• 대한치과교정학회지
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• 제41권3호
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• pp.211-218
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• 2011

Objective: This case report describes orthodontic treatment of contracted mandibular arch using a trombone appliance. Methods: A 14-year-old girl with Class II division 2 malocclusion, retroclined maxillary incisors, and buccally displaced maxillary canines required dental expansion in 3 spatial directions to correct the contracted maxillary and mandibular arches. In the initial phase of treatment, the maxillary arch was expanded and distalized using a quad-helix appliance and cervical headgear. Following the expansion and leveling of the maxillary arch, a trombone appliance was used to expand the mandibular arch. On correction of the mandibular arch and provision of sufficient space to level the mandibular teeth, fixed orthodontic treatment phase was initiated. Results: A trombone appliance proved effective in correcting the contracted mandibular arch. Because of labiolingual and transversal expansion, the mandibular dental arch perimeter was increased by 7.4 mm; the misalignment of the mandibular teeth was corrected successfully. Conclusions: A trombone appliance may serve as an appropriate clinical alternative for treating moderate mandibular arch crowding caused by the contraction of the dental arch.

• Imaging Science in Dentistry
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• 제44권3호
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• pp.185-191
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• 2014

Purpose: This study investigated the developmental stages of third molars in relation to chronological age and compared third molar development according to location and gender. Materials and Methods: A retrospective analysis of panoramic radiographs of 2490 patients aged between 6 and 24 years was conducted, and the developmental stages of the third molars were evaluated using the modified Demirjian's classification. The mean age, standard deviation, minimal and maximal age, and percentile distributions were recorded for each stage of development. A Mann-Whitney U test was performed to test the developmental differences in the third molars between the maxillary and mandibular arches and between genders. A linear regression analysis was used for assessing the correlation between the third molar development and chronological age. Results: The developmental stages of the third molars were more advanced in the maxillary arch than the mandibular arch. Males reached the developmental stages earlier than females. The average age of the initial mineralization of the third molars was 8.57 years, and the average age at apex closure was 21.96 years. The mean age of crown completion was 14.52 and 15.04 years for the maxillary and the mandibular third molars, respectively. Conclusion: The developmental stages of the third molars clearly showed a strong correlation with age. The third molars developed earlier in the upper arch than the lower arch; further, they developed earlier in males than in females.

• 대한치과교정학회지
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• 제30권1호
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• pp.19-31
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• 2000

이 연구는 한국인 태생의 아동 (남자 20명,여자 13명) 을 대상으로 치열궁의 폭경과 고경의 성장 변화를 6.6세부터 13.6세 까지 8년간의 누년적 관찰을 통하여 다음과 같은 결론을 얻었다. 1. 상악 견치간 폭경의 성장변화는 남자에서 13.5세까지 매년 증가하였으며 그 이후에도 증가할 추세를 보였으나 여자 에서는 12.5세까지 증가하고 그 이후의 변화는 거의 없었다. 반면에 하악 견치간 폭경의 성장변화는 남자에서 11.5 세까지, 여자에서 9.6세까지 증가하고 그 이후의 성장변화는 거의 없었다. 2. 상악 제1대구치간 폭경의 성장변화는 남녀 모두에서 13.5세까지 매년 증가하였으나 연간 증가량은 12.5세부터 급격히 감소하였다. 하악 제1대구치간 폭경의 성장변화는 남자에서 13.5세까지 증가하는 추세를 보였으며, 여자에서 12.5세까지 매년 증가하고 그 이후에는 변화가 없었다. 상악 제1대구치간 폭경의 연간 증가량은 남녀 모두에서 하악 제1대구치간 폭경의 연간 증가량보다 컸다. 3. 상악 치열궁 고경의 성장변화는 남녀 모두 10.6세까지 매년 증가하였고, 그 이후부터 13.6세까지 매년 감소하였다. 하악 치열궁 고경의 성장변화는 남자에서 10.5세까지, 여자에서 9.6세까지 매년 증가하였고,그 이후부터 매년 감소하였다. 4. 치열궁 폭경과 고경의 연간 성장량과 성장변화 시기에서 개인별 변화양상의 차이가 많았다.

• 대한치과교정학회지
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• 제52권6호
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• pp.451-460
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• 2022

Moebius syndrome (MBS) is a congenital neurologic disorder that causes cranio-facial abnormalities. It involves paralysis of the VI and VII cranial nerves and causes bilateral or unilateral facial paralysis, eye movement disorder, and deformation of the upper and lower limbs. The orofacial dysfunctions include microstomia, micrognathia, hypotonic mimetic and lip muscles, dental enamel hypoplasia, tongue deformity, open bite or deep overbite, maxillary hypoplasia, high arched palate, mandibular hyperplasia or features indicating mandibular hypoplasia. This case report presents a 7-year-old male patient who was diagnosed with MBS at the age 2 years. The patient displayed typical clinical symptoms and was diagnosed with Class II malocclusion with a large overjet/overbite, tongue deformity and motion limitation, and lip closure incompetency. Treatment was initiated using a removable appliance for left scissor bite correction. After permanent tooth eruption, fixed appliance treatment was performed for correction of the arch width discrepancy and deep overbite. A self-ligation system and wide-width arch form wire were used during the treatment to expand the arch width. After 30 months of phase II treatment, the alignment of the dental arch and stable molar occlusion was achieved. Function and occlusion remained stable with a Class I canine and molar relationship, and a normal overjet/overbite was maintained after 9.4 years of retainer use. In MBS patients, it is important to achieve an accurate early diagnosis, and implement a multidisciplinary treatment approach and long-term retention and follow-up.

• 대한소아치과학회지
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• 제25권2호
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• pp.383-399
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• 1998

Tooth development is usually described in four stages such as bud stage, cap stage, bell stage and crown stage. Exact time of appearance of tooth primordia is different among reports, and up to now there is no timetable regarding initial tooth development. To understand the congenital malformations and other disorders of the orofacial region, there is a need to establish a standard timetable on early tooth development. Till now, studies on the tooth development were mainly on later fetuses, and only few reports on early stage. Also, there were no reports on the time when bud stage turns to cap stage, and cap stage to bell stage. In this study, external morphology of face and the early development of the tooth, and transition of bud stage to cap stage, cap stage to bell stage were studied using 27 staged human embryos and 9 serially sectioned human fetuses. The results are as follows: 1. Mandibular region was formed by union of both mandibular arch at stage 15, and maxillary region by union of maxillary arch, medial nasal prominence, and intermaxillary segment at stage 19. 2. Ectodermal thickening which represents the primordia of tooth appeared in mandibular region at stage 13, and maxillary region at stage 15. 3. Bud stage began from mandibular primary central incisor at stage 17, and maxillary primary central incisor at stage 18. And the sequence of appearance was in the mandibular primary lateral incisor at stage 19, maxillary primary lateral incisor at stage 20, mandibular primary canine at stage 22, maxillary primary canine and primary first molar at stage 23, madibular primary first molar and maxillary primary second molar at 9th week, and mandibular primary second molar at 10th week of development. 4. Cap stage began from the primary anterior teeth at 9th week, and primary second molar still had the characteristics of cap stage at 12th week of development. 5. Transition to bell stage started from the primary anterior teeth at 12th week, and primary second molar started at 16th week of development. 6. Trnasition to crown stage started from primary anterior teeth at 16th week, and primary second molar at 26th week of development.

• 구강회복응용과학지
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• 제16권1호
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• pp.37-49
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• 2000

It was clinically important to substitute the physiologic centric relation to the therapeutic position of the patients who needed the oral rehabilitation or occlusal treatment. There were several methods for recording the centric relation. One of the known methods was to use the gothic arch tracer. However the existing intraoral device was difficult to adjust the three dimensional angulation of the recording plate and recording stylus depending on the hinge movement arch of the individual. The purpose of this study was to develop new intraoral tracer which had adjustable stylus within hinge movement arch for the record of centric relation and to evaluate the clinical application of this device. The results were as follow; 1. A stylus of new developed intraoral tracer was so adjustable that the recording of mandibular positions could be reproducible within the hinge movement arc. 2. A record plate of new developed intraoral tracer was so adjustable to parallel with the occlusal plane that lateral recording of mandibular position was able to obtain stably. This study showed that new developed intraoral tracer allowed the determination of the treatment position which can be used in the full mouth rehabilitation and occlusal treatments.

• 대한치과교정학회지
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• 제26권3호
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• pp.225-239
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• 1996

본 연구는 한국인 남.녀 6세에서 17세 사이의 악안면 성장과 발육에 관한 준종단적 연구의 일부로 시행되었으며 3년간에 걸쳐 남.녀 아동 736명을 대상으로 치열궁의 성장변화를 관찰하고자 치아의 근원심 폭경, 견치간 폭경, 구치간 폭경, 견치 치열궁 장경, 구치 치열궁 장경 그리고 치열궁 주위경을 측정하여 연령별, 성별 평균과 표준편차를 구하고 도표로 표시하여 다음과 같은 결론을 얻었다. 결론 1. 치아의 근원심 폭경 측정에서 상악은 중절치, 제2대구치, 하악은 견치, 제2대구치에서 남.녀 성차이를 인정 할 수 있었다. 2. 견치간 폭경은 11세까지 완만히 증가하는 양상을 보였다. 3. 구치간 폭경은 상악에서는 지속적으로 증가하는 양상을 보이며 그 양상은 9세에서 14세사이에서 가장 두드러지게 나타났다. 하악에서는 9세까지는 다양한 변화를 보이며 이후 14세까지 다소 증가하는 경향을 보였다. 4. 견치 치열궁 장경은 상악에서는 13세까지, 하악에서는 11세까지 증가하는 양상을 보였다. 5. 구치 치열궁 장경은 남자에서는 10세, 여자에서는 9세까지 증가하는 경향을 보이며, 이러한 변화는 상악에서 더 뚜렸하게 나타났다. 이후 상하악 모두에서 감소하는 경향을 보이며 이는 상악에서는 15세, 하악에서는 12세 사이에서 두드러졌다, 6. 치열궁 주위경은 상.하악 모두 10세까지 증가하는 경향을 보이며 그 양상은 상악에서 더 크게 나타났다. 반면에 10세와 14세 사이에서는 감소하는 경향을 보이며 그 양상은 하악에서 더 크게 나타났다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권4호
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• pp.249-254
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• 2012

Bilateral coronoid process hyperplasia is a rare condition characterized by an enlarged mandibular coronoid process. The painless progressive reduction of a mouth opening is caused by coronoid process impingement on the posterior aspect of the zygomatic bone. Hyperplasia of the bilateral coronoid process leads to the restriction of a mandibular opening consequent to the impingement of the enlarged coronoid process on the temporal surface of the zygomatic bone or with the medial surface of the zygomatic arch. The process has been diagnosed as developmental hyperplasia. Otherwise, the development of the coronoid process may be associated with growth hormone. This paper describes a case of trismus caused by coronoid hyperplasia in an idiopathic short-stature patient who received growth hormone therapy by somatropin injections.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.141-145
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• 2002

Purpose : The purpose of this study was to propose standard values for alveolar and basal bone in normal adult mandibles, and radiologically analyze the remodeling process of the edentulous mandible by examining molar areas and comparing them to the established normal values. Materials and Methods : Panoramic and CT scans of mandible were performed on 20 normal adults and 20 edentulous or partially edentulous adults. In both groups, arch half diameter and distance of alveolar bone were measured. Also the distance from the mandibular canal to the caudal edges, the buccal and lingual external borders of basal bone, were measured. A statistical comparison between the mean values of normal and edentulous mandibles was carried out in the selected areas. Results : There was evidence of decreasing arch half diameter and distance in the edentulous mandible, but statistically no significant change was seen between the normal and edentulous alveolar bone. There was evidence of decreasing buccal basal bone and increasing in the lingual basal bone in the edentulous mandible. A statistically significant difference between normal and edentulous mandibles was noted in the buccal basal bone. Conclusion: There was an inward and forward atrophic change of the edentulous mandibular molar area compared to the control. CT scanning required the use of sophisticated and expensive procedures to analyze the remodeling process of edentulous mandibles. Consequently, the development and application of a more simplified and objective radiographic procedure for broad and long-term study of remodeling procedures of edentulous mandible was recommended.

• Journal of Yeungnam Medical Science
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• 제10권1호
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• pp.37-47
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• 1993

인두편도 증식으로 인한 비호흡 장애가 치열 및 핵의 위치에 미치는 영향을 안모형태에 따라 비교 연구하기 위해 인두편도 증식으로 인두편도 절제술을 시행하기로 한 환자의 안모를 형태에 따라 mesofacial, brachyfacial, dolichofacial type으로 분류하여 각 type별로 20명의 환자를 설정하여 서로 비교 연구한 결과 1. 상악 구치부 치열궁 폭경에 있어서 안모 형태에 따른 유의한 차이를 보였으며, dolichofacial type의 안모를 가진 환자에서 가장 좁은 상악 구치부 치열궁 폭경을 보였다. 2. 혀의 수직적 위치에 있어서 안모형태에 따른 유의한 차이를 보였으며, dolichofacial type의 안모를 가진 환자에서 혀가 가장 하방에 위치함을 보였다.