RESUMEN
AIM: A mandible bone-borne Herbst appliance (MBBHA) would avoid the proclination of the lower incisors that occurs with any teeth-borne functional appliance. But mapping of the bone characteristics at potential fixation areas around the mental foramen has not been carried out so far. The aim of this computer tomographic (CT) study was to evaluate bone thickness at specific positions around the mental foramen. MATERIAL AND METHODS: CT scans of 60 randomly chosen adult Hong Kong Chinese subjects (mean age 28 ± 6.3 years) were used to measure the bi-cortical bone thickness in the mandible in the mental foramen area. The thickness of buccal and lingual cortical and cancellous bone was assessed at the following locations: 10 mm (A10 mm) and 5 mm (A5 mm) anterior, 10 mm (P10 mm) and 5 mm (P5 mm) posterior, and 5 mm (Inf5 mm) below the mental foramen. RESULTS: The amount of buccal cortical bone thickness ranged between 1.89 mm, 10 mm anterior of the mental foramen, and 2.16 mm, 10 mm posterior to its location. At the A10 mm level, cortical thickness showed a marginal statistically significant difference between A5 and A10 mm. The total amount of bone thickness ranged from 10.19 to 12.06 mm. CONCLUSION: At the locations studied around the mental foramen, a mean bicortical bone thickness of 10-12 mm was measured. No large variation in the thickness was found between bicortical bone thicknesses in the measured locations around the mental foramen. Thorough evaluation on a case-by-case basis is advisable.
Asunto(s)
Densidad Ósea/fisiología , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Métodos de Anclaje en Ortodoncia/métodos , Aparatos Ortodóncicos , Tomografía Computarizada por Rayos X , Adulto , Femenino , Humanos , Masculino , Interpretación de Imagen Radiográfica Asistida por ComputadorRESUMEN
AIM: To compare 2 groups of mature patients treated with the Herbst appliance and present a new protocol based on tissue responses to enhance skeletal response. METHODS: Lateral cephalograms taken before and after treatment for 2 groups of patients--the first treated with the Herbst appliance with maximum jumping and the second with the Herbst appliance with stepwise advancement--were examined with conventional cephalometric analysis and the sagittal-occlusal analysis of Pancherz to assess the dental, skeletal, and soft tissue changes. RESULTS: The mode of correction of the Class II malocclusion was through skeletal and dental changes. However, in the stepwise sample, the amount of correction due to skeletal changes was higher. In both groups, the soft tissue profile convexity was reduced significantly. CONCLUSION: Herbst appliance therapy can be considered a modality for the correction of skeletal Class II malocclusions in mature patients and should be added to orthodontia's armamentarium.