Unplanned molar intrusion after Invisalign treatment.

INTRODUCTION: The objectives of this study were to analyze and quantify molar intrusion after the use of clear aligners and to analyze the relationship with other variables such as age, duration of treatment, and a series of cephalometric osseous and dental measurements at the start of treatment. METHODS: A retrospective descriptive-analytical study was designed with a sample of 58 patients aged 18-60 years who had undergone treatment with Invisalign. The cephalometric measurements were carried out after lateral x-rays were taken of the cranium; these were compared at the start (T0) and conclusion of treatment. Parametric and nonparametric tests were used to compare means, whereas Pearson correlations and multivariate lineal regression analyses were used to establish the variables associated with molar intrusion. RESULTS: Approximately 74.2% of the patients presented some degree of molar intrusion after treatment. Furthermore, 32.8% of patients presented intrusion only at the mandibular molar, whereas 25.9% experienced intrusion at both molars, maxillary and mandibular, simultaneously. However, 15.5% presented intrusion only at the maxillary molar. The average magnitude of intrusion here was 0.98 ± 0.54 mm, whereas the mandibular molar was 0.84 ± 0.29 mm. Statistically significant reductions exist for the distance L6_MP and U6_SN between T0 and at conclusion of treatment. Maxillary molar intrusion correlates negatively with mandibular molar intrusion (r = -0.270). The number of days of treatment did not correlate with either maxillary or mandibular molar intrusion. CONCLUSIONS: Clear aligners give rise to molar intrusion in 74.2% of patients. The cephalometric variables L6_MP T0, mandibular plane angle T0, and facial axis T0 were negatively and significantly associated with maxillary molar intrusion, whereas age and facial axis T0 were negatively associated with mandibular molar intrusion allowing smaller magnitudes of intrusion to be predicted when these variables present high values at T0.

Comparative Study of Oral Health-Related Quality of Life (OHRQL) between Different Types of Orthodontic Treatment.

Background and objectives: Although the main objective of any orthodontic treatment is to correct malocclusion, a range of psychosocial and/or esthetic factors drive patients to undergo orthodontic treatment. The aim of the present study was to analyze variations in oral health-related quality of life (OHRQL) levels in patients undergoing orthodontic treatment by means of four types of appliances: fixed buccal metal brackets, fixed buccal esthetic/ceramic brackets, fixed lingual brackets, and clear aligners. Material and Methods: The study sample comprised 120 patients aged 18 to 68 years who attended the Orthodontic department at the Dental Clinic of the University of Valencia. The Index of Orthodontic Treatment Need (IOTN) was used to measure orthodontic treatment need. Each patient completed three different intervals of the 14-item Oral Health Impact Profile (OHIP-14): before treatment (T0); six months after placing the orthodontic appliances (T1) and at the end of orthodontic treatment (T2). Results: All groups suffered a reduction in quality of life from T0 to T1 except the metal bracket group which presented the same level for the functional limitation domain (p = 1.000), the lingual bracket group for the psychological discomfort domain (p = 1.000) and clear aligner group for the physical disability domain (p = 0.118) and psychological disability domain (p = 1.000). Nevertheless, quality of life for most domains was similar in all groups at the end of treatment (T2). Conclusions: Patients underwent a significant reduction in quality of life during treatment in comparison with their pre-treatment condition but showed significant improvements at the end of treatment.

Association between third molar agenesis and craniofacial structure development.

INTRODUCTION: The aim of this investigation was to study the relationship between third molar agenesis-including the number of ageneses-and craniofacial structure growth. METHODS: We reviewed 305 clinical histories of patients treated at the Orthodontics Unit of the Faculty of Medicine and Dentistry at the University of Valencia in Spain. This included radiographic records of optimal quality. Of these, 40 patients who had agenesis of at least 1 third molar were included in the study group. A control group was formed with another 40 patients with all 4 third molars present. For both groups, a further criterion for inclusion was cone-beam computed tomography records. The cephalometric analysis was performed with NemoCeph 3D software (version 11.3.1.38; Nemotec, Madrid, Spain). RESULTS: The only significant differences between the 2 groups were in the total gonial angle and the upper gonial angle (P ≤0.05), both of which were smaller in the study group. CONCLUSIONS: Third molar agenesis is associated with a reduction in Jarabak's gonial angle and upper gonial angle, characteristic of patients with a more horizontal or brachyfacial skeletal pattern. No significant differences were found in other measurements.

Orthodontic Treatment and Healthcare Goals: Evaluation of Multibrackets Treatment Results Using PAR Index (Peer Assessment Rating).

BACKGROUND: The evaluation of orthodontic treatment outcomes using an objective method is important in order to maintain high treatment quality and final healthcare of patients. It allows professionals and university students to raise the level of the therapy. The aim of this study was to assess the orthodontic treatment outcomes in an Italian postgraduate School of Orthodontics using Peer Assessment Rating (PAR) Index. METHODS: A sample of 50 patients treated in a postgraduate program was randomly selected. PAR index was used to assess pre-treatment and post-treatment study casts by two different examiners. The influence of different variables such as gender, treatment method, and need for extraction was statistically analyzed. RESULTS: The average numerical reduction of PAR between the beginning and the end of the treatment was 18.74 (CI 95% 16.53-20.95), while the percentage reduction was 94.8% (CI 95% 91.91-97.68). All cases improved: 8% of patients resulted in the improved category, while 92% of them were in the greatly improved group. CONCLUSIONS: According to PAR index, the results showed that patients received a high-standard therapy. None of the factors studied influenced significantly the treatment outcomes.

Arch expansion with the Invisalign system: Efficacy and predictability.

BACKGROUND: In adult patients, treatment of skeletal crossbite requires combined treatment by fixed or removable appliances and orthognathic surgery. In cases of dentoalveolar crossbite, expansion can be achieved with fixed multibrackets and removable transparent aligners. Various researchers have already assessed the Invisalign system's predictability for arch expansion. However, most of this research was conducted using older appliances, making it necessary to assess the characteristics of the updated system SmartTrack. MATERIAL AND METHODS: A sample of 114 patients with transverse malocclusion were treated with SmartTrack. The predictability of the system's software (Clincheck) was assessed by comparing planned measurements (width of canines, premolars and molars rotations and inclinations) with the real measurements achieved at the end of the first treatment phase. Measurements were imported to Clincheck software to create three data sets; T1: initial measurements at start of treatment; T2: Clincheck predicted measurements at end of first treatment phase; T3: measurements taken at start of the second treatment phase. RESULTS: Widths underwent significant advances as a result of treatment. For all widths, virtual planning obtained prognoses of greater expansion than actually achieved: a mean of 0.63 mm more expansion at the canine level (p<0.001), 0.77 mm at first premolar (p<0.001), 0.81 at second premolar (p<0.001), 0.69 mm at first molar (p<0.001), and 0.25 mm at second molar (p = 0.183). All the treatment plan's estimations, with the exception of the second molar, were significantly higher than the actual outcomes. CONCLUSIONS: Aligners are an effective tool for producing arch expansion, being more effective in premolar area and less effective in canine and second molar area. Predictability was reasonable for expansion movement. Overcorrection should be considered at the virtual planning stage in order to obtain the expected outcomes.

One versus two anterior miniscrews for correcting upper incisor overbite and angulation: a retrospective comparative study.

BACKGROUND: Miniscrews are effective devices for performing upper incisor intrusion. Different mechanics can be applied depending on the treatment objectives. This study aimed to evaluate the efficacy of one or two anterior miniscrews for upper incisor correction in cases of overbite and angulation in adult patients. METHODS: Forty-four adults with deep overbite were divided into two groups: group 1 was treated with one miniscrew between upper central incisors and group 2 with two miniscrews between upper lateral incisors and canines. Incisor intrusion and length were measured from lateral cephalograms before treatment, after treatment and at least 12 months into retention (T0, T1 and T2). Forces were applied (90 g) from the miniscrews to the archwire using elastomeric chains. ANOVA analysis was used to determine whether differences between evaluation times were statistically significant. RESULTS: Mean root resorption was 2.15 ± 0.85 mm, which ceased after active treatment. Overbite mean correction was - 3.23 ± 1.73 mm with no statistically significant relapse. Overbite correction and incisor intrusion were significantly greater in group 2 (- 3.80 ± 1.43 versus - 2.75 ± 1.63 for OB and 8.19 ± 3.66 versus 5.69 ± 2.66 for intrusion). Resorption and overbite correction were positively related. No counterclockwise rotation of the mandibular plane was observed. CONCLUSIONS: Overbite correction can be performed by means of upper incisor intrusion without rotation of the mandibular plane. Correction of upper incisor intrusion and overbite is greater in patients treated with two miniscrews. The increase in upper incisor buccal angulation is greater with one miniscrew. Root resorption is positively related to the extent of intrusion. Stability is satisfactory regardless of whether one or two miniscrews are used.

Orthodontic treatment stability predictors: A retrospective longitudinal study.

OBJECTIVE: To examine medium- to long-term orthodontic treatment stability and its possible association with certain variables. MATERIALS AND METHODS: In a retrospective longitudinal study of 70 postretention patients, the Peer Assessment Rating (PAR) index was measured at the start (T1) and end (T2) of treatment and between 4 and 10 years afterwards (T3). The stability was considered absolute when the T2 and T3 values were identical and relative when the difference was within the ±5 range. RESULTS: Among the 70 patients, 65.8% were female and 34.2% were male. Their mean age was 14.5 years. The mean treatment length was 2.4 years. The mean retention phase was 3.3 years. The mean pre- and posttreatment PAR scores were 29.8 (T1) and 6.3 (T2). The mean T1-T2 difference was 23.6. The mean T2-T3 difference was -0.39. CONCLUSIONS: Within the study, 7.1% presented absolute stability and 68.6% presented relative stability. Lower anterior segment alignment and overbite were the most unstable occlusal features and tended to worsen. Fixed retainer (odds ratio [OR] 0.31; 95% confidence interval [CI] 0.10-0.98) as a protective factor and years without retention (OR 1.32; 95% CI 1.03-1.68) as a risk factor are predictor variables of instability in the case of lower anterior segment alignment. The PAR value at the end of treatment (OR 1.29; 95% CI 1.08-1.54) and extractions (OR 4.76; 95% CI 1.05-21.6) before treatment are predictors for midline instability.

Effectiveness of interceptive treatment of class III malocclusions with skeletal anchorage: A systematic review and meta-analysis.

Recently, new strategies for treating class III malocclusions have appeared. Skeletal anchorage appears to reduce the dentoalveolar effects while maximising the orthopaedic effect in growing patients. The purpose of this systematic review and meta-analysis is to examine the effectiveness of bone anchorage devices for interceptive treatment of skeletal class III malocclusions. Searches were made in the Pubmed, Embase, Scopus and Cochrane databases, as well as in a grey literature database, and were complemented by hand-searching. The criteria for eligibility were: patients who had undergone orthodontic treatment with skeletal anchorage (miniplates and miniscrews). Patients with syndromes or craniofacial deformities or who had undergone maxillofacial surgery were excluded. The following variables were recorded for each article: author, year of publication, type of study, sample size, dropouts, demographic variables, treatment carried out, radiographic study (2D or 3D), follow-up time, and quality of the articles on the Newcastle-Ottawa Scale. The means and confidence intervals of the following variables were employed: Wits, overjet, ANB, SNA and SNB. Initially, 239 articles were identified. After removing the duplicates and applying the selection criteria, 9 were included in the qualitative synthesis and 7 in the quantitative synthesis (meta-analysis). It may be concluded that skeletal anchorage is an effective treatment for improving skeletal Class III malocclusion, but when compared with other traditional treatments such as disjunction and face mask, there is no clear evidence that skeletal anchorage improves the results.

Evolución de las características de las arcadas dentarias en dos grupos de edad / Evolution of dental arches characteristics in two age groups

Introducción: Se comparan las características dimensionales de las arcadas dentarias entredos grupos de edades diferentes, adolescentes y adultos jóvenes, para analizar las variaciones asociadasa la edad, sexo y a la influencia del tratamiento ortodóncico. Material y método: Se utilizaron dosmuestras: 88 pares de modelos de escayola de adolescentes (edad media 14,05 años) y 65 de adultos(edad media 22,15 años). Se usó un método digital para la medición de los diámetros mesiodistales delos dientes, distancias intercaninas e intermolares, longitudes de las arcadas y se obtuvo el apiñamientodentario inferior. Para el análisis estadístico se agruparon las muestras de cada grupo de edad porsexos y por tratados/no tratados con ortodoncia. Resultados: Los diámetros mesiodistales de los chicoseran mayores a los de las chicas y los de los adolescentes mayores que los de los adultos, sobretodo en el sexo femenino. La distancia intercanina disminuyó con la edad en las chicas y la intermolarsuperior disminuyó en las chicas no tratadas, mientras que la inferior aumenta en los chicos. Ambaslongitudes de arcada tienden a disminuir en ambos sexos y sobre todo en los grupos de no tratados.Existó un aumento del apiñamiento inferior con la edad en ambos sexos en los individuos tratados.Conclusiones: La pérdida de material dentario con el paso de los años unido a una mayor pérdida delongitud de la arcada podría ser otro factor en el apiñamiento terciario. A su vez, el desplazamientodentario a mesial podría explicar la disminución de los diámetros transversales de caninos y molares,al ocupar una zona más estrecha del arco dentario

Introduction: Dimensional characteristics of dental arches between two groups of age, adolescentsand adults, are compared to analyze the variations associated with age, sex and influence oforthodontic treatment. Material and methods: Two samples of 88 pairs of stone models from adolescents(average age, 14.05 years) and 65 from adults (average age, 22.15 years) were selected. Aftercast scanning, a digital program was used to measure dental mesiodistal diameters, intercanine andintermolar widths, arch lengths and lower dental crowding. For the statistic analysis the samples ofeach age group were divided by sex and by the fact of having been treated or not with orthodontics.Results: The values of the mesiodistal diameters in males were greater than in females, and greater inadolescents than in adults, especially in females. The intercanine distance decreased with age in femalesand the maxillary intermolar distance decreased in untreated females, while the mandibular oneincreased in males. Both arch lengths decreased in both sexes, mainly in the untreated individuals. Thereis an increase of the anteroinferior dental crowding with age in both sexes in the treated group.Conclusions: The loss of dental material with age associated to a greater decrease of arch length couldbe another factor in the later crowding. Also the mesial displacement of the teeth to a narrower partof the arch could explain the decrease in the intercanine and intermolar widths