Stability of Le Fort I maxillary inferior repositioning surgery with rigid internal fixation: a systematic review.

The aim of this study was to evaluate the stability of Le Fort I maxillary inferior repositioning surgery in patients with a vertical maxillary deficiency at least 6 months after surgery. The electronic databases were searched to identify all articles reporting the long-term effects of one-piece maxillary inferior repositioning with rigid fixation. Methodological quality was evaluated according to 15 criteria related to study design, measurements, and statistical analysis. Two articles were identified, with a total of 22 patients. The maxilla was repositioned inferiorly from a mean 3.2 to 4.5mm in the anterior part and from a mean 0.1 to 1.8mm in the posterior part. At 6 months post-treatment, absolute relapse of a mean 1.6mm was measured for the anterior part of the maxilla and 0.3mm for the posterior part of the maxilla. The stability of maxillary inferior repositioning surgery could not be confirmed due to the small sample size, unclear diagnosis, and potential confounding factors.

[Orthodontics in general practice 4. Impaction of maxillary front teeth]. / Orthodontie in de algemene tandartspraktijk 4. Eruptieproblemen in het bovenfront.

Eruption failures in the maxillary frontal region occur during the mixed dentition period. Dislocation and impaction of central incisors are diagnosed during or at the end of the early mixed dentition stage. These failures can be caused by crowding, premature loss of deciduous teeth, trauma or supernumerary teeth. Occasionally, a preventive orthodontic treatment is desirable to release the obstructed eruption path of a canine. Sometimes, a surgical intervention may be indicated to expose an obstructed central incisor and to remove supernumerary teeth. Retention and impaction of canines are generally discovered late in or after the late mixed dentition stage. In the agenesis of the lateral incisors or peg-shaped teeth, there is frequently impaction of the canines. General dental practitioners must be alert for possible deviations in the pattern of change in dentition right from the early mixed dentition period. Conventional two-dimensional radiographs can sometimes unjustifiably suggest a bad prognosis of an impacted tooth. Cone-beam CT scanning, which gives a three-dimensional image, can provide important additional diagnostic information.

[Orthodontics in general practice. 2. Treatment of eruption failures]. / Orthodontie in de algemene tandartspraktijk. 2. Behandeling van eruptieproblemen.

Since the introduction of composites and bonding in orthodontics, the possibilities of aligning impacted teeth into the dental arch after a surgical intervention, have remarkably increased. There are 4 important treatment techniques. The closed-eruption technique includes bracket-bonding to and ligating of the exposed tooth, followed by repositioning of the mucosal flap. The disadvantage of the method is the uncontrollable orthodontic force on the non-visible tooth during orthodontic extrusion. The open-eruption technique aims at keeping the exposed tooth visible, followed by spontaneous eruption. However, the exposure appears often as a radical exposure with unfavourable gingival consequences. The open-eruption technique with apical positioned mucosal flap is designed to expose teeth highly buccally impacted. The mucosal graft may cause a typical thick, stretched and not aesthetically acceptable gum after orthodontic treatment, even in case of using a split-thickness graft. The modified window technique is an open-eruption technique with minimal exposure, resulting in immediate eruption. If orthodontic treatment is required, the tooth is no longer impacted. The success rates of the 4 techniques vary from 75 until 99%. Study of the literature reveals insufficient scientific evidence in favour of 1 treatment technique. However, independent of the surgical technique applied, general practitioners play a crucial role in diagnostics of eruption failures and timely referral to an orthodontist.

Influence of panel composition on aesthetic evaluation of adolescent faces.

The objective of this study was to evaluate the influence of professional background, age, gender, and geographical region of panel members on their evaluation of the facial aesthetics of adolescents, and to assess the optimal panel size for epidemiological studies on facial aesthetics. A panel of 76 adult laymen from two different regions (Belgium and The Netherlands) and a panel of 89 orthodontists from the same two regions, evaluated photographic sets (one frontal, one three-quarter smiling, and one lateral view) of 64 adolescents (32 boys, 32 girls) on a visual analogue scale (VAS) in relation to a reference set of photographs. The effects of the characteristics of the panel members on the VAS scores for boys and girls separately, as well as their interactions, were evaluated by multilevel models. The adolescents entered the model as a random effect and four characteristics of the panel members were included in the model as fixed effects. The multilevel model with main effects and first-order interactions revealed that laymen rated adolescents as more attractive than orthodontists. This finding was significant for all laymen, except for older males, and Belgian laymen, when rating girls. Older panel members rated boys significantly more attractive than younger panel members. Males rated adolescents more attractive than females. The latter was significant for all male subgroups, except for the lay male subgroup. There were regional differences. Based on the intraclass correlation coefficient, a panel of seven randomly selected laymen and/or orthodontists is sufficient to obtain reliable results in the aesthetic evaluation of adolescent faces, using photographs and a VAS.

Objective measures as indicators for facial esthetics in white adolescents.

The objective of this study was to examine the contribution of objective measures representing anterior-posterior and vertical characteristics, dental esthetics, or their combination that are used in daily orthodontic practice in the assessment of facial esthetics. A panel of 78 laymen evaluated facial esthetics of 32 boys and 32 girls, stratified over the four Angle classes, on a visual analogue scale. The relation between the objective parameters and facial esthetics was evaluated by backward multiple regression analysis. Dental esthetics as expressed by the Aesthetic Component of the Index of Orthodontic Treatment Need (AC/IOTN) appeared to be the most important indicator for facial esthetics. A new parameter, the "horizontal sum" was found to be a reliable variable for the anterior-posterior characteristics of the patient. Addition of this newly defined parameter to the AC/IOTN improved the prognostic value from 25% to 31%.

A measuring system for facial aesthetics in Caucasian adolescents: reproducibility and validity.

A new measuring system to judge facial aesthetics in young Caucasians is presented. The system uses sets of three photographs (one frontal, one three-quarter smiling, and one lateral) as a stimulus. Scores are performed on a visual analogue scale (VAS) with separate sets of reference photographs for girls and boys. The choice of the reference photographs was based on a panel evaluation of facial aesthetics of 40 boys and 40 girls from the archive of the orthodontic department. Reproducibility of the new measuring system was tested on a series of photographic sets (one frontal, one three-quarter smiling, and one lateral view) of 64 patients, using a panel of 78 adult laymen and 89 professionals. The panel members assessed these sets of photographs on a VAS, in relation to the reference sets. The system was shown to be reproducible. Although the intra-observer reproducibility was low, the reliability coefficient was excellent (Cronbach's alpha > or = 0.98). Validity was tested by comparing the scores on the new scales with those of the three-quarter smiling photographic views on an earlier published scale. The correlation between the ratings on the new measuring system and the earlier published scale was 0.82 for laymen and 0.77 for professionals. The new system is simple and flexible in its use, and reproducible and valid for assessing facial aesthetics in young Caucasians. The system can be used in further investigations on the evaluation of facial aesthetics.

[Research methods in dentistry 10. Assessment of orthodontic treatment need]. / Onderzoeksmethoden in de tandheelkunde 10. Het bepalen van de orthodontische behandelingsbehoefte.

Approximately one third of the Dutch population has an objective need for orthodontic treatment. Yet, patients mostly seek treatment because of aesthetic reasons. Recent social developments and the increased attention for aesthetics ask for ways to objectively measure treatment need. This is not only important because of the risks of orthodontic treatment, but also because of financial reasons. In this article indices to verify treatment need, i.e. the Index for Orthodontic Treatment Need (IOTN), de Dental Aesthetic Index (DAI) en de Index of Complexity, Outcome and Need (ICON), are discussed. All three indices seem to lead to a reduction of treatment need, especially in borderline cases. They can serve as 'neutral' instruments to discuss treatment need with patients and as instruments to allocate financial resources for orthodontic care.