Biomedical subjects

Albert D Guckes

Publications and source records attributed to Albert D Guckes.

3 recordsLinked to original sources

PubMed2003

Tuned aperture computed tomography (TACT) for cross-sectional implant site assessment in the posterior mandible.

PURPOSE: This study was designed to optimize a new radiographic modality known as tuned aperture computed tomography (TACT) for cross-sectional imaging of implant sites in human dry mandibles. MATERIALS AND METHODS: Five imaging modalities were compared for image quality and measurement accuracy: (1) conventional hypocycloidal tomograms, (2) TACT images reconstructed using the average method produced using a linear x-ray source movement, (3) TACT images reconstructed using the average method produced using a multidirectional x-ray source movement, (4) minimally reconstructed TACT images without a fiducial marker at the site of interest, and (5) minimally reconstructed TACT images with a fiducial marker at the site of interest. RESULTS: The extended Mantel-Haenszel mean score statistic was used to investigate the influence of modality on subjective image quality. A statistically significant difference for certain types of TACT images and multidirectional tomography (P < 0.0001) was observed. Linear TACT and multmin TACT were rated as significantly better than other image modalities (P < 0.0009), whereas multidirectional tomography was rated as being significantly worse than other radiographic modalities (P < 0.0001). For the quantitative assessment, data were normalized and analyzed statistically through a paired-comparisons t test. For each modality, the accuracy for maximum height and height was significantly different from ground truth (P < 0.05). CONCLUSION: The qualitative data suggest that visibility of structures important to the choice of implant location and dimension were seen better with certain TACT methods. Quantitative differences from ground truth (actual measurements of the bone-absolute truth) were clinically negligible. TACT appears to offer the potential of superior image quality over the status quo.

Anatomy, Cross-Sectional↗

PubMed2002

Analysis of craniofacial development in children with hypohidrotic ectodermal dysplasia.

Ectodermal dysplasias (ED) are a heterogeneous group of inheritable disorders characterized by abnormal development of embryologic ectoderm derivatives. The purposes of this study were to: 1) create baseline cephalometric norms for male children with ED; 2) assess craniofacial growth and development in hypohidrotic ED male children with severe hypodontia, compared with non-ED children with class I dental relationships; 3) compare the craniofacial morphology of titanium dental implant-treated ED males with non-implant-treated ED males; and 4) correlate the severity of hypodontia to craniofacial dysmorphology. Cephalometric radiographs of class I individuals and implant-treated and nontreated ED groups were used to evaluate craniofacial morphology. Traditional cephalometric landmarks and measurements were used to compare groups using the generalized estimate equation analysis. Age, gender, and the number of permanent maxillary teeth present had a significant (P =.01) explanatory relationship with the craniofacial measures when comparing untreated ED children to norms. Mean craniofacial differences between ED and non-ED children still existed when the explanatory effects of these variables were controlled, indicating dysmorphology in several craniofacial structures (e.g., cranial base, mandibular length). The number of missing maxillary permanent teeth was significantly related with craniofacial dysmorphology in the ED population. Craniofacial morphology did not differ significantly between implant-treated and nontreated ED children, suggesting that treatment with intraosseous dental implants, as applied in this population, did not rescue normal craniofacial growth and development.

Adolescent↗

PubMed2002

Prospective clinical trial of dental implants in persons with ectodermal dysplasia.

STATEMENT OF PROBLEMS: Ectodermal dysplasia is a hereditary condition in which hypodontia is the second most frequently occurring sign. Hypodontia is associated with lack of development of the alveolar ridge and results in less volume of bone for support of conventional prostheses. Minimal development of the alveolar ridge can affect the bone volume available for the placement of dental implants. PURPOSE: This clinical trial evaluated the survival of implants placed in individuals with a form of ectodermal dysplasia and severe hypodontia. MATERIAL AND METHODS: Two hundred sixty-four titanium endosteal dental implants were placed in 51 subjects: 37 males and 14 females between the ages of 8 and 68 (mean age 20.5 years, median age 16.5 years). Two hundred forty-three implants were placed in the anterior mandible, and 21 were placed in the anterior maxilla with a 2-stage surgical protocol. Either fixed-detachable dentures or bar-clip overdentures were provided. Subjects were followed up for 0 to 78 months after second-stage surgery. Kaplan-Meier survival rates and curves were produced to describe the survival of the implants for the different age groups and implant locations. Repeated-measures Cox regression models were used to evaluate the hazard ratios for age and location, with alpha=.05 as the criteria for significance. RESULTS: Of the 243 implants placed in the anterior mandible, 221 (91%) survived. Of the 21 implants placed in the anterior maxilla, 16 (76%) survived. Fourteen of the 51 (27%) subjects had a failed implant. All but 2 failures occurred before or at second-stage surgery. Implant-supported prostheses were provided for all patients. CONCLUSION: Within the limitations of this study, the results support the continued use of endosteal dental implants in this patient population with appropriate precautions in the maxilla.

Adolescent↗