The admissions officer at one dental school recently told me that, when he asked dental school applicants why they were applying to dentistry, the most common reason cited was a desire to become an orthodontist. Similarly, orthodontists are almost universally positive about their vocational choice. What are the facts about gaining admission to this apparently widely liked and desired career?

Before 1997, no one really knew how many applicants to orthodontic programs actually existed. This was because confidentiality rules kept programs from ever sharing information, and no central data bank ever existed. The result was that each program was totally

Abstract

The purpose of the study was to analyze the ability of computerized tomography (CT) scanning to discriminate maxillary incisor root resorptions caused by ectopically erupting canines. Seventeen maxillary incisors were radiographed in vivo by CT scanning. Contiguous transverse CT scans with a slice thickness of 2 mm were exposed perpendicular to the long axis of the lateral incisors and through the crown of the adjacent, ectopically positioned maxillary canine. Each scan was analyzed and the resorptions on the roots of the laterals were graded according to the maximum depth of the cavity. After the lateral incisors were extracted they were clinically inspected, photographed in different light settings and views, and probed at the contact area between the laterals and the canines. The assessment of the extent of resorption in 4 stages on the CT images compared with the in vitro observations of the extracted roots showed a high degree of agreement for the extent of loss of root substance for all teeth. We conclude that CT scanning performed with good technique accurately reveals tooth root resorption. The presence and influence of the inherent artifacts of tooth root resorption on CT scans are discussed.

Abstract

The purpose of this study was to investigate the movement of the tip and the dorsal surface of the tongue during deglutition in patients with anterior open bite using cineradiography. The subjects were 10 female patients with anterior open bites and 10 female controls with normal overbites. By cineradiography we established 7 stages of tongue movement and bolus position during deglutition and analyzed the tongue position, tongue movement and the time. The tongue-tip position was more protrusive during deglutition in anterior open bite than in the controls. After the head of the bolus arrived at the opening of the esophagus, the rear part of the dorsal surface of the tongue demonstrated slower movement in patients with anterior open bite than in controls. The nasopharynx closed earlier in patients with anterior open bite than in controls. It is suggested that anterior open bite patients had compensatory coordination of tongue movement, soft palate movement and pharyngeal constrictor muscle activity during deglutition.

Abstract

Alterations in the size, morphology and number of teeth are among the many inherited disorders that have been reported in individuals with Down syndrome. By contrast, third molar agenesis and tooth transposition have been largely ignored and the prevalence of canine impaction has not been reported. The intention of this study was to quantify the occurrence of these anomalies in a group of individuals with Down syndrome, using standardized records, which included a clinical examination, dental casts, and a panoramic radiograph. The results show a notably high prevalence of third molar agenesis (74% of individuals older than 14 years), canine impaction (15%), and maxillary canine/first premolar transposition (15%), compared to published figures from random population samples. These anomalies should not be seen as separate, independent entities, but as associated phenomena. The slow rate of cell growth and a consequent reduced cell number that characterize this syndrome may be responsible for the underdevelopment of the upper jaw, the delayed dental development, the reduction in teeth number and size, and the altered path of canine eruption. No explanation, other than genetics, is immediately available to explain why the maxillary canine/first premolar transposition should represent another phenotypic expression of this trisomy.

Effects of printing layer thickness and build orientation on the mechanical properties and color stability of 3D-printed clear aligners

Chengzan Wu,

Utkarsh Mangal,

Na Bai,

Hoon Kim,

Geelsu Hwang,

Jung-Yul Cha,

Kee-Joon Lee,

Jae-Sung Kwon, and

Sung-Hwan Choi

The Facts About Getting Into an Orthodontic Program

What's New in Dentistry

Letters From Our Readers

Author's response:

Incisor Root Resorptions Due to Ectopic Maxillary Canines Imaged by Computerized Tomography: A Comparative Study in Extracted Teeth

Abstract

A Cineradiographic Study of Deglutitive Tongue Movement and Nasopharyngeal Closure in Patients with Anterior Open Bite

Abstract

Prevalence of Tooth Transposition, Third Molar Agenesis, and Maxillary Canine Impaction in Individuals with Down Syndrome

Abstract

Maxillary Arch Size and Shape in American Blacks and Whites

Abstract

Mesiodistal Crown Dimensions and Tooth Size Discrepancy of the Permanent Dentition of Dominican Americans

Abstract

A Comparison of Shear-Peel Band Strengths of 5 Orthodontic Cements

Abstract

Orthopedic Cervical Headgear with an Expanded Inner Bow in Class II Correction

Abstract

Long-Term Changes in Dentoskeletal Pattern in a Case with Beckwith-Wiedemann Syndrome Following Tongue Reduction and Orthodontic Treatment

Abstract

Class II Correction with the Modified Sagittal Appliance and Maxillary Second Molar Extraction

Abstract

Orthodontic Correction of a Transposed Maxillary Canine and Lateral Incisor

Abstract

Effects of printing layer thickness and build orientation on the mechanical properties and color stability of 3D-printed clear aligners

The effect of clear aligner and fixed orthodontic treatment on the development of pulp stones: a retrospective observational study

Orthodontic forces and moments of three-bracket geometries

Accuracy and reliability of automated landmark identification and cephalometric measurements on cone beam computed tomography using Invivo software

Accuracy and reliability of Keynote for tracing and analyzing cephalometric radiographs