Vol 4, No 2 (Spring 2017)

Original Article(s)

  • XML | PDF | downloads: 271 | views: 675 | pages: 328-339
    Background/Objective: Tooth eruption is a foundational subject for every dental practitioner as well as dental students; and literature is replete with different mechanisms of migrationof a tooth from its bony crypt into the oral cavity. The purpose of the part two of this study was to evaluate and test the proposed “neuromuscular theory of tooth eruption” using relevant scientificpapers, as supporting bodies of evidence, to unify the currently accepted mechanisms of tooth eruption under single theory.Materials and Methods: A detailed and systematic analysis, synthesis and integration of the findings from relevant scientific studies (selected according to specific inclusion and exclusioncriteria) on mechanisms of tooth eruption was conducted as it was done with part one of this study.Results: The propelling force of tooth eruption is attributed to piezoelectricity, mechanosensation, mechanotransduction, mechanical pull on the hydroxyapatite crystals; mechano-hydrodynamic force; and mechanics of the mandible and the orofacial muscles with attendant biochemical, electrical, electrochemical, cellular, molecular and enzymic activities to prepare the jaws and other facial bones for coronal migration of a developing tooth from its bony crypt until it emerges in the oral cavity.Conclusion: “Neuromuscular theory of tooth eruption” is based on neuromuscular forces, arising from muscular contractions in the orofacial region. Mechanosensation, mechanotransductionand piezoelectricity are the three principal processes of converting neuromuscular forces into electrical, electrochemical and biochemical energies for initiation and sustenance of cellular, molecular and enzymic activities during the different phases of tooth eruption process. The clinical relevanceof this theory is that it throws more light on the morphological and functional interdependence of the various elements of the maxillo-mandibulo-dental system as well as the need for neuromuscular considerations in the diagnosis, treatment planning, prevention and treatment of pathologicalconditions of tooth eruption.Key words: Mechanosensation, Mechanotransduction, Neuromuscular, Theory, Tooth eruption.
  • XML | PDF | downloads: 163 | views: 483 | pages: 340-344
    Introduction: Anabolic androgenic steroids (AAS) are the synthetic derivatives of testosterone hormone; which are used by athletes; in order to increase muscle size, improve physical image and increase strength. They are usually being used out of medical supervision and in high doses. Thelow age of the athletes using these testosterone analogs and the proven discernable effects on the body organs necessitates a study to evaluate the possible effects on the oral health.Materials and Methods: 50 male bodybuilders with the history of sports professional activity at least for one year ( experimental group) and were using anabolic androgenic steroids and 50male bodybuilders who has not used anabolic androgenic steroids were assessed for the personal habits as: tooth brushing, use of dental floss and mouthwash and the frequency of dentist visit byfulfilling a simple questionnaire. Three indices: PUFA, DMF, and OHI-S were evaluated for both groups.Results: According to personal habits related to oral health, only there was a significant between the athletes for frequency of dentist visit ( P< 0.03 ), indicating that the control group had dentist visit more frequently. According to the three indices evaluated only the OHI-S index was higher in the steroid using group ( P<0.01 ).Conclusion: As the results showed the dental caries indices: PUFA and DMF showed no significant difference among athletes; this could be due the low age of athletes using anabolic androgenicsteroid and the use of these drugs out of medical supervision may suggest that long term studies are needed to verify the cariogenecity of anabolic androgenic steroids in human mouth. And the short term study showed no cariogenic effect.Key words: Testosterone, AAS, Bodybuilding, Dental caries.
  • XML | PDF | downloads: 233 | views: 480 | pages: 345-351
    Introduction: Osteoporosis is a common condition causing significant morbidity and mortality. There is some evidence of a correlation between bone mineral density of the mandible and that of the lumbar spine and hip. The ability to accurately detect osteoporosis based on routine dentalimaging would allow early diagnosis. The aim of this study was to compare the diagnostic accuracy for low bone mineral density using mandibular radio morphometric indices versus simple visual inspection of the mandibular cortex.Materials and Methods: Four independent investigators evaluated radio morphometric indices (mental index, antigonial index and morphology of the cortex) as well as assigning a ratingof thin or normal cortex based on their initial impression on the panoramic radiographs of 49 post menopausal women with decreased bone mineral density and 42 unaffected controls. The sensitivity, specificity and positive predictive value for each index was evaluated.Results: The mental and antegonial index had better sensitivity than specificity and positive predictive value. However the opposite was true for the morphology index and simple visual inspection of cortical thickness. External agreement was moderate to perfect (0.41 -0.93) for cortex morphology, and moderate to substantial (0.49-0.76) for simple visual inspection of cortical thickness but excellent for mandibular and antegonial index (> 0.8).Conclusion: We found that the mandibular cortical thickness is affected in postmenopausal women with low bone mineral density when compared to controls. Furthermore radio morphometricindices and morphology are more accurate in the diagnosis of osteoporosis than simple visual assessment of cortical thickness.Key words: Cortex, Mandible, Osteoporosis, Radiography.
  • XML | PDF | downloads: 191 | views: 369 | pages: 352-359
    Objectives: Stem cells are the best cells that can be used for periodontal tissue regeneration in the treatment of periodontal disease. The aim of the present study was to compare the features of dental follicle stem cells (DFSCs) and periodontal ligament stem cells (PDLSCs).Materials and Methods: In this study, five samples from DF and five samples from PDL were collected from patients. Cells were subsequently expanded by three passages. Cells were evaluatedthen by inverted microscope and flow cytometry. (DFSCs) and (PDLSCs) were stained with markers (CD90, CD166, CD105, CD44, CD73, CD13, CD45, CD34, CD38, and CD31) and examined for as well as for osteogenic and adipogenic differentiation.Results: The DFSCs and PDLSCs expressed MSCs markers, as shown by flow cytometry. The cells were negative for CD45, CD34, CD38, CD31 markers but were positive for CD90, CD166,CD105, CD44, CD73, and CD13 markers. Cell attached to the flask macroscopically, and spindle cells attached to the inverted microscope. DFSCs and PDLSCs also differentiated into osteoblasts and adipocytes in osteogenic and adipogenic media.Conclusion: This study opens the way for further research of human dental follicle and periodontal cells. The present study found that stem cells derived from the PDL and DF express CD90, CD166, CD105, CD44, CD73, and CD13 markers, similar to mesenchymal stem cells. PDL and DFcells differentiated into osteoblasts and adipocytes in osteogenic and adipogenic media.Key words: Antigens, Mesenchymal stromal cells, Periodontal ligament.
  • XML | PDF | downloads: 346 | views: 984 | pages: 360-365
    Introduction: In a balanced and symmetric face no sclera should be exposed below the irises. This study evaluated the inferior sclera exposure changes after maxillary advancement in skeletal cl III patients.Materials and Methods: Eight consecutive patients (4 male and 4 female) with maxillary deficiency who underwent Le Fort I osteotomy were assessed using adobe photoshop CS5. Inferior sclera height to total eye height proportion was determined in both eyes in each patient and the propotional changes before and six month after surgery was statistically analyzed using Wilcoxon signed–rank test.Results: Average maxillary advancement was 3.75 mm at the incisors. Proportion of inferiorsclera to total eye height decreased by a ratio of 8% (p<0.001) in total 16 eyes of 8 patients. All 8patients achieved a decrease of their scleral show. None of the patients required further cosmeticprocedures in preorbital region.Conclusion: Maxillary advancement in CI III patients with existing excessive scleral exporsure changes the lower lid position and leads to significant decreased scleral show.Key words: Sclera show, Le fort osteotomy, skeletal cl III, Orthognathic Surgery.

Case Report(s)

  • XML | PDF | downloads: 141 | views: 264 | pages: 366-371
    Malignant melanoma of the oral cavity is a very rare condition, comprising approximately 0.2–8% of all the malignant melanomas. It is easy to diagnose these lesions clinically because they are pigmented; however, they are asymptomatic in the majority of cases and might only be detected afterulceration of the overlying epithelium or hemorrhage. Treatment of head and neck cancer involves surgery, radiotherapy, chemotherapy, or a combination of the these modalities. However, surgery is the first choice for oral cancers, which is supplemented with radiotherapy in advanced cases. In addition,radiotherapy might give rise to some complications, including oral mucositis, loss of taste, erythema, xerostomia, radiation-induced caries, trismus, glossitis, TMJ disorders, muscle fibrosis,and osteoradionecrosis The most important complications reported by patients in terms of QOLare masticatory, articulation and swallowing problems, as well as problems with appearance. Prosthodonticrehabilitation of these patients is difficult, due to the technical challenges of fabricating prosthetic appliances, repeated prosthetic adjustments or replacements, and management of thepatients’ psychological problems. This paper summarizes the pre- and postsurgical prosthodontic steps in oral rehabilitation of patients undergoing maxillectomy.Key words: Melanoma, Oral rehabilitation, Radiotherapy, Maxillectomy, Obturator.
  • XML | PDF | downloads: 136 | views: 364 | pages: 372-376
    Carcinosarcoma of salivary gland is a rare and aggressive tumor composed of both carcinomatous and sarcomatous components which metastasize together. Most tumors arise in parotid gland from a preexisting pleomorphic adenoma.Methods and Results: We report a case of carcinosarcoma of minor salivary gland of lower lip with subsequent infiltration to mandible and pelvic metastasis after recurrence. The patientwas a 38 year old man who underwent surgical resection and adjuvant chemo radiotherapy and demonstrates recurrence after 9 months with metastasis to left iliac fossa.Conclusion: Carcinosarcoma of minor salivary gland is an extremely rare malignancy with poor prognosis and is best managed by combination of surgical resection and postoperative radiation.Key words: Carcinosarcoma, Salivary gland, Metastasis, Recurrence.
  • XML | PDF | downloads: 195 | views: 348 | pages: 377-382
    Introduction: Ectodermal dysplasia (ED) is a group of syndromes and disorders in the human body characterized by structural anomalies in the ectoderm and often associated with hair, teethand skin abnormalities. There are many syndromes associated with ED.Case report: Here is a case report of two young patients with different manifestations of ectodermal dysplasia.Conclusion: One patient was diagnosed as Rapp-Hodgkin syndrome and the other as Hypohidrotic ectodermal dysplasia, according to clinical findings.Key words: Ectodermal dysplasia, Hypodontia, Hypohydrotia.