A patient in the early mixed dentition was experiencing "difficulty in eating." The right mandibular posterior teeth were telescoped within the maxillary arch. The mandibular midline deviated to the left of the maxillary midline. With the midlines aligned, posterior occlusion was minimal. By activating a lingual arch, the mandibular arch width was increased to establish a posterior occlusion. A...

The morphologic relationship of the crown structures of the maxillary second deciduous molar (m2) and the first permanent molar (M1) was investigated with odontometric methods. Materials used were 124 male dental casts taken from Chinese living in Kaohsiung (Taiwan). The mesiodistal and buccolingual diameters, cusp sizes, and intercusp distances were measured. The mean crown diameters were larg...

Thorough knowledge about the root canal variations is essential for the predictable endodontic treatment outcome. The root and root canal anatomy of maxillary first molar varies greatly. A Pub-med literature search about single rooted single canalled maxillary first molar was done to know its details such as incidence, diagnostic method used, age, sex and ethnic background of patient. This arti...

     Introduction: Objective: This study aimed to assess the possible variations in root canal anatomy and topography of the apices of first and second maxillary molars. Materials and methods: A total of 67 first and second maxillary permanent molars were collected. Access cavity was prepared and 2% methylene blue was injected. The teeth were demineralized by 5% nitric acid and cleared with met...

A common failure in endodontic treatment of the permanent maxillary first molars is likely to be caused by an inability to locate, clean, and obturate the second mesiobuccal (MB) canals. Because of the importance of knowledge on these additional canals, there have been numerous studies which investigated the maxillary first molar MB root canal morphology using in vivo and laboratory methods. In...

This report describes the nonsurgical treatment of a patient with skeletal Class II protrusion and severe crowding. A 20-year-old woman presented with the chief complaint of lip protrusion and crowding. To correct the Class II relationship, severe crowding, and lip protrusion, distal movement of the maxillary first molars using indirect miniscrew anchorage and nickel-titanium coil springs, alon...

Non-evaporable Ti-Zr-V ternary getters (NEGs) were studied by means of excitation energy resolved photoelectron spectroscopy (ERXPS). We attempted a quantitative study of the in-depth redistribution of the NEG components during activation. The samples were prepared ex-situ by DC magnetron sputtering on a stainless-steel substrate. The ERXPS measurements were carried out at two incident photoele...

Background: The thickness of maxillary sinus floor may reduce markedly because of protrusion of root apices of posterior teeth into the sinus. The possibility of oro-antral communication after extraction is highest for a maxillary first molar, as this tooth erupts first and is frequently extracted early. Aim: To assess the relationships between the roots of the maxillary first molar and the max...

The root system of perennials is composed of the roots of different growth years. The nutrient storage capacities and activities of roots are an important basis for judging root components and plant senescence. In this research, changes in the contents of water-soluble carbohydrate (WSC) were used as indicators of the nutrient storage and activity of roots of different life years. From the earl...