Fabrício Pinelli Valarelli

Stability of anterior open bite nonextraction treatment in the permanent dentition

This study cephalometrically evaluated the long-term stability of anterior open bite nonextraction treatment in the permanent dentition after a mean period of 5 years. The experimental group consisted of 21 patients who had undergone orthodontic treatment with fixed appliances from whom cephalometric headfilms were obtained at the pretreatment, posttreatment, and postretention stages. Two control groups were used. The first, with ages comparable with the experimental group before treatment, was used only to characterize it. The second control group, with normal occlusion, was longitudinally followed for a period comparable with the posttretention period and was used to compare the changes between groups during this period. The differences between the observation stages in the experimental group were analyzed with paired t tests, and the postretention changes were compared with the changes of the second control group with independent t tests. A statistically significant decrease of the obtained anterior overbite was demonstrated at the end of the postretention period. The primary factor that contributed to the overbite decrease was the smaller vertical development of the maxillary and mandibular incisors in the postretention period. Neither the pretreatment anterior open bite amount nor the magnitude of correction was associated with the long-term overbite decrease. However, 61.9% of the sample had a clinically stable open bite correction.

Predisposing factors to severe external root resorption associated to orthodontic treatment

OBJECTIVE The aim of this study was to evaluate predisposing factors among patients who developed moderate or severe external root resorption (Malmgrens grades 3 and 4), on the maxillary incisors, during fixed orthodontic treatment in the permanent dentition. METHODS Ninety-nine patients who underwent orthodontic treatment with fixed edgewise appliances were selected. Patients were divided into two groups: G1 - 50 patients with no root resorption or presenting only apical irregularities (Malmgrens grades 0 and 1) at the end of the treatment, with mean initial age of 16.79 years and mean treatment time of 3.21 years; G2 - 49 patients presenting moderate or severe root resorption (Malmgrens grades 3 and 4) at the end of treatment on the maxillary incisors, with mean initial age of 19.92 years and mean treatment time of 3.98 years. Periapical radiographs and lateral cephalograms were evaluated. Factors that could influence the occurrence of severe root resorption were also recorded. Statistical analysis included chi-square tests, Fishers exact test and independent t tests. RESULTS The results demonstrated significant difference between the groups for the variables: Extractions, initial degree of root resorption, root length and crown/root ratio at the beginning, and cortical thickness of the alveolar bone. CONCLUSION It can be concluded that: Presence of root resorption before the beginning of treatment, extractions, reduced root length, decreased crown/root ratio and thin alveolar bone represent risk factors for severe root resorption in maxillary incisors during orthodontic treatment.

PAR Evaluation of Treated Class I Extraction Patients

OBJECTIVE To evaluate treatment changes and quality of finishing occlusion in Class I patients treated with four premolar extractions. MATERIAL AND METHODS Dental casts of 94 subjects (50 males and 44 females) were evaluated. Mean pretreatment age was 13.46 years, and mean treatment time was 2.09 years. The peer assessment rating (PAR) index was obtained from pretreatment and posttreatment dental casts. RESULTS The mean pretreatment PAR index of 29.46 was reduced to 6.32 at posttreatment stage, achieving a reduction of 78.54% with treatment. There was correlation between the initial PAR and correction during treatment, that is, the more severe the malocclusion the greater the treatment changes. CONCLUSION The cases evaluated showed a high-standard orthodontic finishing.

Comparison of the changes of alveolar bone thickness in maxillary incisor area in extraction and non-extraction cases: computerized tomography evaluation

OBJECTIVE To compare, through computed tomography, alveolar bone thickness changes at the maxillary incisors area during orthodontic treatment with and without tooth extraction. METHODS Twelve patients were evaluated. They were divided into 2 groups: G1--6 patients treated with extraction of right and left maxillary first premolars, with mean initial age of 15.83 years and mean treatment length of 2.53 years; G2--6 patients treated without extraction, with mean initial age of 18.26 years and mean treatment length of 2.39 years. Computed tomographies, lateral cephalograms and periapical radiographs were used at the beginning of the treatment (T1) and 18 months after the treatment had started (T2). Extraction space closure occurred in the extraction cases. Intragroup and intergroup comparisons were performed by dependent and independent t test, respectively. RESULTS In G1, the central incisor was retracted and uprighted, while in G2 this tooth showed vestibularization. Additionally, G1 presented a higher increase of labial alveolar bone thickness at the cervical third in comparison with G2. The incidence of root resorption did not present significant differences between groups. CONCLUSION There were no changes in alveolar bone thickness when extraction and nonextraction cases were compared, except for the labial alveolar bone thickness at the cervical third of maxillary incisors.

Posttreatment and physiologic occlusal changes comparison

OBJECTIVE To compare posttreatment and postretention occlusal changes with the physiologic occlusal changes caused by natural development of untreated subjects. MATERIALS AND METHODS The sample was divided into three groups. Group 1 comprised 97 subjects treated with four premolar extractions at a mean pretreatment (T0) age of 13.03 years, a mean posttreatment (T1, first observation) age of 15.12 years, and a mean postretention (T2, second observation) age of 20.52 years. The mean observation period (T2-T1) was 5.39 years. Group 2 comprised 58 subjects treated nonextraction at a mean pretreatment age of 12.83 years, a mean posttreatment age of 14.99 years, a mean postretention age of 20.22 years, and a mean observation period of 5.22 years. Group 3 comprised 114 untreated subjects at a mean age at T1 of 14.91 years and at T2 of 20.48 years. The mean observation period was 5.56 years. Dental casts were evaluated using the Peer Assessment Rating (PAR) index and the Little irregularity index in maxillary and mandibular arches. Changes in PAR and Little indexes were compared among the three groups by analysis of variance and Tukey tests. RESULTS Intergroup comparison showed that at T1 and T2 the treated groups presented smaller PAR and Little indexes than the untreated group. In the observation period, the treated groups showed greater increase in PAR and Little maxillary indexes than the untreated group. The extraction group showed a greater increase of the Little mandibular index than the untreated group. CONCLUSIONS The treated groups showed more changes according to PAR and Little maxillary indexes than the untreated group. The posttreatment change of the mandibular anterior crowding of the treated extraction group was greater than the mandibular crowding caused by physiologic changes in the untreated group.

Dentoskeletal effects of Class II malocclusion treatment with the Twin Block appliance in a Brazilian sample: A prospective study

Objective The aim of this study was to assess the dentoskeletal effects of Class II malocclusion treatment performed with the Twin Block appliance. Methods The experimental group comprised 20 individuals with initial mean age of 11.76 years and was treated for a period of 1.13 years. The control group comprised 25 individuals with initial mean age of 11.39 years and a follow-up period of 1.07 years. Lateral cephalograms were taken at treatment onset and completion to assess treatment outcomes. Intergroup comparison was performed by means of the chi-square and independent t tests. Results The Twin Block appliance did not show significant effects on the maxillary component. The mandibular component showed a statistically significant increase in the effective mandibular length (Co-Gn) and significant improvement in the maxillomandibular relationship. The maxillary and mandibular dentoalveolar components presented a significant inclination of anterior teeth in both arches. The maxillary incisors were lingually tipped and retruded, while the mandibular incisors were labially tipped and protruded. Conclusions The Twin Block appliance has great effectiveness for correction of skeletal Class II malocclusion in individuals with growth potential. Most changes are of dentoalveolar nature with a large component of tooth inclination associated with a significant skeletal effect on the mandible.

Class II malocclusion treatment with the Herbst appliance in patients after the growth peak

OBJECTIVE The objective of this study was to evaluate dentoskeletal effects in the treatment of Class II malocclusion performed with the Herbst appliance in patients at post-peak stage of growth. METHODS The sample consisted of 16 patients with Class II malocclusion and average initial and final ages of 14.04 (ranging from 11.50 to 35.66) and 17.14 (ranging from 13.68 to 38.64) years, respectively, who were treated for an mean time of 2.52 years. Lateral cephalograms were obtained at treatment onset (T1) and completion (T2) to evaluate the effects of therapy. Initial dental casts were also used to evaluate the overjet and the anteroposterior severity of molar relationship at treatment onset. The cephalometric changes between initial and final stages were compared by means of the non-parametric Wilcoxon test. RESULTS The results showed that the Herbst appliance did not promote significant changes in the maxillary component and the effective length of the mandible significantly increased without improving the maxillomandibular relationship. Changes in the maxillary and mandibular dentoalveolar components revealed that the maxillary incisors exhibited retrusion and lingual tipping, while the mandibular incisors presented increased protrusion and buccal tipping. The dental relationships exhibited significant improvements with the treatment. CONCLUSION Based on the present results, it was concluded that the effects of treatment performed with the Herbst appliance in patients at post-peak stage of growth are predominantly of dentoalveolar nature.

Open-bite malocclusion : treatment and stability

List of Contributors Foreword Angelos Metaxas Foreword Greg Huang Acknowledgments 1 Etiology of open-bite malocclusion Karina Freitas and Rodrigo Cancado Environmental factors Deleterious habits Pacifier and thumb-sucking Anterior tongue posture and tongue thrust Mouth breathing Upper respiratory obstacles Lower respiratory obstacles Traumatisms Genetic factors Growth pattern Pathologies Craniofacial anomalies References 2 Open-bite treatment in the deciduous and mixed dentitions Guilherme Janson and Fabricio Valarelli Overbite measurement Treatment in the deciduous dentition Treatment in the mixed dentition Open bite associated with different types of malocclusions Open-bite and Class I malocclusions Open bite associated to Class II and III malocclusions Open-bite and Class II malocclusions Open-bite and Class III malocclusions Treatment stability in the deciduous and mixed dentitions References 3 Open-bite treatment in the permanent dentition Guilherme Janson and Fabricio Valarelli Differential diagnosis Open-bite nonextraction treatment Usual clinical procedures Additional procedures during treatment to aid in open-bite closure Mesial angulation of the attachments Association of tongue crib or spurs during treatment Reversing and accentuating the curve of spee Clinical cases Class I malocclusions Class II malocclusions Class III malocclusions Stability of nonextraction open-bite treatment Open-bite treatment with extractions Clinical cases Class I malocclusions Class II malocclusions Stability of extraction open-bite treatment Stability of extraction versus nonextraction open-bite treatment Treatment of open bite with occlusal adjustment Clinical procedure Patient selection Cephalometric changes expected with the procedure Functional occlusion changes Dentinal sensitivity Clinical considerations Stability of open-bite treatment with occlusal adjustment Open-bite treatment and root resorption Clinical implications References 4 Open-bite correction with posterior teeth intrusion Sergio Barros and Daniela Garib Introduction Types of skeletal anchorage for open-bite correction Skeletal anchorage positioning for molar intrusion Molar intrusion mechanics with skeletal anchorage Dentoskeletal effects of molar intrusion for open-bite closure Open-bite correction with skeletal anchorage, conventional mechanics, and orthognathic surgery: a critical analysis Clinical cases Stability of anterior open-bite treatment by posterior teeth intrusion Clinical cases References 5 Orthodontic-surgical treatment of anterior open bite Eduardo Sant ana, Marcos Janson, and Roberto Bombonatti Combined orthodontic-surgical treatment of skeletal anterior open bite Orthodontic-surgical preparation to correct skeletal anterior open bite Diagnosis of skeletal anterior open bite Stages of combined orthodontic-surgical treatment Treatment planning Orthodontic treatment Presurgical impression and revaluation of dental positioning Presurgical records and definite treatment planning Plaster model surgery and construction of an intermediary splint Orthognathic surgery Bracket rebonding, finishing procedures, and appliance removal Retention and final records Stability of orthodontic-surgical anterior open-bite correction References Index

Treatment times of Class II malocclusion: four premolar and non-extraction protocols

The purpose of this study was to retrospectively compare the treatment times of Class II division 1 malocclusion subjects treated with four first premolar extractions or a non-extraction protocol and fixed edgewise appliances. Eighty-four patients were selected and divided into two groups. Group 1, treated with four first premolar extractions, consisted of 48 patients (27 males and 21 females) with a mean age of 13.03 years and group 2, treated without extractions, consisted of 36 patients (18 males and 18 females) with a mean age of 13.13 years. Group 2 was subdivided into two subgroups, 2A consisting of 16 patients treated in one phase and 2B consisting of 20 patients treated in two phases. The initial and final Treatment Priority Index (TPI), initial ages, initial mandibular crowding, and treatment times of groups 1 and 2 were compared with t-tests. These variables were also compared between group 1 and the subgroups with analysis of variance followed by Tukeys tests. The treatment times for groups 1 and 2 and subgroups 2A and 2B were 2.36, 2.47, 2.25, and 2.64 years, respectively, which were not significantly different. Treatment times with non-extraction and four premolar extraction protocols are similar.

Association between Bolton discrepancy and Angle malocclusions

This study aimed to assess and compare the overall and anterior ratios of tooth size discrepancies in all Angle malocclusion groups. The following null hypothesis (H0) was tested: no difference between tooth size discrepancies (overall and anterior) would be observed among Angle malocclusion groups. The sample comprised of 711 pre-orthodontic treatment study casts of Brazilian patients with a mean age of 17.42 years selected from private practices in Brazil. The casts were divided into 3 groups according to the type of malocclusion: Class I (n = 321), Class II (n = 324), and Class III patients (n = 66). The measurement of the greatest mesiodistal width of the teeth was performed using a centesimal precision digital caliper directly on the study casts, from the distal surface of the left first molar to the distal surface of the right first molar. The overall and anterior ratios between the maxillary and mandibular teeth were evaluated using Boltons method. The following statistical tests were applied: chi-square, independent t-test, and one-way ANOVA. Results showed that all Angle malocclusions groups exhibited a ratio compatible with those recommended by Bolton. With respect to the overall and anterior ratios among the malocclusion groups, no statistically significant differences were found. The null hypothesis was accepted because the results showed no differences in the overall and anterior ratios of tooth size discrepancies among different Angle malocclusion groups.