Developing outcome measures in orthodontics that reflect patient and provider values

Comparison of 2 Invisalign tray generations using the Peer Assessment Rating index

INTRODUCTION

This study aimed to establish if there is a significant difference in effectiveness between 2 generations of Invisalign trays in terms of Peer Assessment Rating (PAR) score reduction for finished patients from a graduate orthodontic clinic.

METHODS

Forty-five pretreatment and posttreatment patients treated with the previous Invisalign material and 49 pretreatment and posttreatment patients treated with SmartTrack material were scored using the Peer Assessment Rating (PAR) index. Both groups were controlled for initial weighted PAR score, age, gender, and treatment time. The 2 generations were compared in regard to absolute reduction, percent reduction, and great improvement in PAR score.

RESULTS

The mean absolute reduction in weighted PAR score between the groups was not statistically significant (P = 0.526). The mean percent reduction in weighted PAR score between the groups was not statistically significant (P = 0.210). The proportion of great improvement between the groups was not significant (P = 0.526). Only 6 of the 8 components of occlusion had enough variation to be modeled. An absolute reduction in unweighted PAR score was not significantly different between the groups for maxillary anterior alignment, overjet, or mandibular anterior alignment (P = 0.996, 1.000, and 0.114, respectively). Percent reduction in unweighted PAR score was not significantly different between the 2 groups for an anteroposterior, overbite, or transverse (P = 1.000, 1.000, and 1.000, respectively) relationships.

CONCLUSIONS

Our study indicates that both generations of Invisalign aligners improved the malocclusion to a similar degree according to the PAR index. Patient-centric benefits of SmartTrack aligner should also be considered by the provider.

Effects of Hawley retainers on consonants and formant frequencies of vowels

OBJECTIVE

To assess (1) whether Hawley retainers cause speech disturbance and (2) the duration of speech adaptation to Hawley retainers with objective and subjective tests.

MATERIALS AND METHODS

Twelve adolescents, aged 11.11 to 18.03 years, were included in this study. The assessment of speech sounds were done subjectively using an articulation test and objectively using acoustic analysis before and after Hawley retainer application.

RESULTS

After wearing Hawley retainers, patients showed statistically significant speech disturbances on consonants [ş] and [z]. Regarding the vowels, statistically significant changes were recorded with [i], while F1 increased and F2 and F3 decreased.

CONCLUSIONS

The tongue changes its target position with the application of a foreign body within the mouth; however, in time it adapts to that new situation.

Acceptability of dental appearance in a group of Finnish 16- to 25-year-olds

OBJECTIVE

To define a grade in the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN) that would differentiate between esthetically acceptable and unacceptable occlusions and that would also be both subjectively and objectively meaningful.

MATERIALS AND METHODS

Dental appearance and self-perceived orthodontic treatment need were analyzed in a group of Finnish young adults (171 males, 263 females, age range 16-25 years). Subjective data were gathered using a questionnaire, and the respondents were requested to score their dental appearance on a visual analog type 10-grade scale. Professional assessment of dental appearance was performed by two orthodontists using the AC of the IOTN. The cutoff value between esthetically acceptable and unacceptable occlusions was defined using receiver operating characteristic curves.

RESULTS

Sixty-six percent of orthodontically treated and 74% of the untreated respondents were satisfied with their own dental appearance. Every third respondent reported one or more disturbing traits in their dentition. The most frequently expressed reason for dissatisfaction was crowding; girls expressed dissatisfaction more often than boys did (P = .005). A self-perceived treatment need was reported infrequently by 8% of orthodontically treated and 6% of untreated respondents. In the logistic regression analysis, self-perceived need for orthodontic treatment was the only significant factor explaining dissatisfaction with own dental esthetics. On the applied scales, grades 1 and 2 fulfilled the criteria for satisfactory dental esthetics.

CONCLUSION

The results suggest that the AC grade 3 could serve as a cutoff value between esthetically acceptable and unacceptable occlusions.

Facial Profile Changes in Early Class II Correction with Cervical Headgear

Objective: To characterize the effects of early cervical headgear treatment on the facial profile of children in Class II division 1 malocclusion.

Materials and Methods: Forty children aged 9.1 (7.2–11.5) years with Class II division 1 malocclusion were treated using a cervical headgear appliance. The headgear consisted of a long outer bow bent upward 15° and a large expanded inner bow. Lateral cephalograms were taken before and after treatment, and the facial profile was estimated from the cephalograms. The results were compared to an age- and sex-matched normal cohort of 644 Finnish children.

Results: Class I molar relationship was achieved in all treated children. The treatment time was 1.6 (0.3–3.1) years on average. Compared to the controls, the treatment restricted the forward growth of maxillary A-point, and the SNA angle decreased 1.4° ± 1.2° per year (P < .00001). Decreased maxillary prognathism was associated with decreased facial convexity, g-sn-pg (P = .02), and the ANB (P < .00001) angles decreased compared to the controls. Upper lip protrusion (distance ls to sn-pg; P < .00001) was decreased, and the nasolabial angle (cm-sn-ls) widened despite the increased facial inclination of the upper incisors (P = .0005). The treatment significantly decreased the gap between the lips (P = .0009) in their relaxed position.

Conclusion: Cervical headgear treatment in Class II correction is associated with a decreased facial convexity caused by the restriction of forward growth of the maxillary A-point, while the rest of the facial profile, including the mandible, continue to grow forward at a normal rate.

Accessing government subsidized specialist orthodontic services in Western Australia

BACKGROUND

In Australia there is growing demand for dental services. This leads to more pressure on the oral health service providers, and in particular government subsidized dental care. Against this backdrop it is important that government dental services (rationed to health care cardholders) are provided equitably on a basis of need, not access. The primary hypothesis investigated in this study was that there would be an even distribution of patients referred for government subsidized orthodontic care across Western Australia when regionally adjusted for socio-economic status.

METHODS

Data were obtained as a de-identified waiting list for orthodontic treatment at The University of Western Australia. The data included all patients on the orthodontic waiting list as at December 2003.

RESULTS

Significant differences between ARIA categories were detected when all waiting list entries were distributed. However, the trend was towards more entries (adjusted for population) in highly accessible areas. It was found that people from relatively wealthy areas tended to be more likely to be on the waiting list than those from more disadvantaged regions.

CONCLUSION

In summary, the results of this study indicate that there is an uneven distribution of demand for orthodontics waiting list positions across Western Australian postcode areas by remoteness (ARIA) and by socio-economic disadvantage (IRSD). The results suggest that demand for subsidized orthodontic care may be influenced by the general demand for treatment of that region and not on what would be expected to be an even need for treatment across all health care cardholders.