Abstract

The aim of this study was to assess the correlation between the Fishman maturation prediction method (FMP) and the cervical vertebral maturation (CVM) method for skeletal maturation stage determination. Hand-wrist and lateral cephalograms from 79 subjects (52 females and 27 males) were used. Hand-wrist radiographs were analyzed using the FMP to determine skeletal maturation level (advanced, average, or delayed) and stage (relative position of the individual in the pubertal growth curve). Cervical vertebrae (C2, C3, and C4) outlines obtained from lateral cephalograms were analyzed using the CVM to determine skeletal maturation stage. Intraexaminer reliability (Intraclass correlation coefficient [ICC]) for both methods was calculated from 10 triplicate hand-wrist and lateral cephalograms from the same patients. An ICC coefficient of 0.985 for FMP and an ICC of 0.889 for CVM were obtained. A Spearman correlation value of 0.72 (P < .001) was found between the skeletal maturation stages of both methods. When the sample was subgrouped according to skeletal maturation level, the following correlation values were found: for early mature adolescents 0.73, for average mature adolescents 0.70, and for late mature adolescents 0.87. All these correlation values were statistically different from zero (P < .024). Correlation values between both skeletal maturation methods were moderately high. This may be high enough to use either of the methods indistinctively for research purposes but not for the assessment of individual patients. Skeletal level influences the correlation values and, therefore, it should be considered whenever possible.

Abstract

The changes in the dental arch dimensions that occur as a result of growth and treatment are of interest to the orthodontist and require careful consideration during treatment planning. A greater understanding of these changes could influence the patient's expectations from treatment as well as the formulation of the treatment and retention plans by the clinician. A retrospective study of the maxillary and mandibular canine and molar arch width changes in 60 patients over 20 years was carried out. Approximately half were treated orthodontically, and measurements were made on dental casts taken at four time points during the study: 1981, 1985, 1989, and 2001. Between baseline and final follow-up, the treated group demonstrated a statistically significant increase in maxillary intercanine arch width and statistically significant decreases in maxillary intermolar and mandibular intercanine and intermolar widths. No significant changes were observed for the untreated group. When comparing the orthodontically treated group with the untreated group, there was a significantly greater increase in maxillary intercanine width and a significantly greater reduction in mandibular intercanine width in the treated group over the duration of the study. No significant difference was observed between treated and untreated groups for maxillary and mandibular intermolar width changes. Sex had no statistically significant effect on these treatment differences. Type of orthodontic treatment had no effect on arch width changes within the treated group; however, the effect of tooth extraction needs further investigation.

Abstract

The sum of the lower incisor tooth width has been proposed as the best predictor for calculating unerupted canine and premolar mesiodistal tooth sizes. The aims of this study were to develop a new, fast, and accurate computerized method to predict unerupted mesiodistal tooth sizes and to determine which reference tooth or combination of reference teeth was the best predictor for canines and premolars in a Spanish sample. The dental casts of 100 Spanish adolescents with permanent dentition were measured to the nearest 0.05 mm with a two-dimensional computerized system. The goal was to predict unerupted canine and premolar mesiodistal tooth sizes using the sizes of the upper central incisor, upper and lower first molar, or a combination of these as a reference and using a specific mesiodistal tooth-size table. The results showed that the Digital Method proposed was very accurate in predicting unerupted canine and premolar tooth size. The combination of the sums of the permanent upper central incisor and the lower first molar was the best predictor for canines and premolars in this sample. Upper arch teeth were better predicted than lower arch teeth. The upper lateral incisor provided the worst predictions.

“We make a living by what we get. We make a life by what we give.”—Sir Winston Churchill

In the last several decades it was hard to be an orthodontist and not be a winner. Just like a perfect storm, orthodontics has been the perfect profession for at least the last half century. Demographics have favored us. The desire of our culture to seek improved esthetics has favored us. The popularity of braces among the youth has favored us. Economic times have favored us.

None of these pluses would have sustained us, however, if we had not delivered a consistently

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