A polygonal chain is a sequence of consecutively joined edges embedded in space. A k-chain is a chain of k edges. A polygonal tree is a set of edges joined into a tree structure embedded in space. A unit tree is a tree with only edges of unit length. A chain or a tree is simple if non-adjacent edges do not intersect. We consider the problem about the reconfiguration of a simple chain or tree th...

Objective: To compare the straightening of root canal curvature, the apical transportation, the loss of working length and the working time using two rotary systems. Study design: Sixty buccal root canals with angles of curvature between 30 to 99o were instrumented with Mtwo and Twisted File rotary instruments. A series of preand post-operative radiographs were superimposed to determine the str...

Let A be a finitely generated domain of GK dimension less than 3 over a field K and let Q(A) denote the quotient division algebra of A. Using the ideas of Smoktunowicz, we show that if D is a finitely generated division subalgebras of Q(A) of GK dimension at least 2, then Q(A) is finite dimensional as a left D-vector space. We use this to show that if A is a finitely generated domain of GK dime...

OBJECTIVES In Peyronie's disease, any kind of plication technique for correcting penile deformities is associated with penile shortening in addition to the disease-related shrinkage. To minimize penile shortening we describe a new technique of penile corporoplasty using a free graft from the tunica albuginea. PATIENTS AND METHODS From October 2001 to February 2003 we treated 18 patients with ...

OBJECTIVES To review the anatomy and dynamics of the hanging columella and to describe a technique to correct the causative anatomical deformity. DESIGN Case series. SETTING A facial plastic surgery private practice in Highland Park, NJ. PATIENTS Consecutive sample of 10 patients (6 women and 4 men), aged from 27 to 52 years (mean age, 32 years). INTERVENTIONS Through an external approa...

INTRODUCTION The aim of this study was to compare the shaping ability of two single-file systems and conventional rotary instruments in severely curved root canals of extracted human molars. METHODS AND MATERIALS Mesiobuccal canals of 120 mandibular molars with angles of curvature ranging between 25(°) and 35(°) and radii of curvature from 5 to 9 mm, were divided into three groups (n=40). In ...