COVID-2019 Alert

The latest information about the 2019 Novel Coronavirus, including vaccine clinics for children ages 6 months and older.

La información más reciente sobre el nuevo Coronavirus de 2019, incluidas las clínicas de vacunación para niños de 6 meses en adelante.


HyeRan Choo, DMD

  • HyeRan Choo
  • “I love sharing hope and happiness for children by creating beautiful healthy smiles.”

As a board-certified craniofacial orthodontist, I am inspired to provide outstanding orthodontic outcomes for my patients from infancy through adulthood. My treatment philosophy is based on a fundamental understanding of facial growth and oral functions. I enjoy helping children gain confidence from a beautiful smile, and improving the family's perspective on their child's life. My research encompasses infant maxillary orthopedics and skeletal anchorage-based orthodontic treatments.

Especialidades médicas y/o especialidades quirúrgicas


Trabajo y educación


Seoul National University, Seoul, 2/26/2002

University of Pennsylvania Dental School & School of Education, Philadelphia, PA, 5/17/2004

Últimos años de residencia

University of Alabama at Birmingham School of Medicine, Birmingham, AL, 4/20/2007

Certificado(s) de especialidad

Orthodontics, American Board of Orthodontics


3-D Imaging

Biocreative Orthodontic Strategies

Craniofacial Defects

Craniofacial Orthodontics

Infant Maxillary Orthopedics

Jaw Surgery

Modified Nasal Alveolar Molding

Nonsurgical Orthodontics and Dentoalveolar Orthopedics

Obstructive Sleep Apnea

Oral and Facial Cleft

Skeletal and Dental Malocclusions

Surgical Orthodontics and Dentoalveolar Orthopedics

Todo Publicaciones

Development and systematic characterization of GelMA/alginate/PEGDMA/xanthan gum hydrogel bioink system for extrusion bioprinting. Biomaterials Li, J., Moeinzadeh, S., Kim, C., Pan, C. C., Weale, G., Kim, S., Abrams, G., James, A. W., Choo, H., Chan, C., Yang, Y. P. 2022; 293: 121969


Gelatin methacryloyl (GelMA)/alginate-based hydrogels have shown great promise in bioprinting, but their printability is limited at room temperature. In this paper, we present our development of a room temperature printable hydrogel bioink by introducing polyethylene glycol dimethacrylate (PEGDMA) and xanthan gum into the GelMA/alginate system. The inclusion of PEGDMA facilitates tuning of the hydrogel's mechanical property, while xanthan gum improves the viscosity of the hydrogel system and allows easy extrusion at room temperature. To fine-tune the mechanical and degradation properties, methacrylated xanthan gum was synthesized and chemically crosslinked to the system. We systematically characterized this hydrogel with attention to printability, strut size, mechanical property, degradation and cytocompatibility, and achieved a broad range of compression modulus (10-100kPa) and degradation profile (100% degradation by 24h-40% by 2 weeks). Moreover, xanthan gum demonstrated solubility in ionic solutions such as cell culture medium, which is essential for biocompatibility. Live/dead staining showed that cell viability in the printed hydrogels was over 90% for 7 days. Metabolic activity analysis demonstrated excellent cell proliferation and survival within 4 weeks of incubation. In summary, the newly developed hydrogel system has demonstrated distinct features including extrusion printability, widely tunable mechanical property and degradation, ionic solubility, and cytocompatibility. It offers great flexibility in bioprinting and tissue engineering.

View details for DOI 10.1016/j.biomaterials.2022.121969

View details for PubMedID 36566553

Split orthodontic airway plate: An innovation to the utilization method of conventional orthodontic airway plate for neonates with Robin sequence KOREAN JOURNAL OF ORTHODONTICS Choo, H., Kim, S., Ahn, H., Poets, C. F., Chung, K. 2022; 52 (4): 308-312


Since the emergence of neonatal infant orthodontics for treatments of cleft lip and palate with or without Robin sequence (RS) in Europe in the 1950s, advancements in design and scope of its application have been remarkable. As the first institution to adopt orthodontic airway plate (OAP) treatment in the United States in 2019, we saw a need for innovation of the original design to streamline the most labor-intensive and time-consuming aspects of OAP utilization. A solution is introduced using a systematic split expansion mechanism to re-size the OAP periodically to accommodate the neonate's maxillary growth. To date, seven RS patients have received this modified treatment protocol at our institution. Each patient completed full treatment using only one OAP. This innovative utilization method is aptly named the split orthodontic airway plate (S-OAP). Details of the S-OAP and its modifications from conventional OAP are reported.

View details for DOI 10.4041/kjod21.238

View details for Web of Science ID 000830678100008

View details for PubMedID 35466088

New Frontier in Advanced Dentistry: CBCT, Intraoral Scanner, Sensors, and Artificial Intelligence in Dentistry. Sensors (Basel, Switzerland) Kim, S., Kim, K. B., Choo, H. 2022; 22 (8)


The advancement of science and technology has brought innovation in the dental field [...].

View details for DOI 10.3390/s22082942

View details for PubMedID 35458927

Bio-Exercise (BioEx) - A biocreative orofacial myofunctional therapy: preliminary cephalometric study and clinical application. Dental press journal of orthodontics Lim, L., Choo, H., Eto, L. F., Chung, K., Kim, S. 2022; 27 (2): e2220367


OBJECTIVE: To introduce newly structured and developed orofacial myofunctional therapy (OFMFT) protocols named Bio-Exercise (BioEx), and evaluate the treatment effect of this method, using lateral cephalometric analysis on malocclusion with low tongue posture in young patients.METHODS: A retrospective preliminary study was performed using orthodontic records from 28 patients (mean age of 8.411.45-year-old, 13 males, 15 females) treated with BioEx therapy using tongue elevators for 18.149.04 months (range: 6 to 37 months). Pretreatment (T0) and post-BioEx therapy (T1) lateral cephalograms were subsequently analyzed for tongue posture changes by linear, anteroposterior and vertical measurements. The data were analyzed by paired t-test, considering a 5% significance level.RESULTS: The tongue length (TGL) and tongue height (TGH) increased statistically significant between T0 and T1. The decrease of the dorsum of the tongue perpendicular to the palatal plane (Td-PP value) was statistically significant. The increase of the tip of the tongue perpendicular to the pterygomaxillary vertical line (TT-PMV) was not statistically significant.CONCLUSIONS: These preliminary cephalometric results indicate that BioEx can be an effective OFMFT modality in increasing the tonicity of the tongue muscles to establish more normalized tongue position at rest.

View details for DOI 10.1590/2177-6709.27.2.e2220367.oar

View details for PubMedID 35613244

Cross-species comparisons reveal resistance of human skeletal stem cells to inhibition by non-steroidal anti-inflammatory drugs. Frontiers in endocrinology Goodnough, L. H., Ambrosi, T. H., Steininger, H. M., Butler, M. G., Hoover, M. Y., Choo, H., Van Rysselberghe, N. L., Bellino, M. J., Bishop, J. A., Gardner, M. J., Chan, C. K. 2022; 13: 924927


Fracture healing is highly dependent on an early inflammatory response in which prostaglandin production by cyclo-oxygenases (COX) plays a crucial role. Current patient analgesia regimens favor opioids over Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) since the latter have been implicated in delayed fracture healing. While animal studies broadly support a deleterious role of NSAID treatment to bone-regenerative processes, data for human fracture healing remains contradictory. In this study, we prospectively isolated mouse and human skeletal stem cells (SSCs) from fractures and compared the effect of various NSAIDs on their function. We found that osteochondrogenic differentiation of COX2-expressing mouse SSCs was impaired by NSAID treatment. In contrast, human SSCs (hSSC) downregulated COX2 expression during differentiation and showed impaired osteogenic capacity if COX2 was lentivirally overexpressed. Accordingly, short- and long-term treatment of hSSCs with non-selective and selective COX2 inhibitors did not affect colony forming ability, chondrogenic, and osteogenic differentiation potential in vitro. When hSSCs were transplanted ectopically into NSG mice treated with Indomethacin, graft mineralization was unaltered compared to vehicle injected mice. Thus, our results might contribute to understanding species-specific differences in NSAID sensitivity during fracture healing and support emerging clinical data which conflicts with other earlier observations that NSAID administration for post-operative analgesia for treatment of bone fractures are unsafe for patients.

View details for DOI 10.3389/fendo.2022.924927

View details for PubMedID 36093067

Disruptive Therapy Using a Nonsurgical Orthodontic Airway Plate for the Management of Neonatal Robin Sequence: 1-Year Follow-up. The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association Choo, H., Galera, R. I., Balakrishnan, K., Lin, H. C., Ahn, H., Lorenz, P., Khosla, R. K., Profit, J., Poets, C. F., Lee, J. S. 2022: 10556656221076980


We recently published the 3-month follow-up of 2 neonates with Robin sequence whose mandibular hypoplasia and restricted airway were successfully treated with an orthodontic airway plate (OAP) without surgical intervention. Both infants were successfully weaned off the OAP after several months of continuous use. We present the course of OAP treatment in these patients with a focus on breathing, feeding, and facial growth during their first year of life. Both infants demonstrated stable mandibular projection, resolution of obstructive sleep apnea, and normal development.

View details for DOI 10.1177/10556656221076980

View details for PubMedID 35167404

Root proximity of the anchoring miniscrews of orthodontic miniplates in the mandibular incisal area: Cone-beam computed tomographic analysis. Korean journal of orthodontics Jeong, D., Oh, S. H., Choo, H., Choi, Y., Kim, S., Lee, J., Hwang, E. 2021; 51 (4): 231-240


Objective: This outcome analysis study evaluated the actual positions of the orthodontic miniplate and miniplate anchoring screws (MPASs) and the risk factors affecting adjacent anatomic structures after miniplate placement in the mandibular incisal area.Methods: Cone-beam computed tomographic images of 97 orthodontic miniplates and their 194 MPASs (diameter, 1.5 mm; length, 4 mm) in patients whose miniplates provided sufficient clinical stability for orthodontic treatment were retrospectively reviewed. For evaluating the actual positions of the miniplates and analyzing the risk factors, including the effects on adjacent roots, MPAS placement height (PH), placement depth (PD), plate angle (PA), mental fossa angle (MA), and root proximity were assessed using the paired t-test, analysis of variance, and generalized linear model and regression analyses.Results: The mean PDs of MPASs at positions 1 (P1) and 2 (P2) were 2.01 mm and 2.23 mm, respectively. PA was significantly higher in the Class III malocclusion group than in the other groups. PH was positively correlated with MA and PD at P1. Of the 97 MPASs at P1, 49 were in the no-root area and 48 in the dentulous area; moreover, 19 showed a degree of root contact (19.6%) without root perforation. All MPASs at P2 were in the no-root area.Conclusions: Positioning the miniplate head approximately 1 mm lower than the mucogingival junction is highly likely to provide sufficient PH for the P1- MPASs to be placed in the no-root area.

View details for DOI 10.4041/kjod.2021.51.4.231

View details for PubMedID 34275879

A Systematic Review of Mandibular Distraction Osteogenesis Versus Orthodontic Airway Plate for Airway Obstruction Treatment in Pierre Robin Sequence. The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association Abbas, D. B., Lavin, C., Fahy, E. J., Choo, H., Truong, M. T., Bruckman, K. C., Khosla, R. K., Lorenz, H. P., Momeni, A., Wan, D. C. 2021: 10556656211011886


OBJECTIVE: Mandibular distraction osteogenesis (MDO) is frequently performed to address airway obstruction in patients with Pierre Robin sequence (PRS), though more recently the technique of orthodontic airway plating (OAP) has gained traction. We aimed to evaluate OAP compared to MDO for airway obstruction in PRS.DESIGN: A systematic literature search across PubMed, Embase, and Google Scholar identified all studies published in English, which involved MDO or any form of OAP as treatments for PRS. All relevant articles were reviewed in detail and reported on, adhering to PRISMA guidelines.MAIN OUTCOME MEASURES: Airway (tracheostomy avoidance, decannulation rate), feeding (full oral feeding tolerance).RESULTS: Literature search identified 970 articles, of which 42 MDO studies and 9 OAP studies met criteria for review. A total of 1159 individuals were treated with MDO, and 322 individuals were treated with OAP. Primary outcomes appear similar for MDO and OAP at face value; however, this must be interpreted with different pretreatment contexts in mind.CONCLUSIONS: Orthodontic airway plating may be considered for airway obstruction in PRS, as some airway-related and feeding-related outcomes appear similar with MDO, per existing evidence in the literature. However, since PRS severity differed between studies, OAP cannot be uniformly considered a replacement for MDO. Further research is required to more comprehensively assess these treatment modalities inclusive of metrics that allow for direct comparison.

View details for DOI 10.1177/10556656211011886

View details for PubMedID 34075816

Evaluation of strategic uprighting of the mandibular molars using an orthodontic miniplate and a nickel-titanium reverse curve arch wire: Preliminary cephalometric study. Korean journal of orthodontics Park, J., Choo, H., Choi, J., Chung, K., Kim, S. 2021; 51 (3): 179-188


Objective: To evaluate the overall treatment effects in terms of the amount of uprighting with changes in the sagittal and vertical positions of mandibular molars after applying an orthodontic miniplate with a nickel-titanium (NiTi) reverse curve arch wire (biocreative reverse curve [BRC] system).Methods: A total of 30 female patients (mean age, 25.99 8.96 years) were treated with the BRC system (mean BRC time, 10.3 4.07 months). An I-shaped C-tube miniplate (Jin Biomed) was placed at the labial aspect for the alveolar bone of the mandibular incisors. A 0.017 * 0.025-inch NiTi reverse curve arch wire was engaged at the C-tube mini-plate anteriorly and the first and second premolars and molars posteriorly in the mandibular arch. Pre- and post-BRC lateral cephalograms were analyzed. A paired t-test was used to analyze the treatment effects of BRC.Results: The mandibular second molars were intrusively uprighted successfully by the BRC system. Distal uprighting with a controlled vertical dimension was noted on the first molars when they remained engaged in the BRC and the distal ends of the arch wire were laid on the second molars. The mandibular first and second premolars showed a slight extrusion. The changes in the mandibular incisors were unremarkable, while the mandibular molar angulation improved significantly. The lower occlusal plane rotated counterclockwise (MP-LOP: 1.13 2.60).Conclusions: The BRC system can provide very effective molar uprighting without compromising the position of the mandibular anterior teeth.

View details for DOI 10.4041/kjod.2021.51.3.179

View details for PubMedID 33984225

Nonsurgical Orthodontic Airway Plate Treatment for Newborns With Robin Sequence. The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association Choo, H., Khosla, R. K., Meister, K. D., Wan, D. C., Lin, H. C., Feczko, R., Bruckman, K., Hopkins, E., Truong, M. T., Lorenz, H. P. 2021: 10556656211007689


Despite promising outcomes for >50 years, nonsurgical orthodontic airway plates (OAP) are only infrequently offered for babies with Robin sequence in a few parts of the world. This article demonstrates possibility of providing functional improvement using an OAP to help these babies overcome their functional and structural difficulties on their own. Two consecutively treated cases are presented exemplifying that OAP treatment that had originated from Europe is reproducible and effective in an institution in the United States.

View details for DOI 10.1177/10556656211007689

View details for PubMedID 33845627

Finite element analysis of C-expanders with different vertical vectors of anchor screws. American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics Choi, J., Choo, H., Oh, S. H., Park, J., Chung, K., Kim, S. 2021


INTRODUCTION: C-expanders are tooth-borne and bone-borne maxillary expanders that are anchored by 6 orthodontic miniscrews, 3 on each side of the palate. The purpose of the study was to investigate the effect of C-expanders on the circummaxillary sutures and bucco-palatal axis of teeth in 3-dimensional finite element analyses when anchor screw vectors are different.METHODS: Five expansion models were studied on the basis of the vertical positions of anchor screws on the palate. Anchor screws for models A, B, and C were placed symmetrically at 4mm, 7mm, and 15mm below the cementoenamel junction (CEJ), respectively. Anchor screws for models D and E were placed asymmetrically at 4mm and 15mm below CEJ and 7mm and 15mm below CEJ, respectively. Stress, displacement, and angular changes of the bone and teeth were measured in elastoplastic behavior models using a static-nonlinear simulation in an implicit method.RESULTS: Symmetrical and asymmetrical anchor screw placement with different vertical vectors were compared using finite element analyses on 5 models.CONCLUSIONS: Using different vectors of anchor screws for C-expanders does change the pattern of palatal expansion (null hypothesis was rejected). The current investigation presents a promising future of controlled asymmetric skeletal maxillary expansion when asymmetric maxillary architecture needs to be corrected for successful orthodontic outcomes without involving orthognathic surgeries.

View details for DOI 10.1016/j.ajodo.2020.02.024

View details for PubMedID 33762139

Use of C-Tube Microplates for Controlling the Vertical Dimension During Maxillary Incisor Intrusion. Journal of clinical orthodontics : JCO Noh, M. K., Seo, K. W., Choo, H. n., Chung, K. R., Kim, S. H. 2019; 53 (7): 41425

View details for PubMedID 31648217

The biocreative strategy. Part 4: Molar distalization in nonextraction treatment. Journal of clinical orthodontics : JCO Chung, K. R., Kim, Y., Choo, H., Kim, S. H., Nelson, G. 2018; 52 (9): 462-475

View details for PubMedID 30256221

Non-extraction correction of Class II malocclusion using Biocreative Therapy Skeletal Anchorage in Orthodontic Treatment of Class II Malocclusion Chung, K., Choo, H., Kim, S. Mosby Elsevier. 2014; 1: 239243


This article introduces technical modifications to the conventional presurgical infant maxillary orthopedics device for newborns with complete bilateral cleft lip and palate, providing procedural simplicity and efficiency as well as therapeutic efficacy. The modifications incorporate a wax block-out on the stone model prior to device fabrication in a manner that the need for periodic acrylic addition and removal is not required, and thus eliminates the risk of natural maxillary growth restriction during infant maxillary orthopedics treatment. The premaxilla is completely excluded from the acrylic palatal plate and is repositioned primarily by the bilateral labial tape alone. In addition, nasal stent wires are installed on the same day of the palatal plate delivery to establish a tripod-like retention mechanism for the intraoral device to be able to replace the conventional mechanical lock-type retention methods. Applying these modifications, infant maxillary orthopedics treatment objectives for bilateral cleft lip and palate can be successfully achieved within 8 weeks of treatment, and the definitive primary cleft lip repair can be performed within 3-4 months of infant maxillary orthopedics treatment at our Center.

View details for DOI 10.1097/PRS.0b013e318230c84c

View details for Web of Science ID 000298857100097

View details for PubMedID 22186513

Modified Technique of Presurgical Infant Maxillary Orthopedics for Complete Bilateral Cleft Lip and Palate PLASTIC AND RECONSTRUCTIVE SURGERY Choo, H., Maguire, M., Low, D. W. 2012; 129 (1): 24448


This article introduces a modified device fabrication and facial taping method that increases the efficiency and efficacy of presurgical infant maxillary orthopedic therapy for babies born with complete cleft lip and palate. Interarch and intra-arch relationships of the maxillary and mandibular dental arches were evaluated on mounted stone models before and after treatment. The palatal plate device was custom-fabricated in a manner that bypassed the need for periodic acrylic addition and removal, thereby eliminating the risk of natural maxillary growth restriction during therapy. Elastic labial tapes were fabricated and applied in a configuration that mimicked normal function of the orbicularis oris muscle. A nasal stent wire was utilized from the initiation of therapy to enhance intraoral retention and stability of the device. Examples of infants undergoing a unilateral complete cleft lip and palate treatment protocol are presented. Treatment objectives were achieved within 7 to 8 weeks of therapy for patients who had an initial alveolar cleft size more than 10 to 12 mm. The modified protocol of presurgical infant maxillary orthopedic therapy is an effective and efficient treatment modality in reversing the pre-existing orofacial dysmorphism by redirecting the infant's natural growth.

View details for DOI 10.1097/PRS.0b013e318230c8bb

View details for Web of Science ID 000298857100098

View details for PubMedID 22186514

Modified Technique of Presurgical Infant Maxillary Orthopedics for Complete Unilateral Cleft Lip and Palate PLASTIC AND RECONSTRUCTIVE SURGERY Choo, H., Maguire, M., Low, D. W. 2012; 129 (1): 24952


The purposes of this study were to quantify the treatment outcomes of speedy surgical orthodontic treatment for adults with maxillary protrusion and to identify the key factors influencing the efficacy of speedy surgical orthodontic biomechanics.Twenty-four adults with maxillary or bimaxillary protrusion were treated with speedy surgical orthodontics, including maxillary perisegmental corticotomy followed by the orthopedic en-masse retraction against C-palatal miniplate anchorage. The average total treatment time was 20 months (range, 11-42 months). Lateral cephalograms were taken at pretreatment, just after the perisegmental corticotomy, and at posttreatment to evaluate the skeletal and soft-tissue changes. The Pearson correlation analysis was used to identify the relationships between hard-tissue, soft-tissue, and perisegmental corticotomy variables.The maxillary central incisors were retracted by 9.19 0.31 mm and retroclined by 19.73 1.17. The change of the maxillary alveolar ridge angle was 13.97 1.04. The extrusion tendency of the retracted maxillary incisors was minimal, measured as 1.17 0.36 mm. The width of the buccal corticotomy showed statistically significant correlations with the angular change of the maxillary central incisors and the maxillary alveolar ridge angle. The retrusion of the maxillary central incisors and the maxillary alveolar ridge angle were the 2 hard-tissue variables that most closely correlated with retrusion of the upper lip.Speedy surgical orthodontic treatment can be an effective modality for adults with severe maxillary protrusion.

View details for DOI 10.1016/j.ajodo.2011.06.029

View details for Web of Science ID 000297994200001

View details for PubMedID 22133959

Treatment outcome analysis of speedy surgical orthodontics for adults with maxillary protrusion AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS Choo, H., Heo, H., Yoon, H., Chung, K., Kim, S. 2011; 140 (6): E251E262


This article reports the use of an orthodontic mini-implant for a temporary crown restoration in a small edentulous space after limited orthodontic treatment.Two clinical cases are presented: a 23-year-old woman and a 14-year-old boy. In the adult patient, a 2-piece orthodontic C-implant (Cimplant, Seoul, Korea) was placed in a 3-mm wide edentulous space to build up a temporary crown restoration after a short orthodontic treatment to regain space for a missing mandibular right permanent lateral incisor. In the boy, a C-implant was placed in the space resulting from an avulsed maxillary right permanent lateral incisor to prevent aggressive alveolar bone resorption after dental trauma. Both patients were followed for more than 4 years of retention to evaluate the stability of the temporary crown restoration built up on the orthodontic mini-implants.Both patients had successful long-term results, confirmed by clinical and radiographic examinations. Both were pleased with the results and plan to retain the orthodontic mini-implant temporary crown restoration until they are ready for a permanent restoration later.A 2-piece orthodontic C-implant system can be used to maintain edentulous space after active orthodontic treatment.

View details for DOI 10.1016/j.ajodo.2009.10.051

View details for PubMedID 21967946

Novel application of the 2-piece orthodontic C-implant for temporary crown restoration after orthodontic treatment. American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics Jeong, D. M., Choi, B., Choo, H., Kim, J. H., Chung, K. R., Kim, S. H. 2011; 140 (4): 569-79
Histologic assessment of the biological effects after speedy surgical orthodontics in a beagle animal model: a preliminary study KOREAN JOURNAL OF ORTHODONTICS Kim, H., Lee, Y., Park, Y., Chung, K., Kang, Y., Choo, H., Kim, S. 2011; 41 (5): 36170
The effects of different pilot-drilling methods on the mechanical stability of a mini-implant system at placement and removal: a preliminary study KOREAN JOURNAL OF ORTHODONTICS Cho, I., Choo, H., Kim, S., Shin, Y., Kim, D., Kim, S., Chung, K., Huang, J. C. 2011; 41 (5): 35460


This report introduces an innovative treatment approach of selecting atypical and unconventional teeth for orthodontic extraction without compromising the quality of treatment outcomes by using temporary skeletal anchorage devices in patients with bimaxillary protrusion. Both patients introduced in this report had solid Class I molar relationships with bimaxillary anterior protrusion without facial or dental midline asymmetry. Their chief concerns were significant facial convexity, which conventionally requires the extraction of all 4 first premolars. However, 3 second premolars and 1 first premolar were removed in the first patient, and 2 second premolars and 2 first premolars were removed in the second patient. All second premolars extracted had previously had root canal treatment and large prosthodontic restorations, which resulted in a compromised short lifespan of the teeth relative to the natural dentition. To manage these cases of asymmetric extraction space in a symmetric dental and skeletal environment, 2 mini-implants were placed in the posterior maxillary interradicular spaces, 1 on each side. Despite the unusual asymmetric extraction of teeth, superimposition of the pretreatment and posttreatment cephalometric tracings shows excellent treatment outcomes of facial convexity reduction by asymetric maximum retraction of the anterior teeth with no change in the molar relationships.

View details for DOI 10.1016/j.ajodo.2009.08.036

View details for Web of Science ID 000294678700031

View details for PubMedID 21889088

Atypical orthodontic extraction pattern managed by differential en-masse retraction against a temporary skeletal anchorage device in the treatment of bimaxillary protrusion AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS Chung, K., Choo, H., Lee, J., Kim, S. 2011; 140 (3): 42332


When mini-implants fail during orthodontic treatment, there is a need to have a backup plan to either replace the failed implant in the adjacent interradicular area or wait for the bone to heal before replacing the mini-implant. We propose a novel way to overcome this problem by replacement with a miniplate so as not to interrupt treatment or prolong treatment time.The indications, advantages, efficacy, and procedures for switching from a mini-implant to a miniplate are discussed. Two patients who required replacement of failed mini-implants are presented. In the first patient, because of the proximity of the buccal vestibule to the mini-implant, it was decided to replace the failed mini-implant by an I-shaped C-tube miniplate. In the second patient, radiolucencies were found around the failed mini-implants, making the adjacent alveolar bone unavailable for immediate placement of another mini-implant. In addition, the maxillary sinus pneumatization was expanded deeply into the interradicular spaces; this further mandated an alternative placement site. One failed mini-implant was examined under a scanning electron microscope for bone attachment.Treatment was completed in both patients after replacement with miniplates without interrupting the treatment mechanics or prolonging the treatments. Examination under the scanning electron microscope showed partial bone growth into the coating pores and titanium substrate interface even after thorough cleaning and sterilization.Replacement with a miniplate is a viable solution for failed mini-implants during orthodontic treatment. The results from microscopic evaluation of the failed mini-implant suggest that stringent guidelines are needed for recycling used mini-implants.

View details for DOI 10.1016/j.ajodo.2009.08.032

View details for PubMedID 21640893

Replacing a failed mini-implant with a miniplate to prevent interruption during orthodontic treatment. American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics Lee, J. H., Choo, H., Kim, S. H., Chung, K. R., Giannuzzi, L. A., Ngan, P. 2011; 139 (6): 849-57
Class III Correction Using Biocreative Therapy (C-Therapy) Seminars in Orthodontics Chung, K., Kim, S., Choo, H. 2011; 17 (2): 108-123


This report describes a novel concept of relocating orthodontic mini-implants during dental distalization to provide unrestricted distal movement of the full maxillary dentition. The patient was an 18-year old Korean woman with a full-step Class II Division 1 malocclusion and mandibular deficiency. Mini-implants were initially placed bilaterally between the maxillary second premolar and the first molar. Sliding jigs were used to distalize the maxillary first and second molars. After the maxillary molars were distalized to a Class I molar relationship, the mini-implants were removed and immediately relocated distally to provide space for retraction of the anterior teeth. The occlusion was completed with Class I molar and canine relationships with optimal overjet and overbite. The 2-year posttreatment records showed a stable treatment with retention.

View details for DOI 10.1016/j.ajodo.2009.02.035

View details for Web of Science ID 000284940000046

View details for PubMedID 21130344

Advanced Applications of Cone Beam Computed Tomography in Orthodontics Seminars in Orthodontics Mah, J. K., Liu, Y., Huang, J. C., Choo, H. 2011; 17 (1): 57-71


Comprehensive visualization and records of the craniofacial complex have been goals in orthodontic imaging. These tasks have been performed by means of plaster, photographs and radiographs. These approaches have evolved across time, and cone-beam computed tomography (CBCT) has emerged as a comprehensive imaging modality for orthodontics.The authors provide a practical guide for applying CBCT in orthodontics, with an emphasis on situations in which conventional imaging is limited. These situations include dental development, limits of tooth movement, airway assessment, craniofacial morphology and superimposition.Complexities of the craniofacial complex, dentition and airway present challenges in obtaining conventional images. CBCT has image-fidelity advantages over conventional imaging that can lead to improved visualization.CBCT is changing orthodontics with respect to clinically assessing patients and is evolving with respect to diagnosis, clinical techniques and outcomes.The clinical value proposition of CBCT is to describe craniofacial anatomy accurately and provide comprehensive information regarding anatomical relationships and individual patient findings for improved diagnosis, treatment planning and prognostication.

View details for DOI 10.14219/jada.archive.2010.0361

View details for Web of Science ID 000282847600002

View details for PubMedID 20884934

Timely relocation of mini-implants for uninterrupted full-arch distalization AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS Chung, K., Choo, H., Kim, S., Ngan, P. 2010; 138 (6): 83949


This article describes the orthodontic treatment for a young woman, aged 23 years 5 months, with a Class III malocclusion and a deviated midline. Two orthodontic mini-implants (C-implants, CIMPLANT Company, Seoul, Korea) were placed in the interdental spaces between the mandibular second premolars and first molars. The treatment plan consisted of distalizing the mandibular dentition asymmetrically and creating space for en-masse retraction of the mandibular anterior teeth. C-implants were placed to provide anchorage for Class I intra-arch elastics. The head design of the C-implant minimizes gingival irritation during orthodontic treatment. Sliding jigs were applied buccally for distalization of the mandibular posterior teeth. The active treatment period was 18 months. Normal overbite and overjet were obtained, and facial balance was improved.

View details for DOI 10.1016/j.ajodo.2007.06.023

View details for Web of Science ID 000274393400021

View details for PubMedID 20122441

Practical applications of cone-beam computed tomography in orthodontics JOURNAL OF THE AMERICAN DENTAL ASSOCIATION Mah, J. K., Huang, J. C., Choo, H. 2010; 141 (10): 7S13S


The purposes of this study were to evaluate the actual postplacement positions of orthodontic miniplate anchoring screws (MPAS) and to determine the risk factors for their failure and iatrogenic effects on the intraoral structures.Three-dimensional cone-beam computed tomography images were generated to examine 31 orthodontic miniplates and their MPAS (diameter, 1.5 mm; length, 4 mm), which showed good clinical stability 6 months after placement in the posterior maxilla of 18 patients. The cone-beam computed tomography data were analyzed with analysis of variance (ANOVA) statistics to evaluate the difference of placement depth and vertical distance of the MPAS from the cementoenamel junction to the center of the screw. The Fisher exact test was used to determine differences in MPAS position, root proximity, and sinus penetration.The mean placement depth of the MPAS was 2.48 mm with no significant difference relative to their position. Twenty-six (of 74) MPAS were placed in the dentition area. Of these 26, 14 were placed in interdental spaces, and the other 12 followed the direction of the roots. Nine MPAS showed root proximity, and 7 MPAS had root penetration, all of which were placed in the central position of the miniplate. Thirty-nine MPAS penetrated the sinus, indicating a low interrelationship between placement depth and cortical bone thickness of the sinus.Miniplates were successfully retained by MPAS even with less-than-ideal placement. Root contact and proximity of MPAS seem to have minimal effects on the successful stabilization of miniplates. Pertinent guidelines should, however, be followed during MPAS placement to minimize the risk of damage to adjacent roots.

View details for DOI 10.1016/j.ajodo.2009.02.023

View details for PubMedID 19892272

Distalization of the mandibular dentition with mini-implants to correct a Class III malocclusion with a midline deviation AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS Chung, K., Kim, S., Choo, H., Kook, Y., Cope, J. B. 2010; 137 (1): 13546


This case report introduces a novel double archwire mechanics concept using orthodontic mini-implants and a miniplate to relocate ectopically impacted maxillary canines in a 14-year-old female with a Class III subdivision left malocclusion. The objective of this orthodontic treatment was to salvage the maxillary lateral incisors so they could be used for conservative restorations upon completion of the orthodontic treatment and to guide the impacted maxillary canines to their correct anatomical positions. The authors report that an iatrogenic root resorption of the maxillary lateral incisors, which is caused by a direct root contact between teeth during the active relocating procedure, can be minimized by using double-archwire mechanics. The optimal overbite, overjet, and occlusal interdigitation were achieved after the orthodontic treatment. The facial balance was also improved. Active orthodontic treatment lasted 26 months, and the results remained stable for 13 months after the removal of orthodontic appliances. This report also shows that the gingival margins of the relocated maxillary canines can be established without postorthodontic periodontal procedures when effective orthodontic mechanics are utilized to retain the canines in the alveolar bone and minimize any contact of the roots with gingival tissues during active relocation of the impacted maxillary canines.

View details for PubMedID 18834008

Cone-beam computed tomography evaluation of orthodontic miniplate anchoring screws in the posterior maxilla. American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics Kim, G. T., Kim, S. H., Choi, Y. S., Park, Y. J., Chung, K. R., Suk, K. E., Choo, H., Huang, J. C. 2009; 136 (5): 628.e1-10; discussion 628-9


To show the clinical application of surface-treated mini-implants (C-Implants) in managing an anterior torque control during en masse retraction of anterior dentition.Nickel-titanium archwire with reverse curve of Spee, which is directly engaged in the hole of C-Implants, and severe curve of Spee can be overlaid on anterior segmented archwires to generate anterior torque on the anterior dentition to resist lingual tipping during en masse retraction. This treatment mechanics is called the biocreative therapy type II technique. The characteristics and procedure of the type II technique for treating maximum anchorage using the C-Implants is shown with case reports of treated patients. The biomechanics and a comparison to the type I technique of this treatment are also described.The authors show the clinical application of type II technique during anterior retraction on various cases, possible indications, and simplicity of the mechanics.Biocreative therapy, which implements partial-osseointegrated mini-implants, presents a novel therapeutic approach in orthodontics. A technique of intrusion overlay archwires for anterior torque control also simplifies the design of orthodontic appliances while eliminating unwanted side effects, such as vertical changes on posterior anchorage teeth during en masse retraction.

View details for PubMedID 18575304

Double-archwire mechanics using temporary anchorage devices to relocate ectopically impacted maxillary canines. World journal of orthodontics Kim, S. H., Choo, H., Hwang, Y. S., Chung, K. R. 2008; 9 (3): 255-66
Anterior torque control using partial-osseointegrated mini-implants: biocreative therapy type II technique. World journal of orthodontics Chung, K. R., Kim, S. H., Kook, Y. A., Choo, H. 2008; 9 (2): 105-13
Cone-beam computed tomography (CBCT) in clinical practice Pacific Coast Society of Orthodontists Bulletin Huang, J. C., Choo, H., Mah, J. K. 2008: 18-22