Complicated crown root fracture is a serious combined fracture of the enamel, dentin, and cementum in dental trauma. The treatment method is complicated. During the procedure, the condition of pulp, periodontal, and tooth body should be thoroughly evaluated, and a multidisciplinary approach combined with sequential treatment is recommended. This case reported the different treatment and repair processes of one case of two affected teeth after complicated crown root fracture of upper anterior teeth, including regrafting of broken crown after flap surgery at the first visit, direct resin repair to remove broken fragments, and pulp treatment and post-crown repair at the second visit. After 18 months of follow-up, the preservation treatment of the affected teeth with complicated crown root fracture was achieved. Therefore, fragment reattachment and post-crown restoration are feasible treatment options for children with complicated crown root fracture.
复杂冠根折是牙外伤中一类累及牙髓的釉质-牙本质-牙骨质联合折断，治疗方法复杂，过程中需综合考虑牙髓、牙周及牙体情况，进行多学科联合序列治疗。本病例报道了1例上前牙复杂冠根折后2颗患牙不同的治疗修复过程，包括初诊时翻瓣术后11牙的断冠再接和21牙腭侧去除断裂碎片直接树脂修复，以及复诊时11、21牙的牙髓治疗及冠部修复，经过18个月的随访，患牙的功能及牙周状况维持良好，美观性也得到了患儿及家长的肯定。对于儿童复杂冠根折上前牙，断冠再接及桩冠修复是一种可行的治疗方案。.

BACKGROUND: Double teeth are dental anomalies that can lead to aesthetic and orthodontic problems.
METHODS: This report discusses two cases involving the multidisciplinary management of permanent maxillary left lateral incisors fused with a supernumerary tooth in two girls aged 9 and 10. Following intraoral and radiographic examinations, one was diagnosed with fusion, and the other was diagnosed with concrescence. The crown of the fused incisor was separated using a burs and extracted intraorally. The concrescent incisor was separated along its length using a laser and intentionally replanted extraorally. After a 6-year follow-up, no pathological signs were observed in the fused incisor. However, after an 11-year follow-up, external resorption was observed in the concrescent incisor.
CONCLUSIONS: Both incisors remained asymptomatic throughout the observation period. This case report highlights two different and effective methods employed to preserve the natural function, form, and aesthetics of double incisors.

Dental trauma is the most frequently encountered injury that requires immediate attention. Several procedures are available to manage broken teeth afflicted by trauma but the choice of procedure depends upon structural, functional, and esthetic considerations. The goal is to choose the least invasive, immediate, and simple technique that can meet the patient\'s expectations. The aim of this case series is to present a minimal intervention approach as a primary treatment option for the reattachment of trauma-induced fractured coronal tooth fragments, to preserve and enhance function, esthetics, and structure.

临床诊疗过程中常见前牙美学区因不同原因导致的牙龈退缩致粉白美学不协调，重建生物学宽度、改善牙周生物型、获得协调的龈缘曲线对再次治疗成功至关重要。本文报道1例上前牙修复多年后多牙位出现牙龈退缩的患者，要求二次修复改善美观，通过明确诊断及数字化微笑设计美学分析，经上皮下结缔组织移植行根面覆盖术解决根面暴露，同期联合牙冠延长术延长临床牙冠，改善患者上前牙龈缘曲线协调性，随访5年龈缘位置稳定，为二次修复重建理想的粉白美学曲线提供了一定的术式参考。.

The use of dental ceramics on anterior teeth is associated with predictable and long-lasting esthetic results. However, treatment on darkened substrates is challenging. Various conservative options, including ceramic veneers, are available to change the shape and color of anterior teeth. The aim of this case report is to describe the esthetic rehabilitation of a darkened central incisor in a maxillary anterior region that had irregular gingival contours, multiple composite resin restorations, and unsatisfactory tooth shapes. Harmony was restored through periodontal recontouring surgery, placement of a lithium disilicate crown (consisting of a veneer cemented to a coping) on the darkened central incisor, and placement of lithium disilicate veneers on the other maxillary anterior teeth.

BACKGROUND: The decoronation technique has been described in literature since 1984 and, based on the available results, it can lead to considerable benefits for the repair and rehabilitation of ankylosed teeth. Based on these reports, one could expect that this procedure would be well known by the dental community. However, this fact does not seem to be true, and this procedure is not widely used.
METHODS: The objective of this paper is to present appropriate literature that discusses decoronation and evaluate the perspectives of the procedure, both in relation to the technique and the long-term benefits for the patient. An integrative literature review at PubMed, ScieELO, and Lilacs databases was performed using the keywords \"decoronation\", \"ridge preservation decoronation\", \"decoronation ankylosis\". In addition, a case report will be presented to demonstrate the technique in a systematic and detailed manner.
RESULTS: Considering the inclusion criteria, 27 articles that present consistency regarding decoronation were selected.
CONCLUSIONS: There is scarce availability of scientific works related to the topic, to corroborate and discuss the technique. The present paper reinforces the benefits of this procedure, and revisit decoronation, attempting to provide a possible treatment for ankylosed teeth in growing patients.

OBJECTIVE: The aim of this case series study is to describe where the crowns of the permanent mandibular canines are located in early childhood in relation to the preceding primary canines.
METHODS: From a sample of 31 orthopantomograms from children, younger than 5 years of age, the location of the mandibular canines was analysed by visual inspection. The radiographs were taken due to different deviations in the dentition and forwarded during a period of 28 years for elucidating different diagnostic questions. From an embryological point of view, the primary canine was considered as a stable structure in the jawbone. A longitudinal axis through the primary canine was named the canine axis. The initial site of the permanent crown was the site, where the permanent lamina \"placed\" the tooth bud for final development. A normal site was determined when the canine axis passed though the permanent crown and a pathological site was determined when this did not happen.
RESULTS: Normal sites for the permanent crowns were observed in 19 cases and abnormal sites in 8 cases. In four cases, the interrelationship between the canine axis and the permanent crown could not be decided. The study demonstrated that the tooth germ for the permanent canine can start initial formation misplaced distally or mesially to the preceding primary tooth.
CONCLUSIONS: The study demonstrates different malpositions of the initial crowns of the permanent mandibular canines in children younger than 5 years of age. The results are considered of importance for future understanding of the aetiology behind ectopic mandibular canines.

Dental trauma in primary teeth can cause irreversible changes in the development of permanent tooth germs, including enamel hypoplasia, crown dilaceration, and root dilaceration. This article discusses multidisciplinary treatment of enamel hypoplasia and root dilaceration in the maxillary left central incisor of an 11-year-old girl. A 10-year follow-up is reported to demonstrate the long-term clinical outcomes. At the initial presentation, the patient\'s mother reported that the child had an accident at the age of 2 years, resulting in intrusive luxation of the primary maxillary left central incisor. After the accident, the patient was monitored for eruption of the permanent successor tooth, and different approaches were proposed during each period of the patient\'s development on the basis of the clinical diagnosis of root dilaceration and enamel hypoplasia. The crown was restored with composite resin, and the root defect was restored with resin-modified glass ionomer cement. After 10 years, the clinical outcomes highlight that the multidisciplinary approach was successful in preserving the natural tooth with good periodontal health conditions.

Two fractured maxillary central incisors were restored via the crown fragment reattachment technique with adhesive systems and composite resin material. A long-term successful outcome was achieved after 4 years of follow-up. The patient presented with fractured maxillary central incisors, and a comprehensive intraoral and radiographic examination revealed that both teeth had extended crown fractures with no pulpal exposure (Class II, Ellis and Davey). The tooth fragments were thoroughly cleaned and inspected before being repositioned. Both fragments were in excellent condition with almost no pieces missing. Therefore, the proposed treatment was fragment reattachment. After verifying the repositioning and adaptation of the fractured fragments, a flowable composite was used to perform the reattachment procedure under rubber dam isolation. With modern dental adhesives, the reattachment of tooth fragments in good condition is considered a more conservative option for restoring tooth morphology, esthetics, and function. Although one tooth showed signs of irreversible pulpitis and required root canal treatment 2 weeks after the restoration, the clinical and radiographic evaluations at the 4-year follow-up visits confirmed the success of the restorative treatment. The restorations showed good functional and esthetic outcomes after 4 years of follow-up.

This case report describes a post-retained crown placed on an anterior tooth that survived 78 years, with restoration repairs at 40 years and 58 years following placement. The history of the patient\'s other dental restorations and care showed a similar longevity.