Long-term profile attractiveness of patients with Class I and II malocclusion treated with and without extractions: A 35-year follow-up.

INTRODUCTION: The objective of this study was to compare the profile attractiveness in subjects treated with and without extractions after the long-term 35-year follow-up, according to laypeople, dentists, and orthodontists. METHODS: A total of 40 patients with Class I and II malocclusion were divided into 2 groups, according to the treatment protocol: extraction (E) group, extractions of 4 premolars (n = 24), with mean pretreatment (T1), posttreatment (T2), and long-term posttreatment (T3) ages of 13.13, 15.50 and 49.56 years, respectively. The mean treatment time (T2 - T1) was 2.37 years, and the long-term follow-up (T3 - T2) was 34.19. Nonextraction (NE) group (n = 16), with mean ages at T1, T2, and T3 of 13.21, 15.07, and 50.32 years, respectively. The mean (T2 - T1) was 1.86 years, and the (T3 - T2) was 35.25 years. Lateral cephalograms were used to perform profile facial silhouettes, and an online evaluation was performed by 72 laypeople, 63 dentists, and 65 orthodontists, rating the attractiveness from 1 (least attractive) to 10 (most attractive). The intragroup comparison was performed with the repeated measures analysis of variance and Tukey tests. Intergroup comparison was performed with t tests, 1-way analysis of variance, and Tukey tests. RESULTS: The E group had a longer treatment time than that of the NE group. In the pretreatment, posttreatment, and long-term posttreatment stages, the E and NE groups showed similar profile attractiveness. Laypersons and dentists were more critical than orthodontists. CONCLUSIONS: At long-term posttreatment follow-up, profile attractiveness was similar in patients treated with and without extractions.

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.

Occlusal changes in orthodontically treated subjects 40 years after treatment and comparison with untreated control subjects.

INTRODUCTION: The objective of this study was to compare the aging changes of the dental arches in orthodontically treated and untreated subjects after a 4-decade follow-up period. METHODS: This retrospective study analyzed 2 groups. The treated group comprised 29 patients (11 male, 18 female) presenting with Class I or Class II malocclusions orthodontically treated with extractions of 4 first premolars. Dental models taken at pretreatment (12.84 years), posttreatment (14.95 years), and long-term posttreatment (51.37 years) were evaluated. The untreated (control) group consisted of 22 untreated patients with dental models taken at 13.32, 17.82, and 60.95 years of age. The dental models were digitized, and the following variables were evaluated: Little irregularity index, intercanine, interpremolar and intermolar widths, arch length, arch perimeter, overjet, and overbite. Interphase comparison of the treated group was performed with repeated measures analysis of variance and Tukey tests. Intergroup comparisons were performed using t tests (P <0.05). RESULTS: Crowding was corrected with treatment but relapsed significantly in the long term. Intercanine width increased with treatment and decreased in the long term. Interpremolar and intermolar widths, arch perimeter, and length decreased with treatment and continued to decrease long-term posttreatment. Overjet and overbite were corrected with treatment and remained stable in the long term. From posttreatment to long-term posttreatment, a greater crowding increase was observed in the treated group than in the untreated group. The treated group demonstrated a greater decrease in mandibular intercanine and maxillary and mandibular interpremolar widths than the untreated sample. Overbite increased in the treated group and decreased in the untreated group. The multiple regression analysis showed that previous 4-premolar extractions orthodontic treatment is significantly associated with anterior crowding in the long term. CONCLUSIONS: In the long-term, the treated patients showed relapse of crowding and a decrease in arch form. Long-term changes of treated patients were different from untreated subjects. Relapse might have contributed to greater changes in incisor crowding and arch widths observed in the treated patients.

Two-phase orthodontic treatment of two different types of tooth transposition in the same patient.

Orthodontic treatment is thoroughly planned considering the patient's facial and dental characteristics, the main complaint, treatment time and the orthodontist's experience. Transposition is a form of ectopia, in which two adjacent teeth exchange positions in the dental arch. Transposition can be partial or complete. This article reports the treatment of a female patient with two kinds of tooth transposition managed in the mixed and permanent dentitions. A girl, aged eight years and three months, came to routine paediatric consultation with an ectopic permanent mandibular left lateral incisor in the mixed dentition. Radiographic analysis indicated partial transposition of the permanent mandibular left lateral incisor and canine (Md.L2.C), and development of a complete tooth transposition between the permanent maxillary right first pre-molar and canine (Mx.C.P1). The patient was treated in two phases. The first, in the mixed dentition, and the second, in the permanent dentition with a three-year follow-up between them. These challenging treatment approaches are described in detail, including the mechanics used. The key points of this treatment were early diagnosis of the ectopic mandibular lateral incisor, use of light forces and interphase patient follow-up. These determined the best time to start the second treatment phase, enabling achievement of aesthetic and functional outcomes, and the results remained stable one year after the end of orthodontic treatment.

Aging of the normal occlusion.

OBJECTIVES: The aim of this study was to evaluate the qualitative occlusal changes in individuals with normal occlusion during a period of 47 years. MATERIALS AND METHODS: The sample comprised dental models of 20 subjects with normal occlusion (8 males; 12 females) taken at 13.2 years (T1) and 60.9 years of age (T2). The occlusal features were evaluated with the objective grading system (OGS) and with the six keys to normal occlusion (SKNO). The subjects also answered a questionnaire on the aesthetic and occlusal self-perception at T2. Comparisons from T1 to T2 were performed with paired t- and McNemar tests (P less than 0.05). RESULTS: OGS analysis showed a significant improvement in the marginal ridge levelling and tooth buccolingual inclination. There was a significant deterioration of the antero-posterior occlusal relationship from T1 to T2. Subjects without tooth loss showed a dental alignment worsening between time points. The marginal ridges, buccolingual inclination, and interproximal contacts improved. The SKNO analysis showed a significant deterioration of the maxillary second molars buccolingual inclination and an improvement of the maxillary second molar angulation. All patients were satisfied with their smiles, and 60 per cent of the subjects had no complaints. Dental crowding caused dissatisfaction in 35 per cent of the sample. LIMITATIONS: A limitation of this study was the high prevalence of tooth loss in the sample from T1 to T2. Only 30 per cent of the subjects had no tooth loss in T2. CONCLUSIONS: The aging process slightly deteriorates some occlusal features of individuals with normal occlusion. However, most individuals were satisfied with their aesthetics and occlusal comfort at the sixth decade of life.

Relapse of anterior crowding 3 and 33 years postretention.

INTRODUCTION: The aim of this study was to evaluate the relapse of occlusal characteristics and maxillary and mandibular anterior crowding 3 and 33 years postretention. METHODS: The sample comprised 28 patients, 15 Class I and 13 Class II, treated with 4 premolar extractions, with a mean initial age of 12.72 years (SD, 0.99), a mean final age of 14.74 years (SD, 1.26), and a mean treatment time of 2.02 years (SD, 0.66). The mean short-term postretention age was 20.15 years (SD, 1.34), and the mean long-term postretention age was 49.40 years (SD, 4.54). The mean time of short-term postretention evaluation was 3.70 years (SD, 0.87) and the mean long-term postretention evaluation was 32.95 years (SD, 4.31). The maxillary and mandibular irregularity indexes were assessed on the initial, final, short-term, and long-term postretention stage dental casts. Peer Assessment Rating and the Little indexes were compared among the 4 stages by repeated measures analysis of variance and Tukey tests. RESULTS: Peer Assessment Rating index and maxillary anterior crowding were significantly improved with treatment, had significant relapses in the short term, and a slight and not statistically significant increase from short-term to long-term postretention evaluation. The mandibular irregularity index significantly decreased with treatment, and then significantly and progressively increased in the postretention stages. CONCLUSIONS: The occlusal characteristics and maxillary anterior crowding had significant relapses in the short term and remained stable from the short-term to the long-term postretention stages. Mandibular anterior crowding significantly decreased with treatment, showed a significant relapse in the short term, and continued to significantly increase in the long-term postretention stage.

Nasolabial angle at rest and upon smiling.

PURPOSE: The objectives of this study were 1) to determine the mean and SD of the nasolabial angle (NLA) and the linear measure pronasale (Prn)-A' at rest and upon smiling and 2) to determine the difference between smile and rest in participants with normal occlusion and facial harmony. MATERIALS AND METHODS: The sample consisted of 40 white Brazilian participants (20 of each gender) aged 20 to 30 years and with normal occlusion, a pleasant profile, and facial harmony. The measures NLA and Prn-A' were analyzed in profile photographs at rest and during smile, with a millimeter ruler in front of the profile during use of the Dolphin software. The statistical analysis included dependent t tests to compare the rest and smiling variables. RESULTS: The mean of the NLA at rest was 104.93°; it was 110.67° during smile; and the difference between them was statistically significant, with a mean of 5.74°. The mean of the linear variable Prn-A' at rest was 23.25 mm, whereas during smile it was 24.04 mm, and the difference between them was statistically significant, with a mean of 0.79 mm. CONCLUSIONS: The variability in the NLA and Prn-A' at rest and upon smiling was found to be significant in a normal sample, and it should be considered as a diagnostic tool in the treatment planning for sagittal dentoskeletal deformities.

Incisor irregularity and dental arch dimensions changes in subjects with different severity of anterior crowding: a 37-year follow-up.

BACKGROUND: Occlusal stability is one of the goals of orthodontic treatment, and keeping teeth aligned in the long term is a challenge for the orthodontist. This study aimed to compare the long-term incisors irregularity and dental arches dimensions changes in subjects treated with 4 premolar extractions with different pretreatment Little's irregularity index (LII). The knowledge of long-term outcomes is evidence-based information for the prognosis of future treatments. METHODS: In total, 41 treated subjects were divided into two groups according to mandibular Little irregularity value at pretreatment (mild or severe). The maxillary and mandibular LII, transversal, and longitudinal widths were assessed at pretreatment, posttreatment, and 37-year posttreatment. Chi-square and independent t tests were used for intergroup comparison. RESULTS: The groups presented similar behavior for all stages of maxillary and mandibular arch dimensions changes. Maxillary irregularity was corrected in both groups after treatment, and the alignment was acceptable in the long term. In the mild group, the mandibular incisor irregularity returned to pretreatment values in the long term. The mandibular LII increased in the severe group but did not return to pretreatment values in the long term. CONCLUSIONS: The mild crowding group presented proportionally more relapse of mandibular incisor irregularity than the severe crowding group in the long term. Even so, the correction of mild and severe crowding with the extraction of 4 premolars showed satisfactory results in the long term, even with the presence of maturational changes and relapse.

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 Tukey's 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.

Stability and relapse of maxillary anterior crowding treatment in class I and class II Division 1 malocclusions.

INTRODUCTION: The maxillary anterior teeth are the most important to facial esthetics because they are the first to show on a smile. Therefore, stability of the maxillary anterior teeth alignment is an important issue. The objective of this study was to compare the stability of maxillary anterior tooth alignment in Class I and Class II Division 1 malocclusions. METHODS: The sample comprised dental casts of 70 patients with Class I and Class II Division 1 malocclusions and a minimum of 3 mm of maxillary anterior crowding measured by an irregularity index. The patients were treated with extractions and evaluated at pretreatment and posttreatment and at least 5 years after treatment. The sample was divided into 3 groups: group 1, Class I malocclusion treated with 4 first premolar extractions comprising 30 subjects, with an initial age of 13.16 years and 8.59 mm of initial maxillary irregularity; group 2, Class II malocclusion treated with 4 first premolar extractions comprising 20 subjects, with an initial age of 12.95 years and 11.10 mm of maxillary irregularity; and group 3, Class II malocclusion treated with 2 first maxillary premolar extractions comprising 20 subjects, with an initial age of 13.09 years and 9.68 mm of maxillary irregularity. RESULTS: The decrease in the maxillary irregularity index was significantly greater in group 2 than in group 1 during treatment. The stability of maxillary anterior alignment was 88.12% over the long term; 77% of the linear displacement of the anatomic contact points tended to return to their original positions. CONCLUSIONS: Stability of maxillary anterior alignment between the 3 groups was similar. The stability of maxillary anterior alignment was high over the long term, but a high percentage of teeth tended to return to their original positions.

Atypical extraction of maxillary central incisors.

This case report describes a Class I crowded malocclusion with an ankylosed maxillary central incisor that was in infraocclusion and labially displaced. The patient had wide maxillary teeth, and the option of extracting the maxillary central incisors followed by space closure, with lateral incisors substituting for the central incisors, was chosen.

Class III subdivision malocclusion corrected with asymmetric intermaxillary elastics.

Correcting a Class III subdivision malocclusion is usually a challenge for an orthodontist, especially if the patient's profile does not allow for any extractions. One treatment option is to use asymmetric intermaxillary elastics to correct the unilateral anteroposterior discrepancy. However, the success of this method depends on the individual response of each patient and his or her compliance in using the elastics. The objectives of this article were to present a successful treatment of a Class III subdivision patient with this approach and to illustrate and discuss the dentoskeletal changes that contributed to the correction.

Orthodontic-surgical treatment of Class III malocclusion with extraction of an impacted canine and multi-segmented maxillary surgery.

Establishment of a treatment plan is based on efficacy and easy application by the clinician, and acceptance by the patient. Treatment of adult patients with Class III malocclusion might require orthognathic surgery, especially when the deformity is severe, with a significant impact on facial esthetics. Impacted teeth can remarkably influence treatment planning, which should be precise and concise to allow a reasonably short treatment time with low biologic cost. We report here the case of a 20-year-old man who had a skeletal Class III malocclusion and impaction of the maxillary right canine, leading to remarkable deviation of the maxillary midline; this was his chief complaint. Because of the severely deviated position of the impacted canine, treatment included extraction of the maxillary right canine and left first premolar for midline correction followed by leveling, alignment, correction of compensatory tooth positioning, and orthognathic surgery to correct the skeletal Class III malocclusion because of the severe maxillary deficiency. This treatment approach allowed correction of the maxillary dental midline discrepancy to the midsagittal plane and establishment of good occlusion and optimal esthetics.

Stability of anterior open-bite treatment with occlusal adjustment.

INTRODUCTION: In this study, we aimed to evaluate the long-term stability of anterior open-bite treatment with occlusal adjustment and the dentinal sensitivity caused by this procedure in the long term. METHODS: The sample comprised 17 open-bite patients who experienced relapse of the negative vertical overbite after orthodontic treatment and were retreated with occlusal adjustment. The cephalometric changes were evaluated on lateral cephalograms obtained before and after the occlusal adjustment and in the long term (mean, 3.4 years after occlusal adjustment). Dentinal sensitivity was also evaluated before the occlusal adjustment, and 1.35 months, 4.61 months, and 3.4 years later. The cephalometric statuses between the 3 evaluations were compared with analysis of variance (ANOVA) and Tukey tests. The percentages of clinically significant relapse were calculated. To compare dentinal sensitivity at the several stages, nonparametric Friedman and Wilcoxon tests were performed. RESULTS: Statistically significant relapse of anterior open bite occurred in 33.3% of the patients. Those who had the procedure before 21 years of age were most likely to experience relapse. Dentinal sensitivity remained within the normal range in the long term. CONCLUSIONS: Despite the statistically significant relapse of anterior open bite, clinically significant stability was found in 66.7% of the patients.

Treatment stability in patients with Class II malocclusion treated with 2 maxillary premolar extractions or without extractions.

INTRODUCTION: The purpose of this study was to compare the occlusal stability of Class II malocclusion treatment with and without extraction of 2 maxillary premolars. METHODS: A sample of 59 records from patients with complete Class II malocclusion was used. This sample was divided into 2 groups with the following characteristics: group 1, comprising 29 patients treated without extractions, and group 2, comprising 30 patients treated with extraction of 2 maxillary premolars. Dental cast measurements were obtained before and after treatment and at a minimum of 2.4 years after treatment. The pretreatment, posttreatment, and postretention occlusal statuses were evaluated with the peer assesment rating index. The occlusal indexes at the postretention stage and the posttreatment changes and percentages of posttreatment changes were compared with t tests. RESULTS: The nonextraction and the 2 maxillary premolar extraction treatment protocols of complete Class II malocclusions had no statistically significant differences in occlusal stability. CONCLUSIONS: Finishing Class II malocclusion treatment with the molars in a Class II relationship has similar occlusal stability as finishing with the molars in a Class I relationship.

Class I malocclusion treatment: influence of a missing mandibular incisor on anterior guidance.

This case report describes the orthodontic treatment of a patient with a deep-overbite Angle Class I malocclusion, agenesis of a mandibular central incisor, and 2 supernumerary teeth, which caused impaction of the mandibular first premolars. The 15-year-old patient also had a convex profile, maxillary dentoalveolar protrusion, and deficiency of space for the correct alignment of teeth. Therefore, treatment consisted of fixed appliance therapy, cervical headgear, extraction of the supernumeraries and the mandibular and maxillary first premolars, and mesiodistal reduction of the maxillary incisors to solve the arch perimeter discrepancy as much as possible with interproximal stripping. This method of treatment significantly improved the patient's facial and dental esthetics and provided a good functional occlusion, despite the absence of a mandibular incisor, which generally impairs achieving adequate incisal guidance.

Lateral open bite: treatment and stability.

Because of their multifactorial etiologies, dental and skeletal open bites are among the most difficult malocclusions to treat to a successful and stable result. Etiologic factors include vertical maxillary excess, skeletal pattern, abnormalities in dental eruption, and tongue-thrust problems. The purpose of this article was to report the treatment of an adult patient with a lateral open bite and a unilateral posterior crossbite. The treatment involved nonextraction therapy, including intermaxillary elastics, to obtain dentoalveolar extrusion in the region of the lateral open bite. The treatment results were successful and remained stable 2 years later.

Influence of rapid palatal expansion on maxillary incisor alignment stability.

INTRODUCTION: The purpose of this retrospective study was to compare the long-term stability of maxillary incisor alignment in patients treated with and without rapid maxillary expansion (RME). METHODS: The sample comprised 48 subjects with Class I and Class II malocclusions, treated without extractions with fixed edgewise appliances, divided into 2 groups according to the treatment protocol: group 1 comprised 25 patients (15 girls, 10 boys) at a mean initial age of 13.53 years (SD, 1.63), who had RME during orthodontic treatment. Group 2 comprised 23 patients (13 girls, 10 boys) at a mean initial age of 13.36 years (SD, 1.81 years), treated with fixed appliances without RME. Maxillary dental cast measurements were obtained at the pretreatment, posttreatment, and long-term posttreatment stages. Variables assessed were the irregularity index and maxillary arch dimensions. Intergroup comparisons were made with independent t tests. RESULTS: Greater transverse increases were found during treatment in the group treated with RME. However, during the long-term posttreatment period, no significant difference was observed in the amount of incisor crowding relapse between the groups. CONCLUSIONS: RME did not influence long-term maxillary anterior alignment stability.