Displacement of the Mandibular Condyles Immediately after Herbst Appliance Insertion - 3D Assessment

OBJECTIVE

To test the following two hypotheses regarding the consequences of Herbst appliance (HA) insertion: 1) a significant clockwise mandibular rotation will occur and 2) the displacement of the condyles will follow the same magnitude of the changes of overjet (OJ) and overbite (OB).

METHODS

Virtual 3D surface models of 25 patients were generated from cone-beam computed tomographs taken before treatment and immediately after HA insertion. Scans were registered on the cranial base and were analyzed using point-to-point measurements, color-coded maps, and semitransparent overlays. Statistical tests included correlation and simple regression analysis.

RESULTS

Pitch rotation, ranging from -2.2° to 2.2° (mean, 0.2°), was observed in clockwise and counterclockwise directions. Condylar sagittal displacement presented a positive correlation with OJ changes. Each millimeter of OJ correction resulted in an anterior condylar displacement of approximately 0.95 mm. Vertical condylar displacement correlated with OB changes and varied mostly between 2 mm and 4.5 mm.

CONCLUSION

Immediately after HA insertion, no significant clockwise mandibular rotation was observed. The condyles were displaced anteriorly and inferiorly. Condylar anterior displacement and OJ correction presented a ratio close to 1:1. The vertical displacement of the condyles did not follow the same magnitude of OB changes.

Dentoskeletal effects produced by a Jasper Jumper with an anterior bite plane

OBJECTIVE

The aim of this retrospective study was to evaluate the dentoskeletal effects produced by a modified Jasper Jumper with an anterior bite plane for the correction of Class II division 1 malocclusion.

MATERIALS AND METHODS

A sample of 32 growing patients (mean age  =  11.9 ± 1.4 years) with Class II division 1 malocclusion and increased overbite were treated with a modified Jasper Jumper (JJ) and anterior bite plane protocol and compared with a matched control group of 30 subjects with untreated Class II malocclusion (mean age 12.2 ± 0.8 years). Lateral cephalograms were taken before treatment (T1) and at the end of comprehensive treatment (T2). Mean treatment duration was 2.1 ± 0.4 years. The T1-T2 changes in the two groups were compared with Student's t-tests for independent samples.

RESULTS

The JJ group was successfully treated to a Class I occlusal relationship with a significant reduction in overjet (-3.9 mm, P < .001) and overbite (-3.1 mm, P < .001). The JJ group exhibited a significant increase in mandibular length and a significant improvement in maxillomandibular sagittal skeletal relationships. The lower incisors were significantly proclined, while the lower first molars demonstrated significant movement in a mesial direction.

CONCLUSIONS

Use of a modified JJ appliance and anterior bite plane is an effective protocol for the treatment of Class II malocclusion with increased overbite and greater skeletal (75%) than dentoalveolar (25%) effects mainly at the mandibular level.

Three-dimensional digital cast analysis of the effects produced by a passive self-ligating system

AIM

To evaluate maxillary and mandibular dental arch changes induced by a passive self-ligating system by analysing digital dental casts.

SUBJECTS AND METHODS

A sample of 25 growing patients (16 females and 9 males, mean age 12.8 years) treated with passive self-ligating brackets was compared to a sample of 25 untreated controls (15 females and 10 males, mean age 13.4 years). Sixty three-dimensional points were digitised on the maxillary and mandibular pre- and post-treatment virtual models to evaluate differences in the transverse and antero-posterior arch dimensions and in the torque values of representative anterior and posterior teeth. Statistical comparisons were performed with independent sample t-tests with Holm-Bonferroni correction for multiple tests.

RESULTS

The greatest increments in arch widths were found at the maxillary and mandibular premolar level (ranging from 2.0 to 2.2mm) and they were associated with significant increases in maxillary and mandibular arch perimeters (2.3 and 2.5mm, respectively), and in buccal crown torque of the upper premolars (with adequate torque control of all other teeth).

CONCLUSIONS

The passive self-ligating system produced a modest but statistically significant widening of both maxillary and mandibular dental arches that were associated with significant net gains in maxillary and mandibular arch perimeters.

Evaluation of maxillary arch morphology in children with unilaterally impacted incisors via three-dimensional analysis of digital dental casts: a controlled study

OBJECTIVE

The purpose of this work was to analyze variations in maxillary arch dimensions in subjects presenting unilaterally impacted maxillary permanent central incisors compared with a control group of subjects without eruption anomalies.

METHODS

A group of 23 Caucasian children [8 females and 15 males, mean age 9.7 years, standard deviation (SD) 1.6 years] displaying unilaterally impacted maxillary permanent central incisors (impacted incisor group: IIG) were compared with a control group (CG) of 23 subjects (9 females; 14 males, mean age 8.8 years, SD 1.9 years) presenting no eruption disorders. Pretreatment dental casts were taken from each subject and the upper arch was scanned using a three-dimensional scanner. Linear measurements were taken on each digital model to analyze maxillary arch dimensions. Significant between-group differences were tested with the Student's t test (p < 0.05).

RESULTS

The transverse and sagittal upper-arch measurements were significantly smaller in the IIG than in the CG. In particular, the anterior arch was 1.35 mm shorter in the IIG, while intercanine width was decreased by 2.51 mm on the impacted side.

CONCLUSION

Children revealing unilaterally impacted maxillary central incisors demonstrated a significantly constricted maxillary transverse width and shorter arch on the impacted side compared with subjects with no eruption disorders.

Diagnostic reliability of the cervical vertebral maturation method and standing height in the identification of the mandibular growth spurt

OBJECTIVE

To evaluate the capability of both cervical vertebral maturation (CVM) stages 3 and 4 (CS3-4 interval) and the peak in standing height to identify the mandibular growth spurt throughout diagnostic reliability analysis.

MATERIALS AND METHODS

A previous longitudinal data set derived from 24 untreated growing subjects (15 females and nine males,) detailed elsewhere were reanalyzed. Mandibular growth was defined as annual increments in Condylion (Co)-Gnathion (Gn) (total mandibular length) and Co-Gonion Intersection (Goi) (ramus height) and their arithmetic mean (mean mandibular growth [mMG]). Subsequently, individual annual increments in standing height, Co-Gn, Co-Goi, and mMG were arranged according to annual age intervals, with the first and last intervals defined as 7-8 years and 15-16 years, respectively. An analysis was performed to establish the diagnostic reliability of the CS3-4 interval or the peak in standing height in the identification of the maximum individual increments of each Co-Gn, Co-Goi, and mMG measurement at each annual age interval.

RESULTS

CS3-4 and standing height peak show similar but variable accuracy across annual age intervals, registering values between 0.61 (standing height peak, Co-Gn) and 0.95 (standing height peak and CS3-4, mMG). Generally, satisfactory diagnostic reliability was seen when the mandibular growth spurt was identified on the basis of the Co-Goi and mMG increments.

CONCLUSIONS

Both CVM interval CS3-4 and peak in standing height may be used in routine clinical practice to enhance efficiency of treatments requiring identification of the mandibular growth spurt.

The role of rapid maxillary expansion in the promotion of oral and general health

Rapid maxillary expansion (RME) is an effective orthopedic procedure that can be used to address problems concerned with the growth of the midface. This procedure also may produce positive side effects on the general health of the patient. The aim of the present consensus paper was to identify and evaluate studies on the changes in airway dimensions and muscular function produced by RME in growing patients. A total of 331 references were retrieved from a database search (PubMed). The widening of the nasal cavity base after midpalatal suture opening in growing patients allows the reduction in nasal airway resistance with an improvement of the respiratory pattern. The effects of RME on the upper airway, however, have been described as limited and local, and these effects become diminished farther down the airway, possibly as a result of soft-tissue adaptation. Moreover, limited information is available about the long-term stability of the airway changes produced by RME. Several studies have shown that maxillary constriction may play a role in the etiology of more severe breathing disorders such as obstructive sleep apnea (OSA) in growing subjects. Early orthodontic treatment with RME is able to reduce the symptoms of OSA and improve polysomnographic variables. Finally, early orthopedic treatment with RME also is beneficial to avoid the development of facial skeletal asymmetry resulting from functional crossbites that otherwise may lead to functional and structural disorders of the stomatognathic system later in life.

Do orthodontists recommend Class II treatment according to evidence-based knowledge?

AbstractIntroductionThe adequate indications for the timing of treatment for Class II malocclusion are mandatory for the ethical and efficient practice of orthodontics, but clinicians are reluctant to accept new information that contradicts their preferred method of treatment.ObjectiveThe aim of this investigation was to assess the agreement regarding the indications for Class II malocclusion interceptive therapy between a group of international opinion-makers on early treatment and a group of orthodontists and to compare their treatment indications with the current evidence-based knowledge.Material and methodAn electronic survey containing photographs of mild, moderate and severe Class II malocclusions in children was sent to two panels of experts. Panel 1 (n=28) was composed of international orthodontists who had authored world-class publications on early orthodontic treatment, and Panel 2 (n=261) was composed of clinical orthodontists. Based on a 5-point Likert-type scale, the orthodontists selected their therapy option for each of the 9 Class II malocclusion cases.ResultThe Class II malocclusion treatment recommendations of Panel 2 were significantly different from those offered by Panel 1 with a skew of at least 1 scale point toward earlier treatment. The Class II malocclusion treatment recommendations of the members of Panel 1 members were in accordance with contemporary evidence-based knowledge.ConclusionClass II malocclusion overtreatment appears to be the tendency among clinical orthodontists but not among orthodontists who are academically involved with early treatment. There is a gap between the scientific knowledge and the practices of orthodontists.

Osteogenesis imperfecta and rapid maxillary expansion: Report of 3 patients

INTRODUCTION

The aim of this study was to analyze the effects of orthopedic therapy with rapid maxillary expansion (RME) in growing patients affected by osteogenesis imperfecta and treated with bisphosphonates.

METHODS

Three boys with osteogenesis imperfecta (mean age, 10.6 years) were treated with RME. They all had treatment with quarterly intravenous infusions of bisphosphonates. They were in either the early or the late mixed dentition and had indications for RME. The expansion screw was activated twice daily until correction of the transverse relationships was achieved. The retention period with the expander in place was 6 months. In 2 Class III patients, RME was associated with the use of a facemask. In all patients, occlusal radiographs were taken at the end of active RME therapy to assess the opening of the midpalatal suture and 1 year after the end of active expansion therapy to evaluate the reossification and reorganization of the midpalatal suture.

RESULTS

In all patients, the opening of the midpalatal suture and the healing with reorganization of the midpalatal suture were documented with the occlusal radiographs. No complications were found after a 1-year follow-up.

CONCLUSIONS

In growing patients affected by osteogenesis imperfecta and treated with bisphosphonates, it is possible to perform RME with a standard protocol with no complications after a 1-year follow-up.

Effectiveness of maxillary protraction using a hybrid hyrax-facemask combination: a controlled clinical study

OBJECTIVE

To evaluate the treatment effects of a hybrid hyrax-facemask (FM) combination in growing Class III patients.

MATERIAL AND METHODS

A sample of 16 prepubertal patients (mean age, 9.5 ± 1.6 years) was investigated by means of pre- and posttreatment cephalograms. The treatment comprised rapid palatal expansion with a hybrid hyrax, a bone- and toothborne device. Simultaneously, maxillary protraction using an FM was performed. Mean treatment duration was 5.8 ± 1.6 months. The treatment group was compared with a matched control group of 16 untreated Class III subjects. Statistical comparisons were performed with the Mann-Whitney U-test.

RESULTS

Significant improvement in skeletal sagittal values could be observed in the treatment group over controls: SNA: 2.4°, SNB: -1.7°, Co-Gn: -2.3 mm, Wits appraisal: 4.5 mm. Regarding vertical changes, maintenance of vertical growth was obtained as shown by a small nonsignificant increase of FMA and a small significant decrease of the Co-Go-Me angle.

CONCLUSIONS

The hybrid hyrax-FM combination was found to be effective for orthopedic treatment in growing Class III patients in the short term. Favorable skeletal changes were observed both in the maxilla and in the mandible. No dentoalveolar compensations were found.

Early treatment of Class III malocclusion with RME and facial mask: evaluation of dentoalveolar effects on digital dental casts

AIM

To analyse the dental effects on digital dental casts in subjects with Class III malocclusion treated with bonded Rapid Maxillary Expansion and Facial Mask (RME/FM).

MATERIALS AND METHODS

A study group sample (SG) of 29 subjects (13 females and 16 males) and mean age of 7.4 years (SD 1.2 years) was selected. A bonded RME was placed and activated 1/4 of a turn per day until overcorrection of the transverse width. At the end of expansion, patients were given FMs and treated at least to a positive overjet. The SG was compared with a control group (CG) of 21 prepubertal subjects (9 females; 12 males) presenting with normal occlusion and mean age of 7.9 years (SD 1.6 years). For each subject of the SG and CG initial (pretreatment, T1) and final (post-treatment, T2) digital dental casts were available. Significant in between-group differences were tested with the Student's t-test.

RESULTS

The transverse dimension of the upper arch was significantly greater in SG vs. CG (IMAW: +2.6 mm; ICAW: +3.1 mm). Anterior arch length and arch depth were significantly smaller in SG when compared with CG (AAL: -3.2 mm, AD: -3.4 mm) at the end of therapy.

CONCLUSION

The orthopaedic treatment with bonded RME/FM produced in subjects treated in the deciduous or early mixed dentition a significant expansion of the maxillary arch and mesialisation of the posterior teeth with a reduction of the arch depth.

Bonded versus banded rapid palatal expander followed by facial mask therapy: analysis on digital dental casts

OBJECTIVES

To compare the dental effects produced by a bonded versus a banded expander combined with facial mask (FM) in patients with Class III malocclusion by means of digital dental casts.

MATERIALS AND METHODS

Two groups of patients with Class III malocclusion and maxillary transverse deficiency in the deciduous or early mixed dentition were selected. The first group consisted of 25 subjects (12 females; 13 males) with a mean age of 7.4 years (SD 1.2 years) treated with a bonded expander and FM. The second group consisted of 25 subjects (13 females; 12 males) with a mean age of 8.1 years (SD 1.3 years) treated with a banded expander and FM. For each subject of the two groups, initial (pre-treatment, T1) and final (post-treatment, T2) dental casts were taken and scanned. Maxillary digital models of T1 and T2 were superimposed on the palatal rugae in order to analyse the maxillary anchorage loss. Significant between-group differences were tested with independent sample t-test (P < 0.05).

RESULTS

No statistical differences were found for any of the variables observed.

CONCLUSION

Orthopaedic treatment of Class III malocclusion with either a bonded or a banded expander and FM during the deciduous or early mixed dentition induced a significant expansion of the maxillary arch and a slight mesialization of the posterior anchoring teeth with no difference between the two intraoral appliance designs.

Treatment effects of fixed functional appliances alone or in combination with multibracket appliances: A systematic review and meta-analysis

OBJECTIVE

To assess skeletal and dentoalveolar effects of fixed functional appliances, alone or in combination with multibracket appliances (comprehensive treatment), on Class II malocclusion in pubertal and postpubertal patients.

MATERIALS AND METHODS

Literature survey was conducted using the Medline, SCOPUS, LILACS, and SciELO databases and The Cochrane Library, and through a manual search. The studies retrieved had to have a matched untreated control group. No restrictions were set regarding the type of fixed appliance, treatment length, or to the cephalometric analysis used. Data extraction was mostly predefined at the protocol stage by two authors. Supplementary mandibular elongation was used for the meta-analysis.

RESULTS

Twelve articles qualified for the final analysis of which eight articles were on pubertal patients and four were on postpubertal patients. Overall supplementary total mandibular elongations as mean (95% confidence interval) were 1.95 mm (1.47 to 2.44) and 2.22 mm (1.63 to 2.82) among pubertal patients and -1.73 mm (-2.60 to -0.86) and 0.44 mm (-0.78 to 1.66) among postpubertal patients, for the functional and comprehensive treatments, respectively. For pubertal subjects, maxillary growth restraint was also reported. Nevertheless, skeletal effects alone would not account for the whole Class II correction even in pubertal subjects with dentoalveolar effects always present.

CONCLUSIONS

Fixed functional treatment is effective in treating Class II malocclusion with skeletal effects when performed during the pubertal growth phase, very few data are available on postpubertal patients.

Treatment effects produced by the Twin-block appliance vs the Forsus Fatigue Resistant Device in growing Class II patients

OBJECTIVE

To compare the dentoskeletal changes produced by the Twin-block appliance (TB) followed by fixed appliances vs the Forsus Fatigue Resistant Device (FRD) in combination with fixed appliances in growing patients having Class II division 1 malocclusion.

MATERIALS AND METHODS

Twenty-eight Class II patients (19 females and 9 males; mean age, 12.4 years) treated consecutively with the TB followed by fixed appliances were compared with a group of 36 patients (16 females and 20 males; mean age, 12.3 years) treated consecutively with the FRD in combination with fixed appliances and with a sample of 27 subjects having untreated Class II malocclusion (13 females and 14 males; mean age, 12.2 years). Mean observation interval was 2.3 years in all groups. Cephalometric changes were compared among the three groups by means of ANOVA and Tukey's post hoc tests.

RESULTS

The FRD produced a significant restraint of the maxilla compared with the TB and control samples (SNA, -1.1° and -1.8°, respectively). The TB sample exhibited significantly greater mandibular advancement and greater increments in total mandibular length than either the FRD or control groups (SNB, 1.9° and 1.5°, respectively; and Co-Gn, 2.0 mm and 3.4 mm, respectively). The FRD produced a significantly greater amount of proclination of the mandibular incisors than what occurred with the TB or the control samples (2.9° and 5.6°, respectively).

CONCLUSION

The TB appliance produced greater skeletal effects in terms of mandibular advancement and growth stimulation while the Forsus caused significant proclination of the mandibular incisors.

Comparisons of two protocols for the early treatment of Class III dentoskeletal disharmony

OBJECTIVE

To assess the short-term outcomes of splints, Class III elastics, and chincup (SEC III) and rapid maxillary expansion and facial mask (RME/FM) protocols.

MATERIALS AND METHODS

25 patients with Class III dentoskeletal disharmony (10 males, 15 females) treated with the SEC III protocol were evaluated at the beginning (T1, mean age 7.5±1.4 years) and at the end of treatment (T2, mean age 8.7±1.4 years). The SEC III group was compared to a matched sample of 32 Class III patients (16 males, 16 females) treated with the RME/FM protocol and to a matched control group (CG) consisting of 23 subjects (12 males, 11 females) with untreated Class III dentoskeletal disharmony. The statistical comparisons between the three groups were performed with analysis of variance with Tukey's post hoc tests.

RESULTS

With respect to the CG the SEC III and the RME/FM groups showed significantly favourable effects in terms of maxillary advancement (SNA +1.2 and +1.4 degrees, respectively), control of mandibular projection (SNB -1.3 and -1.4 degrees, respectively), and intermaxillary relationships (ANB +2.6 and +2.9 degrees, respectively; WITS +3.7 and +2.6mm, respectively). The RME/FM group showed a significantly greater increase in the intermaxillary divergency than the SEC III group (+1.8 degrees) and the CG (+2.0 degrees).

LIMITATIONS

A limitation of this study is its short-term nature.

CONCLUSIONS

Both SEC III and RME/FM protocols are efficient treatments for Class III dentoskeletal disharmony. The SEC III protocol produces more favourable control in intermaxillary vertical relationships than the RME/FM therapy.

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

AIM

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 displacement.

The Smile Esthetic Index (SEI): A method to measure the esthetics of the smile. An intra-rater and inter-rater agreement study

PURPOSE

To propose a method to measure the esthetics of the smile and to report its validation by means of an intra-rater and inter-rater agreement analysis.

MATERIALS AND METHODS

Ten variables were chosen as determinants for the esthetics of a smile: smile line and facial midline, tooth alignment, tooth deformity, tooth dischromy, gingival dischromy, gingival recession, gingival excess, gingival scars and diastema/missing papillae. One examiner consecutively selected seventy smile pictures, which were in the frontal view. Ten examiners, with different levels of clinical experience and specialties, applied the proposed assessment method twice on the selected pictures, independently and blindly. Intraclass correlation coefficient (ICC) and Fleiss' kappa) statistics were performed to analyse the intra-rater and inter-rater agreement.

RESULTS

Considering the cumulative assessment of the Smile Esthetic Index (SEI), the ICC value for the inter-rater agreement of the 10 examiners was 0.62 (95% CI: 0.51 to 0.72), representing a substantial agreement. Intra-rater agreement ranged from 0.86 to 0.99. Inter-rater agreement (Fleiss' kappa statistics) calculated for each variable ranged from 0.17 to 0.75.

CONCLUSION

The SEI was a reproducible method, to assess the esthetic component of the smile, useful for the diagnostic phase and for setting appropriate treatment plans.

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 Tukey's 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.

Morphometric analysis of long-term dentoskeletal effects induced by treatment with Balters bionator

OBJECTIVE

To evaluate the long-term effects of the standard (Class II) Balters bionator in growing patients with Class II malocclusion with mandibular retrusion by using morphometrics (thin-plate spline [TPS] analysis).

MATERIALS AND METHODS

Twenty-three Class II patients (8 male, 15 female) were treated consecutively with the Balters bionator (bionator group). The sample was evaluated at T0, start of treatment; T1, end of bionator therapy; and T2, long-term observation (including fixed appliances). Mean age at the start of treatment was 10 years 2 months (T0); at posttreatment, 12 years 3 months (T1); and at long-term follow-up, 18 years 2 months (T2). The control group consisted of 22 subjects (11 male, 11 female) with untreated Class II malocclusion. Lateral cephalograms were analyzed at the three time points for all groups. TPS analysis evaluated statistical differences (permutation tests) in the craniofacial shape and size between the bionator and control groups.

RESULTS

TPS analysis showed that treatment with the bionator is able to produce favorable mandibular shape changes (forward and downward displacement) that contribute significantly to the correction of the Class II dentoskeletal imbalance. These results are maintained at a long-term observation after completion of growth. The control group showed no statistically significant differences in the correction of Class II malocclusion.

CONCLUSIONS

This study suggests that bionator treatment of Class II malocclusion produces favorable results over the long term with a combination of skeletal and dentoalveolar shape changes.

Effects of cervical headgear and pendulum appliance on vertical dimension in growing subjects: a retrospective controlled clinical trial

OBJECTIVE

To analyze the effects on vertical dentoskeletal dimension produced by cervical headgear (CHG) or Pendulum (P) both followed by full fixed appliances in growing patients with Class II malocclusion.

MATERIAL AND METHODS

The CHG group (CHGG) consisted of 40 patients (25 females, 15 males) with a mean age of 11.5 years. The P group (PG) comprised 40 patients (21 females, 19 males) with a mean age of 11.6 years. Mean treatment duration with the CHG and P appliances were 1.5 years and 8.2 months, respectively. Lateral cephalograms were available before treatment (T1) and at the end of fixed therapy (T2) with a mean interval of 3.5 years. The effects of the 2 protocols were compared with a matched control group (CG) of 25 untreated Class II subjects (13 females, 12 males). The ANOVA with Tukey's post hoc tests was used to evaluate between-group differences at T1 and during the T1-T2 interval (P < 0.05).

RESULTS

CHGG showed significantly greater decreases in both Sella-Nasion to A point angle and A-Nasion-B point anglel when compared with both PG (-1.2 and -0.9 degrees, respectively) and CG (-1.9 and -1.5 degrees, respectively). No significant between-group differences were recorded for any of the vertical skeletal measurements. Both CHGG and PG showed significantly greater improvement in molar relationships with respect to CG (+2.5mm).

CONCLUSIONS

Both distalizing protocols were effective in the correction of Class II malocclusion without increasing the vertical dimension at the end of comprehensive treatment.

Maturation of the middle phalanx of the third finger and cervical vertebrae: a comparative and diagnostic agreement study

OBJECTIVE

Diagnostic agreement on individual basis between the third middle phalanx maturation (MPM) method and the cervical vertebral maturation (CVM) method has conjecturally been based mainly on overall correlation analyses. Herein, the true agreement between methods according to stage and sex has been evaluated through a comprehensive diagnostic performance analysis.

SUBJECTS AND METHODS

Four hundred and fifty-one Caucasian subjects were included in the study, 231 females and 220 males (mean age, 12.2 ± 2.5 years; range, 7.0-17.9 years). The X-rays of the middle phalanx of the third finger and the lateral cephalograms were examined for staging by blinded operators, blinded for MPM stages and subjects' age. The MPM and CVM methods based on six stages, two pre-pubertal (1 and 2), two pubertal (3 and 4), and two post-pubertal (5 and 6), were considered. Specifically, for each MPM stage, the diagnostic performance in the identification of the corresponding CVM stage was described by Bayesian statistics.

RESULTS

For both sexes, overall agreement was 77.6%. Most of the disagreement was due to 1 stage apart. Slight disagreement was seen for the stages 5 and 6, where the third middle phalanx shows an earlier maturation.

CONCLUSIONS

The two maturational methods show an overall satisfactorily diagnostic agreement. However, at post-pubertal stages, the middle phalanx of the third finger appears to mature earlier than the cervical vertebrae. Post-pubertal growth phase should thus be based on the presence of stage 6 in MPM.

Prediction of Class III treatment outcomes through orthodontic data mining

OBJECTIVE

To determine whether it is possible to predict Class III treatment outcomes on the basis of a model derived from a combination of computational analyses derived from complexity science, such as fuzzy clustering repartition and network analysis.

METHODS

Cephalometric data of 54 Class III patients (32 females, 22 males) taken before (T1, mean age 8.2 ± 1.6 years) and after (T2, mean age 14.6 ± 1.8 years) early rapid maxillary expansion and facemask therapy followed by fixed appliances were analysed. Patients were classified at T1 on the basis of high membership grade into three main dentoskeletal fuzzy cluster phenotypes: hyperdivergent (HD), hypermandibular (HM), and balanced (Bal) phenotypes. The prevalence rate of successful and unsuccessful cases at T2 was calculated for the three clusters and compared by means of Fisher's exact test corrected for multiple testing (Holm-Bonferroni method).

RESULTS

Unsuccessful cases were 9 out of 54 patients (16.7%). Once patients were framed into their cluster membership, the individualized pre-treatment prediction of unsuccessful cases was largely differentiated: HD and HM patients showed a significantly greater prevalence rate of unsuccessful cases than Bal patients (0% in Bal cluster, 28.6% in HM cluster, and 33.3% in HD cluster). Network analysis captured some noticeable interdependencies of Class III patients, showing a more connected interactive structure of cephalometric data sets in HM and HD patients compared with Bal patients. The results were confirmed after minimizing the geometrical connections between cephalometric variables in the model.

CONCLUSIONS

Fuzzy clustering repartition can be usefully used to estimate an individualized risk of unsuccessful treatment outcome in Class III patients.