Biomedical subjects

C A Trotman

Publications and source records attributed to C A Trotman.

28 records · Page 2Linked to original sources

PubMed1995

Histomorphologic analysis of the soft palate musculature in prenatal cleft and noncleft A/Jax mice.

The two specific aims of this study were as follows: to evaluate the appropriateness of the A/Jax mouse model in the investigation of the key cellular stages in prenatal soft palate morphogenesis and myogenesis; and to describe structural differences in the histomorphology of the soft palate anatomy from cleft and noncleft mice prior to, during, and after palatogenesis. Cleft-induced and control groups of A/Jax mouse embryos from timed pregnancies were harvested sequentially on gestational days 15 to 19. Embryos were weighed and staged for external body morphology. The heads were removed and fixed for light microscopy, sectioned serially in the frontal plane at 10 microns and stained with hematoxylin-eosin to characterize and compare the soft palate musculature. All observations were made at the head depth of the trigeminal ganglion in both age- and stage-matched embryos. The following findings were made: (1) the A/Jax mouse is a suitable animal model for the study of soft palate myogenesis; (2) there were no discernible morphologic differences between the soft palate muscles in cleft and noncleft A/Jax mice when viewed under light microscopy; (3) the soft palate and related muscles were identifiable as muscle fields, in both the cleft and noncleft fetuses, as early as gestational day 15 and as specific muscles at gestational day 18; (4) in both the cleft and noncleft A/Jax fetuses, the soft palate muscles appeared in a sequential anatomic fashion (the palatine aponeurosis appeared first, next the tensor palatini, and then the levator palatini muscles); and (5) in the cleft palate fetuses, both pterygoid plates were angulated and displaced laterally.

Analysis of Variance↗

PubMed1994

Patterns of abnormal myogenesis in human cleft palates.

To test the hypothesis that soft palate muscles are abnormal in cleft palate, we compared soft palate morphogenesis in fetuses with cleft palate (n = 4) to age-matched (n = 3) and nonmatched (n = 1) control specimens. The morphologic status of all soft palate and masticatory structures were classified into one of six stages based on the level of histogenesis. At 54 mm crown-rump length (CRL), the levator veli palatini (L), palatopharyngeus (PP), and palatoglossus (PG) in cleft subjects demonstrated mesenchymal condensation into myoblastic fields, lagging behind the control specimens (97 mm CRL), which displayed definitive fields of myoblasts and myotube formation. In the 175 mm and 225 mm cleft and the 170 mm and 192 mm control specimens, muscular morphology was similar and had reached its postnatal appearance for the tensor veli palatini (175 m only) and L, PP, PG (225 mm only). Muscle fiber directions were, however, disoriented and disorganized, especially close to the medial epithelial edge of the cleft. The levator veli palatini, could not be distinguished as a discrete muscle in the cleft specimens, and what we believed to be the PP and PG seemed "normal" at the level of light microscopy, but malpositioned in a superior direction. This preliminary study demonstrates for the first time that early myogenesis in cleft palates differs from normal.

Case-Control Studies↗

PubMed1993

Sexual dimorphism in normal craniofacial growth.

The purpose of this investigation is to re-evaluate an existing sample of Caucasian individuals, of mostly Northern European ancestry and undefined ethnic origins, who have been characterized as having excellent occlusions and balanced facial proportions (from a subjective assessment). The focus is the emergence of sexual dimorphism in the skeletal and dental relationships. Serial lateral cephalograms of 51 subjects were obtained from the Bolton-Brush Study at ages 6, 9, 12, 14, 16 and 18 yrs. At each age, the records of 16 males and 16 females were selected. Cephalometric evaluation indicated that the length of the anterior cranial base was larger in males but the cranial base angle was similar for both sexes at all age intervals studied. The effective lengths of the maxilla and mandible were similar in both sexes up to 14 years; thereafter in females this length remained relatively constant while in males it increased. The direction of facial growth was similar for both sexes, with a tendency towards a more horizontal growth pattern in females.

Adolescent↗

PubMed1993

Analyses of craniofacial and dental morphology in monozygotic twins discordant for cleft lip and unilateral cleft lip and palate.

The Michigan Cleft Twin Sample data was analyzed in order to investigate dental arch and craniofacial morphology. The present study consisted of 12 monozygotic twins discordant for either cleft lip or unilateral cleft lip and palate. Individuals having CL (repaired) alone did not differ from their unaffected counterparts in dental arch and skeletal morphology. Repaired UCLP subjects were characterized by having a shorter and more posteriorly positioned maxilla. Although reduction of dental arch width as a result of scar contraction following surgery was evident, the effects of scar tissue pull did not affect maxillary basal width.

Cephalometry↗

PubMed1993

Craniofacial growth in bilateral cleft lip and palate: ages six years to adulthood.

The purpose of the study was to localize the characteristic craniofacial abnormalities in young children with complete bilateral cleft lip and palate, to average their growth changes, and to compare all these to observations from a normative sample. A longitudinal sample of 30 males with complete bilateral cleft lip and palate was obtained from the files of the Craniofacial Center at The Hospital for Sick Children, Toronto. An age-matched noncleft control sample was selected from the Burlington Orthodontic Research Center. All individuals had lateral cephalometric radiographs at approximately 6 years, 12 years, and as adults. These were analyzed by cephalometrics and by tensor biometrics. The results of the two methods of analysis were in agreement and tended to complement each other. In the cleft sample, there was little clefting effect on the midline structures of the cranial base; the premaxilla was initially protruded but became normal in the adult; the nasal bone was longer and more protruded; the posterior maxillary segments were hypoplastic and the bony pharynx narrower; there was over-eruption of the posterior teeth; and the mandibular gonial area was smaller.

Adolescent↗

PubMed1993

Soft-palate myogenesis: a developmental field paradigm.

Surgical correction of clefts of the soft palate leads to varying degrees of normal function although the repair itself is successful. Explanations for this include structural abnormalities of the muscles. Previous studies have focused primarily on gross anatomical features of late fetal and postnatal cleft palate musculature; however, infrequent reference has been made to early prenatal morphologic patterns of soft-palate development, beginning with the embryo. Thus we evaluated the chronology of prenatal myogenesis of the soft palate from its early mesenchymal phase through the appearance of definitive palatal muscles and associated structures in a sample of 22 human fetuses that represented postfertilization weeks 6.5 to 20.5 (18- to 192-mm crown-rump length). Specimens were histologically prepared for descriptive and morphometric light microscopy. Data were collected on the earliest appearance times of identifiable soft palate and associated structures within the mesenchymal field and on their individual stages of myogenesis (e.g., for muscles, from mesenchyme to myoblasts to fascicles). Analyses showed that (1) palatal muscles and related bony structures emerge sequentially as densely staining mesenchymal subfields within the larger mesenchymal soft-palate field during the 6- to 9-week period, with the tensor veli palatini muscle appearing earliest, and the musculus uvulae latest; (2) further morphogenesis of the soft palate and associated structures follows a definite timeline; and (3) by 16 to 17 weeks the postnatal palatal morphology is in place.

Cleft Palate↗

PubMedDate not supplied

Four maxillary incisors: a case report.

This case report describes the dentofacial morphology and treatment of a 9-year-old female who presented with four maxillary incisors, and a combination of rare oral and cervical vertebral anomalies. The patient had a Class II division I malocclusion which was complicated by the presence of supernumerary permanent teeth: two supplemental maxillary central incisors, and a supplemental mandibular central incisor. She also had abnormalities of the cervical vertebrae, which were symptom-free. In addition, a number of surgical procedures had been performed in early childhood to treat a benign oral teratoma, cleft tongue, and an isolated cleft of the secondary palate. The dental treatment involved the extraction of the two most centrally placed maxillary central incisors, and the alignment of the maxillary arch with fixed orthodontic appliances.

Abnormalities, Multiple↗

PubMedDate not supplied

Facial developmental vascular anomalies.

Developmental vascular anomalies of the head and neck may give rise to profound esthetic problems that are a challenge to treat. These vascular anomalies may also be of significance in dentistry, particularly where extractions have to be carried out. This brief report describes a number of children who presented with different variations of these anomalies.

Adolescent↗

PubMedDate not supplied

Focal dermal hypoplasia (Goltz-Gorlin) syndrome with taurodontism.

This paper is a case report of a 10-year-old girl with focal dermal hypoplasia (FDH) who presented for dental care. She displayed many of the well-documented oral features associated with this syndrome. Additionally, she had taurodontism of a permanent mandibular molar. Although taurodontism affected only one tooth in this patient, the presentation of taurodontism with FDH has not been reported previously.

Child↗

PubMedDate not supplied

Gorlin-Goltz: what's in a name?

This paper describes the clinical features of two very distinct syndromes with similar names: Gorlin-Goltz and Goltz-Gorlin Syndromes. A case report is presented that highlights the differences between these syndromes. To avoid errors in diagnosis because of the similarity in names, the authors caution that, based on additional information now available, the preferred names should be Focal Dermal Hypoplasia syndrome for Goltz-Gorlin syndrome and Nevoid Basal Cell Carcinoma syndrome for Gorlin-Goltz syndrome.

Basal Cell Nevus Syndrome↗