Computer-aided three-dimensional reconstruction and measurement of semicircular canals and their cristae in man

We studied the spatial relations of the semicircular canals (SCCs) and their cristae, by computer-aided three-dimensional reconstruction, a graphic method we developed. The angles between pairs of SCCs, between pairs of SCC cristae, and between a SCC and its crista were measured using histology sections of a normal temporal bone from a 14-year-old female. Angles between pairs of SCCs and pairs of cristae deviated 11.3 to 18.2 degrees and 4.8 to 18.0 degrees, respectively, from right angles and the long axis of each crista deviated 25.0 to 30.4 degrees from the line perpendicular to the plane of the corresponding SCC; thus none of these structures lies at a right angle to another. We believe these new anatomical findings will help in the clinical evaluation of SCC function.

Frequency and localization of congenital anomalies of the middle and inner ears: a human temporal bone histopathological study

This study investigated congenital anomalies occurring in the middle and the inner ears, with particular attention to their features, localizations, and frequencies. One hundred human temporal bones obtained from 73 individuals, aged 31 gestational weeks to 39 years, each of whom had anomalies of the middle ear and/or inner ear, were used for this study. The temporal bones had been removed at autopsy, fixed, dehydrated, embedded in celloidin, and sectioned horizontally or vertically at 20 microns. Every 10th horizontal section or every 20th vertical section was stained with hematoxylin and eosin, mounted and studied under a light microscope. In the middle ear the structure most often found to be anomalous was the facial nerve; in the inner ear it was the lateral semicircular canal. The implications of the anomalies observed are discussed as they relate to fetal development, dysfunction of the ear, and clinical interpretation of diagnostic radiological studies.

Histopathologic study of eustachian tube in cleft palate patients

We studied eight temporal bones from eight individuals with cleft palates (CPs) and eight age-matched control temporal bone specimens from our collection. We used the eustachian tube (ET) and its surrounding structures in serial vertical histologic sections. The findings observed in CP specimens were as follows: 1) the angle between axial lines through the tensor veli palatini (TVP) muscle and the superior portion of the ET lumen was narrow, 2) the angle between axial lines through the lateral lamina and the medial lamina of the cartilage was wide, 3) the angle between axial lines through the TVP muscle and the lateral lamina of the cartilage was narrow, and 4) the angle between axial lines through the superior part and the inferior part of the ET lumen was wide. From these findings, we assume that the ET dysfunction that occurs in individuals with CP is the result of abnormalities of the ET and its cartilage and of abnormal anatomic relationships of these structures to the TVP muscle.

Anatomy of the round window. A histopathological study with a graphic reconstruction method

The round window was studied in normal adult and infant temporal bones to provide a knowledge base for the study of congenital anomalies of the round window, and to determine whether the round window develops postnatally. Fifty-three temporal bones were studied. Specimens were processed histologically, sectioned horizontally, stained with hematoxylin and eosin, and studied under the light microscope and microprojector. A special method of graphically reconstructing the round window was developed for this study, and was used to define the contour, area, and angle of the round window. We found that the round window is fan shaped. The area of the superoposteriorly located horizontal part (three-sevenths of the round window) and of the inferoanteriorly located vertical part (four-sevenths of the round window) totals approximately 2.29 mm2. In addition the angle between the plane of the tympanic sulcus and the vertical part of the round window was measured, and found to average 73.3 degrees. Lastly, the round window was found not to develop postnatally.

Computerized data bank system for temporal bone histopathology

A computerized data bank system to store and analyze temporal bone histopathologic data is described. This system uses the University of Pittsburgh's Digital Equipment Corporation System 10 computer and the System 1022 data base management software. Data on histology cases are divided into five files: general information, otologic information, summary, histopathologic information about the external ear and middle ear, and histopathologic information about the inner ear. Eleven general terms are used to describe pathologic findings, surgery, postmortem degeneration, and artifacts. In addition, provision is made for the inclusion of more precise qualitative information to be entered as text.

Computer-aided three-dimensional reconstruction and measurement of the vestibular end-organs

It is very valuable for temporal bone morphologists to be able to recognize temporal bone serial sections in three dimensions and to be able to measure temporal bone structures three-dimensionally. We can now do 3-dimensional reconstruction to visualize the structures of vestibular endorgans (utricular and saccular maculae) and measure these endorgans in space by means of a small computer system and software that we developed. As well as obtaining the dimensions--such as length and area--of the utricular and saccular maculae, we also found that (1) most of the utricular macula lies in one plane, which is the same as the plane of the lateral semicircular canal, (2) the saccular macula is shaped like part of a sphere, and (3) the angle between the two maculae is less than a right angle. Such knowledge is indispensable to the evaluation of the function of the utricular and saccular maculae.

Anomaly of the round window a histopathological study using a graphic reconstruction method

Although literature to date has reported that anomalies of the round window occur infrequently, no study to our knowledge has investigated such anomalies quantitatively. Thus, we developed a graphic reconstruction method and used it to study histology sections of the temporal bones. By this method we studied quantitatively the morphology of the round window of individuals with Mondini dysplasia of the inner ear and compared it to that of individuals with no anomaly. Iit was found that in 3 of 19 individuals with dysplasia, the total area of the round window was more than two standard deviations below the mean, thus small enough to be called anomalous. Moreover, the area of the round window was statistically significantly smaller in the ears from individuals with Mondini dysplasia, as a group, than in normal ears. This round window anomaly seems to be due to interruption of the normal development of the round window early in fetal life, as the result of poor development of the cartilage bar between the tympanic cavity and the subarachnoid space and also of the otic capsule in the hook portion of the basal turn of the cochlea.

Congenital middle and inner ear anomalies

For this study, 100 human temporal bones from 73 individuals, aged 31 gestational weeks to 39 years, each with anomalies of the middle and/or inner ear, were studied to identify the features, locations, and frequencies with which congenital anomalies occurred in these structures. The temporal bones had been removed at autopsy, fixed, dehydrated, embedded in celloidin, sectioned horizontally or vertically at 20 microns, stained with hematoxylin and eosin, and studied under a light microscope. The anomaly in the middle ear most often found was wide dehiscence of the facial canal; hypoplastic cochlea was most frequently observed anomaly in the inner ear. The implications of these findings for development of the ear during fetal life are discussed.

Perilymph fistula resulting from microfissures

Perilymphatic fistulas are well documented in the otolaryngologic literature as a cause for both auditory and vestibular symptoms. The anatomic location of fistulas has been clinically confirmed in both the oval and round windows. Furthermore, membranous tears within the cochlea have been described post mortem and may be the cause of the remaining fistulas which are suspected but not confirmed surgically. A fourth source of perilymph fistula has previously been suggested by Okano and Harada. During the past several years, surgical confirmation of perilymph leakage from two microfissure areas has been observed. These cases will be briefly discussed along with their clinical implications. Speculation as to the type of hearing loss caused by fistulas will be offered. Hypotheses concerning the various symptoms encountered in patients and the location of the defect will also be addressed.

Localization, frequency, and severity of endolymphatic hydrops and the pathology of the labyrinthine membrane in Menière's disease

The localization, frequency, and severity of endolymphatic hydrops in 22 temporal bones of 16 individuals with Meniere's disease were studied histopathologically. Endolymphatic hydrops was more often observed in the pars inferior (22/22) than in the pars superior (13/22) of the temporal bone, and severe hydrops was observed most frequently in the saccule, followed by the cochlea, the utricle, and the three semicircular canals. In the cochlea, the most severe hydrops was observed in the apical turn, followed by the hook portion, the middle turn, and the basal turn. Clinically interesting observations regarding endolymphatic hydrops included bulging into the perilymphatic space of the vestibule. In 17 of 22 bones the saccular membrane bulged into the vestibule laterally and was attached to the footplate of the stapes. In two of 22 bones, Reissner's membrane in the hook portion of the basal turn of the cochlea bulged superiorly into the vestibule, occupying most of the perilymphatic space of the vestibule.

Mesenchyme remaining in temporal bones from patients with congenital anomalies. A quantitative histopathologic study

Our hypothesis that more mesenchyme remains for a longer time in the middle ear clefts of infants with congenital anomalies in the ear and/or other parts of the body than in the ears of infants without such anomalies has been tested. One hundred four human temporal bones obtained from 81 individuals with congenital anomalies in the ear and/or other parts of the body, with ages ranging from 24 weeks' gestation to 35 years, were processed histologically, stained with H & E, and examined under the light microscope. The slides were projected under a microprojector, and the mesenchyme remaining in each of 19 portions of the middle ear cleft was measured by compensating polar planimetry and expressed as a percentage of the total potential middle ear space in that histologic section. By comparing the findings in the present study with those of a previous study in which mesenchyme remaining in ears from normal age-matched controls was measured, we found that more mesenchyme remained for a longer time in the middle ear cavities of infants with congenital anomalies than in those of control infants (p less than .01). In addition, the amount of mesenchyme remaining was in direct proportion to the degree to which development of the middle ear was anomalous.

Postnatal development of the eustachian tube and its surrounding structures. Preliminary study

The postnatal development of the eustachian tube and its surrounding structures (tubal cartilage, tubal gland, tensor veli palatini muscle, and levator veli palatini muscle) was investigated in serial vertical histologic sections from 12 normal temporal bones of individuals whose ages ranged from 39 weeks' gestation to 19 years of age. After projecting tissue sections onto paper and tracing the structures, several measurements were made in order to analyze this development. Findings revealed that the eustachian tube and its accessory structures developed postnatally up to the age of 19 years. The lumen area in a 19-year-old specimen was 4.7 times that of the 1-day-old infant. The development of the tube was greatest in the pharyngeal part. Postnatal development of the eustachian tube appears to be related to growth of the face. The cartilage area in the 19-year-old specimen was 3.6 times that of the 1-day-old infant. The mucosal acinar cells were predominant in infants but no greater than the number of serous acinar cells by the age of 19 years. The areas of the tensor and levator veli palatini muscles in a 19-year-old specimen were 5.1 and 11.1 times, respectively, those of the 1-day-old infant. This preliminary study reports the postnatal development of the eustachian tube and its accessory structures, a subject never thoroughly investigated to date. However, because of the limited number of cases available, further investigation of a greater number of cases should be performed so that the relationship between tubal development and alterations in function that occur with age can be understood clearly.

Mesenchyme remaining in human temporal bones

This study was conducted in order to gain basic information about mesenchyme remaining in the middle ear cleft in normal infants. Because no previous report has objectively described the quantity or quality of such postnatal remnants in normal infants, it has not been possible to accurately evaluate the significance of mesenchyme remaining in the middle ears of infants with pathologic conditions, such as otitis media and congenital anomalies. Thus, 53 temporal bones obtained from 41 individuals reported upon here--from 26 weeks' gestation to 8 years of age--will be controls for future studies of pathologic conditions. The children from whom these temporal bones were obtained had no anomalies of the ear (or any other known part of the body); nor did they have any pathologic conditions in the ear. The temporal bones were prepared for histologic study with hematoxylin and eosin staining and were examined under the light microscope. After areas of the mesenchyme in the histologic sections were projected and illustrated for each of 19 portions in the middle ear cleft under the microprojector, those areas were measured by compensating polar planimetry. The findings obtained in this study were as follows: The amount of mesenchyme remaining in the days after birth seemed to gradually decrease in volume with increased maturity and had nearly disappeared within the first year in normal infants. Where mesenchyme was noted in the temporal bones of infants over 1 year of age, it was usually present only in small niches.(ABSTRACT TRUNCATED AT 250 WORDS)

Temporal bone histopathologic findings in oculoauriculovertebral dysplasia. Goldenhar's syndrome

The right temporal bone of a 6-month-old patient with oculoauriculovertebral dysplasia (Goldenhar's syndrome) was examined histopathologically. The most striking abnormalities were deformity of the auricle, atresia of the external auditory canal, severe malformation of middle ear structures, and incomplete development of the oval window. No inner ear abnormalities were identified in this case.

A method for the histopathological analysis of the temporal bone and the eustachian tube and its accessory structures

A very important contribution to the study of otitis media, one of the diseases most often seen in pediatric patients, is the collection, processing, and study of the specimens of the temporal bone and the entire eustachian tube. During the last few years, we have collected, processed, and studied 100 such specimens, and through these experiences our technique has become refined. We now have some important suggestions for otologists interested in the histological study of otitis media as well as in the pathology of the eustachian tube and its relation to middle ear abnormalities. This report details the most successful method for the study of eustachian tube abnormalities and their relationship to middle ear effusion.

Lymphoma invading the anterior eustachian tube. Temporal bone histopathology of functional tubal obstruction

The temporal bones of a man with poorly differentiated lymphocytic lymphoma, who had had a bilateral conductive hearing loss and incomplete left-sided facial palsy, were obtained. Sections were prepared for histologic study by staining with hematoxylin and eosin and were examined under the light microscope. The left temporal bone showed marked tumor cell involvement, not only of the lateral part of the cartilaginous portion of the eustachian tube (ET) where the tensor veli palatini muscle had been partially destroyed, but also in the anterior part of the temporal bone. A serous middle ear effusion was present, but the lumen of the ET was unaffected by tumor or inflammation. The pathological findings in the right temporal bone were similar to those in the left, although the cartilaginous part of the ET and its surrounding structures were not available for study. The pathogenesis of otitis media with effusion appeared to be secondary to functional ET obstruction, due to the dysfunction of the tensor veli palatini muscle as a result of the tumor destruction. This case is the first to be reported in which functional ET obstruction, secondary to tumor invasion of the active muscle dilator of the ET, has been histologically confirmed.

Vascularity of endolymphatic sac in Meniere's disease. A histopathological study

The vascularity of the endolymphatic sac (ES) in the vestibular aqueduct (VA) and of periaqueductal bony channels was studied in 18 temporal bones from patients with Meniere's disease and in the same number of control bones with no endolymphatic hydrops and no premortem history of otologic disease. The control bones were selected on the basis of having VAs of the same sizes as the hydropic bones. This was important in order to eliminate any possibility that differences in degree of vascularity of the ES could have been due simply to differences in the degree of development of the VA. All specimens were sectioned and stained with hematoxylin and eosin. The ES of each bone was reconstructed two-dimensionally by the medial view graphic reconstruction method, and its vascularity was studied histologically under a light microscope. There were fewer and smaller blood vessels in the ESs of bones from individuals with Meniere's disease than in the ESs of control bones. This was particularly true in the richly rugose and the cranial orifice portions of the sac. However, no significant differences were recognized in the degree of vascularity of the periaqueductal bony channels between control and Meniere's disease bones.

Pneumatization and thickness of the petrous bone in patients with Meniere's disease. A histopathological study

Histological evaluations were made of the degree of pneumatization and thickness of the petrous bone surrounding the vestibular aqueduct, and of the relationships of these parameters to the condition of the vestibular aqueduct in 27 temporal bones with idiopathic endolymphatic hydrops from individuals with Meniere's disease. The results were compared with those from the same parameters in 79 control temporal bones without endolymphatic hydrops from individuals who had no premortem history of otologic disease. Pneumatization of the temporal bones of patients with Meniere's disease was in most cases less than that of control temporal bones; this difference was statistically significant. Poor pneumatization of the temporal bones of individuals with Meniere's disease appeared to be closely associated with hypoplasia of the vestibular aqueduct, an anatomical feature of many individuals with Meniere's disease. However, no statistically significant difference could be found between the thickness of the petrous bone in the periaqueductal region in bones of patients with Meniere's disease and this parameter in control bones.

Paravestibular canaliculus in Meniere's disease. A histopathological study

The paravestibular canaliculus (PVC) and its contents were studied in 27 temporal bones from individuals with Meniere's disease and in the same number of controls. The specimens were examined by the medial view graphic reconstruction method and/or histologically under a light microscope. In most of these bones (88.9% of controls and 85.2% of Meniere's bones) only one PVC was noted; in the remaining bones (11.1% of controls and 14.8% of Meniere's bones) two PVCs were recognized. Most of the PVCs (88.9%) in both control and Meniere's bones were located in the petrous bone anterolateral to the vestibular aqueduct (VA). In one third of both control and Meniere's bones the PVC extended below the inferior margin of the posterior semicircular canal. In 74.1% of the Meniere's bones the PVCs were noted to exit directly to the posterior cranial fossa, whereas such a course was present in only 40.7% of controls. The difference in this parameter between control and Meniere's disease bones is statically significant and appears to be related to the size of the VA. The length of the PVC, however, seems to be independent of both the size of the VA and the degree of development (thickness) of the petrous bones surrounding the PVC. In four Meniere's bones a part of the main vein in the PVC was absent; this was never observed in a control bone. We found no other evidence in this study to link the function or anatomy of the PVC to Meniere's disease.

Histopathology of otitis media in infants with cleft and high-arched palates

The middle ear and the bony and cartilaginous portions of the eustachian tube (ET) were studied histopathologically in 20 temporal bones from 19 infants, aged 45 minutes to 12 months. Otitis media (OM) was observed in 17 of 20 bones, and 16 bones with OM had an effusion. Otitis media was more severe in the ears of cleft palate infants compared to those with high-arched palates. Inflammation was present in the bony portion of the ET in 15 of 17 temporal bones with OM, but appeared to be less marked than that present in the middle ear. In addition, inflammation of the cartilaginous portion of the ET appeared to be less severe than in its bony portion. Inflammation of the middle ear and the ET appeared to be more pronounced in older infants, particularly in those with cleft palates.

How to remove, process, and study the temporal bone with the entire eustachian tube and its accessory structures: a method for histopathological study

A very important contribution to the study of otitis media, one of the diseases most often seen in pediatric patients, is the collection and study of temporal bone specimens which include the entire Eustachian tube. During the last few years, we have collected, processed, and studied more than 100 such specimens. Through these experiences, our technique has become so refined that we have some important suggestions to make to otologists who are interested in the histological study of otitis media as well as in the pathology of the Eustachian tube and its relation to middle ear abnormalities. This report describes the method we have found to be most successful for the study of Eustachian tube abnormalities and their relationship to middle ear effusion.

Endolymphatic duct and sac in patients with Meniere's disease. A temporal bone histopathological study

The endolymphatic ducts and sacs of 25 temporal bones with idiopathic endolymphatic hydrops from individuals with Meniere's disease were studied and compared with the same number of control bones without endolymphatic hydrops from individuals with no premortem history of otologic disease. The control bones were selected so that the sizes of their vestibular aqueducts matched those temporal bones from individuals with Meniere's disease. The endolymphatic ducts and sacs of all bones were studied by the medial view graphic reconstruction method and/or histological observation under a light microscope. In the endolymphatic duct and sac of many of the temporal bones from patients with Meniere's disease were noted a diminution of the width of the endolymphatic duct in its isthmus portion, an increase in the area of the collapsed lumen of the endolymphatic sac, fibrotic changes in the perisaccular loose connective tissue, and an increase in the quantity of intraluminal eosinophilic material. The frequencies with which these pathological findings were noted in bones from individuals with Meniere's disease and in control bones were statistically significantly different. No significant differences were observed under light microscopic study between these two groups with regard to the condition of the epithelial cells, the degree of rugosity of the endolymphatic sac, or the appearance of melanin-like pigmentation of hyalinization in the perisaccular connective tissue.