Evaluation of Aligners and Root Resorption: An Overview of Systematic Reviews.

To evaluate the current evidence on clear aligners and root resorption using 3D and/or combined 2D and 3D methods from available systematic reviews and meta-analyses and to determine the relationship between root resorption and clear aligners using the AMSTAR 2 tool. A comprehensive literature search of systematic reviews investigating aligners and root resorption, published up until 31 December 2022, was conducted. The following electronic databases were searched: MEDLINE via PubMed, EMBASE, Google Scholar, Science Direct, Web of Science, Scopus, LIVIVO, and LILACS.

Accuracy of posteroanterior cephalogram landmarks and measurements identification using a cascaded convolutional neural network algorithm: A multicenter study.

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).

Orthognathic surgical planning using graph CNN with dual embedding module: External validations with multi-hospital datasets.

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.

The prediction of sagittal chin point relapse following two-jaw surgery using machine learning.

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.

Three-dimensional evaluation of the association between tongue position and upper airway morphology in adults: A cross-sectional study.

Objective: This study aimed to evaluate the association between low tongue position (LTP) and the volume and dimensions of the nasopharyngeal, retropalatal, retroglossal, and hypopharyngeal segments of the upper airway.

Methods: A total of 194 subjects, including 91 males and 103 females were divided into a resting tongue position (RTP) group and a LTP group according to their tongue position. Subjects in the LTP group were divided into four subgroups (Q1, Q2, Q3, and Q4) according to the intraoral space volume.

Survival rates of mandibular fixed retainers: comparison of a tube-type retainer and conventional multistrand retainers : A prospective randomized clinical trial.

Objective: The purposes of this study were to evaluate the survival rate of a tube-type mandibular fixed retainer and compare it to conventional multistrand retainers.

Materials And Methods: In all, 66 patients who had completed their orthodontic treatment were enrolled in this study. They were allocated randomly to a tube-type retainer group or a 0.

Long-term follow-up implant site development in the submerged mandibular primary second molars: a case report.

Treatment of ankylosed and submerged primary molars without permanent successors is challenging, as normal vertical dentoalveolar growth is compromised. Thus, grafting techniques and distraction osteogenesis are performed for ridge augmentation before implant restoration. However, these techniques are invasive with limited success.

Comparison of short-term condylar positional changes in mandibular prognathism after surgery-first approach: Symmetric setback versus asymmetric setback.

The aim of this study was to compare how the displacement of the mandibular condyle changed after symmetric or asymmetric mandibular setback surgery using the surgery-first approach (SFA). Patients who underwent mandibular setback surgery using the SFA were selected and divided into a symmetry group (n = 18) with differences of less than 2 mm between the right and left setback, and an asymmetry group (n = 18) with a difference of greater than 2 mm. Cone-beam computed tomography (CBCT)-generated cephalograms were obtained after three-dimensional superimposition of CBCT images taken before surgery (T0), within one week after surgery (T1), and seven months after surgery (T2).

Accuracy of artificial intelligence-assisted landmark identification in serial lateral cephalograms of Class III patients who underwent orthodontic treatment and two-jaw orthognathic surgery.

Objective: To investigate the pattern of accuracy change in artificial intelligence-assisted landmark identification (LI) using a convolutional neural network (CNN) algorithm in serial lateral cephalograms (Lat-cephs) of Class III (C-III) patients who underwent two-jaw orthognathic surgery.

Methods: A total of 3,188 Lat-cephs of C-III patients were allocated into the training and validation sets (3,004 Lat-cephs of 751 patients) and test set (184 Lat-cephs of 46 patients; subdivided into the genioplasty and non-genioplasty groups, n = 23 per group) for LI. Each C-III patient in the test set had four Lat-cephs: initial (T0), pre-surgery (T1, presence of orthodontic brackets [OBs]), post-surgery (T2, presence of OBs and surgical plates and screws [S-PS]), and debonding (T3, presence of S-PS and fixed retainers [FR]).

Sclerostin in periodontal ligament: Homeostatic regulator in biophysical force-induced tooth movement.

Aim: To study the role of sclerostin in periodontal ligament (PDL) as a homeostatic regulator in biophysical-force-induced tooth movement (BFTM).

Materials And Methods: BFTM was performed in rats, followed by microarray, immunofluorescence, in situ hybridization, and real-time polymerase chain reaction for the detection and identification of the molecules. The periodontal space was analysed via micro-computed tomography.

Vertical bony step between proximal and distal segments after mandibular setback is related with relapse: A cone-beam computed tomographic study.

Introduction: Vertical bony step (VBS) occurs between proximal and distal segments of the mandible during mandibular setback surgery with bilateral sagittal split ramus osteotomy. The purpose of this study was to investigate whether VBS is correlated with the relapse of mandibular setback using 3-dimensional models constructed from cone-beam computed tomography.

Methods: The subjects consisted of 30 patients who underwent bilateral sagittal split ramus osteotomy for a mandibular setback.

Periodontal ligament preloading and rapid prototyping of the donor tooth in the autotransplantation of premolars with complete root formation.

This case report describes the successful orthodontic treatment of an 11-year-old girl with skeletal Class II malocclusion and congenitally missing mandibular second premolars. To resolve her upper lip protrusion and restore the missing mandibular premolars, extraction of the maxillary first premolars and subsequent autotransplantation of the extracted premolars onto the site of the missing mandibular second premolars were performed. To ensure the success of the autotransplantation and subsequent orthodontic treatment, an orthodontic force was preapplied on the donor teeth, and the recipient sockets were prepared with the aid of replica teeth.

Association of the three-dimensional skeletal variables with self-recognition of facial asymmetry in skeletal Class III patients.

Objectives: To investigate the association between three-dimensional (3D) skeletal variables and self-recognition of facial asymmetry in skeletal Class III patients.

Materials And Methods: Questionnaires and cone beam computed tomography of 74 patients (42 men and 32 women; mean age: 22.8 ± 4.

Accuracy of auto-identification of the posteroanterior cephalometric landmarks using cascade convolution neural network algorithm and cephalometric images of different quality from nationwide multiple centers.

Introduction: The purpose of this study was to evaluate the accuracy of auto-identification of the posteroanterior (PA) cephalometric landmarks using the cascade convolution neural network (CNN) algorithm and PA cephalogram images of a different quality from nationwide multiple centers nationwide.

Methods: Of the 2798 PA cephalograms from 9 university hospitals, 2418 images (2075 training set and 343 validation set) were used to train the CNN algorithm for auto-identification of 16 PA cephalometric landmarks. Subsequently, 99 pretreatment images from the remaining 380 test set images were used to evaluate the accuracy of auto-identification of the CNN algorithm by comparing with the identification by a human examiner (gold standard) using V-Ceph 8.

Comparison of one-jaw and two-jaw orthognathic surgery in patients with skeletal Class III malocclusion using data from 10 multi-centers in Korea: Part I. Demographic and skeletodental characteristics.

Objective: To investigate demographic and skeletodental characteristics of one-jaw (1J-OGS) and two-jaw orthognathic surgery (2J-OGS) in patients with skeletal Class III malocclusion.

Methods: 750 skeletal Class III patients who underwent OGS at 10 university hospitals in Korea between 2015 and 2019 were investigated; after dividing them into the 1J-OGS (n = 186) and 2J-OGS groups (n = 564), demographic and skeletodental characteristics were statistically analyzed.

Results: 2J-OGS was more frequently performed than 1J-OGS (75.

Accuracy of one-step automated orthodontic diagnosis model using a convolutional neural network and lateral cephalogram images with different qualities obtained from nationwide multi-hospitals.

Objective: The purpose of this study was to investigate the accuracy of one-step automated orthodontic diagnosis of skeletodental discrepancies using a convolutional neural network (CNN) and lateral cephalogram images with different qualities from nationwide multi-hospitals.

Methods: Among 2,174 lateral cephalograms, 1,993 cephalograms from two hospitals were used for training and internal test sets and 181 cephalograms from eight other hospitals were used for an external test set. They were divided into three classification groups according to anteroposterior skeletal discrepancies (Class I, II, and III), vertical skeletal discrepancies (normodivergent, hypodivergent, and hyperdivergent patterns), and vertical dental discrepancies (normal overbite, deep bite, and open bite) as a gold standard.

Infrared Clinical Enamel Crack Detector Based on Silicon CCD and Its Application: A High-Quality and Low-Cost Option.

Enamel cracks generated in the anterior teeth not only affect the function but also the aesthetics of the teeth. Chair-side tooth enamel crack detection is essential for clinicians to formulate treatment plans and prevent related dental disease. This study aimed to develop a dental imaging system using a near-IR light source to detect enamel cracks and to investigate the relationship between anterior enamel cracks and age in vivo.

Accuracy of automated identification of lateral cephalometric landmarks using cascade convolutional neural networks on lateral cephalograms from nationwide multi-centres.

Objective: To investigate the accuracy of automated identification of cephalometric landmarks using the cascade convolutional neural networks (CNN) on lateral cephalograms acquired from nationwide multi-centres.

Settings And Sample Population: A total of 3150 lateral cephalograms were acquired from 10 university hospitals in South Korea for training.

Materials And Methods: We evaluated the accuracy of the developed model with independent 100 lateral cephalograms as an external validation.

Part II. What drives Korean adults to seek orthodontic treatment: Factors contributing to orthodontic treatment decisions.

Objective: This study aimed to identify the perceptions of orthodontic treatment among Korean adults and determine the factors that drive them to seek orthodontic treatment.

Methods: A total of 2,321 adults aged 19-64 years were surveyed using an internet research system from a specialized research company. The participants were divided into the following groups based on their experience of and willingness to undergo orthodontic treatment: experience, acceptance, and non-acceptance groups.

Part I. What drives Korean adults to seek orthodontic treatment: Reliability and validity of a measurement instrument for the perception of orthodontic treatment.

Objective: To develop a standardized instrument to measure the level of cognition for orthodontic treatment in adults, and verify its reliability and validity for assessing perceptions of orthodontic treatment in adults.

Methods: A total of 406 adults aged 19-64 years were surveyed by an internet research system. A tool was developed through the instrument development and verification stages.

Can we estimate root axis using a 3-dimensional tooth model via lingual-surface intraoral scanning?

Introduction: This research aimed to compare the estimation error of the root axis using 3-dimensional (3D) tooth models at the midtreatment stage between the whole-surface scan (WSS) and lingual-surface scan (LSS) methods.

Methods: The sample consisted of 208 teeth (26 each of central incisors, canines, second premolars, and first molars in the maxillary and mandibular dentition) from 13 patients whose pre- and midtreatment intraoral scan and cone-beam computed tomography (CBCT) were available. The 3D tooth models were constructed by merging the intraoral-scan crowns and the CBCT-scan roots obtained at the pretreatment stage.

Unlocking ectopically erupting permanent first molars using light wires.

Background And Overview: Ectopic eruption of permanent molars is one of the challenges that arise in the early mixed dentition period, particularly when the root of the primary second molar is resorbed due to mesial angulation of the impacted first molar. The authors introduce a simple and efficient method to unlock ectopically erupting first molars using a light wire.

Case Description: The authors describe the cases of 2 girls (8 and 7 years old) who sought treatment for locking of their maxillary and mandibular first molars, respectively.

The three-dimensional morphology of mandible and glenoid fossa as contributing factors to menton deviation in facial asymmetry-retrospective study.

Background: The aim of this study is to evaluate whether the three-dimensional (3D) morphology of the mandibular condyle, glenoid fossa, and mandible correlated with menton deviation in facial asymmetry.

Subjects And Methods: Thirty adults (15 males and 15 females; mean age, 23.2 ± 3.

Construction reproducibility of a composite tooth model composed of an intraoral-scanned crown and a cone-beam computed tomography-scanned root.

Objective: To evaluate the construction reproducibility of a composite tooth model (CTM) composed of an intraoral-scanned crown and a cone-beam computed tomography (CBCT)-scanned root.

Methods: The study assessed 240 teeth (30 central incisors, 30 canines, 30 second premolars, and 30 first molars in the maxillary and mandibular arches) from 15 young adult patients whose pre-treatment intraoral scan and CBCT were available. Examiner-Reference (3 years' experience in CTM construction) and Examiners-A and Examiner-B (no experience) constructed the individual CTMs independently by performing the following steps: image acquisition and processing into a three-dimensional model, integration of intraoral-scanned crowns and CBCT-scanned teeth, and replacement of the CBCT-scanned crown with the intraoral-scanned crown.