Biomedical subjects
Publications and source records attributed to H W Fields.
In children aged from six to 11 yr, forces of dental occlusion during swallowing, simulated chewing, and hard biting are similar for normal- and long-face individuals. Forces in the normal- and long-face children are similar to those in long-face adults, but are about half those in normal adults. It appears that individuals with the long-face pattern fail to gain strength normally in the mandibular elevator muscles.
Soft tissue outlines from profile radiographs, with or without supplementary photographs, do not provide enough information to reliably assess the underlying skeletal pattern in children 8 and 12 years old. Assessment was less reliable at 8 than at 12 years of age. Prognathic patterns were not as readily identified as retrognathic patterns. Specialty training did not affect the correctness of these limited assessments.
Explore the source record for details and available documents.
The diagnostic and conventional treatment techniques used to resolve relative mandibular anterior excess tooth-size problems are reviewed. An alternative solution to these problems, which involves an orthodontic-restorative technique, is described. Specific problems which may be encountered with this technique are also discussed. Three cases are presented, with posttreatment documentation for at least one year. It appears that this technique offers a successful semipermanent treatment for selected cases.
Explore the source record for details and available documents.
This paper compares and contrasts two clinical teaching systems in undergraduate pedodontics: the block system and the total patient care system (TPC). Descriptions and rationales are given for specific block and TPC systems at two universities. Theoretical advantages and disadvantages are reviewed. Clinical data are presented that represent experiences of the graduating classes of 1978 at The University of Iowa (block) and the University of North Carolina (TPC). From this limited sample there appears to be little quantitative evidence that one system is better than the other when examining clinical experiences in the two schools studied.
Explore the source record for details and available documents.
Twelve anencephalic and four normal fetuses 26 to 40 weeks gestational age were compared by anatomic, radiographic and histologic methods in order to gain information concerning morphogenesis. In the anencephalics, alterations located within the body of the sphenoid bone led to a reduced cranial floor angle and a more vertical clivus. The reduced lateral extension of the lesser and greater wings of the sphenoid constricted the anterior and middle cranial fossae respectively. The posterior cranial fossa tended to have an increased transverse dimension related to the supraoccipital and exoccipital bone orientation. The increased anterior and inferior position of the lateral end of the petrous temporal ridge was positively correlated with the degree of dorsal schisis in the anencephalics. Alterations in the size, form, or duration of the neural functional matrix are suggested as the cause of changes in the cranial floor.
A detailed study of the calvarium of twelve anencephalic and four normal human fetuses 26 to 40 weeks gestational age using gross dissection, alizarin red S staining, silver nitrate radiography and histology revealed dramatic alterations in the presence, form, location and relationship of the individual bones. In the larger dorsal cranial defects the interparietal portions of the occipital bone were relocated anteriorly to approximate the frontal bone. The occipital components were rotated anterolaterally and inferiorly with lack of fusion of the chondrocranium posterior to the foramen magnum. The squamae of the frontal bone were collapsed horizontally and reduced in size to lie peripheral to the anterior cranial fossa forming most of the orbital roofs. In anencephaly the bones derived from the chondrocranium were not as severely affected morphologically as those derived from the neurocranium. The sutures were narrow and smooth instead of wide and serrated as in the normally developing calvarium. In general the degree of maldevelopment was proportional to the extent of the dorsal cranial defect in anencephaly.
A sample of 12 anencephalic fetuses with gestational ages ranging from 26 to 40 weeks and exhibiting varying degrees of severity of the dorsal cranial defect was compared to three normal fetuses of comparable gestational ages with regard to the morphology and positional relationships of the maxillofacial skeletal complex. Gross dissection, alizarin red S staining, radiographs, cephalometric tracings, and histologic techniques were utilized. It was found that some facial bones were severely affected in morphology, size, spatial and angular relationships. The manner in which these were altered suggests that their morphogenesis is an adaptation to the primary defect of the neurocranium.
Previous studies evaluating parents' attitudes toward behavior management techniques used in pediatric dentistry suggest that parental attitudes are generally negative. The purpose of this study was to reexamine this issue by comparing the effect of prior explanation on parental acceptance of eight behavior management techniques. Videotaped segments were made of children's dental appointments containing examples of eight behavior management techniques. One group of 40 parents viewed a videotape which provided no explanation for each technique before it was shown. Another group of 40 parents viewed a videotape which provided no explanation of the techniques. The parents then were asked to rate the acceptability of each technique using a visual analogue scale. Results indicated that the informed parents were significantly more accepting of behavior management techniques than the uninformed parents but both groups were generally positive about the techniques studied. Further, parents reporting greater stress were less accepting of the techniques studied.
The symptom failure to thrive (FTT) is increasing in the general population, and has a prevalence of 9.6% among infants in the United States. Other factors occur in association with growth failure such as medical and dental anomalies and developmental delays that influence the management of these children. Four cases are presented to demonstrate the spectrum of problems and interdisciplinary management required to provide successful dental treatment.
Theoretical growth and development, and practical aspects are explored in an overview of how growth has been considered by investigators and clinicians during the past twenty years, to the beliefs held today. Diagnostic and treatment methods, where technical innovations are the most apparent, are considered in the context of classical orthodontic thinking. New diagnostic techniques will be introduced that will require changes in our basic understanding of growth and treatment. Orthodontics will continue to be integrated into total patient diagnosis and treatment.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Diagnosis and treatment of open bite malocclusion challenges pediatric dentists who attempt to intercept this malocclusion at an early age. This article updates clinicians on the causes and cures of anterior open bite based on clinical data. Patients with open bite malocclusion can be diagnosed clinically and cephalometrically, however, diagnosis should be viewed in the context of the skeletal and dental structure. Accurate classification of this malocclusion requires experience and training. Simple open bite during the exchange of primary to permanent dentition usually resolves without treatment. Complex open bites that extend farther into the premolar and molar regions, and those that do not resolve by the end of the mixed dentition years may require orthodontic and/or surgical intervention. Vertical malocclusion develops as a result of the interaction of many different etiologic factors including thumb and finger sucking, lip and tongue habits, airway obstruction, and true skeletal growth abnormalities. Treatment for open bite ranges from observation or simple habit control to complex surgical procedures. Successful identification of the etiology improves the chances of treatment success. Vertical growth is the last dimension to be completed, therefore treatment may appear to be successful at one point and fail later. Some treatment may be prolonged, if begun early. Long-term clinical outcomes are needed to determine treatment effectiveness and clinicians should consider the cost-effectiveness of these early initiated and protracted plans.
Etiology of Class III malocclusion can be genetic or environmental. Proclination of mandibular incisors and retroclination of maxillary incisors can cause posturing of the mandible in an anterior position due to incisal interference, a condition called pseudo Class III malocclusion that can be misleading in evaluating a patient with skeletal Class III malocclusion. Unfortunately, cephalometric evaluation may not be the most reliable tool in differentiating whether the maxilla or the mandible contributes to the skeletal disharmony. The most consistent findings seem to be the dental characteristics of Angle's Class III molars and canines, retroclined mandibular incisors, and the presence of an edge-to-edge or an anterior crossbite occlusion. This paper presents a diagnostic scheme to differentiate between dental and skeletal crossbites. Early treatment of Class III malocclusion can help to minimize the adaptations and limitations that are often seen in severe malocclusion of the late adolescence. However, treatment of skeletal crossbites remains a continuous challenge to the profession. Due to the diversity and variability in facial growth, accurate individualized growth prediction is not possible at the moment. Treatment directed at the mandible seems to invite relapse during the pubertal growth period. Treatment directed at the maxilla shows promising results and is awaiting long-term clinical results following early orthopedic interventions. Several intraoral appliances have proved to be successful in eliminating dental crossbites.