RESUMEN
The mental foramen, through which the mental nerve emerges, is an important anatomic landmark in odonto-stomatology. Knowing its anatomic variations, according to the ethnic group or age, is essential when performing local anesthesia or implant and orthognathic surgeries. Besides the presence of a supernumerary foramen and variations in its location, numerous topographies have been described such as unilateral or bilateral triple foramina, hypoplasia or agenesis. The case reported here is extremely rare because it has been observed in a living and asymptomatic patient whose scan shows a bilateral absence of mental foramen.
Asunto(s)
Mandíbula/anomalías , Mandíbula/diagnóstico por imagen , Nervio Mandibular/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: Because of the immediate loading implant process, clinicians must consider implant primary stability issues before initiating surgery. The aim of this study was to assess the correlation between the bone density assessed by computed tomography (CT) images and the primary stability of two implant designs, as determined by resonance frequency analysis (RFA). MATERIALS AND METHODS: Sixty implants (30 NobelActive, 30 NobelSpeedy [Nobel Biocare]) were placed in five totally edentulous fresh cadaver maxillae. Before surgery, CT images were analyzed and bone densities measured. Implant primary stabilities (measured in implant stability quotient [ISQ] units) were determined along the buccolingual and mesiodistal axes by RFA. Correlations were assessed using the Pearson correlation test. RESULTS: Bone densities were similar near NobelActive and NobelSpeedy implants: 434.67 (± 220.53) versus 479.87 (± 209.05) Hounsfield Units (HU). Bone densities and NobelActive primary stabilities were highly correlated with ρ = 0.74 (P = .000) and ρ = 0.78 (P = .000) for the buccolingual and mesiodistal axes, respectively. An association was found between the 350 HU and 50 ISQ values, confirming good primary stabilities. For NobelSpeedy implants, no correlation was found regardless of the axis, with ρ = -0.07 (P = .72) (buccolingual) and ρ = -0.10 (P = .59) (mesiodistal). However, poor and good stabilities were observed in the anterior and posterior areas, respectively. CONCLUSION: This study revealed variations in primary stabilities depending on the implant design. The primary stability of conical implants with a double-lead thread design (NobelActive) seemed bone density-dependent regardless of the area of the maxilla, whereas the primary stability of nearly parallel-wall implants with a classical thread design (NobelSpeedy) seemed dependent on anatomical morphology. These results raise questions about the specific roles of the implant shape and thread design depending on the bone density and alveolar morphology.
Asunto(s)
Densidad Ósea/fisiología , Implantes Dentales , Maxilar/cirugía , Oseointegración/fisiología , Tomografía Computarizada por Rayos X/métodos , Cadáver , Arco Dental/diagnóstico por imagen , Arco Dental/cirugía , Implantación Dental Endoósea/métodos , Diseño de Prótesis Dental , Humanos , Arcada Edéntula/diagnóstico por imagen , Arcada Edéntula/cirugía , Maxilar/diagnóstico por imagen , Propiedades de Superficie , VibraciónRESUMEN
PURPOSE: Inadequate bone width in atrophic edentulous jaws is a challenge for successful oral rehabilitation with endosseous dental implants. The aim of this clinical study was to evaluate the effectiveness of a new method for ridge expansion with sagittal splitting using a new surgical device (Crest-Control Bone Splitting System, Meisinger) and to determine whether it is necessary to fill the expansion area with bone substitute to maintain the expanded bone volume. MATERIALS AND METHODS: During a 3-year period, a prospective study was performed in 32 patients (59% women, 41% men). All participants needed implants in the horizontally atrophied edentulous mandible and were treated in a private practice and a hospital. The only inclusion criteria were a mandibular ridge width between 3 and 4 mm and ridge height of at least 11 mm. Expansion with horizontal splitting of the ridge was performed simultaneously with implant placement. In 17 of the 32 arches, selected alternately, the expanded ridges were filled with a biphasic calcium phosphate (hydroxyapatite 60% and beta-tricalcium phosphate 40%) synthetic bone substitute (SBS 60/40). The other 15 expanded arches were left unfilled. All areas were covered with a resorbable collagen membrane (Bio-Gide, Geistlich). Results were analyzed with the Mann-Whitney and Kruskal-Wallis tests (α=.05). RESULTS: There was a significant difference (α=.02) between the patients who received SBS 60/40 (17 cases) and those who did not (15 cases). The ridges that received SBS 60/40 after expansion showed no bone resorption. CONCLUSION: Horizontal expansion of the ridge is easily reproducible. In this study, in very narrow ridges, a lack of bone substitute resulted in significant resorption of 3- to 4-mm-wide crests (5%), even after expansion. A bone substitute should be placed to maintain the alveolar bone walls after expansion.