Chiara Pavoni

Orthopedic Treatment Outcomes in Class III Malocclusion

OBJECTIVE To assess the scientific evidence on the effectiveness of early orthopedic treatment in Class III subjects. MATERIALS AND METHODS A literature survey was performed by applying the Medline database (Entrez PubMed). The survey covered the period from January 1966 to December 2005 and used the Medical Subject Headings (MeSH). The following study types that reported data on the effects of Class III treatment with orthopedic appliances (facial mask, chincup, FR-3) on intermaxillary sagittal and vertical relationships were included: randomized clinical trials (RCTs), and prospective and retrospective longitudinal controlled clinical trials (CCTs) with untreated Class III controls. RESULTS The search strategy resulted in 536 articles. After selection according to criteria for inclusion and exclusion, 19 articles qualified for the final review analysis. One RCT and 18 CCTs were retrieved. CONCLUSION The quality standard of the retrieved investigations ranged from low (four studies) to medium/high (five studies). Data derived from medium/high quality research described over 75% of success of orthopedic treatment of Class III malocclusion (RME and facial mask therapy) at a follow-up observation 5 years after the end of orthopedic treatment.

Long-term skeletal and dental effects and treatment timing for functional appliances in Class II malocclusion

OBJECTIVE To analyze the long-term skeletal and dentoalveolar effects and to evaluate treatment timing of Class II treatment with functional appliances followed by fixed appliances. MATERIALS AND METHODS A group of 40 patients (22 females and 18 males) with Class II malocclusion consecutively treated either with a Bionator or an Activator followed by fixed appliances was compared with a control group of 20 subjects (9 females and 11 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start of treatment (mean age 10 years), end of treatment with functional appliances (mean age 12 years), and long-term observation (mean age 18.6 years). The treated sample also was divided into two groups according to skeletal maturity. The early-treatment group was composed of 20 subjects (12 females and 8 males) treated before puberty, while the late-treatment group included 20 subjects (10 females and 10 males) treated at puberty. Statistical comparisons were performed with analysis of variance followed by Tukeys post hoc tests. RESULTS Significant long-term mandibular changes (Co-Gn) in the treated group (3.6 mm over the controls) were associated with improvements in the skeletal sagittal intermaxillary relationship, overjet, and molar relationship (∼3.0-3.5 mm). Treatment during the pubertal peak was able to produce significantly greater increases in total mandibular length (4.3 mm) and mandibular ramus height (3.1 mm) associated with a significant advancement of the bony chin (3.9 mm) when compared with treatment before puberty. CONCLUSION Treatment of Class II malocclusion with functional appliances appears to be more effective at puberty.

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.

Short-term effects produced by rapid maxillary expansion and facemask therapy in Class III patients with different vertical skeletal relationships

OBJECTIVE To evaluate the dentoskeletal short-term effects of rapid maxillary expansion and facemask therapy (RME/FM) in a sample of Class III patients showing different vertical skeletal relationships. MATERIALS AND METHODS Seventy-nine patients (35 females and 44 males) having Class III malocclusion were consecutively treated using RME/FM therapy with application of the protraction force in a downward and forward direction and inclination of about 30° to the occlusal plane. All patients were evaluated at the beginning (T1; mean age, 7.7 years) and at the end (T2; mean age, 9.2 years) of orthopedic therapy and divided into three groups according to their vertical skeletal relationships: normal group (NG), hypodivergent group (HypoG), and hyperdivergent group (HyperG). Statistical comparisons between the three groups were performed on the starting forms (T1), the final forms (T2), and the treatment changes (T1-T2) using the ANOVA with Tukeys post hoc tests. RESULTS Favorable modification in terms of maxillary advancement (changes in SNA ranging from 1.4° to 1.8°) and intermaxillary sagittal skeletal relationships (changes in Wits appraisal ranging from 2.5 mm to 3.5 mm) were recorded in all groups. The three groups showed no statistically significant differences in changes in either sagittal or vertical skeletal variables. CONCLUSIONS The various vertical skeletal features do not influence the short-term outcomes of RME/FM therapy.

Long-term evaluation of rapid maxillary expansion and bite-block therapy in open bite growing subjects: A controlled clinical study

OBJECTIVE To evaluate the long-term effects of rapid maxillary expansion (RME) and posterior bite block (BB) in prepubertal subjects with dentoskeletal open bite. MATERIALS AND METHODS The treatment group (TG) comprised 16 subjects (14 girls, 2 boys) with dentoskeletal open bite with a mean age of 8.1 ± 1.1 years treated with RME and BB. Three consecutive lateral cephalograms were available before treatment (T1), at the end of the active treatment with the RME and BB (T2), and at a follow-up observation at least 4 years after the completion of treatment (T3). The TG was compared with a control group (CG) of 16 subjects (14 girls, 2 boys) matched for sex, age, and vertical skeletal pattern. An independent sample t-test was used to compare the T1 to T3, T1 to T2, and T2 to T3 cephalometric changes between the TG and the CG. RESULTS In the long term, the TG showed a significantly greater increase in overbite (+1.8 mm), reduced extrusion of maxillary and mandibular molars (-3.3 mm), and, consequently, a significant decrease in facial divergence (-2.8°) when compared with untreated subjects. CONCLUSIONS The RME and BB protocol led to successful and stable recovery of positive overbite in 100% of the patients considered. Correction of open bite was associated with reduced extrusion of maxillary and mandibular molars with a significant improvement in vertical skeletal relationships when compared with the CG.

Geometric morphometric analysis of the palatal morphology in children with impacted incisors: A three-dimensional evaluation

OBJECTIVE To analyze variations in palatal morphology in subjects presenting unilaterally impacted maxillary permanent central incisors compared with a control group of subjects without eruption anomalies using a three-dimensional (3D) analysis. MATERIALS AND METHODS Twenty-six white subjects (10 girls and 16 boys; mean age 9.5 ± 1.5 years) with unilaterally impacted maxillary permanent central incisors (impacted incisor group [IIG]) were compared with a control group (CG) of 26 subjects (14 girls and 12 boys, mean age 8.7 ± 1.6 years) presenting no eruption disorders. For each subject, dental casts were taken and the upper arch was scanned using a 3D laser scanner. To study the entirety of the shape of the palate in any point of the surface, 3D geometric morphometrics was applied. RESULTS Subjects with impacted maxillary incisors showed skeletal adaptations of the maxilla. In the IIG, both the superior palatal region and lateral palatal surface showed significantly different morphology when compared with CG, with a narrower and higher palatal vault. CONCLUSION The absence of maxillary central incisors over the physiological age of eruption influenced the development of the palatal morphology compared with subjects without eruption anomalies.

Thin-plate spline analysis of mandibular morphological changes induced by early class III treatment: a long-term evaluation

OBJECTIVE To evaluate the long-term mandibular morphological changes induced by early treatment of class III malocclusion with rapid maxillary expansion (RME) and facial mask (FM). MATERIALS AND METHODS Twenty-five subjects [10 boys, 15 girls; mean age at T1 (start of treatment) 9.3±1.6 years] with class III disharmony were treated with RME and FM therapy followed by fixed appliances. The patients were re-evaluated at the end of growth (T2), about 8.5 years after the end of the treatment (mean age, 18.6±2.0 years). Sixteen subjects with untreated class III malocclusion comprised the control group. Mandibular shape changes were analysed on the lateral cephalograms of the subjects of both groups by means of thin-plate spline (TPS) analysis. Procrustes average mandibular configurations were subjected to TPS analysis by means of both cross-sectional between-group comparisons at T1 and at T2 and longitudinal within-group comparisons. Statistical analysis of shape differences was performed using a generalized Goodall F test. RESULTS In the long term, the treated group exhibited a significant upward and forward direction of condylar growth. On the contrary, untreated class III subjects showed an upward and backward direction of condylar growth associated with a downward and forward deformation of the mandibular symphysis. LIMITATIONS Limitations are related to the small sample size of both treated and control groups and to the retrospective nature of the study. CONCLUSIONS Early treatment of class III malocclusion with RME and FM is able to produce significant and favourable long-term mandibular shape changes characterized by an anterior morphogenetic rotation.

Re: response to: Long-term skeletal and dental effects and treatment timing for functional appliances in Class II malocclusion. The Angle Orthodontist 2013(2) 334-340

Because a major reason for orthodontic treatment is to overcome psychosocial difficulties related to facial and dental appearance and enhance social well-being, the evaluation of dental and facial esthetics has become an important part of the clinical examination. Whether a face is considered beautiful is affected substantially by cultural and ethnic factors, but whatever the culture, a severely disproportionate face becomes a psychosocial problem. Differences in facial types and body types obviously must be taken into account when facial proportions are assessed, and variations from the average ratios can be compatible with good facial esthetics. An important point, however, is to avoid treatment outcomes that would change the ratios in the wrong direction, as for example, treatment with interarch elastics that could rotate the mandible downward in a patient whose face already is too long for its width. As for the long-term vertical skeletal effects produced by functional appliances, our study found that treatment did not induce any significant increase in vertical skeletal relationships, as assessed either by the inclination of the palatal plane to Frankfort horizontal or with the inclination of the mandibular plane to the Frankfort horizontal and to the palatal plane. In the Discussion we reported that ‘‘A significant increase in lower anterior facial height in the treated group was associated with a significant increase in the height of the mandibular ramus in the long term. Adequate control of vertical skeletal relationships in the long term was achieved through a good balance between posterior and anterior facial height increases.’’ The case cited by Dr. Mew and published on the Journal of Clinical Orthodontics was included in an unpublished study in which the aesthetics of both the teeth and face were rated by lay and orthodontic judges. We do not know if the evaluation was performed on the comparisons of the photos taken before and after treatment. The main esthetic issue of the face of the specific clinical case can be related to the large nasolabial angle rather than to the increase in the lower anterior facial height that is compatible with the normal vertical growth of the face. However, we certainly look forward to seeing the published data of the study quoted by Dr. Mew.

Correction to: Mandibular response after rapid maxillary expansion in class II growing patients: a pilot randomized controlled trial

In the publication of this article (1) there is an error in the Methods section.

Treatment timing for functional jaw orthopaedics followed by fixed appliances: a controlled long-term study

Objective To evaluate the role of treatment timing on long-term dentoskeletal effects of Class II treatment with removable functional appliances followed by full-fixed appliance therapy. Materials and methods A group of 46 patients (23 females and 23 males) with Class II malocclusion treated consecutively with either Bionator or Activator, followed by fixed appliances was compared with a matched control group of 31 subjects (16 females and 15 males) with untreated Class II malocclusion. The treated sample was evaluated at T1, start of treatment (mean age: 9.9 ± 1.3 years); T2, end of functional treatment and prior to fixed appliances (mean age: 11.9 ± 1.3 years); and T3, long-term observation (mean age: 18.3 ± 2.1 years). The treated and the control samples were divided into pre-pubertal and pubertal groups according to skeletal maturity observed at the start of treatment. Statistical comparisons were performed with independent sample t-tests. Results When treatment was initiated before puberty, Class II correction was mostly confined to the dentoalveolar changes, with significant improvements of both overjet and molar relationships. On the other hand, treatment with the outset at puberty produced significant long-term improvement of sagittal skeletal relationships, which were mainly sustained by mandibular changes. Conclusions Treatment with removable functional appliances (Bionator or Activator) followed by full-fixed appliances produced significant skeletal long-term changes when it begins at puberty. Prepubertal Class II treatment results primarily in dentoalveolar changes.