• The korean journal of orthodontics
• /
• v.35 no.6 s.113
• /
• pp.485-494
• /
• 2005

Maxillary anterior teeth were intruded and lingually root torqued with two maxillary anterior microimplants between the lateral incisors and canines. Overerupted maxillary canines were intruded with two other microimplants between the maxillary canines and first premolars. Maxillary posterior teeth and canines were distalized, then the maxillary incisors were retracted with two maxillary posterior microimplants between the first and second molars. The mandibular anterior teeth were intruded and the mandibular posterior teeth were extruded with conventional method such as anterior bite plane, intrusion arch and Class II elastics. The mandible moved slightly forward after the correction of deep bite and retroclination of the upper incisors. Consequently, microimplant anchorage (MIA) provided absolute anchorage for simultaneous correction of Class II canine and molar relationships and deep overbite.

• The korean journal of orthodontics
• /
• v.39 no.6
• /
• pp.402-419
• /
• 2009

Successful treatment of the non-growing patient with an open bite of either dental skeletal pattern often presents a difficult challenge. The morphologic pattern in anterior open bite is characterized by longer vertical dimensions, an increase in development of the maxillary posterior dento-alveolar structure and a steep mandibular plane. In such cases, molar intrusion would be a good remedy for treatment. This article reports the successful treatment and retention of two anterior open-bite cases. We used orthodontic mini-implants for treatment and a circumferential retainer with posterior bite block or skeletal fixed retainer for retention. The diagnostic criteria and mechanics for appropriate treatment are discussed. Our results suggest that open bite can be reduced successfully with intrusion of molars using orthodontic mini-implants (OMI) without orthognathic surgery, and that circumferential retainer with posterior bite block and skeletal fixed retainer are effective for retention.

• Imaging Science in Dentistry
• /
• v.44 no.1
• /
• pp.15-20
• /
• 2014

Purpose: This study aimed to assess the three-dimensional (3D) facial changes after orthognathic surgery by evaluating the spherical coordinates of facial lines using 3D computed tomography (CT). Materials and Methods: A 19-year-old girl was diagnosed with class III malocclusion and facial asymmetry. Orthognathic surgery was performed after orthodontic treatment. Facial CT scans were taken before and after orthognathic surgery. The patient had a menton deviation of 12.72 mm before surgery and 0.83 mm after surgery. The spherical coordinates of four bilateral facial lines (ramal height, ramal lateral, ramal posterior and mandibular body) were estimated from CT scans before and after surgery on the deviated and opposite side. Results: The spherical coordinates of all facial lines changed after orthognathic surgery. Moreover, the bilateral differences of all facial lines changed after surgery, and no bilateral differences were zero. Conclusion: The spherical coordinate system was useful to compare differences between the presurgical and postsurgical changes to facial lines.

• Imaging Science in Dentistry
• /
• v.52 no.2
• /
• pp.133-140
• /
• 2022

Purpose: The aim of this review was to systematically analyze the available literature on the correlation between the gray values (GVs) of cone-beam computed tomography (CBCT) and the Hounsfield units (HUs) of computed tomography (CT) for assessing bone mineral density. Materials and Methods: A literature search was carried out in PubMed, Cochrane Library, Google Scholar, Scopus, and LILACS for studies published through September 2021. In vitro, in vivo, and animal studies that analyzed the correlations GVs of CBCT and HUs of CT were included in this review. The review was prepared according to the PRISMA checklist for systematic reviews, and the risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. A quantitative analysis was performed using a fixed-effects model. Results: The literature search identified a total of 5,955 studies, of which 14 studies were included for the qualitative analysis and 2 studies for the quantitative analysis. A positive correlation was observed between the GVs of CBCT and HUs of CT. Out of the 14 studies, 100% had low risks of bias for the domains of patient selection, index test, and reference standards, while 95% of studies had a low risk of bias for the domain of flow and timing. The fixed-effects meta-analysis performed for Pearson correlation coefficients between CBCT and CT showed a moderate positive correlation (r=0.669; 95% CI, 0.388 to 0.836; P<0.05). Conclusion: The available evidence showed a positive correlation between the GVs of CBCT and HUs of CT.

• The korean journal of orthodontics
• /
• v.54 no.2
• /
• pp.128-135
• /
• 2024

Objective: The number of three-piece maxillary osteotomies has increased over the years; however, the literature remains controversial. The objective of this study was to evaluate the skeletal stability of this surgical modality compared with that of one-piece maxillary osteotomy. Methods: This retrospective cohort study included 39 individuals who underwent Le Fort I maxillary osteotomies and were divided into two groups: group 1 (three pieces, n = 22) and group 2 (one piece, n = 17). Three cone-beam computed tomography scans from each patient (T1, pre-surgical; T2, post-surgical; and T3, follow-up) were used to evaluate the three-dimensional skeletal changes. Results: The differences within groups were statistically significant only for group 1 in terms of surgical changes (T2-T1) with a mean difference in the canine region of 3.09 mm and the posterior region of 3.08 mm. No significant differences in surgical stability were identified between or within the groups. The mean values of the differences between groups were 0.05 mm (posterior region) and -0.39 mm (canine region). Conclusions: Our findings suggest that one- and three-piece maxillary osteotomies result in similar post-surgical skeletal stability.

• Korean Journal of Cleft Lip And Palate
• /
• v.8 no.1
• /
• pp.11-22
• /
• 2005

There ate anteroposterior$\cdot$vertical maxillary underdevelopment, transverse maxillary deficiency and wide cleft alveolus$\cdot$oroanual fistula among cleft lip ant palate related maxillary deformities. For treatment of these deformities, ones have used conventional treatment methods, there were often unsatisfactory results to patients and operators both. Since llizarov introduced effective technique of bone lengthening and augmentation for a variety of limb defotmities, application of distraction osteogenesis on maxillofacial area has been used to solve those disadvantages of conventional methods. Authors introduced following three cases about use of distraction osteogenesis. The first case is the application of RED(rigid external distraction) II system for the treatment of the anteroposterior$\cdot$vertical maxillary hypoplasia after several times of surgery and end of development in bilateral cleft lip and palate patient. The second case is the application of the USPD(unilateral segmental palatal distraction) for the resolution of the unilateral posterior crossbite and transverse dental arch asymmetry after alveolorraphy in growing unilateral cleft lip and palate patient. The third case is the application of transport distraction osteogenesis far closure of the wide clef alveolus and oroantral fistula in growing bilateral cleft lip and palate patient. There were satisfactory results in these cases. Particularly, in comparison with the decreases of relapse rates, the reduction of the hospitalization time and post-operative discomfort owing to minimal surgical intervention.

• The Journal of Korean Academy of Prosthodontics
• /
• v.53 no.4
• /
• pp.377-391
• /
• 2015

Inter-dental arch discrepancy between maxilla and mandible could cause three dimensional occlusal problems, and collapse of occlusal plane, multiple teeth loss and decrease of masticatory efficiency could be observed in patient having unstable occlusal contact. Patient showing posterior bite collapse, unstable occlusal contact and improper anterior guidance should be treated to recover stable centric occlusion, occlusal contact, and anterior guidance in conjunction between prosthodontics and orthodontic treatment. This clinical report describes the favorable results of orthodontic and prosthodontics rehabilitation of patient with above mentioned problems.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.22 no.3
• /
• pp.187-195
• /
• 2022

Background: This retrospective study investigated the incidence rate of accidental foreign body aspiration and ingestion according to patient sex, age, and dental department. This study aimed to verify whether the incidence rate is higher in geriatric than in younger patients and whether it is different among dental departments. Methods: Accidental foreign body aspiration and ingestion cases were collected from electronic health records and the safety report system of Yonsei University Dental Hospital from January 2011 to December 2017. The collected data included patients' age, sex, medical conditions, treatment procedures, and foreign objects that were accidentally aspirated or ingested. The incidence rate was calculated as the number of accidental foreign body aspirations and ingestions relative to the total number of patient visits. Differences depending on the patients' sex, age, and dental department were statistically identified. Results: There were 2 aspiration and 37 ingestion cases during the 7-year analysis period. The male to female incidence ratio was 2.8:1. The incidence rate increased with age and increased rapidly among those aged 80 years or older. Seven of the 37 patients with accidental foreign body ingestion had intellectual disability, Lou Gehrig's disease, dystonia, or oral and maxillofacial cancer. The incidence rate was highest in the Predoctoral Student Clinic and the Department of Prosthodontics. The most frequently swallowed objects were fixed dental prostheses and dental implant components. Conclusion: The incidence rate of accidental foreign body aspiration and ingestion differed according to patient sex, age, and dental department. Dental practitioners must identify high-risk patients and apply various methods to prevent accidental foreign body aspiration and ingestion in dental clinics. Inexperienced practitioners should be particularly careful.

• The korean journal of orthodontics
• /
• v.22 no.3 s.38
• /
• pp.531-556
• /
• 1992

The majority of the commonly used protraction headgears for the protraction of small and/or retropositioned maxilla not allow a change in the point of force application or direction of the force delivery to attain predictable results because of the position of the upper and lower lips to avoid discomfort to the patient. The purpose of this study was to investigate the initial reaction of maxillofacial complex according to the change of force variables such as direction and point of force application with designing an antenna type-modified protraction head gear. A macerated human skull with well aligned upper teeth was used to experimental model and the investigation was done by double exposure holographic interferometry. Fringe patterns of each protraction conditions were compared and analized. The results were as follows. (Frontal view) 1. The Counterclockwise rotation of the maxilla was showed by parallel protraction to occlusal plane and the fringe was decreased in number as higher point of force application. 2. Generally, the number of fringe was increased in 500gm of protraction force than in 300gm. 3. When apply the protraction force to the maxilla with rapid palatal expansion, the direction of fringe patterns was differed from the protraction without expansion. 4. In most of cases, the counterclockwise rotation was decreased in case of the direction of the force is $20^{\circ}$ downward to occlusal plane compared to the parallel direction. 5. At the point of force application is 15mm above and the direction of force is 20 downward to occlusal plane , the translation of the maxillary complex was showed. (Lateral view) 6. The direction of fringe patterns of the facial bones were differed each other by the sutures, and showed almost parallel when apply the 300gm and 500gm of protraction force. 7. In case of rapid palatal expansion with protraction of the maxilla, the fringe patterns between the maxillary area and the area from the posterior of the maxillary first molar to the pterygomaxillary fissure were differed. In case without rapid palatal expansion, the changes of direction and point of the force application did not affect to the direction and the number of the fringe patterns.

• The korean journal of orthodontics
• /
• v.35 no.4 s.111
• /
• pp.320-329
• /
• 2005

The three-dimensional (3D) changes of bone, soft tissue and the ratio of soft tissue to bony movement was investigated in 8 skeletal Class III patients treated by mandibular setback surgery. CT scans of each patient at pre- and post-operative states were taken. Each scan was segmented by a threshold value and registered to a universal three-dimensional coordinate system, consisting of an FH plane, a mid-sagittal plane, and a coronal plane defined by PNS. In the study, the grid parallel to the coronal plane was proposed for the comparison of the changes. The bone or soft tissue was intersected by the projected line from each point on the gird. The coordinate values of intersected point were measured and compared between the pre- and post-operative models. The facial surface changes after setback surgery occurred not only in the mandible, but also in the mouth corner region. The soft tissue changes of the mandibular area were measured relatively by the proportional ratios to the bone changes. The ratios at the mid-sagittal plane were $77\~102\%(p<0.05)$. The ratios at all other sagittal planes had similar patterns to the mid-sagittal plane, but with decreased values. And, the changes in the maxillary region were calculated as a ratio, relative to the movement of a point representing a mandibular movement. When B point was used as a representative point, the ratios were $14\~29\%$, and when Pog was used, the ratios were $17\~37\%(9<0.05)$. In case of the 83rd point of the grid, the ratios were $11\~22\%(p<0.05)$.