Manuela Mucedero

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 canines.

Early orthodontic treatment of skeletal open-bite malocclusion: A systematic review

The aim of this study was a systematic review of the literature to assess the scientific evidence on the actual outcome of early treatments of open-bite malocclusions. A literature survey was done by applying the Medline database (Entrez PubMed). The survey covered the period from January 1966 to July 2004 and used the MeSH, Medical Subject Headings. The following study types that reported data on the treatment effects included: randomized clinical trials (RCT), prospective and retrospective studies with concurrent untreated as well as normal controls, and clinical trials comparing at least two treatment strategies without any untreated or normal control group involved. The search strategy resulted in 1049 articles. After selection according to the inclusionary/exclusionary criteria, seven articles qualified for the final review analysis. No RCTs of early treatment of anterior open bite have been performed. Two controlled clinical trials of early anterior open bite have been performed, and these two studies indicated the effectiveness of treatment in the mixed dentition with headgears or functional appliances (or both). Most of the studies had serious problems of lack of power because of small sample size, bias and confounding variables, lack of method error analysis, blinding in measurements, and deficient or lack of statistical methods. Thus, the quality level of the studies was not sufficient enough to draw any evidence-based conclusions.

Stability of rapid maxillary expansion and facemask therapy: A long-term controlled study

INTRODUCTION The aim of this prospective controlled study was to evaluate the long-term effects of rapid maxillary expansion and facemask therapy in Class III subjects. METHODS Twenty-two subjects (9 boys, 13 girls; mean age, 9.2 years ± 1.6) with Class III disharmony were treated consecutively with rapid maxillary expansion and facemask therapy followed by fixed appliances. The patients were reevaluated at the end of the 2-phase treatment (mean age, 14.5 years ± 1.9) and then recalled about 8.5 years after the end of rapid maxillary expansion and facemask treatment (mean age, 18.7 years ± 2.1). Two groups of controls with untreated Class III malocclusion were used for statistical comparisons of the short-term and long-term intervals. Statistical comparisons were performed with the Mann-Whitney U test. RESULTS In the long term, no significant differences in maxillary changes were recorded, whereas the treatment group showed significantly smaller increases in mandibular protrusion. The sagittal maxillomandibular skeletal variables maintained significant improvements in the treatment group vs the control groups. CONCLUSIONS In the long term, rapid maxillary expansion and facemask therapy led to successful outcomes in about 73% of the Class III patients. Favorable skeletal changes were mainly due to significant improvements in the sagittal position of the mandible.

Dentoskeletal changes associated with fixed and removable appliances with a crib in open-bite patients in the mixed dentition

INTRODUCTION The aim of this study was to compare the effects of the quad-helix/crib (Q-H/C) appliance and a removable plate with a crib (RP/C) in patients with dentoskeletal open bite. METHODS Both samples consisted of 20 subjects. Lateral cephalograms were analyzed before treatment (T1) and after active treatment (T2). The average age at T1 was 8.4 years, and the mean duration of treatment was 1.5 years in both groups. The T2-T1 changes in the 2 groups were compared with a nonparametric test for independent samples (Mann-Whitney U test). RESULTS AND CONCLUSIONS Both the Q-H/C and the RP/C appliances induced favorable dental effects. However, a compliance-free appliance, such as the Q-H/C appliance, produced more favorable vertical skeletal changes.

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

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.

Stability factors after double-jaw surgery in Class III malocclusion: a systematic review

OBJECTIVE To identify the stability factors of skeletal Class III malocclusion after double-jaw surgery by a systematic review of the literature. MATERIALS AND METHODS The survey covered the period from September 1959 to October 2007 and used the MeSH, Medical Subject Headings. The inclusion criteria were stability of bimaxillary surgery of the permanent dentition, adult patients with skeletal Class III malocclusion, a follow-up of at least 12 months, randomized and nonrandomized controlled clinical trials (RCCTs; CCTs), prospective and retrospective studies with and without concurrent untreated as well as normal controls, and clinical trials (CTs) comparing at least two treatment strategies without any untreated or normal control group. RESULTS The search strategy resulted in 1783 articles. After selection according to the inclusion/ exclusion criteria, 15 articles qualified for the final review analysis. Quality was low in two studies, medium in twelve, and medium/high in one article, which was represented by a RCT (randomized clinical trial). Most of the studies had sufficient sample size, method error analysis, and adequate statistical methods. Thus, the quality level of the studies was sufficient to draw evidence-based conclusions. CONCLUSIONS Surgical correction of skeletal Class III malocclusion after combined maxillary and mandibular procedures appears to be stable for maxillary advancements up to 5 mm and for the correction of presurgical sagittal intermaxillary discrepancies smaller than 7 mm.

Effects of maxillary protraction with or without expansion on the sagittal pharyngeal dimensions in Class III subjects

INTRODUCTION The aim of this cephalometric study was to analyze the effects of rapid maxillary expansion (RME) and facemask (FM), or FM combined with bite block (BB), on the sagittal pharyngeal dimensions in subjects with Class III malocclusion when compared with an untreated Class III control group. METHODS Thirty-nine subjects (22 girls, 17 boys) were divided into 2 groups: the FM/BB group (22 subjects; mean ages, 8.9 years +/- 1.5 before treatment and 10.5 years +/- 1.3 after treatment) and the RME/FM group (17 subjects; mean ages, 7.1 years +/- 1.8 before treatment and 9.2 years +/- 1.8 after treatment). The treated groups were compared with an untreated Class III control group of 20 subjects (mean ages, 8.1 years +/- 1.2 at the first observation and 10 years +/- 1.7 at the second observation). All subjects were at prepubertal stage of skeletal maturity at both times. Comparisons of these changes between the 3 groups were analyzed with the Kruskal-Wallis 1-way analysis of variance (ANOVA) on ranks with post-hoc tests. RESULTS The favorable skeletal maxillary and mandibular changes produced by maxillary protraction with or without RME were not associated with significant changes in the sagittal oropharygeal and nasopharyngeal airway dimensions. CONCLUSIONS Orthopedic treatment of Class III malocclusion does not produce a significant increase in airway dimensions in the short term.

Treatment and Posttreatment Effects of Quad-Helix/Crib Therapy of Dentoskeletal Open Bite

OBJECTIVE To investigate the effects of the quad-helix/crib (Q-H/C) appliance in subjects with thumb-sucking habits and dentoskeletal open bite at 2 years after the end of active treatment. MATERIALS AND METHODS The records of 21 subjects treated with the Q-H/C appliance were compared with a control group of 21 untreated subjects with similar vertical relationships. Lateral cephalograms were obtained before treatment (T1; mean age 8.4 +/- 1.4 years) and at about 2 years after treatment (T2; mean age 11.7 +/- 1.9 years) and analyzed. Mean treatment duration was 1.5 years +/- 7 months. The T2-T1 changes in the two groups were compared with a nonparametric test for independent samples. RESULTS The mean increase in overbite during Q-H/C therapy (4.1 mm) represented an overcorrection of the amount of anterior open bite at T2. Both the maxillary and mandibular incisors showed significantly greater extrusion in the Q-H/C group than in the control group. The treated group showed a greater downward rotation (1.8 degrees ) of the palatal plane than did the control group. This change was associated with a clinically significant reduction in the palatal plane/mandibular plane angle (-2.5 degrees ) in the Q-H/C group. The upper lip showed significant retraction relative to the E-plane in the treated group (3.6 mm) compared with the controls. CONCLUSIONS The Q-H/C appliance was effective in correcting dental open bite in 85% of the growing subjects with thumb-sucking habits and dentoskeletal open bites. Correction of anterior open bite was associated with a clinically significant improvement in maxillomandibular vertical skeletal relationships.

Treatment and post-treatment effects of facemask therapy on the sagittal pharyngeal dimensions in Class III subjects

The purpose of this cephalometric study was to analyse the treatment and post-treatment craniofacial effects of a facemask (FM) combined with a bite block (BB) with specific regard to the sagittal pharyngeal dimensions in subjects with a Class III malocclusion when compared with an untreated Class III control group. The FM/BB group (22 subjects, 12 females and 10 males) had a mean age pre-treatment (T1) of 8.9 +/- 1.5 years, at the end of active treatment (T2) of 10.5 +/- 1.3 years, and post-treatment (T3) of 12.6 +/- 1.9 years. The treated group was compared with a control group of 14 subjects (6 females and 8 males) with untreated Class III malocclusions that matched the FM/BB group as to age at T1, T2, and T3, observation periods and skeletal maturation. Comparisons of the T2-T1 and T3-T1 changes between the two groups were analysed with the Mann-Whitney test. Significant favourable skeletal changes in the maxilla and mandible were observed in the treated group both after Ts2 and T3. No significant short- or long-term changes in the sagittal oropharyngeal and nasopharyngeal airway dimensions were induced by maxillary protraction in subjects with a Class III malocclusion when compared with untreated controls.

Stability of quad-helix/crib therapy in dentoskeletal open bite: a long-term controlled study.

INTRODUCTION The purpose of this study was to evaluate the long-term stability of quad-helix/crib treatment in subjects with dentoskeletal open bite. METHODS Twenty-eight subjects (11 boys, 17 girls; mean age, 8.2 ± 1.3 years) were treated consecutively with quad-helix/crib appliances. The patients were reevaluated at the end of active treatment with the quad-helix/crib (mean age, 9.7 ± 1.6 years) and at least 5 years after the completion of treatment (mean age, 14.6 ± 1.9 years). A control group of 20 untreated subjects with the same dentoskeletal disharmony was used for the statistical comparison (Mann-Whitney U test). RESULTS In the long term, the quad-helix/crib group showed a significant reduction in the ANB angle (-1.3°), a downward rotation of the palatal plane (1.8°), a greater increase in overbite (2.1 mm), and a decrease in overjet (-1.5 mm) when compared with the controls. CONCLUSIONS In the long term, the use of the quad-helix/crib appliance led to successful outcomes in about 93% of the patients considered. Correction of dentoskeletal open bite was associated with a clinically significant downward rotation of the palatal plane.