Maxillary incisor root morphology in patients with nonsyndromic tooth agenesis: A controlled cross-sectional pilot study.

INTRODUCTION: This study aimed to investigate the association between root morphology of maxillary incisors and nonsyndromic tooth agenesis in patients compared with a control group without agenesis. METHODS: This controlled cross-sectional pilot study (1:4) was performed with a random sample of 335 records from Brazilian applicants for orthodontic treatment, paired by sex and age. Panoramic and periapical radiographs were analyzed to diagnose tooth agenesis and to assess root morphology. The agenesis group (n = 67) included patients with nonsyndromic tooth agenesis, and the control group (n = 268) included patients without tooth agenesis. The statistical analysis included the Student t test and z test, conditional logistic regression, and odds ratio estimates. RESULTS: Occurrence of root morphological changes was significantly higher among patients with agenesis (P <0.05). Significant morphological changes (short, blunt, apically bent, and pipette-shaped roots) were found in the roots of remaining teeth when comparing agenesis and control groups (P <0.05). Patients with agenesis were more likely to show root morphological changes (odds ratio, 74.23; 95% confidence interval, 16.93-325.46; P <0.001). CONCLUSION: Patients with agenesis are more likely to present root morphological changes, which should be considered to minimize problems during orthodontic treatments.

Influence of maxillary canine gingival margin asymmetries on the perception of smile esthetics among orthodontists and laypersons.

INTRODUCTION: Our objective was to determine the perception of smile esthetics among orthodontists and laypeople with respect to asymmetries in the maxillary canines' gingival margins in full-face and close-up smile analyses. METHODS: Full-face and close-up photographs of the frontal smiles of 4 subjects (2 women, 2 men) were used. The images were digitally altered to create a symmetrical image with the gingival margin levels of the maxillary canines matching the central incisors. From this new image, 5 stages of alterations were made in the gingival margin of the right canine in 0.5-mm increments. Final full-face and close-up images of the smiles were assessed by 50 orthodontists and 50 laypeople, who indicated the level of attractiveness of each smile on visual analog scales. The data collected were statistically analyzed by means of 1-way analysis of variance with the Tukey post-hoc test and the unpaired Student t test. RESULTS: In general, the most attractive smiles for the orthodontists were those without asymmetries and the one with a 0.5-mm asymmetry, whereas laypersons could not detect an asymmetry up to 1.5 mm (P <0.05). For both groups of raters, the lowest scores were assigned for the smiles with asymmetries of 2.0 and 2.5 mm (P <0.05). When opinions of orthodontists and laypersons were compared, in most situations a statistically significant difference was found, with orthodontists more sensitive in detecting deviations (P <0.001). Moreover, there was no significant difference (P >0.05) between the full-face and close-up assessments of the smiles. CONCLUSIONS: It can be concluded that the perceptions of unilateral asymmetries in the gingival margin levels of the maxillary canines were 1.0 mm for orthodontists and 1.5 to 2.0 mm for laypersons.

Evaluation of anteroposterior and vertical stability 25 years after Angle class II division 1 treatment with cervical headgear.

PURPOSE: The goal was to investigate long-term (minimum 20 years) skeletal and dental changes in Angle class II division 1 patients treated with full-fixed orthodontic appliances and cervical pull headgear. METHODS: A longitudinal retrospective study was performed with 20 orthodontic patients, who were treated exclusively by one experienced clinician and whose treatment had been completed a minimum of 20 years ago. Former patients who had been treated from the mid-1970s to the early 1990s were actively sought. After the recall, 20 patients agreed to participate in the study. Lateral cephalometric radiographs at pretreatment (T1), posttreatment (T2), and long-term follow-up (T3) were digitized and measurements were performed. Angular variables used were SNA, SNB, ANB, OcclPl-FH, PalPl-FH, GoMe-FH, 1­NA, and Y axis. Linear measures were A­NPerp, Pg-NPerp, 1­NAmm, Wits, and LAFH. RESULTS: From T1 to T2, a significant reduction (p < 0.01) in ANB angle from 4.70 to 2.48° and in Wits value from 3.42 to 0.98 mm were observed. It was also noticed a significant increase (p < 0.01) in LAFH from 62.02 to 67.39 mm, probably due to normal facial growth. From T2 to T3, these variables remained stable. No significant changes were observed for any other measure in any of the periods studied. CONCLUSIONS: In the assessed sample, Angle class II division 1 patients treated with cervical pull headgear presented cephalometric outcome stability of treatment, even after a long-term follow-up of a mean of 25 years postretention.