Langerhans Cell Histiocytosis Mimicking Periapical Pathology in a 39-year-old Man.

Langerhans cell histiocytosis (LCH) is a clonal neoplastic proliferation of Langerhans-type dendritic cells, with more than 50% of cases of LCH seen in children younger than 15 years of age. The most common clinical presentation of LCH is solitary or multiple bony lesions. The jaws are affected in approximately 10%-20% of cases, with a strong predilection for the mandible. The maxilla is involved in only 1% of head and neck cases. When the jaws are involved, lesions of LCH may mimic periapical pathology as seen in patients requiring endodontic therapy or bone loss as seen in periodontal disease. We report the case of a 39-year-old man with LCH involving the posterior maxilla. This is a rare presentation of LCH with respect to both location and patient age. Clinicians should consider LCH when developing a differential diagnosis of an apical radiolucency of vital teeth or teeth that fail to respond to endodontic therapy and be aware of its clinical and radiographic mimics.

Patient-Based Comparison of Traditional Instruments and Piezoelectric Bone Surgery in Osseous Resective Surgery.

Osseous resective surgery has been widely advocated in the treatment of periodontitis. The treatment traditionally has been done with rotary and manual instruments, but piezoelectric devices recently have also been used. A total of 20 adult patients diagnosed with moderate to severe chronic periodontitis were selected. A split-mouth study design was conducted such that one sextant was operated using piezoelectric bone surgery (test) and one with traditional instruments (control) in two separate sessions. Patients were asked to evaluate their perception of cold sensitivity, spontaneous pain, bleeding, swelling, and chewing discomfort. Piezoelectric bone surgery seems to be tolerated slightly better than conventional rotary instruments.

Obliteration of the nasopalatine canal in conjunction with horizontal ridge augmentation.

The presence of a wide nasopalatine canal and the lack of an adequate ridge width may affect the correct placement of implants in the central incisor area. This could lead to functional and esthetic problems. This article describes bone grafting of the canal and concurrent ridge augmentation to obtain adequate bone quantity and quality and to allow correct 3-dimensional placement of the implant. The lack of sensorial complications utilizing this technique is also reported here.

The effect of patient-centered plaque control and periodontal maintenance therapy on adverse outcomes of periodontitis.

The purpose of this study was to evaluate systematic reviews that addressed the effectiveness of periodontal maintenance therapy for the management of patients with periodontitis. Recent surveys of dental care patterns suggest a marked increase in preventive and maintenance periodontal care in populations that retain the dentition for an increasingly longer lifetime. A considerable body of clinical investigation concludes that a multitherapy periodontal maintenance approach is effective in improving periodontal outcomes in patients treated for periodontitis. Individual components of such maintenance therapy were assessed, including the effects of an oral examination, personal oral hygiene instructions, supragingival scaling and polishing, subgingival scaling and root planing, adjunctive procedures, and maintenance frequency. There is much controversy about improvement in oral health that may accrue from the placebo effect of an examination and the maintenance ritual. Improved plaque control by the patient in anticipation of a forthcoming examination alone might be reflected in decreased measurements for plaque accumulation and gingival inflammation but the role of placebo effects on periodontitis remains unclear. There are insufficient randomized controlled trials to reach conclusions regarding the individual beneficial effects of repeated oral hygiene instructions or routine scaling/polishing on the recurrence of periodontitis. While subgingival root planing seems an effective component of periodontal maintenance, neither clinical investigations nor randomly controlled trial evidence have established an ideal maintenance frequency based on individual patient risk for periodontitis. The adjunctive beneficial effects of both locally and systemically administered antimicrobial agents were statistically significant for some formulations, and may be particularly useful clinically in patients who are resistant to mechanical therapy. We conclude that few clinical or randomized controlled studies have evaluated the individual benefit or required frequency of the periodontal maintenance ritual for patients who are relatively resistant or susceptible to periodontitis.

Dlx proteins position the neural plate border and determine adjacent cell fates.

The lateral border of the neural plate is a major source of signals that induce primary neurons, neural crest cells and cranial placodes as well as provide patterning cues to mesodermal structures such as somites and heart. Whereas secreted BMP, FGF and Wnt proteins influence the differentiation of neural and non-neural ectoderm, we show here that members of the Dlx family of transcription factors position the border between neural and non-neural ectoderm and are required for the specification of adjacent cell fates. Inhibition of endogenous Dlx activity in Xenopus embryos with an EnR-Dlx homeodomain fusion protein expands the neural plate into non-neural ectoderm tissue whereas ectopic activation of Dlx target genes inhibits neural plate differentiation. Importantly, the stereotypic pattern of border cell fates in the adjacent ectoderm is re-established only under conditions where the expanded neural plate abuts Dlx-positive non-neural ectoderm. Experiments in which presumptive neural plate was grafted to ventral ectoderm reiterate induction of neural crest and placodal lineages and also demonstrate that Dlx activity is required in non-neural ectoderm for the production of signals needed for induction of these cells. We propose that Dlx proteins regulate intercellular signaling across the interface between neural and non-neural ectoderm that is critical for inducing and patterning adjacent cell fates.