Facial bone

Abstract: Introduction: Cranio-maxillofacial trauma management requires pertinent documentation. Using a large computerized database, injury surveillance and research data describe the whole spectrum of injuries. The goal of this study was to assess the effect of the five main causes of accidents resulting in facial injury on the severity of cranio-maxillofacial trauma. Patients and Methods: During a period of 10 years (1991-2000) 9543 patients were admitted to the Department of Oral and Maxillofacial Surgery, University Hospital of Innsbruck with cranio-maxillofacial trauma. Data of patients were prospectively recorded including cause of injury, age and gender, type of injury, injury mechanisms, location and frequency of soft tissue injuries, dentoalveolar trauma, facial bone fractures and concomitant injuries. Statistical analyses performed included descriptive analysis, chi square test, Fisher's exact test, and Mann-Whitney's U test. This was followed by logistic regression analyses for the three injury types to determine the impact of the five main causes on the type of injury at different ages in facial trauma patients. Results: Five major categories/mechanisms of injury existed: in 3613 (38%) cases it was activity of daily life, in 2991 (31%) sports, 1170 (12%) violence, in 1116 (12%) traffic accidents, in 504 (5%) work accidents and in 149 (2%) other causes. A total of 3578 patients (37.5%) had 7061 facial bone fractures, 4763 patients (49.9%) suffered from 6237 dentoalveolar, and 5968 patients (62.5%) from 7769 soft tissue injuries. Gender distribution showed an overall male-to-female ratio of 2.1 to 1 and the mean age was 25.8±19.9 years; but both varied greatly depending on the injury mechanism (facial bone fractures: 35.4±19.5 years, higher risk for males; soft tissue injuries: 28.7±20.5, no gender preference; dentoalveolar trauma: 18±15.6, elevated risk for females). For patients sustaining facial trauma, logistic regression analyses revealed increased risks for facial bone fractures (225%), soft tissue lesions (58%) in patients involved in traffic accidents, and dental trauma (49%) during activities of daily life and play accidents. When compared with other causes, the probability of suffering soft tissue injuries and dental trauma, but not facial bone fractures, is higher in sports-related accidents, 12 and 16%, respectively. Conclusion: This study differentiated between injury mechanisms in cranio-maxillofacial trauma. The specially trained surgeons treating cranio-maxillofacial trauma are the primary source of information for the public and legislators on implementing preventive measures for high-risk activities. In facial trauma, older persons are prone to bone fractures (increase of 4.4%/year of age) and soft tissue injuries (increase of 2%/year of age) while younger persons are more susceptible to dentoalveolar trauma (decrease of 4.5%/year of age).

Abstract: Background: Various causes of facial bone loss around dental implants are reported in the literature; however, reports on the influence of residual facial bone thickness on the facial bone response (loss or gain) have not been published. This study measured changes in vertical dimension of facial bone between implant insertion and uncovering and compared these changes to facial bone thickness for more than 3,000 hydroxyapatite (HA)-coated and non–HA-coated root-form dental implants. Methods: Subjects were predominantly white males, 18 to 80+ years of age (mean 62.9 years), who were patients at 30 Department of Veterans Affairs Medical Centers and two university dental clinics. Alveolar ridges ranged from normal to resorbed with intact basal bone. Following preparation of the osteotomy site, direct measurements with calipers were made of the residual facial bone thickness, approximately 0.5 mm below the crest of the bone. The distance from the top of the implants to the crest of the facial bone was also me...

Abstract: PURPOSE The objectives of this systematic review are (1) to quantitatively estimate the esthetic outcomes of implants placed in postextraction sites, and (2) to evaluate the influence of simultaneous bone augmentation procedures on these outcomes. MATERIALS AND METHODS Electronic and manual searches of the dental literature were performed to collect information on esthetic outcomes based on objective criteria with implants placed after extraction of maxillary anterior and premolar teeth. All levels of evidence were accepted (case series studies required a minimum of 5 cases). RESULTS From 1,686 titles, 114 full-text articles were evaluated and 50 records included for data extraction. The included studies reported on single-tooth implants adjacent to natural teeth, with no studies on multiple missing teeth identified (6 randomized controlled trials, 6 cohort studies, 5 cross-sectional studies, and 33 case series studies). Considerable heterogeneity in study design was found. A meta-analysis of controlled studies was not possible. The available evidence suggests that esthetic outcomes, determined by esthetic indices (predominantly the pink esthetic score) and positional changes of the peri-implant mucosa, may be achieved for single-tooth implants placed after tooth extraction. Immediate (type 1) implant placement, however, is associated with a greater variability in outcomes and a higher frequency of recession of > 1 mm of the midfacial mucosa (eight studies; range 9% to 41% and median 26% of sites, 1 to 3 years after placement) compared to early (type 2 and type 3) implant placement (2 studies; no sites with recession > 1 mm). In two retrospective studies of immediate (type 1) implant placement with bone graft, the facial bone wall was not detectable on cone beam CT in 36% and 57% of sites. These sites had more recession of the midfacial mucosa compared to sites with detectable facial bone. Two studies of early implant placement (types 2 and 3) combined with simultaneous bone augmentation with GBR (contour augmentation) demonstrated a high frequency (above 90%) of facial bone wall visible on CBCT. Recent studies of immediate (type 1) placement imposed specific selection criteria, including thick tissue biotype and an intact facial socket wall, to reduce esthetic risk. There were no specific selection criteria for early (type 2 and type 3) implant placement. CONCLUSIONS Acceptable esthetic outcomes may be achieved with implants placed after extraction of teeth in the maxillary anterior and premolar areas of the dentition. Recession of the midfacial mucosa is a risk with immediate (type 1) placement. Further research is needed to investigate the most suitable biomaterials to reconstruct the facial bone and the relationship between long-term mucosal stability and presence/absence of the facial bone, the thickness of the facial bone, and the position of the facial bone crest.