Iatrogenic absence of maxillary canines: Bolton discrepancy treated with mandibular incisor extraction.

This case report describes the orthodontic treatment of an adult patient with iatrogenic absence of the maxillary canines, moderate maxillary and severe mandibular dental crowding, a Bolton discrepancy with a large mandibular anterior excess, a maxillary right lateral incisor crossbite, and Angle Class II molar relationships. The treatment consisted of fixed appliance therapy, mandibular incisor extraction, tooth bleaching, and dental recontouring. This method of treatment maintained the patient's good facial appearance, improved the dental esthetics, and provided a good functional occlusion, eliminating the arch length and Bolton discrepancies and providing a good outcome with minimal undesirable effects.

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.

Influence of the cephalometric characteristics on the occlusal success rate of Class II malocclusions treated with nonextraction or with two maxillary premolar extraction protocols.

AIM: To compare the initial cephalometric characteristics of complete Class II malocclusions treated with nonextraction or with two maxillary premolar extractions and to verify their degree of influence on the occlusal success rate. METHODS: A sample of 84 records from patients with complete Class II malocclusions was divided into two groups. Group 1 consisted of 31 patients treated with nonextraction at an initial mean age of 12.95 years, while group 2 included 53 patients treated with two maxillary premolar extractions at an initial mean age of 13.3 years. Initial and final occlusal statuses were evaluated on dental casts with Grainger's Treatment Priority Index (TPI); the initial cephalometric characteristics were obtained on the pretreatment cephalograms. The initial cephalometric characteristics of the groups were compared by t test. A multiple linear regression analysis was used to evaluate the influence of all variables in the percentage of TPI reduction. RESULTS: The pretreatment cephalometric characteristics of the two maxillary premolar extraction cases were a greater vertical growth pattern, greater max illary and mandibular incisor protrusion, greater maxillary incisor and molar dentoalveolar heights, and greater upper and lower lip protrusion than the nonextraction group. However, the regression analysis demonstrated that only the extraction protocol was significantly associated with the occlusal success rate in the groups. CONCLUSIONS: It was concluded that the initial cephalometric characteristics of the groups did not influence the occlusal success rate of the two treatment protocols investigated.

Avaliação das alterações dentoesqueléticas e tegumentares do tratamento da má oclusão de Classe II com extrações de dois pré-molares superiores, quatro pré-molares e sem extrações / Evaluation dentoskeletal and soft-tissue changes of class II malocclusion treatment with two maxillary premolar, four premolar and nonextraction protocols

O objetivo do estudo foi avaliar as estruturas dentoesqueléticas e tegumentares finais, principalmente, a posição dos incisivos superiores de pacientes submetidos ao tratamento sem extrações, com extrações de 2 pré-molares superiores e 4 pré-molares no tratamento da má oclusão de Classe II, divisão 1. Um grupo de oclusão normal também foi utilizado. A amostra de 120 indivíduos foi dividida em quatro grupos, sendo três grupos experimentais e um grupo controle. O grupo 1 constituiu-se de 30 pacientes (19 feminino e 11 masculino), com idade média inicial e final de 12,38 e 14,95 anos, respectivamente, tratados sem extrações. O grupo 2 constituiu-se de 30 pacientes (17 feminino e 13 masculino), com idade média inicial e final de 12,68 e 15,28 anos, respectivamente, tratados com extrações de 2 pré-molares superiores. O grupo 3 constituiu-se de 30 pacientes (15 feminino e 15 masculino), com idade média inicial e final de 13,10 e 15,55 anos, respectivamente, tratados com extrações de 4 pré-molares. O grupo 4 foi constituído de 30 indivíduos (15 feminino e 15 masculino), com idade média de 14,93 anos e oclusão normal derivado do Burlington Growth Centre, Departamento de Ortodontia da Faculdade de Odontologia, Universidade de Toronto, Canadá. As condições oclusais inicial e final dos grupos experimentais foram avaliadas nos modelos de gesso utilizando o Índice Peer Assessment Rating (PAR), e as variáveis cefalométricas finais da amostra foram obtidas em telerradiografias norma lateral e comparadas pelo teste Análise de Variância (ANOVA). Os resultados demonstraram que, o grupo 3 apresentou comprimento maxilar menor do que aquele dos grupos 1 e controle; padrão de crescimento mais vertical, incisivos superiores e inferiores mais extruídos do que nos outros grupos. Os grupos experimentais apresentaram maxila e mandíbula retruídas em relação ao grupo controle. Os incisivos superiores apresentaram-se semelhantes entre os grupos experimentais, porém mais...

The objective of this investigation was to evaluate the posttreatment dentoskeletal and soft-tissue characteristics, mainly, the maxillary incisor position of Class II, division 1 patients treated nonextraction, with two maxillary premolar and with four premolar extraction protocols. A control group of normal occlusion was also employed. The sample of 120 subjects was divided into four groups, three experimental groups and one control group. Group 1 comprised 30 patients (19 girls, 11 boys) with initial and final mean age of 12.38 and 14.95 years, respectively, and treated without extraction. Group 2 comprised 30 patients (17 girls, 13 boys) with initial and final mean age of 12.68 and 15.28 years, respectively, treated with extraction of 2 maxillary premolars. Group 3 comprised 30 patients (15 girls, 15 boys) with initial and final mean age of 13.10 and 15.55 years, respectively, treated with extraction of 4 premolars. Group 4 comprised 30 individuals (15 girls, 15 boys) with a mean age of 14.93 years and with normal occlusion from the Burlington Growth Centre, Orthodontics Department of the University of Toronto Dental School, Canada. The initial and final occlusal features of the experimental groups were evaluated on dental casts by Peer Assessment Rating (PAR) and the final cephalometric characteristics of the sample were obtained in lateral cephalogram and compared using ANOVA. The results demonstrated that the maxillary showed a smaller length in group 3 than in group 1 and control group; greater vertical growth pattern and greater maxillary and mandible incisors extrusion in group 3 than in the other groups. The experimental group showed maxillary and mandible retrusion regarding the control group. The maxillary incisors were similar among the experimental groups; however they showed greater upright position in groups 2 and 3 than in the control group. The mandibular incisor presented greater buccal displacement in group 1 than the three...

Avaliação das alterações dentoesqueléticas e tegumentares do tratamento da má oclusão de Classe II com extrações de dois pré-molares superiores, quatro pré-molares e sem extrações / Evaluation dentoskeletal and soft-tissue changes of class II malocclusion treatment with two maxillary premolar, four premolar and nonextraction protocols

O objetivo do estudo foi avaliar as estruturas dentoesqueléticas e tegumentares finais, principalmente, a posição dos incisivos superiores de pacientes submetidos ao tratamento sem extrações, com extrações de 2 pré-molares superiores e 4 pré-molares no tratamento da má oclusão de Classe II, divisão 1. Um grupo de oclusão normal também foi utilizado. A amostra de 120 indivíduos foi dividida em quatro grupos, sendo três grupos experimentais e um grupo controle. O grupo 1 constituiu-se de 30 pacientes (19 feminino e 11 masculino), com idade média inicial e final de 12,38 e 14,95 anos, respectivamente, tratados sem extrações. O grupo 2 constituiu-se de 30 pacientes (17 feminino e 13 masculino), com idade média inicial e final de 12,68 e 15,28 anos, respectivamente, tratados com extrações de 2 pré-molares superiores. O grupo 3 constituiu-se de 30 pacientes (15 feminino e 15 masculino), com idade média inicial e final de 13,10 e 15,55 anos, respectivamente, tratados com extrações de 4 pré-molares. O grupo 4 foi constituído de 30 indivíduos (15 feminino e 15 masculino), com idade média de 14,93 anos e oclusão normal derivado do Burlington Growth Centre, Departamento de Ortodontia da Faculdade de Odontologia, Universidade de Toronto, Canadá. As condições oclusais inicial e final dos grupos experimentais foram avaliadas nos modelos de gesso utilizando o Índice Peer Assessment Rating (PAR), e as variáveis cefalométricas finais da amostra foram obtidas em telerradiografias norma lateral e comparadas pelo teste Análise de Variância (ANOVA). Os resultados demonstraram que, o grupo 3 apresentou comprimento maxilar menor do que aquele dos grupos 1 e controle; padrão de crescimento mais vertical, incisivos superiores e inferiores mais extruídos do que nos outros grupos. Os grupos experimentais apresentaram maxila e mandíbula retruídas em relação ao grupo controle. Os incisivos superiores apresentaram-se semelhantes entre os grupos experimentais, porém mais...

The objective of this investigation was to evaluate the posttreatment dentoskeletal and soft-tissue characteristics, mainly, the maxillary incisor position of Class II, division 1 patients treated nonextraction, with two maxillary premolar and with four premolar extraction protocols. A control group of normal occlusion was also employed. The sample of 120 subjects was divided into four groups, three experimental groups and one control group. Group 1 comprised 30 patients (19 girls, 11 boys) with initial and final mean age of 12.38 and 14.95 years, respectively, and treated without extraction. Group 2 comprised 30 patients (17 girls, 13 boys) with initial and final mean age of 12.68 and 15.28 years, respectively, treated with extraction of 2 maxillary premolars. Group 3 comprised 30 patients (15 girls, 15 boys) with initial and final mean age of 13.10 and 15.55 years, respectively, treated with extraction of 4 premolars. Group 4 comprised 30 individuals (15 girls, 15 boys) with a mean age of 14.93 years and with normal occlusion from the Burlington Growth Centre, Orthodontics Department of the University of Toronto Dental School, Canada. The initial and final occlusal features of the experimental groups were evaluated on dental casts by Peer Assessment Rating (PAR) and the final cephalometric characteristics of the sample were obtained in lateral cephalogram and compared using ANOVA. The results demonstrated that the maxillary showed a smaller length in group 3 than in group 1 and control group; greater vertical growth pattern and greater maxillary and mandible incisors extrusion in group 3 than in the other groups. The experimental group showed maxillary and mandible retrusion regarding the control group. The maxillary incisors were similar among the experimental groups; however they showed greater upright position in groups 2 and 3 than in the control group. The mandibular incisor presented greater buccal displacement in group 1 than the three...

Variáveis relevantes no tratamento da má oclusão de Classe II: [revisão] / Relevant variables of Class II malocclusion treatment: [review]

Os resultados do tratamento da má oclusão de Classe II podem ser influenciados por características que são inerentes ao paciente - como a idade, a severidade da má oclusão e o grau de colaboração - ou, ainda, por fatores relacionados à conduta do profissional - como a escolha do protocolo de tratamento. Basicamente, o tratamento da Classe II pode ser realizado sem extrações ou com extrações de dois ou quatro pré-molares. Contudo, uma maior proporção de sucesso do tratamento pode ser esperada com extrações de dois pré-molares superiores, independentemente do padrão facial e da relação maxilomandibular. Considerando esta revisão, pôde-se concluir que os resultados oclusais do tratamento da Classe II são fortemente influenciados pelo protocolo de tratamento, enquanto o padrão facial não parece exercer uma influência significativa.

Results of orthodontic Class II malocclusion treatment can be influenced by inherent characteristics such as patient age, malocclusion severity and degree of compliance, or even by factors regarding the orthodontist's subjective preference such as the treatment protocol. Basically, Class II treatment protocols involve nonextraction or extraction of two or four premolars. However, a greater treatment success rate can be expected with the extraction protocol of two maxillary premolars, regardless of the skeletal pattern or the amount of maxillomandibular anteroposterior discrepancy. According to this review, it was concluded that Class II malocclusion treatment results are strongly influenced by the treatment protocol, while skeletal characteristics do not seem to exert significant influence.

An orthodontic-surgical approach to Class II subdivision malocclusion treatment

Despite the different orthodontic approaches to Class II subdivision malocclusions one has also to consider the skeletal components before undertaking any treatment protocol. Significant involvement of the skeletal structures may require a combined surgical orthodontic treatment, which has remained stable for more than four years, as illustrated in this case report.

An orthodontic-surgical approach to Class II subdivision malocclusion treatment.

Despite the different orthodontic approaches to Class II subdivision malocclusions one has also to consider the skeletal components before undertaking any treatment protocol. Significant involvement of the skeletal structures may require a combined surgical orthodontic treatment, which has remained stable for more than four years, as illustrated in this case report.