Helicoid occlusion has long been recognized as a feature characterizing the human dentition and has been viewed as an important morphological marker in the transition from Australopithecus to Homo. The hallmark of helicoidal wear is a buccal wear slope in anterior mandibular molars (and a corresponding lingual slope of wear in anterior maxillary molars) reversing to a flat or lingual-oriented o...

E ctopic eruption of the permanent first molar is a local eruption disturbance in the developing permanent dentition. This abnormal eruption pattern is most commonly seen in the maxillary arch. The abnormal mesioangular eruption path of the maxillary first molar causes resorption of the distal root of the adjacent primary second molar. Progression of ectopic eruption may cause impacted permanen...

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...

Abstract: Human maxillary first molars are usually considered as three-rooted teeth with four root canals for the presence of a second canal in the Mesio Buccal root (MB2). In addition, lateral ramifications and apical delta of the root canal system may frequently occur, increasing the probability of leaving untreated spaces after the root canal therapy. A thorough knowledge of root canal mor...

This report describes a novel concept of relocating orthodontic mini-implants during dental distalization to provide unrestricted distal movement of the full maxillary dentition. The patient was an 18-year old Korean woman with a full-step Class II Division 1 malocclusion and mandibular deficiency. Mini-implants were initially placed bilaterally between the maxillary second premolar and the fir...

BACKGROUND The success of pit and fissure sealants is directly related to their retention. The purpose of this study was to assess and compare the retention of pit and fissure sealants placed using acid etch alone and a combination of air abrasion and acid etch techniques. MATERIAL AND METHODS 50 subjects aged 6-8 years were included in the study. Primary second molars and permanent first mol...

Talon cusp is an uncommon anomaly, whose etiology may be disturbances in the morphodifferentiation stage. Dens in dente is also a rare anomaly that is challenging in clinic as it may cause pulp necrosis or periapical lesions due to the communication with the oral cavity. This article reports multiple talon cusps on permanent maxillary and mandibular incisors and molars in 3 siblings. A 9-year-o...

PURPOSE This study determined and compared the distances from the maxillary root apices of posterior teeth to the floor of the maxillary sinus, or maxillary sinus distances (MSDs), and the distances from the mandibular root apices of the posterior teeth to the mandibular canal, or mandibular canal distances (MCDs), in Thai subjects with skeletal open bite and skeletal normal bite. MATERIALS A...

If the concept of mesial movement of molars to reduce the "wedge effect" and decrease facial vertical dimension (FVD) is valid, it is important to investigate the effect of first (P1) and second premolar (P2) extraction on FVD. This study compares the mesial movement of molars and changes in FVD between P1 and P2 extraction groups in Class I malocclusion with a hyperdivergent facial type. We co...

Maxillary molars present variable root canal and root morphologies. This report describes the endodontic management of two cases of midbuccal canals found in maxillary molars. Midbuccal canals were present in a maxillary first molar with a single buccal root (Case 1), and in a maxillary second molar with three buccal roots (Case 2). An assessment of the internal configuration of these teeth was...