Browsing by Author "Sondhi, Anoop"

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    A Cephalometric Investigation of Hypohidrotic Ectodermal Dysplasia
    (1981) Harbour, John P.; Bixler, David; Garner, LaForrest D.; Sondhi, Anoop; Shanks, James C.; Bowman, Sally A.
    The characteristic features of hypohidrotic ectodermal dysplasia were first reported in 1848 by Thurnam. Since this first classification, the characteristic facies of this syndrome have often been reported. Individuals with this disease have been described by various authors as having a prognathic mandible, an underdeveloped mandible, a small face, an elongated maxilla, an anteriorly positioned maxilla, a midface hypoplasia, and more. Only one cephalometric study of this syndrome exists and it was performed to study growth. The present study was designed to describe and quantify, through the use of cephalometric analysis, any facial and cranial variations in these patients. The study also attempted to describe the variations found in female heterozygotes. Nine hypohidrotic ectodermal dysplasia patients and their families were studied. A total of 31 individuals participated. When the data obtained from the cephalometric measurements were grouped into probands, gene carriers (heterozygous females), and normals, it was found that certain variations did exist. The size and position of cranial base and the mandible in all three groups were within normal limits (±2 S.D.). The maxillae of the probands were significantly short, yet positioned normally. The gene carriers also showed this trend, but the results were not significant. Profiles (soft and hard tissue) were significantly concave in the proband and gene carrier groups due to a combined effect of altered maxillary and mandibular positions.
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    A Comparison of Frictional Forces During Simulated Cuspid Retraction on a Continuous Edgewise Archwire
    (1982) Allai, W. Wesley; Garner, LaForrest D.; Sondhi, Anoop; Shanks, James C.; Swartz, Marjorie L.; Barton, Paul
    This investigation was designed to compare the force (grams) required to overcome a simulated cuspid retraction assembly capable of three dimensional control during the retraction process. It was hypothesized that a significant difference in the mean retraction values exists between the newer orthodontic alloys of Nitinol, Beta-Titanium, as well as Stainless Steel. One hundred eighty bracket and archwire combinations were examined as follows: Sample # Wire Cross-section Wire Material 30 .016”x.022” Stainless Steel 30 .017”x.025” ” 30 .016”x.022” Nitinol 30 .017”x.025” ” 30 .016”x.022 Beta-Titanium (TMA) 30 .017”x.025” ” A statistically significant difference was shown to exist between all six groups examined regarding the variables of wire size and wire material. The statistical analysis revealed that increasing rectangular archwire cross-sectional size from .016"x.022" to .017"x.025” rectangular wire when simulating canine retraction using an .018" slotted Lewis bracket will lead to significantly greater functional forces. The analysis of wire materials indicated that a significant difference (p=.01) exists between rectangular Beta-Titanium (TMA), Nitinol, and stainless steel during simulated cuspid retraction utilizing a narrow .018" Lewis bracket ligated with A-lastik ligatures. The least frictional force was observed with the .016"x.022" stainless steel test cells. The largest frictional force was found in the .017”'x.025" Beta-Titanium retraction specimens. Nitinol revealed force data intermediate between stainless steel and Beta-Titanium. The maximum resistance assembly developed 2.3 times the minimum frictional force observed. The mean grams of frictional force within these test cells ranged from 55.03 grams for the .016"x.022" retraction assembly to 132.68 grams for the .017"x.025" Beta-Titanium assembly. A topographical scanning electron microscope survey of the brackets and archwires utilized was included to provide qualitative insights into the quantitative results described.
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    Effects of Occlusal Splints and Occlusal Equilibration on Skeletal Muscles in TMJ Patients
    (1987) Larson, Robert Gardner; Garner, LaForrest D.; Goldblatt, Lawrence; Koerber, Leonard G.; Shanks, James; Schnell, Richard; Sondhi, Anoop; Barton, Paul
    Increased interest in "sports dentistry" has led investigators to adopt divergent views. Some believe that the position of the mandible in relation to the cranium may be critical to peak athletic performance. Others believe that mandibular position does not affect the performance of skeletal muscles, and that mouthguards or orthopedic repositioning splints used to alter mandibular position are nothing more than expensive placebos. These critics state that there is no scientific evidence to support claims of increased athletic performance. This study investigated whether correcting temporanandibular dysfunction with an occlusal splint could affect skeletal muscle strength, and whether any increase in strength could be attributable dimensions of the splint. Ten patients with a temporomandibular joint problem were selected. Isometric skeletal muscle strength was tested with an occlusal splint, a placebo splint, and no splint. The notions tested were horizontal arm adduction, hip flexion with knee bent, and shoulder abduction. Nine of the patients were treated until they were asymptomatic and then tested again with and without the occlusal splint. An occlusal equilibration was performed, and then patients were again tested with and without the splint. The placebo splint never showed a significant increase in strength. The treatment splint showed a significant increase in the horizontal arm adduction and hip flexion at the initial placement, both at the .05 level of significance. After the patients were asymptomatic, all three notions tested stronger with the splint versus the original occlusion at the .05 level of significance. Following occlusal equilibration the splint showed no significant change as compared to no splint. With experimental design or interpretation, proponents and opponents of the increased muscle strength theory usually prove their point. Although empirical results seem to indicate an increase in muscle strength, the results were inconsistent in some areas. The increases shown were possibly within the range of error and subjectivity. There was some indication that the skeletal muscle performance may have been increased; however, the increases were not large, and the sample size was small.
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    Histologic Tissue Rearrangement Following a Circumferential Supracrestal Fiberotomy on Orthodontically Rotated Teeth in Dogs
    (1987) Powell, Mark L. M.; Garner, LaForrest D.; Sondhi, Anoop; Kafrawy, Abdel; Standish, S. Miles; Shanks, James
    The purpose of this study was to determine whether a circumferential supracrestal fiberotomy has a biologic basis in the management of rotational relapse. The maxillary second incisors of seven beagle dogs, approximately two years of age, were rotated orthodontically from nine to 52 degrees. The incisors were retained. A circumferential supracrestal fiberotomy was performed twice unilaterally on the maxillary left second incisor of six dogs by incising through the gingival crevice parallel to the long axis of the tooth. The seventh dog was sacrificed and used for comparison of the tissue rearrangement after rotation but before fiberotomy and/or retention. The remaining dogs were paired for retention periods of one, three, and six months. Ten days before sacrifice all seven dogs were injected intraperitoneally with procion brilliant red H-8BS to determine appositional activity. At the end of the respective retention periods, the dogs were sacrificed and the specimens were fixed, decalcified, and serially sectioned horizontally, perpendicular to the long axis of the teeth. Sections were stained with H and E for histologic examination using light microscopy. Some sections were left unstained for evaluation of procion labelling using fluorescent light microscopy. The rearrangement of the subcrestal periodontal ligament fibers was determined by whether they produced a force capable of causing an increased alveolar and/or cemental apposition and not by their angulation to the root surface. The results failed to support a biologic basis for performing circumferential supracrestal fiberotomies on orthodontically rotated teeth. The supracrestal fiberotomy combined with retention had no additional effect on increasing the rearrangement of the supracrestal tissues compared to retention alone. Six months of retention, with and without a supracrestal circumferential fiberotomy, was sufficient for the supracrestal tissues to rearrange. Some of the subcrestal periodontal fibers in the tension and pressure areas at six months in retention may play a role in relapse. Undermining root resorption was evident in some pressure areas. Neither the angulation of the subcrestal and supracrestal periodontal fibers to the tooth surface nor the angulation of the epithelium was an accurate measure of the amount of tissue rearrangement. The circumferential supracrestal fiberotomy caused a cemental hyperplasia adjacent to areas nicked by the scalpel blade.