2016 Jan-Mar; Vol 7, No 1
Effect of Head and Tongue Posture on the Pharyngeal Airway Dimensions and Morphology in Three-Dimensional Imaging: a Systematic Review
J Oral Maxillofac Res 2016;7(1):e1
Objectives: Natural head position is recommended to be optimal at cone-beam computed tomography acquisition. For standardization purposes in control of treatment outcome, it is clinically relevant to discuss, if a change of posture from natural head position may have an effect on the pharyngeal airway dimensions and morphology, during computed tomography, cone-beam computed tomography or magnetic resonance imaging acquisition. This was the aim of the present literature review study for purposes of valid evidence, which was hypothesized, to be present.
Material and Methods: This systematic literature review has been registered in PROSPERO database with following number: CRD42015024567. A systematic literature search performed in PubMed, Embase and Cochrane was carried out in order to evaluate if the effect of human head or tongue posture has an effect on upper airway dimensions and morphology in CT, CBCT or MRI. Study quality assessment was performed. Predictor variable was head and tongue posture. Endpoints were numerical values of upper airway dimensions and morphology.
Results: Overall 1344 articles (Embase 1063, PubMed 269, and Cochrane 12) resulted in four included publications. Quality assessments revealed poor quality and low-level evidence by 46 - 67% of the maximum achievable score. Heterogeneous methodology made a meta-analysis impossible, consequently a narrative synthesis was performed.
Conclusions: Limited, poor quality and low evidence level literature is available on the effect of head posture on upper airway dimensions and morphology in three-dimensional imaging. Valid evidence requires a standardized method of head and tongue posture during image acquisition in future studies.
Keywords: cone-beam computed tomography; magnetic resonance imaging; obstructive sleep apnea; orthognathic surgery; posture.
The Correlation between Maternal Exposure to Air Pollution and the Risk of Orofacial Clefts in Infants: a Systematic Review and Meta-Analysis
J Oral Maxillofac Res 2016;7(1):e2
Objectives: The authors performed a systematic review and meta-analysis to investigate the possible correlation between ambient air pollution and orofacial cleft anomalies in newborns.
Material and Methods: A literature search was performed using the PubMed and Google Scholar, using the keywords “air pollution”, “cleft lip”, “cleft palate”, “carbon monoxide”, “ozone”, “sulfur dioxide”, “nitrogen oxide”, “nitrogen dioxide”, and “aerodynamic diameter”. Eight epidemiologic articles met the criteria of correlating either carbon monoxide (CO), ozone (O3), nitrogen oxides (NOx), airborne particulate matter of less than 10 µm in diameter (PM10), or sulfur dioxide (SO2) exposures with clefting of the palate alone, clefting of the lip alone, or clefting of the lip and palate. Odds ratios were extracted from the eight studies and tabulated in this meta-analysis. Quality analysis showed six high quality, one medium quality, and one low quality study.
Results: Meta-analysis of the combined data confirmed the association of O3 exposure and risk of orofacial cleft anomalies (OR = 1.08; P = 0.02). NOx was consistently associated with decreased risk of cleft lip with or without palate and cleft palate.
Conclusions: Ozone showed the strongest correlation with cleft lip and cleft palate anomalies. However, the studies overall showed an inconsistent correlation between orofacial clefts and air pollutants.
Keywords: air pollution; cleft palate; cleft lip; ozone; systematic review.
Clinical, Radiographic, and Histologic Evaluation of Maxillary Sinus Lift Procedure Using a Highly Purified Xenogenic Graft (Laddec®)
J Oral Maxillofac Res 2016;7(1):e3
Objectives: The aim of this study was to evaluate the clinical, radiographic and histologic results when a highly purified xenogenic bone (Laddec®) was used as grafting material in maxillary sinuses.
Material and Methods: In fifteen patients requiring unilateral maxillary sinus augmentation, the grafting procedure was performed with Laddec®. Forty-two implants were installed after a 6 month healing period. The height of the augmented sinus was measured radiographically immediately after augmentation and postoperatively up to 36 months. At the time of implant placement, a bone core was harvested in each patient for histological examination.
Results: The cumulative implant survival rate was 97.6%. The original height was 3.65 (SD 0.7) mm and the augmented sinus height was 13.8 (SD 1.4) mm after the surgery. The reduced height of grafted xenogenic material (RDL) at the implant insertion was 0.83 (SD 0.38) mm, and at the final postoperative visit was 0.91 (SD 0.25) mm, showing no significant correlation with the follow-up periods by Spearman’s test (P = 0.118). In addition, no significant difference in the RDL was observed according to the site of implantation (P = 0.682). The mean implant marginal bone loss was 0.38 (SD 0.24) mm. Histological analysis showed the bone cores were composed of 64.72 (SD 3.44)% newly formed bone, 17.41 (SD 2.02)% connective tissue, 16.93 (SD 2.83)% residual graft particles, and 0.94 (SD 0.11)% inflammatory cells.
Conclusions: According to our data, the highly purified xenogenic bone (Laddec®), used as graft material in the sinus lift procedure, may create adequate bone volume, and appropriate osseointegration of dental implants.
Keywords: bone; bone replacement materials; bone substitutes; maxillary sinus floor augmentation; osteogenesis; sintered bovine bone.
Effects of Non-Collagenous Proteins, TGF-β1, and PDGF-BB on Viability and Proliferation of Dental Pulp Stem Cells
J Oral Maxillofac Res 2016;7(1):e4
Objectives: The dentin matrix servers as a reservoir of growth factors, sequestered during dentinogenesis. The aim of this study was to assess the viability and proliferation of dental pulp stem cells in the presence of dentin matrix-derived non-collagenous proteins and two growth factors; platelet-derived growth factor BB and transforming growth factor beta 1.
Material and Methods: The dental pulp cells were isolated and cultured. The dentin proteins were extracted and purified. The MTT assay was performed for assessment of cell viability and proliferation in the presence of different concentrations of dentin proteins and growth factors during 24 - 72 h post-treatment.
Results: The cells treated with 250 ng/mL dentin proteins had the best viability and proliferation ability in comparison with other concentrations (P < 0.05). The MTT assay demonstrated that cells cultured with 5 ng/mL platelet-derived growth factor BB had the highest viability at each time point as compared to other groups (P < 0.05). However, in presence of platelet-derived growth factor BB alone and in combination with transforming growth factor beta 1 and dentin proteins (10 ng/mL), significant higher viability was seen at all time points (P < 0.05). The least viability and proliferation at each growth factor concentration was seen in cells treated with combination of transforming growth factor beta 1 and dentin proteins at 72 h (P < 0.05).
Conclusions: The results indicated that the triple combination of growth factors and matrix-derived non-collagenous proteins (especially at 10 ng/mL concentration) has mitogenic effect on dental pulp stem cells.
Keywords: dental pulp; dentin protein (non-collagenous); platelet-derived growth factor bb; transforming growth factor beta.
Metastasizing Maxillary Ameloblastoma: Report of a Case with Molecular Characterization
J Oral Maxillofac Res 2016;7(1):e5
Background: Ameloblastoma is a benign odontogenic tumour that may exhibit aggressive biological behaviour with local recurrence and metastasis following initial surgical resection. Surgery is the most acceptable modality of treatment, even if a biological approach is currently on study. We report a case of maxillary ameloblastoma with development of neck and brain metastases after repeated local recurrences. Molecular analysis was performed with the aim to better characterize this neoplasm and its peculiar behaviour.
Methods: We investigated the status of tumour protein p53 (TP53), epidermal growth factor receptor (EGFR), BRAF and human epidermal growth factor receptor 2 (HER2) genes with immunohistochemical, fluorescent in situ hybridization and/or direct sequencing in order to clarify their possible role in the development of this neoplasm and the possibility of a targeted treatment.
Results: The histological appearance of the tumour was the same in the primary lesion, in the recurrence and in the metastases. EGFR positivity was present in the recurrence and the brain metastasis, while HER2 was negative in all samples tested. Fluorescent in situ hybridization analysis for EGFR showed disomy of neoplastic cells. Direct DNA sequencing of TP53 gene exons 5 - 9 was carried out in tumour samples from the infratemporal recurrence and brain metastasis, with no mutational alteration detected. Similarly, sequencing analysis of BRAF exon 15 (V600) and EGFR gene showed wild type results in all samples tested.
Conclusions: Further studies are needed to identify molecular pathways that may provide an opportunity of alternative treatments and/or new potential predictive markers of local and distant spread of this rare tumour.
Keywords: ameloblastoma; human EGFR protein; human HER2 protein; metastasis; tumor suppressor protein p53.