Spatiotemporal expression of NGFR during pre-natal human tooth development.

OBJECTIVES: The relation between nerve growth factor receptor (NGFR) in the human pre-natal tooth buds and the dental follicle was investigated. In particular, we sought to determine if there is a specific pattern of p75NGFR expression in developing human tooth buds and their surrounding tissue. SETTING AND SAMPLE POPULATION: The Department of Orthodontics at Copenhagen University, Denmark. Histological sections from 11 fetuses, aged 11-21 gestational weeks. METHOD: The sections were studied by conventional immunohistochemistry. RESULTS: Specific spatiotemporal patterns of p75NGFR reactions were observed in the tooth buds and dental follicle: Before matrix production by the ameloblasts, the entire inner enamel epithelium and the entire dental follicle display p75NGFR immunoreactivity; after matrix production is initiated, the immunoreactivity of the matrix producing cells is lost, as is that of the dental follicle adjacent to these matrix-producing cells. CONCLUSION: A unique spatiotemporal distribution of NGFR in the pre-eruptive human tooth bud was demonstrated.

Segmental odontomaxillary dysplasia: clinical, radiological and histological aspects of four cases.

Segmental odontomaxillary dysplasia (SOD) is a rare developmental disorder of the maxilla, primarily involving the posterior part of the maxilla. Clinically, the disorder is often diagnosed in early childhood due to a unilateral buccolingual expansion of the posterior alveolar process, gingival enlargement, absence of one or both premolars in the affected region, delayed eruption of the adjacent teeth and malformations of the primary molars. In this report, four patients with SOD are described. The findings were similar to earlier reports, but for the first time an ipsilateral rough erythema on the skin in two of the subjects is reported.

Craniofacial and dental manifestations of Proteus syndrome: a case report.

The Proteus syndrome is a rare congenital hamartomatous condition that is characterized by a wide range of malformations, sometimes involving the face. Common manifestations include partial gigantism, congenital lipomas, and plantar hyperplasia. In this report we describe the craniofacial clinicopathological development in a girl with Proteus syndrome from age 6 to 20 years. The patient had pronounced hemifacial hypertrophy, exostoses in the left parietal region, and enlargement of the inferior alveolar nerve and mandibular canal in the affected region. The dental development of the affected left mandible and maxilla was characterized by extremely premature development and eruption of the primary and permanent teeth and by pronounced idiopathic root resorptions. The multidisciplinary management of the patient and the treatment outcome is reported. A review of the Proteus patients in the literature who exhibited manifestation in the craniofacial region is presented.

Craniofacial morphology, dentition, and skeletal maturity in four siblings with Seckel syndrome.

OBJECTIVE: To describe the craniofacial morphology, dentition, and hand maturity in four siblings with Seckel syndrome. PATIENTS: Two boys and two girls, with Seckel syndrome. The children studied showed extreme growth retardation, severe microcephaly, bird-headed profile with receding chin, prominent nose, mental retardation, and extremely delayed skeletal maturation. The growth hormone axis and pituitary thyroid function was normal. METHODS: Skeletal and dental development were investigated from radiographic material, and a cephalometric analysis was performed from profile radiographs. RESULTS: The craniums were remarkably small with an extremely short anterior cranial base (-4.3 to -5.5 standard units) and maxillary length (-3.8 to -4.7 SU). Differences in the morphology of the sella turcica were observed in girls and boys. Tooth maturity progressed normally. Tooth agenesis and tooth malformations were observed. Taurodontic root morphology was observed only in the girls. The approximate skeletal maturity showed retardation from 4 years 3 months to 4 years 11 months. Malformations of the hand-wrist skeleton occurred in the epiphyseal ossification centers of the middle phalangeal bone in the second, third, and fourth finger and in the distal phalangeal bone in the fifth finger. The epiphyseal ossification centers were lacking in the middle and distal phalangeal bones of the fifth finger. CONCLUSION: The underlying gene defect in the affected children seemingly affects bone development and growth but not dental maturation and eruption.

Face, palate, and craniofacial morphology in patients with a solitary median maxillary central incisor.

The occurrence of a solitary median maxillary central incisor (SMMCI) is a very rare condition and might be a sign of a mild degree of holoprosencephaly. In this investigation, material from 10 patients, nine girls and one boy with a SMMCI (8-17 years of age) registered in orthodontic clinics was examined. The purpose was to evaluate the clinical characteristics and craniofacial morphology in this group of patients. Oral photographs, study casts, profile radiographs, and orthopantomograms were analysed. The study showed that this group of SMMCI patients were characterized by an indistinct philtrum, an arch-shaped upper lip, absence of the fraenulum of the upper lip, a complete or incomplete mid-palatal ridge, a SMMCI, and nasal obstruction or septum deviation. The craniofacial morphology of the nine girls, compared with normal standards for girls showed a short anterior cranial base, a short, retrognathic and posteriorly inclined maxilla, and a retrognathic and posteriorly inclined mandible. Furthermore, the sella turcica had a deviant morphology in five of the 10 subjects. The results indicate that the presence of a SMMCI should not be considered as a simple dental anomaly, since it may be associated with other clinical characteristics and more complex craniofacial malformations. It is therefore suggested that the SMMCI condition in future studies is classified according to clinical symptoms and craniofacial morphology.

Growth analysis of a patient with ectodermal dysplasia treated with endosseous implants: a case report.

Congenital absence of multiple teeth and poorly developed alveolar ridges are associated with ectodermal dysplasia. Affected patients often require dental prosthetic treatment during their developmental years. Maxillofacial growth and development in a preadolescent female patient with ectodermal dysplasia following oral rehabilitation with maxillary and mandibular endosseous dental implants is reported. Four maxillary and 4 mandibular implants were successfully integrated and restored at 8 years of age. Growth analysis 12 years later revealed that the implants followed maxillary and mandibular growth displacement. Minor impaction of the maxillary implants was observed, and mandibular implants were affected by the mandibular growth rotation, which led to a change in implant inclination. The treatment outcome is compared to similar previously reported studies and cases.

Eruption of the central incisor, the intermaxillary suture, and maxillary growth in patients with a single median maxillary central incisor.

The occurrence of a single median maxillary central incisor (SMMCI) is a very rare condition and might be a sign of a more severe midline defect, which could be a mild degree of holoprosencephaly. Absence of the internasal and partial absence of the intermaxillary suture has been observed in a fetus with holoprosencephaly. The purpose of this study was to evaluate the intermaxillary suture, the eruption pattern of the single central incisor in the SMMCI condition, and the growth of the maxilla in a group of patients with SMMCI. A similar study was not found in the scientific literature. The material included orthopantomographs, dental radiographs, and lateral cephalometric radiographs from 11 patients with an SMMCI. The orthopantomographs and dental radiographs showed that the intermaxillary suture was abnormal anterior to the incisive foramen; however, the SMMCI erupted within the expected time interval. Superimposition on stable structures on lateral cephalometric radiographs from two untreated patients, in which growth analysis was possible, showed that the horizontal and vertical growth of the maxilla was normal. Due to the sutural midline defect it is suggested that a transversal growth analysis is included in all treatment planning of SMMCI patients.

The association between prenatal sella turcica morphology and notochordal remnants in the dorsum sellae.

The purpose of this study was to describe the location and morphology of notochordal remnants in the cranial base in normal and pathological conditions and to relate these findings to the morphological appearance of the sella turcica. Serially cut sagittal sections of paraffin-embedded sella turcica tissue blocks from 88 normal and pathological fetuses, 13 to 24 weeks of gestation, were examined. Twenty-seven specimens out of 88 had visible notochordal remnants in the cranial base, and these constituted the material available for this study. A straight notochordal course is always seen in normal sella turcica morphology, and a non-straight notochordal course is always seen in malformed sella turcica. Among the fetuses diagnosed at autopsy as "normal fetuses," both normal and pathological findings in the sella turcica regions were observed. The pathological findings were always found in the spontaneously aborted fetuses (five cases). Among the fetuses diagnosed at autopsy as "pathological fetuses," both normal and pathological findings were also observed in the sella region. Our conclusion is that the morphological appearance of the notochordal remnants in the dorsum sellae is associated with the morphology of the sella turcica. These structures ought to be analyzed on larger materials of both normal and pathological fetuses. One of the more obvious perspectives opened up by the present study is the probable disclosure of malformations in spontaneously aborted fetuses without external malformations.