[Transient pink tooth discoloration during orthodontic treatment]. / Voorbijgaande roze coronale verkleuring van een gebitselement tijdens orthodontische behandeling.

A healthy adult male patient presented himself, 11 days after a fixed orthodontic appliance was placed, with a sudden pink discoloration of the dental crown of tooth 21. The emergency dentist on call diagnosed the discoloration as non-painful peri-apical periodontitis, partly on the basis of a radiograph, and recommended endodontic treatment of tooth 21. Prior to endodontic treatment, the patient was first seen by the orthodontist who had initiated treatment. Tooth 21 was investigated and reacted normally to percussion and palpation but did not react to the cold test. The patient was referred to an endodontist who made the likely diagnosis: 'Transient apical breakdown'. No endodontic treatment was carried out and the orthodontic treatment was not interrupted. Six weeks after the discoloration appeared, visible recovery was evident.

[Variation in the assessment of facial aesthetics of women during the past 150 years]. / Variatie in beoordeling van aangezichtsesthetiek van vrouwen gedurende de afgelopen 150 jaar.

Variation in the assessment of facial aesthetics through time was investigated with the help of measurements of actresses from 1875 to 2020 most widely considered to be beautiful. Measurements were carried out on reasonably standardised profile and frontal photographs. During the length of the period studied, the following trends in changing attitudes to facial beauty were recognised: a steady increase in the redness and prominence of lips, a decrease in eye height and an increase in eye width, and with it, a decrease in the height/width ratio or the eyes. In addition, the chin-neck angle and the nasolabial angle became sharper. This trend was especially evident after 1950. Both the group of actresses from 1875 to 1900 and a group of British female students from 2005 showed a relatively flatter lip profile, a more prominent chin and a larger nasolabial angle. After 2000 a mild preference developed for somewhat more redness of the upper and lower lips both frontally and from the side, somewhat more prominent lips, sharper nasolabial and chin-neck angles and a narrower eye height.

Does playing a wind instrument influence tooth position and facial morphology? : Systematic review and meta-analysis.

PURPOSE: To systematically search the scientific literature concerning the influence of playing a wind instrument on tooth position and/or facial morphology. METHODS: The PubMed, EMBASE and Cochrane databases were searched up to September 2019. Orthodontic journals were hand searched and grey literature was sought via Google Scholar. Observational studies and (randomized) controlled clinical trials that assessed tooth position and/or facial morphology by profile cephalograms, dental casts or clinical examination were included. The potential risk of bias was assessed. Data from wind instrument players and controls were extracted. Descriptive analysis and meta-analysis were performed. RESULTS: In total, 10 eligible studies with a cross-sectional (n = 7) or longitudinal design (n = 3) and an estimated low to serious risk of bias were included. Sample sizes ranged from 36 to 170 participants, varying from children to professional musicians. Descriptive analysis indicated that adults playing a single-reed instrument may have a larger overjet than controls. Playing a brass instrument might be associated with an increase in maxillary and mandibular intermolar width among children. Longitudinal data showed less increase in anterior facial height among brass and single-reed players between the age of 6 and 15. Children playing a wind instrument showed thicker lips than controls. Meta-analysis revealed that after a follow-up of 6 months to 3 years, children playing brass instruments had a significant reduction in overjet as compared to controls. The magnitude of the effect was of questionable clinical relevance and the generalizability was limited. CONCLUSIONS: Playing a wind instrument can influence tooth position and facial morphology in both children and adults. Aspects that stand out are overjet, arch width, facial divergence/convergence and lip thickness. However, evidence was sparse and the strength of the premise emerging from this review was graded to be "very low".

[Orthodontic treatment of a malocclusion with a compromised central upper incisor]. / Orthodontische behandeling van een malocclusie met een gecompromitteerde centrale bovenincisief.

An 11-year-old girl presented at an orthodontist asking for the correction of the crooked position of her upper and lower front teeth. In addition, the patient was concerned about the abnormal shape and size of tooth 21. There was a disto-occlusion, crowding and tooth gemination of tooth 21 with the shape of a dens invaginatus. The tooth, moreover, was infected. Teeth 21 and 14 were extracted as part of the treatment. By means of a guided transposition, tooth 23 was brought to the extraction site of tooth 21. Treatment was performed with hybrid fixed appliance techniques.

[Possibilities and limitations of treatment with clear aligners. An orientation]. / Mogelijkheden en beperkingen van orthodontische behandeling met clear aligners. Een verkenning.

The aim of this research was to evaluate the efficiency and effectiveness of an orthodontic treatment with clear-aligner systems, specifically with Invisalign®. In addition to a review of the literature, 4 orthodontists and 9 patients treated with fixed orthodontic therapy and Invisalign® were interviewed. The literature showed that it is difficult to correct an extrusion, rotation or overjet with clear aligners. Often 'refinement' (additional intervention during treatment) is necessary to achieve the best possible end result. The patients interviewed experienced few limitations in their daily lives caused by the clear aligners and hardly any pain. Treatment duration was comparable to that with fixed appliances; it depended on the experience of the orthodontist, the complexity of the case and cooperation of the patient. The cost of an Invisalign® treatment is higher than that of fixed-appliance therapy. Additionally, making a plan for clear-aligner treatment often takes more time for the orthodontist than planning treatment for fixed-appliance therapy.

Influence of tooth position on wind instrumentalists' performance and embouchure comfort : A systematic review.

PURPOSE: To systematically search the scientific literature concerning the influence of tooth position on wind instrumentalists' performance and embouchure comfort. METHODS: The PubMed, Cochrane, and Embase databases were searched up to November 2017. The main orthodontic journals were searched for papers older than the inception date of PubMed. Grey literature was sought via Google Scholar. Eligible studies were critically appraised and analysed. RESULTS: The searches retrieved 54 papers. Only two met the inclusion criteria. Searching the orthodontic journals and Google Scholar resulted in two additional eligible studies. All four studies had a cross-sectional design. The sample sizes ranged from 20-100 participants, varying from children to professional musicians. Because of a large heterogeneity in outcome variables, no meta-analysis could be performed. Descriptive analysis shows that there are indications that tooth irregularities have a negative influence on embouchure comfort and performance of a wind instrument player. A large overjet may impede the embouchure of brass musicians and may have a negative influence on trumpet player performance. A wide jaw form seems more beneficial to trumpet player performance than a small jaw form. Furthermore, players of all types of wind instruments can experience embouchure difficulties from extreme spacing or an open bite. CONCLUSION: Tooth position can influence musical performance and embouchure comfort of wind instrumentalists. A Class I relationship without malocclusion seems appropriate for every type of wind instrument. The more extreme the malocclusion, the greater the interference with wind instrumentalists' performance and embouchure comfort. Evidence however is limited.

[Smoking and orthodontics]. / Roken en orthodontie.

In view of the severe adverse effects that smoking has on health, much energy is being invested especially to prevent adolescents from starting to smoke or to get them to stop. Since orthodontists have regular contact with a rather large group of young people during the period when they begin to smoke, a study was conducted to determine whether these specialists could be engaged in an organized anti-smoking programme. One of the relevant considerations was that orthodontists are succesful in motivating adolescents to wear braces. Research has shown that dentists in an organized programme in the United States were able to achieve a significant reduction in the percentage of adult smokers. The research findings revealed, however, that the orthodontists nevertheless lacked sufficient training and motivation to be effectively employed in an anti-smoking programme. The results of some clinical trials with adolescent patients were disappointing, but they did make clear what needs to be done to achieve improvements. Well organized involvement in a sound anti-smoking programme in The Netherlands will require very careful preparation and will only be able to start after well designed and successful clinical trials.

[Ectopic eruption of the maxillary first permanent molar]. / Ectopische eruptie van de eerste blijvende molaar in de bovenkaak.

Ectopic eruption of the maxillary first permanent molar is an eruption disturbance. This article discusses current literature views on diagnosis, prevalence, aetiology and treatment of this disturbance. It is a relatively uncommon disturbance and its aetiology remains unclear. A combination of extraction of the maxillary second primary molar and cervical headgear treatment seems the treatment of choice, although this treatment option is successful in only 70% of cases. More research has to be conducted to compare the effectiveness of treatment options.

[Orthodontic treatment for adults]. / Orthodontische behandeling van volwassenen.

The number of adults undergoing orthodontic treatment has increased strongly and the average age that adult patients undergo orthodontic treatment increased steadily although 3/4 is still younger than 27 years. In adults the facial skeletal pattern can only be changed in a very confined way, consequently in case of an abnormal skeletal pattern one has to choose between a combined orthodontic-surgical approach (which is the case in 18% of the patients) and a compromised orthodontic treatment, if necessary combined with other disciplines. It is still controversial whether tooth movement in adults is slower and more difficult than in adolescents. The same holds true for the risk for loss of periodontal support, for root resorption, for gnathologic problems and for relapse. As related to these variables there appears to be a large individual variation. Many adults show one or more problems in their dentition that may influence their orthodontic treatment. About 60% of the adult patients need a multidisciplinary approach. The development of implantology and of bone regeneration and bone grafting has lead to more combined treatments. The risks of such complex treatment plans are generally larger than those for more simple kinds of treatment. A very careful treatment planning and good communication between the different specialists is essential. Moreover the treatment plan with all its (dis)advantages has to be extensively discussed with the patient.

Alveolar and skeletal dimensions associated with lower face height.

In this study, the relationships between the lower face height and the structure of the frontal alveolar and basal bone were investigated. The areas and the dimensions of the anterior alveolar and basal midsagittal cross-sectional bone from the maxilla and the mandible were recorded on lateral cephalograms from 460 untreated adults. An index was calculated dividing the sagittal by the vertical dimension of the midsagittal cross-sectional area. The subjects with a normal overbite between 0.5 and 4 mm (N=165) were divided into three groups according to the lower face height. A larger lower face height coincided with a larger maxillary alveolar and basal area and with a smaller mandibular alveolar index. Correlations between the lower face height and the maxillary alveolar index and the mandibular alveolar and basal area were low. It is concluded that long-faced subjects have a large mandibular alveolar height, which is more associated with a narrowed shape than with a large volume of the symphysis.

Alveolar and skeletal dimensions associated with overbite.

The aim of this study was to investigate whether in the maxilla and in the mandible the structure of the anterior medial sagittal alveolar and basal bone is related to the overbite. A total of 460 untreated adult subjects were divided into four groups with either deep bite, normal overbite, end-to-end bite, or open bite and were compared. The overbite, lower face height, and anterior alveolar and basal midsagittal cross-sectional areas from the maxilla and the mandible were assessed on lateral cephalometric radiographs. An index was calculated, dividing the sagittal by the vertical dimension of the midsagittal cross-sectional area. A deeper bite coincided with smaller lower face height, larger alveolar and basal areas, and a more widened shape of the symphysis. If the lower face height was introduced as a covariable, the open bite group showed significantly smaller maxillary and mandibular alveolar and basal cross-sectional areas compared with the end-to-end group, the normal overbite group, or the deep bite group. Vertical variation of the overbite probably coincides with a relative hyperdevelopment or hypodevelopment of the symphysis.

Clinical relevance of third permanent molars in relation to crowding after orthodontic treatment.

OBJECTIVES: The purpose of this study was to determine the relationship between dental crowding and the clinical presence or absence of third permanent molar teeth. METHODS: Ninety-nine patients were analysed before and after orthodontic treatment and at least three years after the end of retention. The sample consisted of four groups: subjects whose third permanent molar teeth had erupted into the mouth, were non-erupted, were extracted, and were congenitally absent. Arch Length Discrepancy, Irregularity Index and observer bias were examined. Multivariate analysis of variance with repeated measurements was used to analyse differences between the four groups. RESULTS: Significant differences in Arch Length Discrepancy during time were shown between the premolar segment and the frontal area. The group with third permanent molar teeth congenitally missing showed a significant higher positive Arch Length Discrepancy in the premolar segment of the upper jaw. No significant differences in Irregularity Index were found between the third molar groups. CONCLUSIONS: It can be concluded that there is no relation between crowding and the presence or absence of third permanent molar teeth.

[The stability of orthodontic treatment over the long term]. / De stabiliteit van het orthodontisch behandelings-resultaat op lange termijn.

The long term stability of orthodontic treatment was evaluated in 7 orthodontic patients who were three to 12 years out of retention. Dental relationships and irregularities in the dental arch were recorded and scored on study models taken prior to orthodontic treatment, at the end of active treatment, and at long term follow up. Lateral skull radiographs taken at the start of active treatment were also analysed. According to the (mal)occlusion observed on the post-retention study models it appeared that the sample could be subdivided into three groups. The group of patients with relatively good results after active treatment showed less relapse than the group with relatively moderate results after active treatment. The patients with relatively good treatment results were mostly treated with extractions followed by fixed appliances in both jaws. This observation indicates that treatment planning in this group generally was correct. Patients showing skeletal Class II features before orthodontic treatment showed most relapse in overjet and overbite.

Tissue changes in the rabbit periodontal ligament during orthodontic tooth movement.

In this (semi) quantitative animal study the reaction of the periodontal ligament (PDL) to experimental tooth movement is described. To this end, rabbit first incisors were moved sideways with helical torsion springs for periods varying from 3-24 hours. The initial force of the springs was 50 gf. The histomorphology of the PDL was studied in 5 microns thick plastic sections. Comparison with control animals and animals wearing passive springs showed that tooth movement leads to an increased trauma in the PDL within only a few hours. This trauma is characterized by hyalinization, tears and ruptures in the fibres and blood vessels, and by the presence of extravascular erythrocytes and pyknosis. Tissue damage significantly increased with time. After 24 hours of tooth movement, the PDL fibers are compressed or stretched in 68% of the sections and the blood vessels in the PDL are compressed or stretched in 62% of the sections. Even in the controls, more than 15% of the sections displayed slightly stretched or compressed fibers, and about 10% showed slightly compressed or stretched blood vessels. This indicates that some damage is regularly present in a normally functioning PDL. Increases in the percentage of sections with blood vessel compression are found in all groups wearing passive springs, especially after 6 hours. A high concordancy in compression and tension patterns of blood vessels and fibers is present in 83% of the sections. Pyknotic cells are practically confined to areas with compressed PDL fibers in rabbits wearing active springs. Extravascular erythrocytes were found in sections with all types of fiber patterns. A significant majority of extravascular erythrocytes, however, was found in areas with compressed fibers.