PATIEN'l' J. Z., a white boy 13 years 9 months of age, had a Class II, Division 1 malocclusion. This diagnosis could be determined only in the canine area, since no mandibular molars were present on either the right or the left side. The maxillary arch was normal in width and in protraction. The maxillary right second premolar was blocked out lingually and rotated mesially, and the maxillary le...

The dactylocycline antibiotics were found through circular dichroism measurements, NMR spectroscopy and chemical transformations to possess the usual tetracycline family absolute configuration at carbons 4, 4a, 5a and 12a. The absolute stereochemistry about the C-6 carbon, however, was the reverse of that found with previously investigated tetracyclines.

BACKGROUND This study cephalometrically compared the dentoskeletal and soft tissue changes consequent to one and three-premolar extraction protocols of class II subdivision malocclusion treatment. METHODS A sample of 126 lateral cephalometric radiographs from 63 patients was selected and divided into two groups. Group 1 consisted of 31 type 1 class II subdivision malocclusion patients treated...

Background: The most commonly impacted teeth are the third molars, maxillary canines, maxillary central incisors and premolars. Impacted premolars may lead to aesthetic concerns, masticatory inefficiency and oral hygiene difficulties as well as follicle pathology and destruction of adjacent structures, including neighboring teeth, the purpose of this study to shade light on the prevalence of im...

Tooth transposition, which is a rare condition, is ascribed to the disturbance of tooth eruption and the subsequent abnormal occlusal relationships. Transpositions mostly involve the upper jaw and more frequently occur between the maxillary canine and first premolar. Herein, we present a case of a maxillary canine‒second molar transposition in a thalassemic patient.

A family of previously reported ring-closing metathesis (RCM)-derived macrocycles that exhibit potent Grb2 SH2 domain-binding affinity is characterized by stereoselectively-introduced upper ring junctions that bear bicyclic aryl substituents. However, the synthetic complexity of these macrocycles presents a potential limit to their therapeutic application. Therefore, the current study was under...

INTRODUCTION Maxillary premolars are often extracted to resolve incisor proclination in presurgical orthodontic treatment for severe skeletal Class III patients. The aim of this article was to compare arch-width changes and orthodontic tooth movements between maxillary premolar extraction and nonextraction modalities, and to provide an additional indication for presurgical maxillary premolar ex...

Familiarity with the normal and abnormal anatomy of the root canal system is essential for successful root canal treatment. The possibility of concomitant three-rooted and three- canalled maxillary and mandibular premolars are extremely rare. The purpose of this paper was to report a case with a three-rooted maxillary first premolar and two three-rooted mandibular premolars.

Cyclocondensation of 2-[bis(methylthio)methylene]malononitrile (1) and cysteamine (2) afforded 2-(thiazolidin-2-ylidene)malononitrile (3). This compound on treatment with NaSH gave the corresponding thioamide derivative 4a in a regioselective manner on the basis of its single crystal X-ray diffraction analysis. Reaction of this compound with several alpha-bromocarbonyl compounds gave new 2-(E)-...

A divergent approach was developed toward the total synthesis of taiwaniaquinoids. An advanced intermediate 5a with trans A/B ring junction was concisely assembled by employing a Bi(OTf)3-catalyzed cationic cyclization and a Wolff-type ring contraction as key steps. This common intermediate was readily converted to racemic taiwaniaquinones A and F and taiwaniaquinols B and D, respectively.