Dalla malposizione all'inclusione del canino mascellare: diagnosi e previsione di eruzione

obiettivi. Scopo del lavoro è illustrare le più recenti strategie di trattamento intercettivo in una fase di dentizione mista precoce nei pazienti con malposizione del canino permanente mascellare. Materiali e metodi. Dopo aver eseguito la diagnosi di dislocamento del canino è possibile attuare una serie di manovre di terapia intercettiva per favorire la sua eruzione. Sono descritte singolarmente tutte le metodiche di trattamento proposte dalla letteratura, specificando per ogni opzione l’apporto e la validità scientifica. Risultati. Da un’attenta analisi e revisione bibliografica emerge come l’approccio terapeutico nei confronti di una malposizione canina abbia subito un’importante evoluzione nel corso degli anni. Si passa infatti da un metodo di tipo passivo/ osservazionale, che prevede la semplice estrazione del canino deciduo e il monitoraggio radiografico, a interventi di terapia attiva più complessi che possono prevedere l’espansione del mascellare superiore, in associazione o meno alla distalizzazione dei settori latero-posteriori. Discussione. Nei casi di diagnosi precoce, il recupero del canino malposto prevede un nuovo approccio che integra le manovre già descritte con l’estrazione del canino e del primo molare decidui come elementi determinanti nella programmazione ortodontica. Conclusioni. L’obiettivo del trattamento intercettivo del canino mascellare è quello di aumentare le percentuali di successo di eruzione spontanea del canino permanente mascellare diagnosticato in una fase precoce di sviluppo, evitando meccaniche ortodontiche più complesse e biologicamente invasive per il paziente

Treatment and posttreatment effects of a facial mask combined with a bite-block appliance in Class III malocclusion.

Abstract INTRODUCTION: In this cephalometric investigation, we analyzed the treatment and posttreatment effects of an orthopedic protocol for Class III malocclusion consisting of a facial mask combined with a removable bite-block appliance. METHODS: The treated sample consisted of 22 Class III patients treated with the facial mask and bite-block protocol before the pubertal growth spurt (mean age, 8.9 +/- 1.5 years). Treated subjects were evaluated after facial mask and bite-block therapy and at a posttreatment observation in absence of retention. The treated group was compared with a matched control group of 12 untreated Class III subjects. All treated and control subjects were postpubertal at the final observation. Significant differences between the treated and control groups were assessed with the Mann-Whitney U test (P <0.05). RESULTS: Both angular and linear sagittal measurements of the maxilla showed significant improvements during active treatment. Significant improvements of SNA angle, ANB angle, overjet, and molar relationship remained stable during the posttreatment period. No significant effect was found in the mandibular skeletal measures. No significant protraction of the maxillary incisors or retraction of the mandibular incisors was observed. CONCLUSIONS: A bite-block appliance in the mandibular arch with a facial mask enabled effective control of mandibular rotation with progressive closure of the gonial angle. This added to the favorable maxillary outcomes of the treatment protocol. 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved

Association between mesially displaced maxillary first premolars and early displaced maxillary canines

To evaluate the association between the mesially displaced maxillary first premolar (MDP) and the early displacement of the adjacent permanent canine (EDC) before their eruption. MATERIALS AND METHODS: A sample of 1247 subjects in the intermediate mixed dentition stage was assessed for the presence of MDP and EDC. All subjects were divided into two groups: MDP group and noMDP group. For each subject two angular measurements (premolar-occlusal plane η and л premolar-midline angles) were analysed on panoramic radiographs. The chi-square test with Yates correction was performed to compare the prevalence rate of EDC in MDP (MDP-EDC) and noMDP groups. The statistical comparisons for the values of η and л angles between MDP vs noMDP, MDP vs MDP-EDC, and noMDP vs MDP-EDC groups were performed by means of ANOVA with Bonferroni correction. RESULTS: The prevalence rate of EDC in the MDP group was significantly greater than in the noMDP group (66% vs. 12.1%). MDP-EDC group showed a significantly larger л angle than in the MDP group resulting in an increased mesial inclination of displaced premolars. CONCLUSION: MDP can be considered a dental anomaly associated to maxillary canine displacemen

An orthopaedic approach to the treatment of Class III malocclusions in the early mixed dentition

The aim of this investigation was to study cephalometrically the skeletal, dental and soft tissue modifications induced by a Delaire facemask and Bionator III appliance in a sample of 30 patients (17 boys and 13 girls), aged 4.1-9 years [mean 5.85 years, confidence interval (Cl) 5.41-6.29], in the early mixed dentition with a skeletal Class III malocclusion caused by maxillary retrognathism (group 1) and compared with a control sample of 24 subjects (14 boys and 10 girls), aged 4-9 years (mean 5.97 years, Cl 5.35-6.58) with untreated Class III malocclusions (group 2). For each patient a lateral cephalogram was taken before treatment (TO), after facemask removal (T1), and at the end of the retention period with a Bionator III (T2). Cephalometric analysis was carried out. The post-treatment cephalometric values in the treated group showed a forward displacement of the maxilla resulting in a statistically significant increase (P < 0.001) in the SNA angle, A-NPg (mm) and PNS-A (mm) linear values. There was a clockwise rotation of the mandible, with a decrease in the SNB angle and a satisfactory correction of the Class III relationship. The beneficial effects on the facial profile were confirmed by an increase in UL-EL distance and in NB<^>HL and NsPgs<^>HL angles, and by a decrease in the facial convexity angle. These findings indicate that the Delaire facemask and Bionator III treatment is effective for correcting skeletal Class III malocclusions caused by maxillary retrognathism in the early mixed dentition

Interceptive treatment of palatal impaction of maxillary canines with rapid maxillary expansion: a randomized clinical trial.

INTRODUCTION: Our aim in this prospective randomized clinical study was to assess the prevalence rate of eruption of palatally displaced canines, diagnosed at an early developmental stage with posteroanterior radiographs and consequently treated by rapid maxillary expansion. METHODS: A sample of 60 subjects in the early mixed dentition with palatally displaced canines diagnosed on posteroanterior radiographs was enrolled in the trial. Their age range at the first observation (T1) was 7.6 to 9.6 years, with a prepubertal stage of skeletal maturity (CS1 or CS2). The 60 subjects were randomly allocated to the treatment group (TG, 35 subjects) or the no-treatment group (NTG, 25 subjects). The TG was treated with a banded rapid maxillary expander; after expansion, all patients were retained with the expander in place for 6 months. Thereafter, the expander was removed, and the patients wore a retention plate at night for a year. The NTG received no treatment. All subjects were reevaluated in the early permanent dentition (T2) (postpubertal CS4). The number of dropouts was recorded. The main outcome recorded at T2 was successful or unsuccessful eruption of the maxillary permanent canines. The starting forms at T1 for measurements on posteroanterior and panoramic films were compared in the 2 groups with the Mann-Whitney U test (P <0.05). The prevalence rates of successful and unsuccessful treatments in the TG were compared with those in NTG with chi-square tests (P <0.05). From T1 to T2, there were 3 dropouts in each group. RESULTS: The final sample comprised 32 subjects in the TG and 22 subjects in the NTG. No statistically significant differences were found for any variable at T1. The prevalence rates of successful eruption of the maxillary canines were 65.7% (21 subjects) in the TG and 13.6% (3 subjects) in the NTG. The comparison was statistically significant (chi-square = 12.4; P <0.001). Subjects with palatally displaced canines in the early mixed dentition do not have transverse deficiency of the maxillary arch. CONCLUSIONS: The use of a rapid maxillary expander as an early interceptive approach is effective for increasing the rate of eruption of palatally displaced canine