Stella Chaushu

Success rate and duration of orthodontic treatment for adult patients with palatally impacted maxillary canines

This study was undertaken to examine the success rate and the length of orthodontic treatment of impacted maxillary canines in adult patients. A sample of 19 adults (mean age, 28.8 +/- 8.6 years; range, 20-47 years), who had been treated for a total of 23 impacted maxillary canines, was compared with a younger control group (mean age, 13.7 +/- 1.3 years; range, 12-16 years). The control subjects were chosen for a similar degree of impaction difficulty by carefully matching the positions of the impacted canines in the 3 planes of space. The success rate among the adults was 69.5% compared with 100% among the younger controls. The lower success rate was due to 5 canines that had failed to erupt and 2 canines that had been partially extruded but could not be aligned in the arch. The duration of treating the overall malocclusion of the adults and young subjects did not materially differ. However, the adults showed significant increases in the duration and number of treatment visits required for resolving the canine impaction, in both the simpler and the more difficult cases. When further divided by age, all the failed canines were found in the older (over 30) adult subgroup. It was concluded that the prognosis for successful orthodontic resolution of an impacted canine in an adult is lower than that in a younger patient and that the prognosis worsens with age. Furthermore, when such treatment is undertaken, its successful completion should be expected to take considerably longer.

Prevalence of Tooth Transposition, Third Molar Agenesis, and Maxillary Canine Impaction in Individuals with Down Syndrome

Alterations in the size, morphology and number of teeth are among the many inherited disorders that have been reported in individuals with Down syndrome. By contrast, third molar agenesis and tooth transposition have been largely ignored and the prevalence of canine impaction has not been reported. The intention of this study was to quantify the occurrence of these anomalies in a group of individuals with Down syndrome, using standardized records, which included a clinical examination, dental casts, and a panoramic radiograph. The results show a notably high prevalence of third molar agenesis (74% of individuals older than 14 years), canine impaction (15%), and maxillary canine/first premolar transposition (15%), compared to published figures from random population samples. These anomalies should not be seen as separate, independent entities, but as associated phenomena. The slow rate of cell growth and a consequent reduced cell number that characterize this syndrome may be responsible for the underdevelopment of the upper jaw, the delayed dental development, the reduction in teeth number and size, and the altered path of canine eruption. No explanation, other than genetics, is immediately available to explain why the maxillary canine/first premolar transposition should represent another phenotypic expression of this trisomy.

Fap2 Mediates Fusobacterium nucleatum Colorectal Adenocarcinoma Enrichment by Binding to Tumor-Expressed Gal-GalNAc

Fusobacterium nucleatum is associated with colorectal cancer and promotes colonic tumor formation in preclinical models. However, fusobacteria are core members of the human oral microbiome and less prevalent inxa0the healthy gut, raising questions about how fusobacteria localize to CRC. We identify a host polysaccharide and fusobacterial lectin that explicates fusobacteria abundance in CRC. Gal-GalNAc, which is overexpressed in CRC, is recognized by fusobacterial Fap2, which functions as a Gal-GalNAc lectin. F.xa0nucleatum binding to clinical adenocarcinomas correlates with Gal-GalNAc expression and is reduced upon O-glycanase treatment. Clinical fusobacteria strains naturally lacking Fap2 or inactivated Fap2 mutants show reduced binding to Gal-GalNAc-expressing CRC cells and established CRCs in mice. Additionally, intravenously injected F.xa0nucleatum localizes to mouse tumor tissues in a Fap2-dependent manner, suggesting that fusobacteria use a hematogenous route to reach colon adenocarcinomas. Thus, targeting F.xa0nucleatum Fap2 or host epithelial Gal-GalNAc may reduce fusobacteria potentiation of CRC.

Direct Recognition of Fusobacterium nucleatum by the NK Cell Natural Cytotoxicity Receptor NKp46 Aggravates Periodontal Disease

Periodontitis is a common human chronic inflammatory disease that results in the destruction of the tooth attachment apparatus and tooth loss. Although infections with periopathogenic bacteria such as Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum) are essential for inducing periodontitis, the nature and magnitude of the disease is determined by the hosts immune response. Here, we investigate the role played by the NK killer receptor NKp46 (NCR1 in mice), in the pathogenesis of periodontitis. Using an oral infection periodontitis model we demonstrate that following F. nucleatum infection no alveolar bone loss is observed in mice deficient for NCR1 expression, whereas around 20% bone loss is observed in wild type mice and in mice infected with P. gingivalis. By using subcutaneous chambers inoculated with F. nucleatum we demonstrate that immune cells, including NK cells, rapidly accumulate in the chambers and that this leads to a fast and transient, NCR1-dependant TNF-α secretion. We further show that both the mouse NCR1 and the human NKp46 bind directly to F. nucleatum and we demonstrate that this binding is sensitive to heat, to proteinase K and to pronase treatments. Finally, we show in vitro that the interaction of NK cells with F. nucleatum leads to an NCR1-dependent secretion of TNF-α. Thus, the present study provides the first evidence that NCR1 and NKp46 directly recognize a periodontal pathogen and that this interaction influences the outcome of F. nucleatum-mediated periodontitis.

Dental age in maxillary canine ectopia

An etiologic connection between palatally ectopic canines and small and missing teeth is well established in the literature. Additionally, it has been observed that patients with palatally ectopic canines have a delayed dental development. The present study was designed to examine the validity of this latter observation. We radiographically assessed the subjects dental ages using criteria of tooth calcification, rather than tooth eruption pattern. A similar determination was made in relation to subjects in whom buccally ectopic canines were present. The experimental group consisted of panoramic radiographs of 55 consecutively treated patients with palatally displaced maxillary canines and of 47 consecutively treated patients with buccally displaced canines. They were compared with a control group of 57 consecutively treated patients with normally placed canines. Approximately half the subjects with palatal displacement exhibited a late-developing dentition, whereas the timing of dentition in the remaining subjects appeared to be normal. Buccal displacement was not associated with a retarded dental development, and the ranges of the dental age values were similar to those seen in the control group. The results support the idea that there are different etiologies for the occurrence of buccal versus palatal ectopia in maxillary canines. They also suggest that dentitions with a palatal canine appear to be of 2 distinct varieties, with different dental characteristics and, perhaps, different etiologies.

Analysis of failure in the treatment of impacted maxillary canines.

INTRODUCTIONnIn this study, we aimed to evaluate the reasons for failure of orthodontic treatment for impacted maxillary canines and to recommend measures to overcome them.nnnMETHODSnTwenty-eight patients (ages, 17.4 +/- 4.3 years) with 37 maxillary impacted canines were referred after a failed attempt to resolve the impaction. Reasons for failure were analyzed, and corrective measures undertaken. The success rate of the revised treatments and the durations of both treatments were recorded.nnnRESULTSnThe mean duration of the failed treatments was 26.2 +/- 17.2 months. The failed treatments were mostly based on plane radiographs, intra-arch dental anchorage, and elastic traction directly to the labial archwire. The major reasons for failure were inadequate anchorage (48.6%), mistaken location and directional traction (40.5%), and ankylosis (32.4%). In several patients, there was more than 1 possible reason for failure. The success rate of the revised treatments was 71.4%, and the mean duration was 14.4 +/- 7.2 months. Repeat surgery was needed for 62.9% of the canines in which corrective treatment was started, mostly to redirect the ligature wires. The corrective measures included the use of 3-dimensional imaging and a change in the direction of traction. Anchorage was reinforced by dental and skeletal means.nnnCONCLUSIONSnInaccurate 3-dimensional diagnosis of location and orientation of impacted teeth and failure to appreciate anchorage demands were the major reasons for failure in the treatment of impacted canines.

Maxillary incisor impaction and its relationship to canine displacement

This study aimed to examine the eruption status of unerupted maxillary permanent canines in patients who also had an impacted central incisor. Seventy-five unilateral cases of the incisor anomaly were retrospectively examined. Using the initial panoramic films, we assessed the positions of the ipsilateral and contralateral canines and the lateral incisors and the timing (eruption progress) of the canines. The final position of the canines was evaluated from patient records and progress photographs. The data showed a significant increase in prevalence and severity of displaced canines in the ipsilateral side (41.3%) compared with the contralateral side (4.7%). Palatally displaced canines occurred in 9.5%, buccally displaced canines in 30.2%, and canine-lateral incisor transposition in 1.6% of the patients. Half of the buccally displaced canines in the ipsilateral side were pseudotransposed with the adjacent lateral incisor. The eruption timing of ipsilateral undisplaced canines was either similar or delayed, relative to the contralateral tooth, but never accelerated. The ipsilateral lateral incisor was strongly angulated because of a more distally located apex (5 mm) rather than a mesially tipped crown. The ipsilateral canine was relatively more superiorly positioned (undererupted). Patients who had trauma had a significantly higher prevalence and severity of canine displacement and more distally displaced lateral incisor apices. Initial height of incisor impaction did not influence the results. These data provide evidence of a significant environmental influence of an impacted maxillary central incisor in delaying and altering the eruption path of the ipsilateral maxillary canine.

Adult patients' adjustability to orthodontic appliances. Part I: a comparison between Labial, Lingual, and Invisalign™.

This prospective study examined the adult patients perception of recovery after insertion of three types of orthodontic appliances: Buccal, Lingual and Invisalign. The sample consisted of sixty-eight adult patients (45 females and 23 males) who comprised three groups: 28 Buccal, 19 Lingual, and 21 Invisalign patients. After appliance insertion, patients completed a Health-Related Quality of Life questionnaire daily for the first week and again on day 14, in order to assess patients perception of pain and analgesic consumption. In addition, four areas of dysfunction were assessed: oral dysfunction, eating disturbances, general activity parameters, and oral symptoms. Lingual appliance was associated with more severe pain and analgesic consumption, the greatest oral and general dysfunction, and the most difficult and longest recovery. The Invisalign patients complained of relatively high levels of pain in the first days after insertion; however this group was characterized by the lowest level of oral symptoms and by a similar level of general activity disturbances and oral dysfunction compared to the Buccal appliance. Many Lingual and some Buccal patients did not reach a full recovery from their eating difficulties by the end of the study period. The present study provides information to adult patients and clinicians assisting them in choosing the most appropriate treatment modality in relation to Health-Related Quality of Life parameters.

Saliva Enables the Antimicrobial Activity of LL-37 in the Presence of Proteases of Porphyromonas gingivalis

ABSTRACT Proteolysis is a common microbial virulence mechanism that enables the destruction of host tissue and evasion from host defense mechanisms. Antimicrobial peptides, also known as host defense peptides, are effector molecules of the innate immunity that demonstrate a broad range of antimicrobial and immunoregulatory activities. Deficiency of the human LL-37 antimicrobial peptide was previously correlated with severe periodontal disease. Porphyromonas gingivalis, the major pathogen associated with periodontitis, is highly proteolytic. In this study, P. gingivalis was found capable of degrading LL-37 by utilizing its arginine-specific gingipains. Saliva collected from volunteers with a healthy periodontium protected LL-37 from proteolysis by P. gingivalis. Salivary protection of LL-37 was heat resistant and specific and enabled LL-37 to inhibit growth of Escherichia coli in the presence of the P. gingivalis proteases. Previously, saliva and other body fluids have been shown to inhibit the antimicrobial activity of LL-37. Here we demonstrate that at a cost of a small reduction in the bactericidal activity of LL-37, saliva enables the antibacterial activity of LL-37 despite the presence of proteases secreted by the main periodontopathogen.

Salivary LL-37 Secretion in Individuals with Down Syndrome is Normal

Antimicrobial peptides play an important role in the innate immune response. Deficiency in salivary LL-37 antimicrobial peptide has been implicated in periodontitis in patients with morbus Kostman syndrome. Down syndrome is associated with periodontitis, diminished salivary flow, and salivary immunoglobulin deficiency. In the present study, levels of LL-37 and its hCAP18 precursor were measured in saliva samples from young individuals with Down syndrome and compared with levels in those from age-matched healthy controls. LL-37 and human cathelicidin antimicrobial protein (hCAP18) were detected in whole but not in parotid saliva. hCAP18 was more abundant than LL-37. The concentrations of salivary hCAP18 and LL-37 were found to be higher in individuals with Down syndrome than in healthy controls, but their secretion rates were similar. We concluded that, while the adaptive immunity of individuals with Down syndrome is impaired at the oral mucosa, the secretion rate of the LL-37 component of the innate immune system is normal.