RESUMEN

Maxillary sinus augmentation (MSA) and guided bone regeneration (GBR) have shown successful clinical, radiological, and histological outcomes for implant-related bone reconstruction and have been used to augment bony defects of various shapes and sizes. This study demonstrated that the lateral sinus bony window obtained during MSA can be used as an autogenous block bone graft for the augmentation of wide post-extraction defects. During the uncovering procedure performed 6 months after surgery, the grafted lateral bony window was well integrated with the adjacent native bone, and complete bone filling was observed in all bony defects around the implants. All of the implants survived. Within the limitations of this study, autogenous block bone obtained from lateral window sites can be used as novel donors for the resolution of wide bony defects around implants.

Asunto(s)

RESUMEN

PURPOSE: The aim of this study was to evaluate the possibility of using the zygomatic buttress as an intraoral bone harvesting donor site and determine the safety of this harvesting procedure for later optimal positioning of dental implants in accordance with prosthodontic and functional principles. MATERIAL AND METHODS: A consecutive retrospective study was conducted on patients who had been treated at the Department of Oral and Maxillofacial Surgery of Ulm military and academic hospital, over a 3-year period (January 2008 to December 2010). Medical history, smoking status, area of surgery, and complications were recorded. The need for bone grafting was defined by the impossibility of installing implants of adequate length or diameter to fulfill prosthetic requirements, or for esthetic reasons. The patients were treated using a 2-stage technique. During the first operation, bone blocks harvested from the zygomatic buttress region were placed as lateral onlay grafts and fixed with titanium osteosynthesis screws after exposure of the deficient alveolar ridge. After 3-6 months of healing, the flap was reopened, the screws removed and the implants placed. RESULTS: A total of 113 zygomatic buttress bone block grafts in 112 patients were performed. Graft loss and graft removal were defined as failure; swelling, wound dehiscence, infection with pus, temporary paresthesia, and perforations of the maxillary sinus membrane were defined as complications. According to our criteria, 4 (3.5%) of the patients presented postoperative complications of the donor site and 20 (17.8%) of the recipient site. Throughout, 93 (82.3%) of the bone grafts were successful and 20 (17.6%) had complications, regardless of the final success of the implant procedure. Smoking was associated with a high rate of complications and graft failure. Early graft exposure appeared to compromise the results, whereas pain and swelling were comparable to usual dentoalveolar procedures. However, in 1.7% of all cases, concerning 2 patients, the final rehabilitation with dental implants was not possible. CONCLUSIONS: The zygomatic buttress block bone graft is a safe intraoral donor site for the reconstruction of small- to medium-sized alveolar defects, providing the greatest surgical access with minimal postoperative complications.

Asunto(s)

RESUMEN

El retiro de hueso de sínfisis mandibular ha sido utilizado ampliamente para diferentes procedimientos reconstructivos maxilofaciales. El objetivo de esta investigación fue establecer la existencia de la reparación ósea en el defecto creado en sínfisis debido al retiro de hueso. Treinta pacientes (22 mujeres, 8 hombres) de entre 21 y 65 años fueron operados para retirar hueso de mentón que fue posteriormente aplicado en reconstrucción ósea alveolar; las cirugías fueron realizadas por dos cirujanos maxilofaciales y los pacientes fueron evaluados con telerradiografías en la etapa preoperatoria, postoperatoria inmediata (PIn) y postoperatoria tardía (PTar), donde se realizaron medidas horizontales y verticales del defecto óseo; los valores fueron estudiados con la prueba t de Student con valor de p<0,05. Luego del retiro óseo se observó un defecto vertical promedio de 12,80+/-1,99 y horizontal de 8,33+/-1,77; luego de un año, se obtuvo una disminución de 32,8 por ciento en el sentido vertical y 50,3 por ciento horizontal, presentando significancia estadística en relación al PIn. Se concluye que existe reparación ósea del defecto originado en sínfisis siendo próximo al 30 por ciento-50 por ciento en la evaluación de un año posterior a la cirugía.

Bone harvest of mandibular symphysis has been used in maxillofacial reconstruction procedures. The aim of this research was to establish the presence of bone repair into osseous defect caused by removal of bone. Thirty patient s, 2 female and 8 male, ranging between 21 and 65 years of age underwent surgery for chin bone harvest and alveolar reconstruction. The surgery was performed by two maxillofacial surgeons and the patients were evaluated with lateral radiography in the pre-operatory stage, in early post-operatory and in late post-operatory stages. Horizontal and vertical measures of bone defect were realized; the dates were analyzed by Student t test with a value of p<0.05. After bone harvest, a vertical defect of 12.80 +/-1.99 was observed and a horizontal defect of 8.33 +/- 1.77 was observed. After one year the defect decreased to 32.8 percent in vertical evaluation, and 50.3 percent in the horizontal evaluation with a statistical significance (p<0.05) in relation to the early post-operatory stage. Therefore, we conclude that in bone repair of mandibular symphysis defect is close to 30 ­ 50 percent in a one-year follow-up.

Asunto(s)