Applications of digital medical techniques for dental dysplasia / 中华口腔医学杂志

Dental dysplasia are abnormalities in teeth structure, morphology, number and eruption caused by genetic and environmental factors during dental development. Digital medical techniques, as the current hot spot of medical research, bring great challenges and opportunities to modern stomatology. The applications of digital techniques, such as digital diagnosis method, digital virtual simulated design, three-dimensional printing, static and dynamic guidance and artificial intelligence, can provide a more accurate, efficient, automatic and intelligent modern concepts and patterns for epidemiology, diagnosis, multidisciplinary treatment and outcome assessment of dental developmental anomalies.

Erupción dentaria, actualización en los mecanismos eruptivos: a propósito de un caso / Dental eruption, update in eruptive mechanisms: on the purpose of a case

Introducción: El presente artículo ahonda en las teorías más aceptadas sobre el proceso de erupción dental en la literatura de hoy en día y, desde este enfoque, expone el caso clínico de una paciente de 12 años de edad que presentaba retención de caninos y molares temporales. A dicha paciente se le trató clínicamente mediante exodoncias seriadas y se muestra su evolución posterior al tratamiento dental. Objetivos: Lograr entender de mejor manera el proceso de la erupción dental en base a la actual bibliografía. Materiales y métodos: Se realizó una revisión bibliográfica con palabras claves: "erupción dental", "extracciones seriadas", "retención dental" y "evolución dental". La paciente fue evaluada y tratada ortodóncicamente, mediante extracciones seriadas y se realizaron controles dentales periódicos con toma de radiografía panorámica para evaluar su evolución. Conclusión: El folículo dental y el retículo estrellado son las estructuras encargadas de generar el proceso eruptivo del diente mediante la interacción de diversas moléculas. Estas moléculas deben encajar dentro de un contexto para que cada diente erupcione de manera independiente.

Introduction: This article delves into the most accepted theories about the dental eruption process in today's literature and, from this perspective, presents the clinical case of a 12-year-old patient who presented retention of temporary canines and molars. This patient was treated clinically by means of serial extractions and her evolution after dental treatment is shown. Objectives: This article delves into the most accepted theories about the dental eruption process in today's literature and, from this perspective, presents the clinical case of a 12-year-old patient who presented retention of temporary canines and molars. This patient was treated clinically by means of serial extractions and her evolution after dental treatment is shown. Materials and methods: A bibliographic review was carried out with key words: "dental eruption", "serial extractions", "dental retention" and "dental evolution". The patient was evaluated and treated orthodontically by serial extractions and periodic dental check-ups were carried out with panoramic radiography to evaluate her evolution. Conclusion: The dental follicle and the stellate reticulum are the structures responsible for generating the eruptive process of the tooth through the interaction of various molecules. These molecules must fit into a context for each tooth to erupt independently.

Irrompimento do primeiro molar permanente em crianças da zona urbana e rural do município de Santa Helena - Paraná / Irrompement of the first permanent molar in children from the urban and rural area of the city of Santa Helena - Paraná

O objetivo deste trabalho foi comparar a cronologia de erupção do primeiro molar permanente em crianças de ambos os sexos, residentes na zona urbana e rural do munícipio de Santa Helena - PR, Brasil. Foi realizado um estudo transversal com 154 crianças da zona rural e 300 crianças da área urbana de 04 a 07 anos (48 a 84 meses). Os primeiros molares avaliados foram considerados irrompidos quando qualquer porção de sua coroa estivesse clinicamente visível. A média de idade para erupção do primeiro molar permanente se mostrou de 72 a 83 meses. Destes, o grupo da zona rural apresentou uma média para idade de erupção mais precoce. Contudo, verificou-se um resultado considerável em crianças na faixa de 48 a 59 meses (4 anos), mostrando mais uma vez a erupção precoce nas crianças da zona rural. Este dente irrompeu primeiro na mandíbula, irrompendo primeiro nas meninas do que nos meninos, e o dente 46 foi o que mais se mostrou presente. A média de idade para erupção do primeiro molar permanente correspondeu àquela descrita pela literatura aos seis anos, mas não correspondeu ao atraso na erupção das crianças residentes em zona rural. Bem como este dente irrompeu primeiro na mandíbula... (AU)

The objective of this study was to compare the chronology of eruption of the first permanent molar in children of both sexes, living in the urban and rural areas of the city of Santa Helena-PR, Brazil. A cross-sectional study was carried out with 154 children from the rural area and 300 children from the urban area from 4 to 7 years old (48 to 84 months). The first molars evaluated were considered erupted when any portion of their crown was clinically visible. The average age for eruption of the first permanent molar was 72 to 83 months. Of these, the rural group had an earlier average age for eruption than the urban group. However, a considerable result was found in children 48-59 months showing once again the early eruption in rural children. This tooth erupted first in the jaw, erupting first in girls rather than boys, and tooth 46 was most present. The mean age of eruption of the first permanent molar corresponded to that described in the literature at age six, but did not correspond to the delayed eruption of children living in rural areas. Just like this tooth erupted in the jaw first... (AU)

Management of an unerupted tooth and odontoma after trauma in predecessor

The purpose of this case report was to describe the surgical exposure and orthodontic management of an unerupted and ectopic maxillary right central incisor after trauma to the primary predecessor. Case report: An 11-year-old girl was referred to the Pediatric Dentistry Clinic due to eruption failure of the maxillary right central incisor. Radiographs showed the impacted central incisor located below the anterior nasal spine and its apex parallel to the palatal plane and the presence of an odontoma. General surgery was performed to remove the odontoma and two perforations in the crown of the impacted tooth were made to carry out orthodontic traction. Correct alignment was achieved after 18 months and no significant clinical or radiographic alterations were founded. Conclusion: The orthodontic management was performed successfully, and a positive esthetic outcome combined with adequate occlusion demonstrated the satisfactory results of this case.

Objetivo: O objetivo deste relato de caso foi descrever a exposição cirúrgica e o tratamento ortodôntico de um incisivo central superior direito ectópico e não irrompido após trauma do predecessor decíduo. Relato do caso: Uma menina de 11 anos de idade foi encaminhada à Clínica de Odontopediatria devido ao atraso na erupção do incisivo central superior direito. As radiografias mostraram o incisivo central impactado localizado abaixo da espinha nasal anterior e seu ápice paralelo ao plano palatino e a presença de um odontoma. A cirurgia para remoção do odontoma foi realizada sob anestesia geral e duas perfurações na coroa do dente impactado foram realizadas para a tração ortodôntica. O alinhamento correto foi alcançado após 18 meses e não foram encontradas alterações clínicas ou radiográficas significativas. Conclusão: O manejo ortodôntico foi realizado com sucesso, e um resultado estético positivo combinado à oclusão adequada demonstrou os resultados satisfatórios deste caso.

Judgement in artificial eruption of embedded teeth from an oral surgery perspective: review article

Impacted teeth are a frequent phenomenon encountered by every clinician. The artificial eruption of embedded teeth is the process of directing an impacted tooth into normal occlusion. This procedure is currently attracting attention, with the aim of finding the best technique to use according to each case. This article presents key information regarding impacted incisors, canines, and premolars. In addition, we describe the most common techniques to use for artificial eruption, the open and closed techniques. We review the literature concerning these techniques and outline how clinicians can manage every type of impacted tooth.

Lesión quística en un premolar superior relacionada con un molar primario pulpotomizado / Lesão cística num pré-molar superior relacionada com um molar decíduo pulpotomizado / Cystic lesion on an upper premolar related to pulpotomized primary molar

La pulpotomía es un tratamiento endodóncico frecuentemente realizado en niños. A pesar de que se trata de un procedimiento seguro, se han reportado efectos secundarios. Caso clínico: Un niño de 10 años de edad llegó para revisión dental. Los resultados de los rayos X mostraron una lesión radiolúcida por encima del segundo molar primario superior izquierdo, relacionada con el diente permanente. La extracción de los primeros y segundos molares primarios se realizó bajo anestesia local. La lesión quística se eliminó quirúrgicamente, y el análisis histopatológico mostró un quiste dentígero inflamatorio. Una cavidad casomarsupialización fue creada para permitir la erupción de los premolares. Después de un año de seguimiento, el hueso se había regenerado totalmente y los premolares habían erupcionado completamente. Conclusión: Este caso resalta la necesidad de una supervisión regular de los dientes pulpotomizados, incluso si están asintomáticos, además de la fase de erupción de los dientes permanentes y primarios. La marsupialización del quiste dentígero permitió el tratamiento eficaz y la preservación del premolar involucrado.

A pulpotomia é um tratamento endodôntico frequentemente realizado em crianças. Ainda que seja um procedimento seguro, efeitos colaterais foram reportados. Relato de caso: Um menino de 10 anos veio para um check-up dentário. Os resultados da radiografia mostraram uma lesão radiolúcida acima do segundo molar superior esquerdo, relacionada com o dente permanente. A extração dos primeiros e segundos molares decíduos foi realizada sob anestesia local. A lesão cística foi removida cirurgicamente e a análise histopatológica revelou um cisto dentígero inflamado. Uma cavidade marsupialização foi criada para permitir a erupção dos pré-molares. Depois de um ano de acompanhamento, o osso encontrava-se completamente regenerado e os pré-molares tinham erupcionado completamente. Conclusão: Este relato de caso destaca a necessidade de uma supervisão regular dos dentes pulpotomizados, mesmo se estes são assintomáticos, tal como acontece na fase de erupção dos dentes permanentes e decíduos. A marsupialização do cisto dentígero proporcionou um tratamento eficaz e permitiu a preservação do pré-molar envolvido.

Pulpotomy is a frequent endodontic treatment performed in children. Even though it is a safe procedure, side effects have been reported. Case Report: A 10-year-old boy came for a dental checkup. X-ray findings showed a radiolucent lesion above the maxillary second deciduous left molar, related to the permanent tooth. Extraction of the first and second deciduous molars was realized under local anesthesia. The cystic lesion was removed surgically, and histo-pathological analysis showed an inflammatory dentigerous cyst. A marsupialization cavity was created to allow eruption of the premolars. After a one-year follow-up, the bone had completely regenerated, and premolars had completely erupted. Conclusion: This case report highlights the need for regular supervision of pulp treated teeth, even if they are asymptomatic, as well as eruption phase of permanent and deciduous teeth. Marsupialization of the dentigerous cyst provided effective treatment and allowed preservation of the involved premolar.

Concurrent SHORT syndrome and 3q duplication syndrome

SHORT syndrome is an extremely rare congenital condition due to a chromosomal mutation of the PIK3R1 gene found at 5q13.1. SHORT is a mnemonic representing six manifestations of the syndrome: (S) short stature, (H) hyperextensibility of joints and/or inguinal hernia, (O) ocular depression, (R) Rieger anomaly, and (T) teething delay. Other key aspects of this syndrome not found in the mnemonic include lipodystrophy, triangular face with dimpled chin (progeroid facies, commonly referred to as facial gestalt), hearing loss, vision loss, insulin resistance, and intrauterine growth restriction (IUGR). 3q duplication syndrome is rare syndrome that occurs due to a gain of function mutation found at 3q25.31-33 that presents with a wide array of manifestations including internal organ defects, genitourinary malformations, hand and foot deformities, and mental disability. We present a case of a 2 year and 3 month old male with SHORT syndrome and concurrent 3q duplication syndrome. The patient presented at birth with many of the common manifestations of SHORT syndrome such as bossing of frontal bone of skull, triangular shaped face, lipodystrophy, micrognathia, sunken eyes, and thin, wrinkled skin (progeroid appearance). Additionally, he presented with findings associated with 3q duplication syndrome such as cleft palate and cryptorchidism. Although there is no specific treatment for these conditions, pediatricians should focus on referring patients to various specialists in order to treat each individual manifestation.

Surgical extrusion of a maxillary premolar after orthodontic extrusion: a retrospective study

OBJECTIVES: Crown-root fracture and cervical caries in maxillary premolars constitute a challenge in cases of subgingival placement of restoration margins. Surgical extrusion has been practiced successfully in permanent anterior teeth. The aim of the present retrospective study was to assess the clinical outcome of surgical extrusion after orthodontic extrusion in maxillary premolars. MATERIALS AND METHODS: Twenty-one single, tapered root maxillary premolars with subgingival crown-root fracture or caries were included. Presurgical orthodontic extrusion was performed on all teeth to prevent root resorption. Extent of extrusion and rotation was determined based on crown/root ratio. The postoperative splinting period was 7 to 14 days. Clinical and radiographic examination was performed at an interval of 1, 2, and 3 months. RESULTS: After the mean follow-up of 41.9±15.2 months, failure was observed as increased mobility in 3 of 21 cases. No significant difference was observed in the outcome of surgical extrusion based on tooth type, age, sex, 180° rotation, or time for extraction. Furthermore, marginal bone loss was not observed. CONCLUSION: Surgical extrusion of maxillary premolars can be a possible therapeutic option in cases of subgingival crown-root fracture.

Full mouth rehabilitation in patient with loss of vertical dimension and deep bite due to tooth wear / 대한치과보철학회지

Excessive tooth wear can cause irreversible damage to the occlusal surface and can alter the anterior occlusal relationship by destroying the structure of the anterior teeth needed for esthetics and proper anterior guidance. The anterior deep bite is not a morbid occlusion by itself, but it may cause problems such as soft tissue trauma, opposing tooth eruption, tooth wear, and occlusal trauma if there are no stable occlusal contacts between the lower incisal edge against its upper lingual surface. The most important goal of treatment is to form stable occlusal contact in centric relation. In this case report, patients with decrease in vertical dimension and anterior deep bite due to maxillary posterior tooth loss and excessive tooth wear were treated full mouth rehabilitation with increased vertical dimension to regain the space for restoration and improve anterior occlusal relationship and esthetics. The functional and aesthetic problems of the patient could be solved by the equal intensity contact of all the teeth in centic relation (CR), anterior guidance in harmony with the functional movement, and restoration of the wear surface beyond the enamel range.

A case of unexpected adjacent tooth extrusion after implant fixed prosthetic treatment, who had undergone mandibular resection and reconstruction due to ameloblastoma / 대한치과보철학회지

Ameloblastoma is a benign odontogenic epithelial tumor with high recurrence rate and requires extensive resection of the surrounding tissue and reconstruction of defect site. Because of the anatomical limitation of the reconstruction site, prosthetic treatment with implants is the first recommendation. This is a case of prosthetic restoration of the reconstruction site with implant fixed prosthesis in patient who underwent mandibular resection and iliac bone reconstruction due to ameloblastoma. However 14 months after completion of implant prosthesis, adjacent natural tooth erupted unexpectedly, resulting in 1mm infra-occlusion occurred including posterior implant prosthesis and anterior natural teeth. In adults, implant infra-occlusion may occur due to residual growth after placement of the maxillary anterior implant. But this case, hypo-occlusion of molar implant and open bite of anterior natural teeth is occurred due to extrusion of adjacent tooth, is rare. Thus we report the treatment process including orthodontic treatment with intrusion of the posterior tooth, and investigate the causes of sudden, unexpected tooth extrusion.

A Novel RUNX2 Mutation in a Korean Family with Cleidocranial Dysplasia / 대한소아치과학회지

Cleidocranial dysplasia (CCD) is an autosomal-dominant disease characterized by the delayed closure of cranial sutures, defects in clavicle formation, supernumerary teeth, and delayed tooth eruption. Defects in the Runt-related transcription factor 2 (RUNX2), a master regulator of bone formation, have been identified in CCD patients. The aim of this study was to identify the molecular genetic causes in a CCD family with delayed tooth eruption.The 23-year-old female proband and her mother underwent clinical and radiographic examinations, and all coding exons of the RUNX2 were sequenced. Mutational analysis revealed a single nucleotide deletion mutation (NM_001024630.4 : c.357delC) in exon 3 in the proband and her mother. The single C deletion would result in a frameshift in translation and introduce a premature stop codon [p.(Asn120Thrfs*24)]. This would result in the impaired function of RUNX2 protein, which may be the cause of delayed eruption of permanent teeth in the family.

Eruption Stage of Permanent Teeth Using Diagnostic Model Analysis in Kyung Hee Dental Hospital / 대한소아치과학회지

Individual dental age is used as an index of chronological age estimation and is an important indicator of the child's growth stage. Dental age does change greatly over time, but it changes constantly. And updating information about this change is important. The purpose of this study was to provide information about tooth eruption stage using diagnostic model analysis and to investigate tooth eruption sequence and estimate chronological age based on this information.Tooth eruption stages were measured on a diagnostic model from 488 patients in 5 – 13 year old children. Based on the information on eruption stage, eruption sequence in maxilla was first permanent molar, central incisor, lateral incisor, first premolar, canine, second premolar and second permanent molar. Eruption sequence in mandible was first permanent molar, central incisor, lateral incisor, canine, first premolar, second premolar and second permanent molar. There were significant differences between males and females in the eruption stage of canine, first and second premolar, and second molar at several ages. The chronological age of male and female was estimated by the coefficient of determination of 0.816, 0.826 respectively.

Case series of cleidocranial dysplasia: Radiographic follow-up study of delayed eruption of impacted permanent teeth

This report describes 3 cases of cleidocranial dysplasia (CCD) and presents relevant findings on long-term follow-up radiographic images of impacted permanent teeth with delayed eruption. Radiographic images of 3 CCD patients were reviewed retrospectively. These images were mainly composed of panoramic and skull radiographs, and the follow-up periods were 3, 13, and 13 years, respectively. The distinct features revealed by the images were described, and the eruption state of impacted permanent teeth was evaluated. The features common to the 3 cases were multiple supernumerary teeth, the presence of Wormian bone, underdevelopment of the maxilla and the maxillary sinus, and clavicular hypoplasia. The eruption of impacted permanent teeth was not observed without proper dental treatment in adult CCD cases, even after long time periods had elapsed. When proper orthodontic force was applied, tooth movement was observed in a manner not significantly different from the general population.

Mandibular anterior crowding: normal or pathological?

ABSTRACT The teeth become very close to each other when they are crowded, but their structures remain individualized and, in this situation, the role of the epithelial rests of Malassez is fundamental to release the EGF. The concept of tensegrity is fundamental to understand the responses of tissues submitted to forces in body movements, including teeth and their stability in this process. The factors of tooth position stability in the arch - or dental tensegrity - should be considered when one plans and perform an orthodontic treatment. The direct causes of the mandibular anterior crowding are decisive to decide about the correct retainer indication: Should they be applied and indicated throughout life? Should they really be permanently used for lifetime? These aspects of the mandibular anterior crowding and their implication at the orthodontic practice will be discussed here to induct reflections and insights for new researches, as well as advances in knowledge and technology on this subject.

RESUMO Os dentes ficam muito próximos quando estão apinhados, mas suas estruturas permanecem individualizadas e, nessa situação, o papel dos restos epiteliais de Malassez é fundamental para liberar o EGF. A tensigridade é um conceito chave para compreender as respostas dos tecidos submetidos às forças nos movimentos corporais, incluindo os dentes e sua estabilidade nesse processo. Os fatores da estabilidade de posição de um dente na arcada dentária — ou tensigridade dentária — devem ser considerados quando se planeja e finaliza um caso na prática clínica ortodôntica. As causas diretas do apinhamento dentário anteroinferior são determinantes para se refletir se a contenção deve ser mesmo indicada e aplicada por toda a vida e se, necessariamente, deve ser usada de forma permanente. Esses aspectos do apinhamento dentário anteroinferior e suas implicações na prática clínica serão aqui abordados para induzir reflexões e insights de novas pesquisas, bem como avanços no conhecimento e tecnologia sobre esse assunto.

Craniometaphyseal dysplasia: Report of 2 cases with an emphasis on panoramic imaging features

Craniometaphyseal dysplasia (CMD) is a rare hereditary disorder characterized by hyperostosis of the craniofacial bones and flared metaphyses of the long bones. Although some reports have described the dentomaxillofacial characteristics of CMD, including increased density of the jaw, malocclusion, and delayed eruption of the permanent teeth, only a few studies have reported the distinct imaging features of CMD on panoramic radiography. This report presents 2 cases of confirmed CMD patients with an emphasis on panoramic imaging features. The patients' images revealed hyperostosis and sclerosis of the maxilla and mandibular alveolar bone, but there was no change in the mandibular basal bone. In both cases, the mandibular condyle heads exhibited a short clubbed shape with hyperplasia of the coronoid process. For patients without clear otorhinolaryngological symptoms, common radiologic features of CMD could be visualized by routinely-taken panoramic radiographs, and further medical examinations and treatment can be recommended.

A case of full mouth rehabilitation in patient with loss of vertical dimension and deep bite due to tooth wear / 대한치과보철학회지

The collapse of the posterior occlusion destroys the normal occlusal plane and causes excessive wear reducing the vertical dimension. Reduced vertical dimension of occlusion causes not only aesthetic and functional problems but also overloading on the temporomandibular joints and abnormalities of muscle nerve system. In order to improve the collapsed occlusal relationship, it is necessary to consider the change of the vertical dimension. It is necessary to make a precise diagnosis and analysis before the treatment and to evaluate the adaption of patient to the new vertical dimension of occlusion. A patient with excessive overbite often has occlusal problems of tooth wear and tooth eruption. Considering these considerations, overall prosthodontic restoration is required to solve the problem. A patient of 68 year old man in this case who suffered major tooth wear and maxillary posterior teeth loss was treated with elevation of vertical dimension of occlusion by maxillary removable dental prosthesis and mandibular fixed prosthesis.

Postoperative malocclusion after maxillofacial fracture management: a retrospective case study / 대한악안면성형재건외과학회지

PURPOSE: Various complications occur when a maxillofacial fracture is malunionized or improperly resolved. Malocclusion is the most common complication, followed by facial deformity, temporomandibular joint disorder (TMD), and neurological symptoms. The purpose of this study was to evaluate the dental treatment of postoperative complications after maxillofacial fracture. MATERIALS AND METHODS: In this study, nine patients with a postoperative complication after maxillofacial fracture who had been performed the initial operation from other units and were referred to the authors’ department had been included. Of the nine patients, six had mandibular fractures, one had maxillary fractures, one had maxillary and mandibular complex fractures, and one had multiple facial fractures. All the patients had tooth fractures, dislocations, displacements, and alveolar bone fractures at the time of trauma, but complications occurred because none of the patients underwent preoperative and postoperative dental treatment. Malocclusion and TMD are the most common complications, followed by dental problems (pulp necrosis, tooth extrusion, osteomyelitis, etc.) due to improper treatment of teeth and alveolar bone injuries. The patients were referred to the department of dentistry to undergo treatment for the complications. One of the nine patients underwent orthognathic surgery for a severe open bite. Another patient underwent bone reconstruction using an iliac bone graft and vestibuloplasty with extensive bone loss. The other patients, who complained of moderate occlusal abnormalities and TMDs such as mouth-opening limitation, underwent occlusal treatment by prosthodontic repair and temporomandibular joint treatment instead of surgery. RESULTS: One patient who underwent orthognathic surgery had complete loss of open bite and TMD after surgery. One patient who underwent reconstruction using an iliac bone graft had a good healing process. Other patients were treated with splint, injection, and physical therapy for mouth-opening limitation and temporomandibular joint pain. After treatment, the TMDs were resolved, but the remaining occlusal abnormalities were resolved with prosthetic restoration. CONCLUSIONS: Considering the severity of malocclusion and TMJ symptom and the feasibillity of reoperation, nonsurgical methods such as orthodontic and prosthodontic treatments and splint therapy can be used to manage the dental and TMD complication after the trauma surgery. However, reoperation needs to be strongly considered for severe malocclusion and TMD problem. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40902-018-0167-z) contains supplementary material, which is available to authorized users.

Classical oral manifestations of Dyke-Davidoff-Masson syndrome: a case report with review of the literature

Dyke-Davidoff-Masson syndrome is a non-inherited rare condition that presents during childhood and is characterized by seizures, hemiplegia, mental retardation, cerebral hemiatrophy, calvarial thickening, and hyperpneumatization of the frontal sinuses. The present article highlights a case of a 12-year-old male child with additional clinical findings of café-au-late pigmentation and ocular lipodermoid. This is the first case report of Dyke-Davidoff-Masson syndrome to describe oral manifestations, such as unilateral delayed eruption of teeth, hypoplasia, and taurodontism, which could be unique and characteristic of this condition. Oral health care providers and physicians should be aware of these oral observations as dental referrals could warrant early dental prophylactic care and can be useful in diagnosing the possible time of injury and type of Dyke-Davidoff-Masson syndrome.

Factors Affecting Length of Impacted Maxillary Central Incisors after Surgical-Orthodontic Treatment / 대한소아치과학회지

The purpose of this study is to identify the factors affecting the treatment outcome after surgical-orthodontic treatment of the maxillary impacted incisors using multiple regression analysis. The study enrolled 83 patients who had surgical-orthodontic treatment in impacted maxillary central incisor between January 2005 and December 2015. Possible explanatory variables related to the prognosis of impacted incisor were age, gender, tooth developmental stage, height, position and angle of the teeth.The results of multiple regression analysis showed that as the height of the stem cell from apical papilla (SCAP) increased, the tooth length ratio increased by 0.345 units (p < 0.01). There was no statistically significant difference in gender, tooth development stage, distance and angle between the center line and the tooth, and the height of incisal tip of the tooth. In conclusion, the height of the SCAP of the impacted central incisor is factor affecting the tooth length after orthodontic traction.

Relationship between Pre-Eruptive Buccal Pit Radiolucency and Restoration in Mandibular First Molar / 대한소아치과학회지

Pre-eruptive intracoronal resorption (PEIR) is a developmental defect in the crown of a pre-eruptive tooth. The purpose of this study was to investigate the relationship between the size of the pre-eruptive buccal pit radiolucency, which is suspected as PEIR on a panoramic radiography, and the need for restoration after the eruption of a mandibular first molar.The experimental group included 35 mandibular first molars, in which lesions requiring definite restoration were observed during eruption. The control group consisted of 64 sound mandibular first molars after eruption. The sex, age, tooth position, tooth formation stage, size of the pre-eruptive buccal pit radiolucency, and restoration methods in the experimental group and control group were examined.Compared with the control group, the experimental group showed a statistically significant difference in the size of the buccal pit before eruption. The buccal pit size for predicting the need for restoration was further examined by receiver operating characteristic curve analyses, and the area under the curve was 0.813 ± 0.047.If radiolucency is observed at the buccal pit of the mandibular first molar before eruption, periodic observations and post-eruption examinations are required.