Alveolar bone thickness and lower incisor position in skeletal Class I and Class II malocclusions assessed with cone-beam computed tomography

Abstract

ObjectiveTo evaluate lower incisor position and bony support between patients with Class II average- and high-angle malocclusions and compare with the patients presenting Class I malocclusions.MethodsCBCT records of 79 patients were divided into 2 groups according to sagittal jaw relationships: Class I and II. Each group was further divided into average- and high-angle subgroups. Six angular and 6 linear measurements were performed. Independent samples t-test, Kruskal-Wallis, and Dunn post-hoc tests were performed for statistical comparisons.ResultsLabial alveolar bone thickness was significantly higher in Class I group compared to Class II group (p = 0.003). Lingual alveolar bone angle (p = 0.004), lower incisor protrusion (p = 0.007) and proclination (p = 0.046) were greatest in Class II average-angle patients. Spongious bone was thinner (p = 0.016) and root apex was closer to the labial cortex in high-angle subgroups when compared to the Class II average-angle subgroup (p = 0.004).ConclusionsMandibular anterior bony support and lower incisor position were different between average- and high-angle Class II patients. Clinicians should be aware that the range of lower incisor movement in high-angle Class II patients is limited compared to average- angle Class II patients.

Evaluation of Bone Thickness and Density in the Lower Incisors’ Region in Adults with Different Types of Skeletal Malocclusion using Cone-beam Computed Tomography

“…a mean of 1.2 mm difference). 18 The amount of alveolar bone thickness was significantly higher at the apical region as compared to the other two regions. These results were similar to the findings of Nauert et al and Nahm et al, who found gradual increase of bone thickness from the CEJ till the root apex level.…”

“…17 When Baysal et al compared alveolar bone thickness between skeletal class I and II malocclusions, the observations were that buccal alveolar bone thicknesses in class I patients were significantly greater than those in class II patients, and that the buccal apical alveolar bone thickness was greater than lingual in class II malocclusions. 18 Earlier studies about the density of the lower alveolar bone were made with the help of pyknometry, microradiography or histoquantification. 19 At present, bone density can be evaluated by different methods, as different tissue types absorb different amount of radiation.…”

“…23 For a power of 80%, a significance level of 5% and an effect size of 0.40 mm (based on the results of a previous report) to detect a significant difference in the alveolar bone thickness between the three groups [using one-way analysis of variance (ANOVA)], 16 patients were found to be required for each group. 18 The sampling frame included patients who had CBCT images and fulfilled the following inclusion criteria: (1) age between 18 and 25, (2) no congenitally missing or extracted teeth, (3) no previous orthodontic treatment, (4) mild to moderate crowding, and (5) acceptable oral hygiene without periodontal conditions. In total, 168 CBCT images were found.…”

“…18 Buccal bone thickness was greater than lingual bone thickness in class II patients. The current study also showed differences in the ABT between the two surfaces in class II and III groups only.…”

Morfología Ósea de Sínfisis Mandibular: Estudio Piloto

“…Joshi et al (2014) determinó diferencias morfológicas en situación espacial y morfología máxilo mandibular en sujetos con deformidades faciales, transformándolo en un elemento importante para definir condiciones de la morfología asociada. Baysal et al (2013) indicaron diferencias significativas entre sujetos clase I y clase II dentaria al comparar el tamaño sagital de la cortical ósea en tomografía computarizada; ellos confirmaron que los sujetos clase II presentan menor tamaño óseo de la cortical anterior en áreas próximas al diente. También, Sharma et al (2012), indicaron que el tamaño de la cortical ósea bucal seria asociada al modelo de crecimiento craneofacial, estableciendo relaciones entre el tipo de deformidad facial y las características del hueso cortical.…”