Search

Purpose: This study investigated histochemically the elastic fibers in human temporomandibular joint (TMJ) discs with varying degrees of tissue degeneration/regeneration to determine whether there are differences that correlate with the histologic findings. Materials and Methods: Ten diseased human TMJ discs and 2 control specimens were studied histochemically by staining with Weigert's resorcin-fuchsin after oxidation with peracetic acid. This technique selectively stains elastic, elaunin, (pre-elastic), and oxytalan fibers. Results: In TMJ discs with an abnormal collagen fiber arrangement, an increased number of oxytalan fibers could be observed, contrary to discs with scar-like tissue transformation in which oxytalan fibers were decreased in number. In discs showing tears and clefts, the oxytalan fibers run perpendicular to the defects, whereas elaunin and elastic fibers were mainly circumferentially arranged. In discs with chondroid metaplasia, elastic, elaunin, and oxytalan fibers were extensively detected. Conclusions: It is hypothesized that the elastic, elauinin, and oxytalan fibers found in severely damaged discs appear to ensure biomechanical compliance by reinforcing regions devoid of collagen bundles and thus function as shock absorbers of stretch and compression. © 2001 American Association of Oral and Maxillofacial Surgeons

OBJECTIVE: To investigate condylar symmetry and condyle fossa relationships in subjects with functional posterior crossbite comparing findings before and after rapid maxillary expansion (RME) treatment through low-dose computed tomography (CT). MATERIALS AND METHODS: Twenty-six patients (14 girls and 12 boys, mean age 9.6 ± 1.4 years) with functional posterior crossbite (FPXB) diagnosis underwent rapid palatal expansion with a Hyrax appliance. Patients' temporomandibular joints (TMJ) underwent multislice CT scans before rapid palatal expansion (T0) and after (T1). Joint spaces were compared with those of a control sample of 13 subjects (7 girls and 5 boys, mean age 11 ± 0.6 years). RESULTS: Anterior space (AS), superior space (SS), and posterior space (PS) joint space measurements at T0 between the FPXB side and contralateral side demonstrated no statistically significant differences. After RME treatment (T1), all three joint spaces increased on both the FPXB side and the non-crossbite side. However, differences were statistically significant only for the SS when comparing the two sides at T1. SS increased more than AS and PS in the non-crossbite condyle (0.28 mm) and FPXB condyle (0.37 mm), and PS increased only on the FPXB side (0.34 mm). CONCLUSIONS: There were no statistically significant differences in condyle position within the glenoid fossa between the FPXB and non-crossbite side before treatment. Increases in joint spaces were observed after treatment with RME on both sides. These changes were, however, of small amounts.

To evaluate the apoptosis involvement in the angiogenesis as a self-limiting process in patients with temporomandibular joint (TMJ) degenerated disc vessels, we assessed, by immunohistochemistry, the detection of TRAIL, its death receptor DR5 and caspase 3. TRAIL, its death receptor DR5 and caspase 3 expression were studied by immunohistochemistry in 15 TMJ discs displaced without reduction and in 4 unaffected discs. These apoptosis molecules were detected in the intima and media layers of newly formed vessels affected discs. In conclusion, vessels apoptosis activation in TMJ disc with ID could be regarded as a self-limiting process that try to leads to vessel regression; in this way an inhibition of angiogenic vessels may prove a key strategy in limiting pathological angiogenesis, by cutting off blood supply to tumors, or by reducing harmful inflammation.

Craniofacial morphology of patients with nevoid basal cell carcinoma syndrome (NBCCS) has sometimes been reported at clinical examination, but any investigation has described it on the basis of cephalometric measurements.The purpose of this study was to conduct a cephalometric analysis of patients with NBCCS and to compare measurements with non-NBCCS subjects of similar ages, to elucidate if there is any relationship between NBCCS and craniofacial morphology.The study population consisted of 14 adult patients (9 men and 5 women), ranging in age from 18.2 to 56.8 years, with the diagnosis of NBCCS, with good-quality lateral cephalometric radiographs, and 14 adult healthy patients matched for age and sex to the NBCCS group. Cephalometric measurements were carried out on radiographs, and measurements of angles and distances were performed.Statistical differences between NBCCS subjects and controls were observed. Data analysis displayed that the measurements of the anterior cranial base (P

Objective: To test the null hypothesis that there is no increased prevalence of skeletal anomalies and/or normal variants as evidenced by the cephalometric radiographs of patients with palatally displaced canines (PDC). Materials and Methods: The treatment records of 38 white subjects between 14 and 20 years old with PDC were collected and evaluated retrospectively. Inclusion criteria for the study required that the case records include good-quality panoramic radiographs and lateral cephalometric radiographs with the first four cervical vertebrae clearly visible. The anomalies recorded for each case included sella bridge, atlanto-occipital ligament calcification or ponticulus posticus, and posterior arch atlas deficiency. A control group consisted of 70 consecutively treated subjects who had no other dental anomalies and whose maxillary canines had erupted normally. Fisher's exact test and Pearson's chi-square test were used to determine possible statistically significant differences in the incidence of skeletal anomalies and/or normal variants between the group of patients with PDC and the control group. Results: The prevalence of skull anomalies and normal variants seen in cephalometric radiographs was increased in patients with PDC. Because of the presence of ponticulus posticus (Pearson's chi-square, P < .050; Fisher's exact test, P < .052), sella bridge (Pearson's chi-square, P < .042; Fisher's exact test, P < .042), and posterior arch deficiency (Pearson's chi-square, P < .047; Fisher's exact test, P < .039), statistically significant differences were observed between subjects with PDC and the control group. Conclusions: The null hypothesis was rejected. There is an increased prevalence of skull skeletal anomalies and/or normal variants in patients with PDC.

To evaluate the reliability of landmark identification in posteroanterior cephalometrics.A literature search was conducted to identify all articles concerning landmark identification error in the frontal radiograph. Electronic databases (PubMed, Web of Science, Cochrane Database, PubMed Central, and HubMed) were searched. Abstracts that appeared to fulfill the initial selection criteria were selected, and the full-text original articles were then retrieved and analyzed. Only articles that fulfilled the initial selection criteria were finally considered. Their references were also hand searched for possible missing articles from the database searches.Twelve abstracts met the initial inclusion criteria, and these articles were retrieved. From these, eight were immediately rejected because of methodological issues. Only the four articles remaining seemed to fulfill the selection criteria, but two articles were later rejected, one because no landmark identification error mean values were provided and the other because of the sample. Only one article fulfilled the inclusion and exclusion criteria of this study. Midline landmarks were more reproducible than bilateral skeletal landmarks.Only one study fulfilled the additional inclusion and exclusion criteria. Few studies exist about the random error in localization of landmarks in posteroanterior cephalograms, and several methodological issues affected these few studies. Thus, future well-designed studies are needed to allow the orthodontist to choose the most appropriate cephalometric analysis.

The aim of this longitudinal cephalometric study was to analyze the growth characteristics of the mandible in subjects with infraocclusion of the mandibular deciduous molars. A group of 28 subjects with bilateral infraocclusion of mandibular deciduous molars (IG) were enrolled in a prospective longitudinal study on the growth characteristics of the mandible and compared with a control group (CG) of 28 subjects. Lateral cephalograms were collected in both groups at T1 and at T2, after a mean 19-month interval in the IG and after a mean 16-month interval in the CG. All subjects were observed in the early mixed dentition before the pubertal peak and did not receive any orthodontic treatment during the observation interval. Cephalometric analysis at T1 and superimposition of tracings at T1 and T2 were performed, and statistical comparisons between the two groups were carried out by means of independent sample t-tests. Discriminant analysis on the superimposition data identified Co-Gn angle (angle formed by line Co-Gn at T1 and at T2) as the single discriminant variable between IG and CG. There were significant differences between the two groups as to morphological changes of the mandible and direction of condylar growth, thus demonstrating anterior growth rotation of the mandible in subjects with infraocclusion. Because of the high levels of alveolar bone turnover and remodeling in anterior rotating mandibles, this study suggested that skeletal growth characteristics of the mandible may influence the clinical expression of infraocclusion.

Calcification of the interclinoid ligament (ICL) of the sella turcica, or sella turcica bridging, has been associated with severe craniofacial deviations. Despite no comprehensive study on the sella turcica bridge, a relationship with tooth and eruption disturbances has been reported. In order to investigate whether congenital absence of the second mandibular premolar, or the presence of a palatally displaced canine (PDC), is associated with sella bridging, a retrospective study was performed. Lateral cephalometric radiographs from 20 males and 14 females, aged between 8 and 16 years, with a PDC and second mandibular premolar aplasia were reviewed and compared with a control group. A standardized scoring scale was established to quantify the extent of a sella turcica bridge from each radiograph (no calcification, partially calcified, and completely calcified). The prevalence of complete calcification of the ICL in adolescents with dental anomalies was equal to 17.6 per cent, while an incidence 9.9 per cent was found in the control group. A partially calcified sella turcica was observed in 58.8 per cent of adolescents with dental anomalies compared with 33.7 per cent in the control group. The association between the degree of calcification of the ICL and the presence of dental anomalies in the studied adolescents was statistically significant according to chi-square statistics (P = 0.004). This was confirmed by Fisher's exact test (P = 0.003). According to these findings, the prevalence of a sella turcica bridge in adolescents with dental anomalies is increased, while age and gender do not greatly influence ossification of the ICL. The very early appearance during development of a sella turcica bridge should alert clinicians to possible tooth anomalies in life later.

Heat shock protein (HSP) 27 is a member of the small HSP family that plays a part in the regulation of epithelial cell growth and differentiation, wound healing, apoptosis and cell protection against inflammatory cytotoxicity mediators. Thus the expression of HSP27 was investigated immunohistochemically in periapical granulomas with epithelial rests of Malassez and in radicular cysts. Anti-HSP27 mouse monoclonal antibody and peroxidase-labeled streptavidin-biotin standard technique were used to study the expression of HSP27. Proliferating epithelial cell rests, and islands of epithelium and epithelial lining of microcysts strongly reacted throughout all layers, whereas radicular cysts epithelial lining presented mainly a moderate suprabasal staining pattern. However both the proliferating epithelial cell rests and the radicular cysts shared an over-expression of HSP27 immunostaining intensity in coincidence with the presence of local infiltration of immune cells. HSP27 may play several roles in periapical lesions that include contributing to the migration of epithelial cell rests and an increased resistance both to necrotic and apoptotic cell deaths.

The original article to which this Erratum refers was published in Am J Med Genet 110:400–403.

Heat shock proteins (HSPs) are believed to represent a cellular stress response mechanism that protects intracellular proteins from damaging events. Some studies have demonstrated an enhanced expression of large-molecular-weight HSPs in diseased systematic joints. Small heat shock proteins, and among these HSP27, have been studied to a lesser extent. HSP27 has cytoprotective and biosynthetic functions within chondrocytes, and it is an estrogen-associated protein that is under hormonal modulation. To improve understanding at a molecular level of the pathophysiology of certain temporomandibular joint disorders, the authors carried out this immunohistochemical study to assess the presence of HSP27 in human TMJ discs. Twelve adult human TMJ discs (10 diseased and 2 healthy discs) and 5 TMJ fetal human discs were used in this study. Adult discs and TMJ tissues of human fetuses were fixed in 10% buffered formalin. Samples were then processed for histologic examination. Sections were immunohistochemically stained using the streptavidin-biotin detection method. No reaction product for HSP27 in the discs of fetuses was noted. HSP27 was weakly expressed in normal TMJ discs and highly up-regulated in discs of patients showing new vessel formation and chondroid metaplasia. Any correlation between gender and HSP27 was found in the sample, being the up-regulation of HSP27 related mostly to major histopathological changes. This different pattern of HSP27 immunostaining in human TMJ discs detected in the authors' specimens suggests that the expression of this small HSP is functionally modulated. In fact HSP27 up-regulates in internal derangement specimens with major histopathological changes; on the other hand, it is not expressed or only weakly expressed in TMJ discs of fetuses and normal TMJ discs.