Bone thickness and height of the buccal shelf area and the mandibular canal position for miniscrew insertion in patients with different vertical facial patterns, age, and sex.

OBJECTIVES: The objectives of this article were the following: (1) to analyze bone thickness and height (BTH) of the buccal shelf area (BS) quantitatively in four different potentially eligible sites for miniscrew insertion; (2) to compare and contrast BTH and the changes in spatial position of the inferior alveolar nerve canal (IANC); and (3) to assess differences with age among vertical facial patterns (hypodivergent, normodivergent, and hyperdivergent) and well as by sex. MATERIALS AND METHODS: Cone-beam computed tomography scans of 205 individuals (110 women and 95 men) were divided into groups according to age, vertical facial pattern, and sex. The BTH of the BS and the BTH to the IANC were measured in the mesial and distal roots of the first and second molars. RESULTS: BTH progressively increased in a posterior direction (P < .001), while BTH to the IANC increased and decreased (P < .001) for thickness and height, respectively, in the same direction in all age groups, for the three different vertical facial patterns, and in both sexes. Women showed significantly less BTH to the IANC (P < .002). Hypodivergent patients had greater BTH (P < .024) and a smaller bone height to the IANC (P < .018) only in the first molar region. Patients over 40 years of age had lower bone height in the second molar area (P < .003). CONCLUSIONS: The ideal place for BS miniscrew insertion is the region of the distal root of the second molars, regardless of facial pattern, sex, and age. The BS in women has less BTH and less BTH to the IANC.

Modified Arnold expander: an alternative for mandibular arch expansion.

INTRODUCTION: Due to the anatomical constraints of the mandible, mandibular dental arch usually serves as a guideline to determine the required changes in the maxillary transverse dimension. The Schwarz appliance and the Lip Bumper are the traditional orthodontic appliances for mandibular arch expansion in patients with borderline amounts of crowding, and/or transverse discrepancy. However, they often require patient cooperation, which may be a concern for orthodontists in daily practice. OBJECTIVES: This article illustrates a simple fixed orthodontic device as an alternative to achieve mandibular arch expansion in patients with moderate tooth-size/arch-length discrepancy. The four reported cases refer to 8 to 10-year-old patients in the mixed dentition, with an Angle Class I or Class II malocclusion, transverse deficiency in both arches, moderate crowding and/or posterior crossbite, combined with compromised smile aesthetics. The patients were treated with rapid maxillary expansion (RME) using Hass expander appliance and the modified Arnold expander (MAE). CONCLUSION: This low-cost compliance-free orthodontic appliance provided dentoalveolar decompensation by means of uprighting the posterior teeth, with minimal or no adjustments during treatment. The final results were achieved in only three to four months, and fulfilled all treatment objectives, such as an increase in the arch perimeter and width, and a better teeth alignment.

Modified Arnold expander: an alternative for mandibular arch expansion

ABSTRACT Introduction: Due to the anatomical constraints of the mandible, mandibular dental arch usually serves as a guideline to determine the required changes in the maxillary transverse dimension. The Schwarz appliance and the Lip Bumper are the traditional orthodontic appliances for mandibular arch expansion in patients with borderline amounts of crowding, and/or transverse discrepancy. However, they often require patient cooperation, which may be a concern for orthodontists in daily practice. Objectives: This article illustrates a simple fixed orthodontic device as an alternative to achieve mandibular arch expansion in patients with moderate tooth-size/arch-length discrepancy. The four reported cases refer to 8 to 10-year-old patients in the mixed dentition, with an Angle Class I or Class II malocclusion, transverse deficiency in both arches, moderate crowding and/or posterior crossbite, combined with compromised smile aesthetics. The patients were treated with rapid maxillary expansion (RME) using Hass expander appliance and the modified Arnold expander (MAE). Conclusion: This low-cost compliance-free orthodontic appliance provided dentoalveolar decompensation by means of uprighting the posterior teeth, with minimal or no adjustments during treatment. The final results were achieved in only three to four months, and fulfilled all treatment objectives, such as an increase in the arch perimeter and width, and a better teeth alignment.

RESUMO Introdução: Devido aos limites anatômicos da mandíbula, a arcada dentária inferior geralmente serve como guia para determinar as alterações necessárias na dimensão transversal da maxila. O aparelho de Schwarz e o Lip Bumper são os aparelhos usados tradicionalmente para expansão da arcada inferior em pacientes com quantidades limítrofes de apinhamento e/ou discrepância transversal. No entanto, eles requerem a cooperação do paciente, o que pode ser uma preocupação para os ortodontistas na prática diária. Objetivos: O presente artigo ilustra uma alternativa diferente de aparelho fixo para se obter a expansão da arcada inferior em pacientes com discrepância moderada de tamanho dentário e/ou comprimento da arcada. Os quatro casos relatados referem-se a pacientes com 8 a 10 anos de idade, na dentição mista, com má oclusão de Classe I ou II de Angle, deficiência transversal em ambas as arcadas, apinhamento moderado e/ou mordida cruzada posterior, apresentando comprometimento da estética do sorriso. Os pacientes foram tratados com expansão rápida da maxila (ERM), usando aparelho expansor de Hass, e expansor Arnold modificado (EAM). Conclusão: O EAM, que é um aparelho de baixo custo e não depende da colaboração do paciente, promoveu uma descompensação dentoalveolar por meio da verticalização dos dentes posteriores, necessitando de mínimo ou nenhum ajuste durante o tratamento. Os resultados pretendidos foram alcançados em três a quatro meses e cumpriram todos os objetivos do tratamento, como aumento do perímetro e largura da arcada, assim como o melhor alinhamento dos dentes.

Predisposing factors for external apical root resorption associated with orthodontic treatment.

OBJECTIVE: This study aimed to identify possible risk factors for external apical root resorption (EARR) in the maxillary incisors after orthodontic treatment. METHODS: The root length of 2,173 maxillary incisors was measured on periapical radiographs of 564 patients who received orthodontic treatment. The Kappa test was performed to evaluate intraexaminer and interexaminer reproducibility. Multiple binary logistic regression was used to determine the association between EARR and various factors. Odds ratios and 95% confidence intervals were reported. RESULTS: The risk of developing EARR was 70% higher in orthodontic treatment with maxillary premolar extraction (p = 0.004), 58% higher in patients with increased overjet (p = 0.012), 41% lower in two-phase orthodontic treatment (p = 0.037), and 33% lower in patients with deep bite (p = 0.039). The lateral incisors were 54% more likely to develop EARR (p < 0.001), dilacerated roots were 2.26 times more likely to develop EARR (p < 0.001), and for each additional millimeter of root length, the risk of EARR increased by 29% (p < 0.001). CONCLUSIONS: The potential risk factors for EARR after orthodontic treatment included treatment with maxillary premolar extraction, increased overjet at the beginning of treatment, and dilacerated roots.