by age and sex.
  • Women exhibited earlier and faster skeletal maturation compared to men, with specific stages of cervical vertebrae maturation index (CVMI) and SOSF correlating strongly with age.
  • Statistical models were used to establish the relationship between age, CVMI, and SOSF stages, indicating that females generally reached advanced SOSF stages sooner than males, providing valuable data for understanding skeletal development.
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Background And Objective: Despite recent development of AI, prediction of the surgical movement in the maxilla and mandible by OGS might be more difficult than that of tooth movement by orthodontic treatment. To evaluate the prediction accuracy of the surgical movement using pairs of pre-(T0) and post-surgical (T1) lateral cephalograms (lat-ceph) of orthognathic surgery (OGS) patients and dual embedding module-graph convolution neural network (DEM-GCNN) model.

Methods: 599 pairs from 3 institutions were used as training, internal validation, and internal test sets and 201 pairs from other 6 institutions were used as external test set.

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The study aimed to identify critical factors associated with the surgical stability of pogonion (Pog) by applying machine learning (ML) to predict relapse following two-jaw orthognathic surgery (2 J-OGJ). The sample set comprised 227 patients (110 males and 117 females, 207 training and 20 test sets). Using lateral cephalograms taken at the initial evaluation (T0), pretreatment (T1), after (T2) 2 J-OGS, and post treatment (T3), 55 linear and angular skeletal and dental surgical movements (T2-T1) were measured.

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This study aimed to classify the skeletal phenotypes of preadolescent patients with isolated cleft palate using principal component analysis and cluster analysis. Sixty-four preadolescent female patients with isolated cleft palate (incomplete hard palate and complete soft palate cleft group, n=51; complete cleft of the hard and soft palate group, n=13; the mean age when lateral cephalograms were taken, 7.08±0.

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Objective: To characterize the patterns of somatic catch-up growth from infancy to adolescence in patients with cleft palate (CP).

Study Design: We assessed 474 nonsyndromic patients with isolated cleft palate (n = 69) and unilateral and bilateral cleft lip and palate (n = 271; n = 134) who underwent palatoplasty between 1988 and 2017 and had longitudinal physical growth data at birth (T0), cheiloplasty (T1), palatoplasty (T2), childhood (T3), and adolescence (T4). The z scores of weight (ZWT), height (ZHT), and body mass index (ZBMI) were compared among the CP types (isolated cleft palate, unilateral cleft lip and palate, and bilateral cleft lip and palate) and time points (T1, T2, T3, and T4).

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The purpose of this study was to classify the skeletal phenotypes of adult patients with skeletal class III (C-III) malocclusion and unilateral or bilateral cleft lip and palate using principal component analysis and cluster analysis. The samples consisted of 81 adult C-III patients with cleft lip and palate (CLP) who underwent orthognathic surgery (OGS) or distraction osteogenesis (59 males and 22 females; 50 unilateral cleft lip and palate and 31 bilateral cleft lip and palate; mean age when lateral cephalograms were taken, 22.2±4.

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Article Synopsis
  • The study aimed to explore the characteristics and occurrence of Goldenhar syndrome (GS) in 18 patients, noting their age and gender, and collected data from those treated at Seoul National University Dental Hospital from 1999 to 2021.
  • Key findings include a balance between unilateral and bilateral mandibular deformities, with severe cases more prevalent in unilateral instances, as well as a significant occurrence of midface and dental anomalies.
  • The results highlight the need for careful diagnosis and treatment planning for GS, revealing common issues like ear problems and missing teeth among patients, while also showing links to various other anomalies.
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Background: This study aimed to assess the error range of cephalometric measurements based on the landmarks detected using cascaded CNNs and determine how horizontal and vertical positional errors of individual landmarks affect lateral cephalometric measurements.

Methods: In total, 120 lateral cephalograms were obtained consecutively from patients (mean age, 32.5 ± 11.

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Facial asymmetry can be defined as differences in the left and right sides of the face, and most of the patients with facial asymmetry have different left and right frontal-ramal inclinations (FRIs). Restoring the symmetry of both FRIs is important in the surgery of facial asymmetry patients, but it is very difficult to achieve perfect symmetry through conventional orthognathic surgery. However, by using 3-dimensional (3D) virtual planning and CAD/CAM technolo gies, intentional change of FRIs can be possible so the symmetry can be improved.

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Objective: Maxillomandibular advancement (MMA) is the most effective surgical method for treating obstructive sleep apnea, and it moves the maxillomandibular complex forward to increase the entire upper airway volume. By using 3-dimensional (D) virtual surgery, computer-aided design/computer-aided manufacturing, and 3D printing technologies, it is possible to overcome all the limitations of conventional methods.

Materials And Methods: In this study, (modified) MMA was performed by applying 3D technologies to obstructive sleep apnea patients.

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The purpose of this study was to classify and characterize facial asymmetry (FA) phenotypes in adult patients with unilateral cleft lip and palate (UCLP) and skeletal class III malocclusion. The samples comprised 52 adult UCLP patients (36 men and 16 women; mean age, 22.43 y) who had undergone orthognathic surgery for correction of class III malocclusion.

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Objective: To investigate the causes of reoperation consultation, and the actual percentage and procedures of reoperation after previous orthognathic surgery.

Methods: The samples consisted of 30 patients who visited our clinic for reoperation consultation from October 2015 to September 2021 (6 males and 24 females; mean age at reoperation consultation, 28.4 y).

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Recent deep learning algorithms have further improved risk classification capabilities. However, an appropriate feature selection method is required to overcome dimensionality issues in population-based genetic studies. In this Korean case-control study of nonsyndromic cleft lip with or without cleft palate (NSCL/P), we compared the predictive performance of models that were developed by using the genetic-algorithm-optimized neural networks ensemble (GANNE) technique with those models that were generated by eight conventional risk classification methods, including polygenic risk score (PRS), random forest (RF), support vector machine (SVM), extreme gradient boosting (XGBoost), and deep-learning-based artificial neural network (ANN).

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Objective: To introduce a guideline for selecting proper surgical modalities for correction of skeletal Class II malocclusion with moderate-to-severe vertical height deficiency (VHD) of the condyle/ramus complex (CRC) using bimaxillary surgery in conjunction with total joint replacement (TJR) or inverted-L osteotomy (ILO) assisted by 3D virtual surgical planning and CAD/CAM technologies.

Cases: Four cases of severe skeletal Class II patients with moderate-to-severe VHD of CRC were presented. They underwent bimaxillary surgery using Le Fort I osteotomy in the maxilla and TJR or ILO in the mandible, with the help of virtual surgical planning (VSP) and computer-aided design/computer-aided manufacturing (CAD/CAM)-printed surgical guides and osteosynthesis plates.

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