Crown root fracture imaging on Cone Beam Computed Tomography

Objectives: This case report is aimed to describe the features of CBCT in assessing tooth fracture. Case Report: A 50-year-old man came with complaints of discomfort in the right lower jaw area, especially when used for chewing. The results of the percussion test were positive. CBCT examination showed that there was a radiolucent image of the enamel in the middle of the crown root to the 1/3 apical of the mesial and distal roots of tooth 47 which resembled a fracture line. The fracture line also appears to have reached the pulp. In addition, there is a well-defined radiolucent appearance with an irregular shape along the root from the buccal to lingual alveolar crest and accompanied by a decrease in the alveolar crest. The fracture that occurred in this case was from the enamel to the apical and involved the pulp, thus the radiodiagnosis on tooth 47 was a complicated crown root fracture with lateral periodontal cyst. Conclusion: CBCT can be used to help identify tooth fractures by obtaining a more accurate and useful value in differentiating conditions associated with fractures. CBCT provides data on the size and length of the fracture line and the size of the lesion.

Multidisciplinary Approach to Complicated Crown-root Fracture Treatment: A Case Report

SUMMARY Treatment of complicated crown-root fractures is one of the most challenging within the various types of dental trauma and requires a multidisciplinary approach. This paper reports the complicated crown-root fracture of a maxillary right central incisor, in which there was esthetic, functional, and biologic (endodontic and biologic width invasion) involvement. A 15-year-old male patient presented to the dental clinic one month after suffering trauma with a complicated crown-root fracture on tooth 8. The patient had previously undergone endodontic treatment and was sent to have periodontal surgery to reestablish the biological width on the palatal surface. Following the surgery, a fiberglass post was cemented, and the fragment was reattached. This approach allows the exposure of the cervical margin, adequate isolation, and subsequent fragment reattachment in the same clinical appointment. Fragment reattachment is a viable approach as it is a simple and conservative procedure that restores the natural esthetic of the tooth and has superior resistance compared to a composite restoration. The patient’s cooperation in understanding the limitations of the treatment and maintaining adequate oral hygiene are very important to achieving a good prognosis of the case. After a 2-year clinical and radiographic follow-up period, the clinical protocol was found to be successful, and the tooth remained functional, esthetically favorable and asymptomatic.

Role of adhesive attachments in traumatic dental injury

Crown root cracking is uncommon, accounting for less than 7% of irreversible damage. All the hard tissues of the teeth (crust, dentin, and cementum), as well as the pulp and periodontal ligament, are commonly involved in these complicated fractures. The care of such instances offers major biological hurdles, and success is dependent on considering a variety of regenerative, endodontic, and temporal variables. Numerous clinical investigations demonstrate that adhesive coronal attachment might be an essential therapy for fractured teeth with crown roots. Because it maintains the original tooth, this technique may save the gums and decrease the time and expense of therapy. Before considering adhesive attachments for dental fractures, several factors should be considered-the site and size of the fracture, the fracture pattern, and the position of traumatized teeth. The aim of the article was to review the role of adhesive attachments in a traumatic dental injury.

APEXIFICATION REVISITED

Pulpal necrosis in permanent teeth with immature roots leads to development of roots which are very short, thin walled and an inadequate crown-root ratio, which overshadows their survival prognosis. Traditionally, the apexication procedure has consisted of multiple and long-term applications of calcium hydroxide to create an apical barrier to aid the obturation. Recently, articial apical barriers such as those made with mineral trioxide aggregate (MTA) have been used in teeth with necrotic pulps and open apices. More recently, procedures referred to as regenerative endodontics have received much attention as an option for these teeth. This paper reviews the past, present and recent concepts used for apexication.

Management of complicated crown root fracture using pizeo surgery, fiber post and fragment reattachment: A case report

A common type of fracture involving tooth is complicated crown root fracture of anterior teeth. The reattachment of the coronal fragment to the remaining tooth will provide better and long-lasting aesthetics, improved function and a positive psychological reaction. It is a simple and less difficult procedure if the original tooth fragments are retained after fracture. This paper reports about a case of complicated crown root fracture that was treated successfully using broken fragment adhesive reattachment and post placement.

Identification and Characterization of Short Crown Root 8, a Temperature-Sensitive Mutant Associated with Crown Root Development in Rice

Crown roots are essential for plants to obtain water and nutrients, perceive environmental changes, and synthesize plant hormones. In this study, we identified and characterized short crown root 8 (scr8), which exhibited a defective phenotype of crown root and vegetative development. Temperature treatment showed that scr8 was sensitive to temperature and that the mutant phenotypes were rescued when grown under low temperature condition (20 °C). Histological and EdU staining analysis showed that the crown root formation was hampered and that the root meristem activity was decreased in scr8. With map-based cloning strategy, the SCR8 gene was fine-mapped to an interval of 126.4 kb on chromosome 8. Sequencing analysis revealed that the sequence variations were only found in LOC_Os08g14850, which encodes a CC-NBS-LRR protein. Expression and inoculation test analysis showed that the expression level of LOC_Os08g14850 was significantly decreased under low temperature (20 °C) and that the resistance to Xanthomonas oryzae pv. Oryzae (Xoo) was enhanced in scr8. These results indicated that LOC_Os08g14850 may be the candidate of SCR8 and that its mutation activated the plant defense response, resulting in a crown root growth defect.

Conservative Treatment of Complicated Crown Fracture and Crown-Root Fracture of Young Permanent Incisor—A Case Report with 24-Month Follow-Up

The complicated crown-root fracture of young permanent teeth is an uncommon traumatic dental injury that is usually treated in a complex way and is demanding not only for the dentist but even for the treated child. In this case report, we present the conservative treatment of a maxillary central incisor in a 10-year-old boy after a traumatic dental injury. Treatment included partial pulpotomy and adhesive fragment reattachment after reflection of the mucoperiosteal flap. The patient was fully asymptomatic at 24-month follow-up, with an aesthetically acceptable outcome. Vital pulp therapy and adhesive fragment reattachment can be a viable treatment option for complicated crown-root fractures, especially when treating immature permanent teeth.

Exploiting natural variation in crown root traits via genome-wide association studies in maize

Background Root system architecture (RSA), which is determined by the crown root angle (CRA), crown root diameter (CRD), and crown root number (CRN), is an important factor affecting the ability of plants to obtain nutrients and water from the soil. However, the genetic mechanisms regulating crown root traits in the field remain unclear. Methods In this study, the CRA, CRD, and CRN of 316 diverse maize inbred lines were analysed in three field trials. Substantial phenotypic variations were observed for the three crown root traits in all environments. A genome-wide association study was conducted using two single-locus methods (GLM and MLM) and three multi-locus methods (FarmCPU, FASTmrMLM, and FASTmrEMMA) with 140,421 SNP. Results A total of 38 QTL including 126 SNPs were detected for CRA, CRD, and CRN. Additionally, 113 candidate genes within 50 kb of the significant SNPs were identified. Combining the gene annotation information and the expression profiles, 3 genes including GRMZM2G141205 (IAA), GRMZM2G138511 (HSP) and GRMZM2G175910 (cytokinin-O-glucosyltransferase) were selected as potentially candidate genes related to crown root development. Moreover, GRMZM2G141205, encoding an AUX/IAA transcriptional regulator, was resequenced in all tested lines. Five variants were identified as significantly associated with CRN in different environments. Four haplotypes were detected based on these significant variants, and Hap1 has more CRN. Conclusions These findings may be useful for clarifying the genetic basis of maize root system architecture. Furthermore, the identified candidate genes and variants may be relevant for breeding new maize varieties with root traits suitable for diverse environmental conditions.