• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.1
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• pp.61-71
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• 2009

Anchorage control is important in orthodontic treatment. Recently miniscrew is widly used as maximum anchorage in orthodontic treatment, and then it is important to install miniscrew safely without damaging adjacent anatomic structure. In a view of Miniscrew's stability, maxilla is unfavorable than mandible, and moreover maxillary soft buccal bone has disadvantage on stability. so palatal area comes into notice for installation area. We measured distance between palatal roots and bone thickness at midpalatal area using 3D computed tomography, and have found following results. 1. On the comparison of distance between palatal roots, the distance between 2nd premolar and 1st molar was significantly longest and the distance between premolars was significantly shortest. 2. Going toward lateral area from midpalatal suture and posterior area from zero point, bone thickness significantly became shorter and shorter. And 5.0mm palatal sagittal plane has more significance decrease of bone thickness than 2.5mm palatal sagittal plane. According to these results, we can conclude that the palatal installation of miniscrew between 2nd premolar and 1st molar is safest. And it is more safe that comes closer to midpalatal suture and to anterior area in regard to incisive canal.

• Korean Journal of Cleft Lip And Palate
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• v.12 no.1
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• pp.1-6
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• 2009

Oronasal fistula are a well-known complication of surgical treatment of cleft palate, occurring most frequently in the alveolus and hard palate. Previous reports have demonstrated that oronasal fistulas, particularly if greater than l cm in diameter, had an adverse effect on speech. The aim of this study was to demonstrate the relationship between the size of the fistula and the influence on velopharyngeal function. The site and size of the fistula were indicated on graph paper with calipers and measured in $mm^2$. Speech assessment was carried out using a Nasometer, VPI articulation differential test, spectrography. Patient whose fistulas affected their speech had significantly larger fistulas than those whose fistulas did not. The study shows that the larger the fistula, the greater the risk of hypernasality and nasal emission, but even small fistulas can cause speech problems. If obstruction of the nasal passage is eliminated in a patient with a previously asymptomatic fistula, it may result in a fistula becoming symptomatic, resulting in hypernasality and nasal emission. In conclusion, even small fistulas can influence speech production and should be considered before any treatment is planned. The study lends support to early closure of oronasal fistulas, particularly before pharyngeal flap surgery is contemplated.

• Korean Journal of Ichthyology
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• v.31 no.4
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• pp.214-221
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• 2019

This study suggests basic data for taxonomic research among similar species by observing osteological development of larvae of Hemibarbus longirostris. Newly hatched yolk-sac larvae were 8.10±0.02 mm (n=5) in mean total length, and frontal, parasphenoid, and basioccipital in the cranium were ossified. On the 6 days after hatching, flexion-larvae were 10.9±0.26 mm (n=5) in mean total length, hyomandibular, sympletic, and ectopterygoid in the cranium were ossified. On the 12 days after hatching, post-larvae were 12.2±0.55 mm (n=5) in mean total length, interopercle in operculum region and postclavicle in shoulder girdle bone were ossified. On the 25 days after hatching, post-larvae were 16.1±0.27 mm (n=5) in mean total length, epihyal and interhyal in hyoid arch, two epural in caudal skeleton, interneural processes, and interhaemal processes were ossified. On the 40 days after hatching, juvenile were 27.9±3.74 mm (n=5) in mean total length, all skeletal development completed with hypural bone in the caudal skeleton region fused in three forms (1, 2+3, 4+5).

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.6
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• pp.509-512
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• 2007

Purpose: The Le Fort I osteotomy is a commonly performed maxillary procedure for dentofacial deformity. One of the risks of this procedure is major hemorrhage resulting from injury to the descending palatine artery. So it is very important to know the exact position of the descending platine artery. An increased understanding of the position of this artery can minimize the intra-operative bleeding while allowing extension of the bone cuts to achieve exact positioning maxilla. The aim of this investigation was to study the position of the descending palatine artery as it relates to the Le Fort I osteotomy. Methods and patients: Total 40 patients who underwent Le Fort I osteotomy in SNUDH OMFS were studied in this study. We measured the distance from the pyriform aperture to the descending palatine artery (DPA distance) using a ruler. We investigated the relationship between DPA distance, the distance from A point to the McNamara line on lateral cephalography and the patient's body height. Results: The average distances from the pyriform rim to the descending palatine artery were 35.3 mm on the right (range: $30{\sim}40mm$) and 33.7mm (range: $30{\sim}41mm$) on the left in males. Those in females were 33.4 mm on the right (range: $28{\sim}40mm)$ and 32.8mm (range: $27{\sim}38mm$) on the left. The significances between the distance the DPA distance, the body height and the distance from A point to McNamara line were not found. Conclusion: Injury to the descending palatine artery during Le Fort I osteotomy can be minimized by not extending the osteotomy more than 30 mm posterior to the pyriform aperture in mal, and 27 mm in female.

• The korean journal of orthodontics
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• v.38 no.1
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• pp.41-51
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• 2008

Objective: The aim of this study was to compare the initial lateral cephalometric characteristics in two groups of patients: those that had mandibular setback surgery only and those that had mandibular setback surgery with advancement genioplasty. Methods: The lateral cephalograms of thirty-one patients were studied. Twenty-one Class III patients (group A) had only madibular setback surgery Twelve Class III patients (group B) had mandibular setback surgery with advancement genioplasty. Results: Differences between two groups were found in N-Me, ANS-Me, Occlusal Plane angle, Palatal Plane to U1, Mandibular Plane to L1, Mandibular Plane to L6, SN to U1, Sn-Stms, and Pog' projection. Compared to group A, group B showed more linguoversion and extrusion of upper incisors, more extrusion of lower incisors and lower first molar, and more steepness of the occlusal plane. N-Me, ANS-Me, and Sn-Stms were also longer in group B. But Pog' projection was shorter than group A. Conclusion: We conclude that certain initial lateral cephalometric characteristics may help indicate the inclusion of advancement genioplasty when mandibular setback surgery is planned in skeletal Class III patients.

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.573-580
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• 2004

The Palatal masticatory mucosa was widely used as a donor site in periodontal and implant surgery. but there were relatively few studies investigating the thickness of the palatal mucosa in dentate subjects. The purpose of this study was to study the thickness of palatal masticatory mucosa in korean subjects by direct clinical technique. Forty systemically and periodontally healthy subjects(20 males:20 females) participated in this study. A bone sounding method using a periodontal probe with minimal anesthesia and a prepared clear acrylic stent was utilized to assess the thickness of palatal mucosa at 24 measurement points defined according to the gingival margin and mid palatal suture. The results are as follows; 1. Mean thickness of palatal masticatory mucosa was $3.5{\pm}0.4mm$. and no gender differences were identified in the thickness of palatal masticatory mucosa. 2. The thickness of palatal masticatory mucosa increased from canine to second molar area(with the exception of the first molar area). canine and first molar areas were significantly thinner than other areas(P<0.05). 3. The thickness of palatal masticatory mucosa significantly increased in the sites farther from the gingival margin towarding the mid-palate(P<0.05). The results suggest that within the limits of the present study, premolar area appears to be the most appropriate donor site for soft tissue grafting procedures.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.1_2
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• pp.1-21
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• 1992

In order to find the causes of velopharyngeal incompetency after primary palatorrhaphy in cleft patients, we analyzed the form and function of the velopharyngeal space of fifteen operated cleft palate patients and five normal subjects. The velopharyngeal function was evaluated by lateral cephalometric radiography, velopharyngography and hypernasality cul-de-sac test. The obtained results were as follows. 1. The rate of velopharyngeal incompetency was twenty percent, three of the fifteen operated patients. Two of them were complete cleft palate and the other was incomplete one. 2. The length of soft palate and levator eminence were longer in normal group than those of good speech group and complete cleft palate group during phonation of /i/ (P<0.05). The lengthening rate of soft palate was smaller in good and poor speech group than that of normal group(P<0.05), and, reduced in order, normal group, complete cleft palate group and incomplete palate group(P<0.05). 3. The nasopharyngeal distance had no significant difference between all groups at rest, but, smaller in normal group than that of both cleft palate group(P<0.05), good speech group and poor speech group(P<0.05) during phonation of /i/ The difference in nasopharyngeal distance between rest and /i/ phonation was greater in normal group than that of both cleft palate group, good speech group and poor speech group. 4. The moving distance of sop palate reduced in order, normal group, incomplete cleft palate group, complete cleft palate group(P<0.05). 5. The distance between lateral pharyngeal wall had no significant difference between all groups in rest, but, smaller than that of complete cleft palate group in normal group(P<0.01) and increased in order normal group, good speech group, poor speech group(P<0.01) during phonation of /a/. The mobility of lateral wall was reduced in order, normal group, good speech group poor speech group(P<0. 01). 6. There was low corelationship between the mobility of lateral pharyngeal wall and soft palate. Therfore, it suggest that the movements of lateral pharyngeal wall and soft palate occurs independently.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.4
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• pp.380-385
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• 2008

Microstomia can be occurred as a result of direct injury to tissues such as chemical, thermal and electrical burns, and animal bites. It also may be secondary to contracture of burned perioral skin, or may result from scarring after reconstructive lip surgery. Narrowing of the oral aperture is not only disfiguring, but also limiting the oral access needed for introduction of food, insertion of dentures, oral hygiene, and dental treatment. Limited mouth opening may also interfere with mastication and speech. Few reports exist regarding correction of microstomia and reconstruction of the corners of the mouth. A 16-year-old girl with a bilateral cleft lip and palate presented with the limited mouth opening (approximately 20 mm), the esthetic problem due to the small lip, and the cleft lip-nasal deformity. The microstomia was corrected by bilateral commissuroplasty using "over and out" buccal mucosa flaps proposed by Converse. The intercommissure distance was increased from the preoperative 40 mm to the postoperative 60 mm. The one-year postoperative intercommissure distance was 54 mm, because the 6 mm relapse was occurred. The bilateral commissuroplasty using "over and out" buccal mucosa flap could increase the width and general size of the oral aperture and improve the lip appearance.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.55-63
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• 1997

The purpose of thus study was to measure the changes of arch and dentition of maxillary posterior teeth before and after treatment and postretentios in patients treated with Quad-helix. Measurements and analysis were performed on study model with carlipers. Seventeen cases, eight boys and nine girls, were selected with average ages of 12.7 years. Mean retention period was 4 months, and mean wearing time was. 127 days. The result were as follows 1. The interpremolar widths and intermolar width were significantly increased in maxillary first piennolar and molar when compared between before and after treatment and postretention. The maxillary second premolar resulted in significant increase in interpremolar between after tretment and post retention. 2. The long axis of maxillary first premolar and first molar accompaning buccal tipping was significant increased before and after Tx and post retention. Significant increase of the lingual inclination of maxillary second premolar was obsered both in before and after Tx, and before Tx and post retention. 3. The distance between the height of tooth contour was significantly increased in the first and second premolar before and after Tx, and was significant increased in the first molar before and after Tx and post retention. 4. Intermolar width at the palatal groove was increased in before and after Tx. and post retention. The palatal depth was significant increased in before and after Tx. In conclusion expansion of maxillary dental arch showed no relapse and results were stable retention

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.4
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• pp.400-408
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• 2019

The purpose of this study is to identify the most common canal type in primary molars and the correlation between their roots and canals. A comprehensive understanding of root canal morphology will lead to more successful root canal treatment. Computed Tomography (CT) images from 114 children (81 boys, 33 girls) aged 3 - 7 years were obtained. The locations and numbers of roots and canals were evaluated, and the relationship between root and canal parameters was determined. The most commonly observed canal morphology in primary maxillary molars were mesio-buccal, disto-buccal and palatal canal. Primary mandibular molars most frequently contain mesio-buccal, mesio-lingual, disto-buccal and distolingual canal. All the roots of the primary maxillary molars except for the mesio-buccal root, each had 1 canal while there were 2 canals observed in each root of primary mandibular molars. Without exception, all mesial roots in primary mandibular 2nd molars had 2 canals. In case when either the palatal root in a primary maxillary molar or the distal root in a primary mandibular molar was separated into 2 roots, each root seemed to have its own canal. Even though the disto-buccal and palatal roots were fused into 1 root in primary maxillary molars, this fused root had tendency to have 2 separate canals. Primary mandibular molars showed similar canal morphologies between left and right molars in the same patient, while the primary maxillary molars did not.