Occlusal outcomes and efficiency of 1- and 2-phase protocols in the treatment of Class II Division 1 malocclusion

Assessment of the condylar response of two differently anchored fixed functional appliances in class II malocclusion in young adult orthodontic patients: A randomized clinical trial

OBJECTIVE

Measuring the condylar volume changes after treatment with skeletally anchored type IV Herbst appliance vs. Twin Force Bite Corrector (TFBC) in class II malocclusion in young adult patients.

MATERIALS AND METHODS

Twenty class II malocclusion participants were randomly involved in our randomized clinical study. They are divided equally into two groups: group I (10 patients with an age range of 16 to 18 years and a mean age of (17.15 ± 0.62) (five males and five females) with a mean Angle formed between (A) point and (Nasion) point and (B) point, to determine anteroposterior relation between maxilla and mandible (ANB) of 6.20 (1.03) and a mean mandibular length of 106.1 (1.7), who were treated by a skeletally anchored type IV Herbst appliance, supported at the mandible by two mini-plates fixed bilaterally at the mandibular symphysis; group II (10 patients with an age range of 15 to 18 years and a mean age of (16.85 ± 0.33) (six males and four females) with a mean ANB of 6.80 (0.89) and a mean mandibular length of 107.3 (2.36), who were treated by a TFBC that was installed just mesial to the tube of the maxillary first permanent molar and distal to the bracket of the lower canine for 4 months. According to the Index of Orthognathic Functional Treatment Need (IOFTN) index, the participants in both groups have grade 4 (great need for treatment) as they have excessive overjet (6-9 mm). Cone-beam computed tomography (CBCT) was taken just before installing fixed functional appliances and after the removal. The condylar volume was measured using Dolphin software. Parametric measurements were performed by the independent t-test, while non-parametric variables (percent change) were compared by the Mann-Whitney U-test.

RESULTS

On the right side, the Herbst group recorded a percent increase (median = 1.23%), while TFBC recorded a median percent decrease (-7.85%). This change is statistically significant (P = 0.008).

CONCLUSIONS

The difference in the condylar volume was significantly higher with the mini-plate anchored Herbst appliance than with the dentally anchored TFBC group.

Mandibular incisor inclination and gingival recession after treatment with the Jasper Jumper: a 10-year follow-up

OBJECTIVE

To evaluate the long-term outcomes of Class II treatment with the Jasper Jumper appliance and comprehensive orthodontic treatment concerning inclination of the mandibular incisors and gingival recession.

METHODS

Sixteen patients with Class II malocclusion at a mean age of 12.54y (SD = 1.17) were treated with the Jasper Jumper appliance and comprehensive orthodontic treatment. The mean treatment time was 2.05y (SD = 0.21). Dental records were taken before (T1), after treatment (T2) and 11.90y (SD = 0.48) after debonding (T3). The frequency of gingival recession, clinical crown height and mandibular incisor position were evaluated using intraoral photographs, digital models and lateral cephalograms. Interphase changes were evaluated using dependent t and McNemar's tests. Correlation between clinical crown height and final position of the mandibular incisors was evaluated using Pearson correlation test (P < 0.05).

RESULTS

The frequency of gingival recessions increased over time and was observed in 6 (9.4%), 12 (18.8%) and 24 (37.5%) of the mandibular incisors at T1, T2 and T3, respectively. A significant increase in labial inclination and protrusion of the mandibular incisors was observed between T1 and T2 interval. The clinical crown height significantly increased in the follow-up period (T3-T2) and in the complete observation time (T3-T1). There was no correlation between the amount of labial inclination and protrusion of the mandibular incisors and clinical crown height for all time intervals.

CONCLUSION

No significant correlation between the amount of labial movement of the mandibular incisor and clinical crown height increase was found.

Pretreatment dentoskeletal comparison between individuals treated with extractions in the 1970s and in the new millennium

OBJECTIVE

This retrospective study aimed to compare the occlusal and dentoskeletal initial features of patients treated with four first premolar extractions in the 1970s and after 2000.

MATERIALS AND METHODS

Group 70' was composed by 30 subjects with Class I malocclusion (mean age of 12.8 years, 10 male, 20 female) treated in the 1970s with four first premolar extractions and comprehensive orthodontic treatment. Group NM comprised 30 subjects with Class I malocclusion (mean age of 13.4 years, 13 male, 17 female) treated in the new millennium, similarly to Group 70'. Initial dental models and lateral cephalograms were digitized and measured using OrthoAnalyzerTM 3D software and Dolphin Imaging 11.0 software, respectively. Initial occlusal and dentoskeletal features were analyzed and compared. Intergroup comparison was performed using t tests (p < 0.05). Holm-Bonferroni correction for multiple comparison was applied.

RESULTS

Group NM showed significantly greater maxillary and mandibular effective lengths and greater maxillary and mandibular incisor protrusion in comparison with Group 70'. Group NM presented a significantly greater lower anterior facial height. Group NM also showed significantly smaller nasolabial angle and protruded inferior lip.

CONCLUSION

Patients with Class I malocclusion treated with four first premolar extractions in the new millennium present a greater degree of dental and labial protrusion, increased lower anterior facial height, and more acute nasolabial angle compared with patients treated similarly in the 1970s. Greater dental and labial protrusion determines first premolar extractions in the new millennium.

CLINICAL RELEVANCE

Despite the decrease of tooth extraction frequency, four first premolar extractions may be justified in cases with severe dental and skeletal protrusions.

Treatment effects of the Jasper Jumper and the Bionator associated with fixed appliances

BACKGROUND

The aim of this study was to evaluate the effects of Class II malocclusion treatment with the Jasper Jumper and the Bionator, associated with fixed appliances.

METHODS

The sample comprised 77 young individuals divided into 3 groups: Group 1 consisted of 25 patients treated with the Jasper Jumper appliance associated with fixed appliances for a mean period of 2.15 years; group 2 had 30 patients, treated with the Bionator and fixed appliances, for a mean treatment time of 3.92 years; and the control group included 22 subjects followed for a mean period of 2.13 years. The initial and final lateral cephalograms of the patients were evaluated. Intergroup comparison at the initial stage and of the treatment changes were performed by analysis of variance.

RESULTS

Their effects consisted in a restrictive effect on the maxilla, a slight increase in anterior face height, retrusion and extrusion of the maxillary incisors, labial tipping and protrusion of the mandibular incisors in both groups and intrusion with the Jasper Jumper appliance, maxillary molar distalization with the Jasper Jumper, extrusion and mesialization of the mandibular molars, both appliances provided significant improvement of the maxillomandibular relationship, overjet, overbite and molar relationship.

CONCLUSIONS

The effects of both appliances in class II malocclusion treatment are similar; however, treatment with the Jasper Jumper was shorter than with the Bionator.

Frequency evaluation of different extraction protocols in orthodontic treatment during 35 years

BACKGROUND

Studies that show frequencies of different orthodontic treatment protocols can be used as valuable parameters in the interpretation of treatment tendency with time. The purpose of this retrospective study was to evaluate all orthodontic treatment planning conducted at the Orthodontic Department at Bauru Dental School, University of São Paulo, Brazil, since 1973, in order to investigate extraction and non-extraction protocol frequencies selected at each considered period.

METHODS

The sample comprised 3,413 records of treated patients and was evaluated according to the protocol choice, divided into 10 groups: Protocol 0 (non-extraction); Protocol 1 (four first premolar extractions); Protocol 2 (two first maxillary and two second mandibular premolars); Protocol 3 (two maxillary premolar extractions); Protocol 4 (four second premolars); Protocol 5 (asymmetric premolar extractions); Protocol 6 (incisor or canine extractions); Protocol 7 (first or second molar extractions); Protocol 8 (atypical extractions) and Protocol 9 (agenesis and previously missing permanent teeth). These protocols were evaluated in seven 5-year intervals: Interval 1 (1973 to 1977); Interval 2 (1978 to 1982); Interval 3 (1983 to 1987); Interval 4 (1988 to 1992); Interval 5 (1993 to 1997); Interval 6 (1998 to 2002); Interval 7 (2003 to 2007). The frequency of each protocol was compared between the seven intervals, using the proportion test (P < 0.05).

RESULTS

The results showed that 10 protocol frequencies were significantly different among the 7 time intervals.

CONCLUSIONS

The non-extraction protocol frequency increased gradually with consequent reduction of extraction treatments. The four premolar extraction protocol frequency decreased gradually while the two maxillary premolar extraction protocol has maintained the same frequency of indications throughout time.

Dentoskeletal changes induced by the Jasper jumper and the activator-headgear combination appliances followed by fixed orthodontic treatment

INTRODUCTION

The aim of this study was to compare the dentoskeletal changes of patients with Class II Division 1 malocclusion treated with either the Jasper jumper appliance or the activator-headgear combination, both associated with fixed appliances.

METHODS

The sample comprised 72 subjects with Class II Division 1 malocclusion divided into 3 groups: group 1 included 25 subjects treated with fixed appliances and the force modules of the Jasper jumper at an initial mean age of 12.72 years, group 2 included 25 subjects treated with the activator-headgear combination followed by fixed appliances at an initial mean age of 11.07 years, and group 3 included 22 untreated subjects at an initial mean age of 12.67 years. Initial cephalometric characteristics and dentoskeletal changes were compared with analysis of variance.

RESULTS

Both experimental groups had similar dentoskeletal changes: restrictive effect on the maxilla, clockwise mandibular rotation and a slight increase in anterior face height, retrusion of the maxillary incisors, distalization of the maxillary molars, protrusion of the mandibular incisors, extrusion of the mandibular molars, and significant improvements of the maxillomandibular relationship, overjet, overbite, and the molar relationship.

CONCLUSIONS

The effects of the Jasper jumper and the activator-headgear combination followed by fixed orthodontic appliances were similar in Class II malocclusion treatment.

Prospective study of dentoskeletal changes in Class II division malocclusion treatment with twin force bite corrector

OBJECTIVE

To evaluate the dentoskeletal changes of Class II malocclusion treatment with the Twin Force Bite Corrector (TFBC).

MATERIALS AND METHODS

The sample comprised 86 lateral cephalograms obtained from 43 subjects with Class II division 1 malocclusion; the subjects were divided into two groups. The experimental group comprised 23 patients with a mean initial age of 12.11 years who were treated with the TFBC for a mean period of 2.19 years. The control group included 40 lateral cephalograms from 20 Class II nontreated patients, with an initial mean age of 12.55 years and a mean observation period of 2.19 years. The lateral cephalograms were evaluated before and after orthodontic treatment in group 1 and in the beginning and end of the observation period in group 2. t-Tests were used to compare the initial and final cephalometric characteristics of the groups as well as the amount of change.

RESULTS

The experimental group presented greater maxillary growth restriction and mandibular retrusion than the control group, as well as greater maxillomandibular relationship improvement and greater labial tipping of the mandibular incisors. The results also showed a greater decrease in overbite and overjet in the experimental group, and there were no statistically significant differences in the craniofacial growth pattern between groups.

CONCLUSIONS

The TFBC promotes restriction of anterior maxillary displacement without significant changes in mandibular length and position and improvement of maxillomandibular relationship without changes in facial growth and significant buccal tipping of mandibular incisors. Class II correction with the TFBC occurred primarily as a result of dentoalveolar changes.