Fused roots of maxillary molars: characterization and prevalence in a Latin American sub-population: a cone beam computed tomography study

OBJECTIVES: The upper molars generally have three roots; therefore, different combinations of fusion can occur, increasing the possibility of finding more complex root canal systems. The purpose of this study was to evaluate the prevalence and characterization of fused roots in first and second maxillary molars using cone-beam computed tomography (CBCT) in a Colombian population. MATERIALS AND METHODS: A total of 1274 teeth were evaluated, of which 534 were maxillary first molars and 740 were maxillary second molars. Axial sections were made at the cervical, middle, and apical levels to determine the prevalence of root fusion and the types of fusion. RESULTS: Overall, 43% of the molars (n = 551) presented some type of fused root. Root fusion was present in 23.4% of the maxillary first molars. The most frequent type of fused root was type 3 (distobuccal-palatal; DB-P) (58.9%). Root fusion was observed in 57.6% of the maxillary second molars, and the most prevalent type of fused root was type 6 (cone-shaped) (45.2%). Of the maxillary molars, 12.5% were classified as C-shaped. CONCLUSION: Within the limitations of this study, there was a high prevalence of fused roots in maxillary molars in the Colombian population, mainly in the maxillary second molars. In first molars, the most common type of fused root was type 3 (DB-P) and in second molars, the most common type was type 6 (cone-shaped). Additionally, molars with root fusion presented variation at different levels of the radicular portion, with implications for treatment quality.

Reto de la endodoncia: conducto en "C" / Endodontics challenge: C-shaped root canal

El correcto manejo de la configuración del sistema de conductos radiculares en forma de C es un reto en la práctica endodóntica. La complejidad de este tipo de conductos hace que su diagnóstico, instrumentación y sobretodo su limpieza y obturación sea una tarea ardua en la mayoría de las ocasiones. El sistema de conductos tipo C en molares inferiores fue descripto por primera vez en 1979, por Cooke y Cox. Es una variación anatómica vista principalmente en segundos molares inferiores con una prevalencia de hasta un 31,5% en población asiática, aunque también puede ocurrir en premolares y molares, tanto superiores como inferiores. El rasgo anatómico principal de los conductos en C es la presencia de una aleta o cortina que conecta los conductos radiculares individuales. La cámara pulpar tiene un orificio que describe un arco de 180° o más. Se realiza un reporte de dos casos clínicos de conductos en C en segundo molar superior e inferior (AU)

The right management of the configuration of C-shaped root canal system is a challenge in endodontic practice. The complexity of this type of canals makes its diagnosis, instrumentation and especially its cleaning and obturation an arduous task in most of the occasions. The C-shaped canal system in mandibular molars was first described in 1979 by Cooke and Cox.It is an anatomical variation mainly seen in mandibular second molars with a prevalence of up to 31.5% in Asian population, although it can also occur in premolars and molars, both maxillary and mandibular. The main anatomical feature of the C-shaped canals is the presence of a fin or web connecting the individual root canals. The pulp chamber has an orifice that describes an arc of 180° or more. A report of two clinical cases of C-shaped canals in second maxillary and mandibular molar is presented (AU)

Cone Beam Computed Tomography for Exploring Morphology of Mandibular First Molar.

Aims: The root canals have complex morphology and vary widely among individuals variations. The objective of this research was to analyse the morphology of root canals and existence of extra canals in mandibular first molar in subpopulation of Al-Medina Al-Munawarah. Study Design: Experimental/Analytical. Place and Duration of Study: College of dentistry, Taibah University, Madinah Munawwarrah, Saudi Arabia, 2014. Methodology: This study was conducted using freshly extracted mandibular first molars (n=100). All teeth were examined for morphology of roots, root canals and apical foramen by Cone Beam Computed Tomography (CBCT). The root canals configuration was classified using Vertucci's classification. Results: All mandibular first molars (100%) had two distinct and clearly separated roots. There was a high probability of two canals (92.5%) in mesial root compared to the distal root that contain two canals only in 20% of teeth. There was no occurrence of more than two roots or more than two canals in any of the roots in the selected teeth. The majority of distal roots (80%) had single canal with type I canal configuration followed by type III (10%), type V (7.5%) and type II (2.5%). The mesial roots presented comparatively complex canals configuration. Type I canal configuration was observed in only 7.5% teeth. The incidence of C shaped canals was very low (2.5%). Conclusion: The occurrence of single rooted mandibular first molars as well as supernumerary roots is very unlikely. The incidence of two distinct canals in mesial root is high (>92%), however distal roots mainly represented one canal (80%).

Prominent zygomatic complex reduction by C-type osteotomy / 中华医学美学美容杂志

Objective To explore the operation of C-type osteotomy for reduction of prominent zygomatic complex. Methods Based on the severity and characteristics of prominent zygomaitc complex, Ctype osteotomy was designed for the malar complex reduction by using oral and minor pre-auricular approaches under general anaesthesia. Two paralleled osteotomic lines of C-type were marked from zygomatic alveola to the conjunction of lateral orbital margin and zygomatic arch through the inferio-lateral edge of orbit. The extension of zygomatic arch reduction was determined the width of two osteotomic lines. The bone which marked lines was removed by reciprocating saw and osteotome. The zygomatic arch root was osteotomiced by pre-auricular approaches. Then, the zygomatic complex could move freely towards superior-medial position. Finally, the zygoma was fixed with titanium mini-plates. Results 12 patients with prominent zygomatic complex had been successfully operated by C-type osteotomy from July 2006 to April 2009. Of them, six cases were symmetrical and six cases were unsymmetrical. Postoperative follow-up for 4-24 months, infection was not occurred, and the scar of pre-auricular incision was not obvious. All the patients obtained positive results. Conclusion C-type osteotomy for correction of prominent zygomtic complex through intra-oral and minor pre-auricular approach is an effective surgical method and gives superior results. It preserves the intactness of maxillary sinus, prevents facial slack, and is especially effective for patients with prominent zygomatic arch.