• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.37.1-37.5
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• 2016

Background: The dimensions and shape of the forehead determine the esthetics of the upper third of the face. Korean young people consider a broad and smooth, rounded forehead more attractive. As a result, frontal augmentation becomes more popular in patients with dentofacial deformities. Various surgical procedures and materials have been used in frontal augmentation surgery, with associated advantages and disadvantages. Silicone is a good candidate for frontal augmentation. The author presents two cases of esthetic frontal augmentation with a prefabricated silicone implant in female patients with dentofacial deformities. Case presentation: In case 1, a 24-year-old female patient underwent frontal augmentation surgery with simultaneous maxillomandibular and zygomatic osteotomies to correct facial asymmetry. A silicone implant was fabricated preoperatively using a positive template stone mold of her forehead. In case 2, a 23-year-old female patient underwent total facial contouring surgery including frontal augmentation for improved facial esthetics. A computed tomography (CT)-guided rapid prototype (RP) model was used to make the silicone implants. The operative procedure was safe and simple, and the silicone implants were reliable for a larger degree of frontal augmentation. Six months later, both patients had recovered from the surgery and were satisfied with their frontal shape and projection. Conclusions: Frontal augmentation with silicone implants can be an effective adjuvant strategy to improve facial esthetics in patients with a flat and narrow forehead who undergo orthognathic reconstruction or total facial contouring surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제49권3호
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• pp.107-113
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• 2023

Bimaxillary transverse width discrepancies are commonly encountered among patients with dentofacial deformities. Skeletal discrepancies should be diagnosed and managed appropriately with possible surgical corrections. Transverse width deficiencies can present in varieties of combinations involving the maxilla and mandible. We observed that in a significant proportion of cases, the maxilla is normal, and the mandible showed deficiency in the transverse dimension after pre-surgical orthodontics. We designed novel osteotomy techniques to enhance mandibular transverse width correction, as well as simultaneous genioplasty. Chin repositioning along any plane is applicable concomitant with mandibular midline arch widening. When there is a requirement for larger widening, gonial angle reduction may be necessary. This technical note focuses on key points in management of patients with transversely deficient mandible and the factors affecting the outcome and stability. Further research on the maximum amount of stable widening will be conducted. We believe that developing evidence-based additional modifications to existing conventional surgical procedures can aid precise correction of complex dentofacial deformities.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제12권3호
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• pp.1-7
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• 1990

In the treatment of dentofacial deformities, analysis of skeletal pattern, with evaluation of plaster dental cast, is essential procedure. This study was based on 20 patients with dentofacial deformity who were admitted to the department of oral and maxillofacial surgery Kngnam sacred heart Hospital during the period of Jan 1988 through Aug 1989. We studied serial cephalometric radiogarphs of patients (pre-op, postop immediately, postop 6 moth). The obtained results indicates the good resistance of rigid fixation against relapse in orthognathic surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권3호
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• pp.370-375
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• 2008

Sagittal split ramus osteotomy (SSRO) is widely used in treatment of dentofacial deformities. But, many complications can occur including unfavorable fractures during osteotomy. To prevent these complications, it is necessary to understand comprehensively the anatomy of the mandiular ramus. The purpose of this study was to evaluate the morphology of the madibular ramus in manibular prognathism patients by computed tomography comparing with normal control group. The study group consisted of 33 skeletal class III patients (20 males, 13 females) and the control group consisted of the 52 patients without dentofacial deformities (32 males, 20 females). The mean age of study group was 22.0-year old, and that of control group was 37.1-year. For the CT examination, following scan parameters was used: 1mm slice thickness, 0.5 second scan time, 120kV and 100mA/s. The axial scans of the head were made parallel to the mandibular occlusal plane. The anteroposterior length of the ramus, the distance from anterior border of the ramus to lingula, the relative distance from the anterior border of the ramus to lingula compared to the anteroposterior length of the ramus, the thickness of anterior and posterior cortical plate, the thickness of medial cortical plate of the ramus at lingula level, the thickness of cancellous bone of the ramus at lingula level were measured. The skeletal class III mandibular prognathism patients exhibited shorter anteroposterior length of the ramus, thicker anterior and posterior cortical plate, thinner mediolateral cancellous bone thickness. The lingula has a relative stable anteroposterior position in ramus in all groups. There was higher possibility of fusion of medial and lateral cortical plate at lingula level in the mandibular prognathism group. In conclusion, the mandibular prognathism patients have narrow rami with scanty cancellous bone, which means that careful preoperative examination including CT scan can prevent undesirable fractures during osteotomy.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권2호
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• pp.124-129
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• 2013

Multiple segment osteotomy orthognathic surgery serves to combine the total or segmental maxillary and mandibular correction of the dentofacial deformities with concurrent procedures to provide immediate repositioning to the dento-osseous elements. In addition, splitting the palate may often be necessary to correct a functionally poor relationship of the maxilla to the mandible or the facial skeleton by realigning the maxillary arch. In this case, the discrepancy in a bimaxillary horizontal relationship and the space between the 2nd premolar and 2nd molar was retained after lengthy preoperative orthodontic treatment. However, we could correct these dento-osseous discrepancies immediately by performing midpalatal expansion, anterior segmental osteotomy and symphyseal osteotomy with bimaxillary osteotomies. If the blood supply to each segment segments was maintained and primary closure of the operation site was feasible, multiple segment osteotomy was considered as a very effective technique for treating dentofacial deformities in vertical, transverse, and sagittal dimensions with differential repositioning of all segments.

• 대한치과교정학회지
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• 제52권2호
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• pp.112-122
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• 2022

Objective: This study aimed to present and evaluate a new deep learning model for determining cervical vertebral maturation (CVM) degree and growth spurts by analyzing lateral cephalometric radiographs. Methods: The study sample included 890 cephalograms. The images were classified into six cervical stages independently by two orthodontists. The images were also categorized into three degrees on the basis of the growth spurt: pre-pubertal, growth spurt, and post-pubertal. Subsequently, the samples were fed to a transfer learning model implemented using the Python programming language and PyTorch library. In the last step, the test set of cephalograms was randomly coded and provided to two new orthodontists in order to compare their diagnosis to the artificial intelligence (AI) model's performance using weighted kappa and Cohen's kappa statistical analyses. Results: The model's validation and test accuracy for the six-class CVM diagnosis were 62.63% and 61.62%, respectively. Moreover, the model's validation and test accuracy for the three-class classification were 75.76% and 82.83%, respectively. Furthermore, substantial agreements were observed between the two orthodontists as well as one of them and the AI model. Conclusions: The newly developed AI model had reasonable accuracy in detecting the CVM stage and high reliability in detecting the pubertal stage. However, its accuracy was still less than that of human observers. With further improvements in data quality, this model should be able to provide practical assistance to practicing dentists in the future.

• 대한치과교정학회지
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• 제46권6호
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• pp.395-408
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• 2016

We report a case involving a young female patient with severe mandibular retrognathism accompanied by mandibular condylar deformity that was effectively treated with Le Fort I osteotomy and two genioplasty procedures. At 9 years and 9 months of age, she was diagnosed with Angle Class III malocclusion, a skeletal Class II jaw relationship, an anterior crossbite, congenital absence of some teeth, and a left-sided cleft lip and palate. Although the anterior crossbite and narrow maxillary arch were corrected by interceptive orthodontic treatment, severe mandibular hypogrowth resulted in unexpectedly severe mandibular retrognathism after growth completion. Moreover, bilateral condylar deformities were observed, and we suspected progressive condylar resorption (PCR). There was a high risk of further condylar resorption with mandibular advancement surgery; therefore, Le Fort I osteotomy with two genioplasty procedures was performed to achieve counterclockwise rotation of the mandible and avoid ingravescence of the condylar deformities. The total duration of active treatment was 42 months. The maxilla was impacted by 7.0 mm and 5.0 mm in the incisor and molar regions, respectively, while the pogonion was advanced by 18.0 mm. This significantly resolved both skeletal disharmony and malocclusion. Furthermore, the hyoid bone was advanced, the pharyngeal airway space was increased, and the morphology of the mandibular condyle was maintained. At the 30-month follow-up examination, the patient exhibited a satisfactory facial profile. The findings from our case suggest that severe mandibular retrognathism with condylar deformities can be effectively treated without surgical mandibular advancement, thus decreasing the risk of PCR.

• 대한치과의사협회지
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• 제58권9호
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• pp.546-555
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• 2020

Allergic rhinitis is a specific IgE mediated inflammatory disease of the nasal mucosa, characterized by symptoms such as rhinorrhea, nasal congestion, nasal obstruction, nasal and eye itching, and sneezing. The prevalence of allergic rhinitis varies according to country, age, and surveying methods, but it seems to increase worldwide, also in Korea. Prolonged mouth breathing caused by allergic rhinitis can produce muscular and postural alterations, causing alterations on the morphology, position, growth direction of the jaws, and malocclusion. Also, mouth breathing leads to dryness of the mouth, causing various oral diseases; gingivitis, halitosis, inflammation of tonsil, increased risk of dental caries and dental erosion. In dental clinic, using rapid maxillary expansion to persistent allergic rhinitis patients with narrow maxilla can enlarge maxillary dental arch and nasal cavity anatomy, improving nasal breathing and reducing nasal cavity resistance. However, it is desirable to use along with otolaryngologic treatment. Dentists should be aware of the characteristics of allergic rhinitis and its effects on patients, and consider when planning dental treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제17권4호
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• pp.311-316
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• 1995

This is to study the presurgical motivation, psychological changes and self satisfaction after the surgical treatment of dentofacial deformities. The subjects were 34 patients that the orthognathic surgeies were rendered and followed-up over 6 months. The results were as followings ; 1. The analysis of MMPI profiles in clinical scale reveals that 8.8%(3 patients) of neurologic type, 2.9% (1 patient) of personality problem type and none of psychotic type, while 88.3% of showed no abnormal findings in psychologic status. 2. The significant differences of personality characteristics were noticed in the Depression(D), Hypochondriasis(Hs), Musculinity-Feminity(Mf) were changed significantly following the orthognathic surgeries.(P<0.05) 3. The self assesment of the esthetic results were satisfactory in 78.6%, while no changes in 14.3%.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권3호
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• pp.254-261
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• 2006

Moderate to severe dentofacial deformities usually require combined orthodontic treatment and orthognathic surgery to obtain the most stable result with optimal function and facial esthetics. Accordingly, the orthodontist and oral maxillofacial surgeon must be able to exactly diagnose existing deformities, establish an appropriate treatment plan, and execute the recommended treatment. Especially, to obtain optimal result of the maxillary surgery, model surgery is essential. But, the preoperatively planned position of the maxillary dental arch often cannot be sufficiently achieved during actual surgery, and deviations in the sagittal and vertical dimensions are common. To achieve three dimensional repositioning of the maxilla exactly, several methods have been introduced so far. Recently Model Repositioning Instrument (MRI, SAM, Inc., $M\ddot{u}nchen$, Germany), one of these methods, has been introduced and applied clinically, which is reported as accurate, effective and prompt method for three dimensional repositioning of the maxilla. This article describes an introduction and a clinical application of this MRI.