IU Indianapolis ScholarWorks :: Browsing by Author "Bixler, David"

Browsing by Author "Bixler, David"

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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.
A Cephalometric Study of Non-Cleft Parents of Children with Cleft Lip, Cleft Lip and Palate, and Cleft Palate : Evidence to Support a Different Etiology for Isolated Cleft Palate Versus Cleft Lip?
(1993) Sadler, Charles A., Jr.; Ward, Richard E.; Bixler, David; Hathaway, Ronald R.; Shanks, James C.; Roberts, W. Eugene
Cleft lip with or without cleft palate (CLI P) and isolated cleft palate (CP) have been shown to be separate epidemiologic and embryologic entities. Furthermore, it has been proposed that noncleft biologic parents of children with facial clefts may demonstrate craniofacial differences genetically predisposing them to pass on the cleft phenotype to their offspring. With these two hypotheses in mind, the objective of the present study was to determine if differences exist in the craniofacial morphology between parents of CL/P children and parents of CP children. Twenty-seven measurements were obtained from anterior-posterior (AP) cephalograms on 127 biologic parents of sporadic CL/P and CP children. Each measurement was compared with sex and age-matched normals, and Z-scores were determined. The mean Z-scores for each group were tested for significant differences from normal and from each other. In agreement with past literature, the craniofacial morphology of parents of cleft children was generally found to have greater facial widths and shorter facial heights. Differences between the findings of the present study and the past literature are discussed. Although CL/P and CP are thought to be separate entities, differences between the parents of CL/P and CP children were not statistically evident.
Apert Syndrome : A Descriptive Analysis of Selected Computed Tomographic Images of the Craniofacial Complex
(1988) Schafer, Alan Boulware; Garner, LaForrest D.; Bixler, David; Hennon, David K.; Kasle, Myron J.; Miller, James R.; Shanks, James C.
The purpose of this study was to demonstrate how selected computed tomographic images of the craniofacial complex may be used in a descriptive evaluation of cranial dysmorphology in living subjects with Apert syndrome. Computed tomographic images using coronal sections through the optic disc, planum sphenoidale, and axial sections through petrous ridges, pterygopalatine fossa, and midorbital level from two Apert syndrome and two non-syndrome controls were evaluated. Reference lines were established using actual and constructed landmarks. The results were tabulated for all four subjects. The two Apert subjects (in contrast to the non-syndrome subjects) demonstrated the following: a) orbital proptosis with a reduced bony orbital depth and elongation of the orbits in a superior direction with an altered vertical orbital axis b) increased lateral orbital wall angle c) alteration of the anterior cranial base with depression of the ethmoid complex d) midface regression Interestingly, ocular hypertelorism, which has been reported to be a feature of Apert syndrome, could not be confirmed by use of these CT scans. The findings obtained from this study are consistent with the published characteristics of Apert syndrome. In conclusion, this study demonstrates the utility of computed tomographic images in the evaluation of craniofacial dysmorphology.
A Cephalometric Investigation of Cleidocranial Dysplasia
(1974-06) Davis, James Paul; Garner, LaForrest D.; Tomich, Charles E.; Bixler, David; Weinberg, R. Bernd; Dirlam, James H.
The characteristics of cleidocranial dysplasia were first reported in 1897 by Pierre Marie and Paul Sainton. Since this first classification of the disease, many radiographic and clinical signs have been associated with this entity. Individuals with this disease have been repeatedly described as having a relative prognathism of the mandible due to a small, retropositioned maxilla and an enlarged cranial base. The present study was designed to determine, through the use of cephalometric measurements, if there is truly a difference in the size and position of the maxilla and an enlargement of the cranial base in these affected individuals. Ten cleidocranial dysplasia patients ranging in age from three years to 53 years, and their immediate families were studied. Non-affected members were studied to provide an intrafamilial comparison of skeletal development. The data obtained from the cephalometric measurements showed that the cranial bases for this group were within normal limits, or tending towards the small size. The maxilla was of normal size and the position was normal or anteriorly positioned in all cases. The mandible was considerably larger in 70% of the affecteds studied. Radiographic investigation showed this group to have delayed ossification of cranial sutures and mandibular symphysis. Absent frontal and mastoid sinuses, orbital hypertelorism, osteopetrotic appearance of the cranium, and absent or hypoplastic nasal bones were also observed.
A Cephalometric study of velar stretch in 8 and 10-year old children
(1974) Mourino, Arthur P.; Roche, James R.; Katz, Simon, 1920-1987; Bixler, David; Garner, La Forrest Dean, 1933-
This investigation examined the prevalence, relative magnitude, and selected components of velar stretch in normal-speaking 8 and 10-year-old children. For twenty 8-year-old and twenty 10-year-old children, lateral cephalometric films were obtained under three conditions: (1) subject at rest, (2) subject sustaining the vowel /u/, and (3) subject sustaining the voiceless fricative /s/. The cephalometric films were traced on acetate paper and specific radiographic measurements were made to describe important facets of velar stretch in children. Data were obtained on the resting length of the soft palate, the antero-posterior depth of the pharynx, and the prevalence of velopharyngeal closure and/or the degree of velopharyngeal opening observed during selected speech utterances in normal-speaking 8 and 10-year-old children. Such information is expected to be useful to dentists, speech pathologists, and physicians who use lateral headplates to assess velopharyngeal adequacy. Velar stretch per se was not observed in all 40 normal-speaking children. During the production of /u/, 36 children (90%) exhibited velar stretch; for /s/, 32 children (80%) manifested stretch. Paired- comparison t-test results showed that the length of the soft palate measured during speech was significantly greater than its resting length in both 8 and 10-year-old children. Moreover, significantly more total velar stretch was found during the production of the vowel /u/ than during the production of the consonant /s/ in both 8 and 10-year-old children. Although there was a significant increase in the length of the entire soft palate during the functional activities of speech, no significant increase in the anterior portion of the soft palate was associated with speech. Analysis of variance techniques showed that 10-year-old children exhibited significantly greater velar stretch during both /u/ and /s/ utterances than did 8-year-old children. In addition, 10-year-old children exhibited significantly greater velar height and greater velar length characteristics during both /u/ and /s/ utterances than did 8-year-old. children. Correlation procedures were used to examine the relationships between velar stretch and other commonly employed cephalometric measures. These analyses indicated that although velar stretch was significantly correlated with a number of commonly employed cephalometric measures, the amount of velar stretch was not well predicted by any single cephalometric measure used in this research.
Craniofacial Morphology in familial cases of cleft lip/palate: phenotypic heterogeneity and genetic predisposition in unaffected family members
(1993) Litz, Stephanie M.; Bixler, David; Fleener, Donald E.; Hennon, David Kent, 1933-; Sadove, A. Michael; Ward, Richard E.; Avery, David R.
This study investigated familial cases of cleft lip with or without cleft palate to determine whether the unaffected members of each family can be identified as gene carriers for the cleft trait. This research presumes that such carriers will have henotypic features identifiable by cephalometric analysis that are associated with an increased risk to cleft offspring. Using population genetics methodology, a pedigree analysis was made for each family member was assigned to one of four groups: (1) obligate normal, (2) affected, (3) carrier, and (4) unknown. LA and PA cephalographs were taken on each subject and a clinical oral-facial examination carried out on participating family members. Various anatomic landmarks located on the LA and PA films were digitized and from them, a total of 28 linear measurements were made. To eliminate the effect of sex and differential age responses, Z scores were calculated. Through univariate analysis, only one variable, NCR-MO, was shown to be significantly different between the two groups. This variable difference by itself is not adequate to differentiate those in the normal group from the carrier group. Even though only one variable was significant, other differences in the variables between these groups become obvious when the group variables were plotted as Z scores. Since Z scores are pure values with no limits (2--the number of standard deviations in a given variable differs from normal). Thereby, age-related growth differences were minimized. Further information is gained when these Z scores are plotted as pattern profiles, Figures 5-7. These profiles of mean Z scores for each variable pointed out areas of the face in which the differences were so great that specific anatomic areas appeared to be associated with one of the four groups. For example, gene carriers demonstrated specific alterations in facial height that might conceivably be used to discriminate that group from the other three groups. The family normals and carriers were then analyzed by using a stepwise multivariate analysis. By this approach, a discriminant function was generated consisting of six variables (three each from the lateral and frontal headplates), which proved to be significant in distinguishing an individual's phenotype. These variables define facial height, width and depth. The specific findings included a decrease in mid-facial height and depth along with an increased lower facial height and width in the gene carrier population as compared to the normals. The function then was used to predict group membership of the same two groups. Comparing this analytical prediction to that of the grouping system that resulted from the pedigree analysis, all but one individual was classified correctly in both the normal and carrier population. A discriminant score was also determined for the unknown population of family members which were defined as non-cleft blood relatives of cleft probands. Thus, they were a mixture of two types--those unaffected who carried a genetic liability for producing a cleft child and those unaffected who did not. A prediction of their placement into either the normal or carrier group was made with the discriminate function. One-third were classed in the normal group and two-thirds as gene carriers. The results of this study confirm that the phenotype of these unaffected family members designated as obligate gene carriers differs significantly from that of the family normals. This information is not only quite useful for genetic counselling but gives both a better understanding or the genetic control of clefting and can lead to molecular research to identify the specific gene in question.
Craniofacial pattern profile analysis of individuals with frontonasal malformation
(1994) Hiester, John David, 1964-; Bixler, David; Hathaway, Ronald R.; Sadove, A. Michael; Shanks, James C.; Avery, David R.
Frontonasal malformation, FNM, was first described by Hoppe in 1859. FNM is an anomaly that is characterized by ocular hypertelorism, broad nasal root, lack of a nasal tip, V-shaped hair, prolongation onto the forehead (widow's peak), anterior cranium bifidum occultum, median facial cleft affecting the nose, upper lip, and/or palate, and uni- or bilateral clefting of the ala nasi. The anomalies noted in FNM may be explained as a single malformation. If the nasal capsule fails to develop properly, the primitive brain vesicle fills the space normally occupied by the capsule, thus producing anterior cranium bifidum occultum, an arrest in the positioning of the eyes, and a lack of formation of the nasal tip. The condition presents clinically with variable expressions as sporadic cases and infrequently in familial cases. The present study is the first attempting to quantify and characterize FNM via anatomic radiographic measurements. The lateral (LA) and posterior-anterior (PA) cephalometric radiographs of twenty-four individuals, both sporadic and familial, with FNM were analyzed for comparison of linear and angular measurements with previously published data of a "normal," i.e. unaffected, population standard. Usual and customary cephalometric points were identified and located, then digitized into the computer. Twenty-nine measurements included the previously diagnosed anomalous features of hypertelorism, medial nasal cavity, and palatal shelves, as well as other facial features. The radiographs of individuals with FNM have anatomic features that are unusual and distinct to the specific malformation. The data from this research suggest that patients with FNM, regardless of a genetic or sporadic predisposition, have a midface deficiency in height and depth, an increased interorbital width with possible increased orbital socket width, and a longer zygomatic buttress. Also, the familial cases tend to have a flatter cranial base than the sporadic cases. Furthermore, the familial patients might be a different type of FNM since this subgroup shows narrower zygomatic widths. The patients with surgical procedures demonstrated improvement different from the growth of those patients who did not have surgery. The hypothesis that the facies of a patient with frontonasal malformation is different from the "normal" control population is supported by this research. The differences between the familial and sporadic patients tend to support the general theory that genetic predisposition is less severe than FNM that occurs randomly.
Craniofacial Pattern Profile, Analysis of Individuals with Frontonasal Malformation
(1994) Hiester, John David; Bixler, David; Avery, David R.; Hathaway, Ronald R.; Sadove, A. Michael; Shanks, James C.
Frontonasal malformation, FNM, was first described by Hoppe in 1859. FNM is an anomaly that is characterized by ocular hypertelorism, broad nasal root, lack of a nasal tip, V-shaped hair prolongation onto the forehead (widow's peak), anterior cranium bifidum occultum, median facial cleft affecting the nose, upper lip, and/or palate, and uni- or bilateral clefting of the ala nasi. The anomalies noted in FNM may be explained as a single malformation. If the nasal capsule fails to develop properly, the primitive brain vesicle fills the space normally occupied by the capsule, thus producing anterior cranium bifidum occultum, an arrest in the positioning of the eyes, and a lack of formation of the nasal tip. The condition presents clinically with variable expressions as sporadic cases and infrequently in familial cases. The present study is the first attempting to quantify and characterize FNM via anatomic radiographic measurements. The lateral (LA) and posterior-anterior (PA) cephalometric radiographs of twenty-four individuals, both sporadic and familial, with FNM were analyzed for comparison of linear and angular measurements with previously published data of a "normal," i.e. unaffected, population standard. Usual and customary cephalometric points were identified and located, then digitized into the computer. Twenty-nine measurements included the previously diagnosed anomalous features of hypertelorism, medial nasal cavity, and palatal shelves, as well as other facial features. The radiographs of individuals with FNM have anatomic features that are unusual and distinct to the specific malformation. The data from this research suggest that patients with FNM, regardless of a genetic or sporadic predisposition, have a midface deficiency in height and depth, an increased interorbital width with possible increased orbital socket width, and a longer zygomatic buttress. Also, the familial cases tend to have a flatter cranial base than the sporadic cases. Furthermore, the familial patients might be a different type of FNM since this subgroup shows narrower zygomatic widths. The patients with surgical procedures demonstrated improvement different from the growth of those patients who did not have surgery. The hypothesis that the facies of a patient with frontonasal malformation is different from the "normal" control population is supported by this research. The differences between the familial and sporadic patients tend to support the general theory that genetic predisposition is less severe than FNM that occurs randomly.
A critical clinical and television radiographic evaluation of indirect pulp capping
(1967) Traubman, Lionel; Bixler, David; Shafer, William G.; Phillips, Ralph W.
The purpose of this study was to quantitatively measure the rate and amount of calcification and secondary dentin deposition below deep carious lesions of otherwise radiographically and clinically sound teeth treated by calcium hydroxide - methyl cellulose indirect pulp capping. Standardized, reproducible serial radiographs of 50 treated young posterior teeth were exposed preoperatively at one, three, six, nine and, in some cases, 12 months. At the final appointment, the silver amalgam restorations were removed and all residual caries was excavated. A barium sulphate radiographic indicator paste identified the pulpal floor level at the first and last appointments. Ninety per cent of the teeth studied remained asymptomatic and were not pulpally exposed. Television density and linear measurement instrumentation was utilized to register calcification changes, pulpal floor thicknesses, and secondary dentin deposition. Following treatment, increased secondary dentin deposition and Calcification activity, or sclerosis, was initiated. Higher levels of calcification activity were related to increased thickness of pulpal floors, but this dimension had little influence on the total amount of reparative dentin formed. The rate of reparative dentin formation was highest during the first month and steadily diminished with time. Calcification activity experienced a cyclical change, or "exchange," with an initial activity peak. This was followed by an apparent, but temporary mobilization of mineral content •out of the affected dentin. With time, a steady rise in calcification level was observed. Measurement of longitudinal records showed that apparent pulp exposures can be avoided by allowing significant amounts of protective secondary dentin to form, before complete caries excavation.
Effects of cardiac glycosides on the composition of whole-mixed human saliva
(1978) McDonald, John S., 1947-; Shafer, William G.; Barton, Paul; Bixler, David; El-Kafrawy, Abdel Hady, 1935-; Standish, S. Miles, 1923-2003
Electrolyte levels were measured in whole-mixed human saliva collected from cardiology out-patients, to investigate any salivary electrolyte changes occurring in such patients after digitalization. Several recent reports have indicated that clinical symptoms of digitalis intoxication were associated with increased saliva concentrations of K+ and/or Ca++. Because salivary glands contain a highly active Na+, K+-ATPase it seemed logical that these and other salivary electrolytes might be predictably affected by the circulating levels of digitalis. Patients receiving digitoxin (Dtxn) had a higher concentration of Salivary K+ and Ca++ (25.8 ± 2.2 and 2.2 ± 0.2 meq/l, respectively), than the controls not receiving cardiac glycosides (20.1 ± 1.4 and 2.0 ± 0.1 meq/1, respectively). A similar pattern was not found for patients receiving digoxin (Dxn), although the mean Ca++ concentration for females in this group was significantly elevated (control: 1.7 ± 0.2; Dxn: 2.4 ± 0.2 meq/1). The mean serum concentration (ng/ml) of Dtxn was 20.3 ± 1. 9; of Dxn, 1.4 ± 0.2. No change was found in P04, and protein concentrations, or in salivary flow rates between control and experimental groups. The results suggest that salivary electrolyte changes occur after digitalization, but that these changes do not adequately reflect the serum level of digitalis in individual patients. This study was supported in part by PHS 80l-RR5312.

Browsing by Author "Bixler, David"

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