Evaluation of Retentive Strength of 50 Endodontically-Treated Single-Rooted Mandibular Second Premolars Restored with Cast Post Cores Using 5 Common Luting (Cement) Agents.

BACKGROUND A luting agent is a dental cement used to secure a dental restoration. This study aimed to evaluate retentive strength of 50 endodontically-treated single-rooted mandibular second premolars (extracted) restored using 5 common luting (cement) agents. MATERIAL AND METHODS Fifty single-rooted mandibular second premolars with adequate root length and uniform size/shape were decoronated. After completing endodontic biomechanical preparation and obturation, root canals of all specimens were prepared to receive a cast post core. Depending upon cementation type, CPC specimens were divided in 5 groups (10 each) (Gp): Zinc phosphate (Gp ZP), polycarboxylate (Gp PC), glass ionomer (Gp GI), resin-modified glass ionomer (Gp RGI), and resin cement (Gp RC). Retentive strength was determined using the adhesive failure pull-out test. Mean/standard deviations were calculated for tensile forces (in kilograms) and differences were determined using analysis of variance (ANOVA). Multiple comparison was performed using the t test. A P value of ≤0.05 indicated a statistically significant difference. RESULTS The order of mean tensile strength from higher to lower was Gp RC (21.46) >Gp RGI (18.17) >Gp GI (16.07) >Gp ZP (15.33) >Gp PC (13.63). Differences in retentive strengths between the cements were significant (P≤0.05). Multiple-group comparisons showed that except for Gp ZP and Gp GI, all groups differed significantly from each other. CONCLUSIONS All investigated cements provided optimal retentive strengths, with wide differences between them. Resin cements should be used when CPC removal is not anticipated, while polycarboxylate or zinc phosphate should be used if CPC removal is anticipated.

Current Knowledge on the Healing of the Extraction Socket: A Narrative Review.

The concept of extraction socket healing has been severally researched and reported over the years, since tooth extraction remains one of the most common procedures performed in the dental clinic. Understanding this healing process is of utmost importance because the outcome has a direct bearing on future prosthetic rehabilitation and, by extension, on patients' esthetics and masticatory function, among others. This mini review, therefore, summarized the current knowledge on the different stages of socket healing, including the biologic and clinical events that occur following tooth extraction up until the complete closure of the socket. Additionally, the modeling of the alveolar bone/process post extraction, and the resultant dimensional changes that, altogether, shape the bone, were reviewed and documented. The effects of various socket preservation interventions to mitigate these dimensional changes, and therefore preserve the alveolar process in a condition suitable for future prosthetic rehabilitation, were highlighted. Finally, a review of some of the factors that influence the entire process was also carried out.

Modified micromarsupialization technique as an alternative primary treatment for ranulas: A case series in a resource-challenged economy.

OBJECTIVES: Ranula is one of the commonest salivary gland cysts that mostly occur due to mucus extravasation from the sublingual salivary gland. Treatment of this lesion is still somewhat shrouded in controversy and varies from conservative treatment to surgical excision of the causative gland. MATERIALS AND METHODS: This was a case series in quasi-experimental design that evaluated the outcome and complications of the modified micromarsupialization technique as a newly introduced treatment at our center for simple sublingual ranula over a 2-year period. RESULTS: Twenty patients were treated by the modified micromarsupialization technique and followed up for 1 year. There was complete resolution following this technique in 17 patients (85%) with no evidence of recurrence or complications, whereas 2 patients (10%) showed partial resolution and the remaining 1 patient (5%) showed a failure and recurrence. The age of the patient, the size of the ranula, and the retention of sutures throughout the study period did not significantly affect the treatment outcome. CONCLUSIONS: The modified micromarsupialization technique was a simple and effective treatment that should be used as a primary treatment option for simple ranulas and we recommend it to be the first-choice treatment before surgical excision of the sublingual gland, especially in a resource-challenged economy like ours.

Chronic metabolic and induced stress impacts mesenchymal stromal cell differentiation and modulation of dental origin in-vitro.

The impact of induced (smoking) and metabolic stress (diabetes) on dental stem cells with respect to pre-impact consideration on differentiation and bone formation were investigated. The progenitor stem cells isolated from dental pulp, follicle and gingival tissues were phenotyped and subjected to nicotine and high glucose stress mimicking the smoking and diabetic condition in-vitro. The results showed that the cellular viability post treatment with 100 µM nicotine and 10uM glucose was about 86% to 89% respectively in all the three cell types while about 73% in combined nicotine and glucose treatment. No variation in the expression of pro-inflammatory TNF-α, IL-1ß and IL-12 in all the three cell types were noticed. The observed viability in nicotine treated cells were due to elevated IL-6, IL-10 while in glucose was due to brain derived neurotropic factor (BDNF). Higher expression of IL-4, IL-6, IL-10, TGF-ß and heme oxygenase -1 (HO-1) were found high in both stressors treated cells. Differentiation and mineralization markers Alkaline phosphatase (ALP), Collagenase I (COL1), Osteocalcin, Runt related transcription factor 2 (RUNX2), Osteopontin and Bone sialoprotein were expressed in the dental pulp stem cells (DPSCs) and gingival mesenchymal stem cells (GMSCs) at varying levels post nicotine or glucose treatment while not significantly observed in dental follicular stem cells (DFSCs). Therefore, it is evident that the stem cells of varied dental origin responded to the stress are more or less uniform with physiological delay in differentiation into osteoblast. It is evident from the study that, the metabolic or induced stress subverts the process of regenerative healing by mesenchymal stromal cells with their anatomical niche.

Ultrastructural and physicochemical characterization of pH receptive chlorhexidine-loaded poly-L-glycolic acid-modified orthodontic adhesive.

This study aims to evaluate the feasibility of chlorhexidine (CHX)-loaded poly-L-glycolic acid (PLGA) nanoparticles as a modifier of a commercial orthodontic adhesive via the assessment of physicochemical, biological, and mechanical properties at tooth-bracket interface. CHX-loaded PLGA nanoparticles were synthesized using double emulsion-solvent evaporation method and characterized using transmission electron microscopy and Raman analysis. CHX-loaded PLGA nanoparticles in Transbond XT orthodontic adhesive were prepared using two different concentrations of the CHX (25 and 50%) and characterized for degree of conversion (DC), antimicrobial, and cytotoxicity testing. Bonded specimens were tested for shear bond strength (SBS) and adhesive remnant index (ARI) at tooth-bracket interface. The synthesized PLGA nanoparticles averaged between 60 and 80 nm in size. After loading CHX inside PLGA nanoparticles, the morphology of the PLGA nanoparticles was considerably changed. Orthodontic bracket bonded with 25% CHX-loaded PLGA-modified adhesive demonstrated DC scores similar to control group. Both 25 and 50% CHX-loaded PLGA-modified adhesive specimens showed higher antibacterial activity against S. mutans compared to control group. The least mean SBS values were exhibited by 50% CHX-loaded PLGA-modified adhesive samples, while a statistically significant difference was observed in the mean ARI values among all study groups at all-time points (p = .018). This study indicates that the addition of CHX-loaded PLGA nanoparticles in Transbond XT achieved stable bonds with enhanced antimicrobial and mechanical properties.

Effect of ultrasonic scaling with adjunctive photodynamic therapy on the treatment of gingival inflammation among diabetic patients undergoing fixed orthodontic treatment.

BACKGROUND: The aim of the present clinical trial was to evaluate the effect of methylene blue-mediated antimicrobial photodynamic therapy (aPDT) on the gingival and immunological parameters in diabetic adolescent patients undergoing fixed orthodontic treatment. METHODS: The selected 40 participants were randomized equally into two groups; Group I (ultrasonic scaling + oral hygiene instructions) and Group II (ultrasonic scaling/oral hygiene instructions + aPDT). Serum HbA1c levels was assessed for all the participants at chairside. Plaque index (Pi), and bleeding on probing (BOP) were analyzed. Moreover, the assessment of crevicular fluid matrix metalloproteinase 8 (MMP-8) and macrophage inflammatory protein 1 alpha (MIP-1α) was performed using enzyme-linked immunosorbent assay technique. All measurements were recorded at baseline, 6 weeks, and 12 weeks follow-up periods, respectively. Intergroup comparisons for p-value were computed using Mann-Whitney test and Wilcoxon singed ranks test to compute p-value for intra-group comparisons. Stepwise logistic regression analysis was used to identify explanatory variables for reduction in plaque scores and bleeding on probing, after controlling for the effects of other covariates. Odds ratios and 95% confidence intervals were used to assess the direction and strength for associations. Significance level was set at 5% for all analyses. RESULTS: All 40 individuals completed the clinical trial. There was a statistically significant reduction in Pi and BOP in both Group I and Group II from baseline to 12 weeks of follow up (P<0.05). However, there was slight reduction in the plaque scores in Group-II as compared to Group-I at 12 weeks visit (P<0.05). There was also a statistically significant difference for BOP when Group-I was compared with Group-II on 12 weeks follow up assessment (P<0.05). HbA1c assessment indicated no statistically significant difference either within or between groups at any time point (P>0.05). Both MMP-8 and MIP-1α reported a significant decrease for both Groups I and II at 6 weeks and 12 weeks follow-up periods in comparison to baseline (P<0.05). Inter-group comparison indicated a statistically significant difference noted at both 6 weeks follow up that was maintained at 12 weeks follow up (P<0.05). The logistic regression analysis revealed that even after controlling the mean BMI as a predictor, the change of biomarker levels along with the improvement in plaque scores and bleeding on probing was not significant (p> 0.05). CONCLUSION: aPDT significantly improved bleeding on probing and proinflammatory biomarkers among diabetic adolescent patients undergoing fixed orthodontic therapy.

Impact of riboflavin mediated photodynamic disinfection around fixed orthodontic system infected with oral bacteria.

PURPOSE: The aim of this laboratory study was to investigate the amount of bacterial destruction through riboflavin mediated photodynamic therapy (PDT) around fixed orthodontic devices by using the two strains of bacteria Streptococcus mutans and Streptococcus sanguinis. MATERIALS AND METHODS: A total of 80 metallic brackets were divided into four groups consisting of 20 brackets each. Group-I: riboflavin + LED irradiation; Group-II: riboflavin alone; Group-III: immersion in 0.2 % chlorhexidine gluconate solution and Group-IV: not submitted to any treatment. All metallic brackets were immersed in the standard bacterial solutions and incubated at 48 h. All samples were subjected to MTT assay for microbial cell viability testing after treatment. After 24 h of incubation, biofilms adhered on the mesh of metallic brackets after treatment were assessed by confocal laser microscopy. The total CFU/mL was estimated, and the results were log-transformed (log10) and analyzed using one-way analysis of variance and Tukey-Kramer test. P-value was set to <0.05 that indicated statistical significance. RESULTS: The samples from group-IV showed the highest amount of relative biofilm viability compared to any other group while group-I (PDT) showed the least viability of the two bacterial strains studied (p < 0.05). Group-I showed no significant difference when compared with group-III (chlorhexidine) (p > 0.05). The biofilms on the samples from group-II and group-IV were largely viable indicating thick green staining across the mesh of the brackets. Among the group-III samples, there were predominantly dead cells as compared to the live cell staining. A considerable amount of red staining was observed with noticeable less green staining in group-I samples. CONCLUSION: This laboratory investigation revealed that riboflavin mediated PDT significantly reduced the amounts of S. mutans and S. sanguinis around the orthodontic brackets.

Does preoperative dental anxiety play a role in postoperative pain perception after third molar surgery?

Background: Surgical removal of the impacted third molar is associated with inflammatory morbidities which include swelling, trismus, and pain. Pain is the most common postsurgical morbidity associated with third molar surgery. It remains an important factor in patients' perception of recovery after third molar surgery with dental anxiety reported to exert influence on its threshold. Objective: The aim of the study was to determine if preoperative dental anxiety has any significant role on postoperative pain perception after third molar surgery. Materials and Methods: This was a cohort study involving sixty consecutive adult patients requiring extraction of impacted mandibular third molars under local anesthesia. Modified Dental Anxiety Scale Questionnaire was administered to each participant in the waiting area before the surgery. The visual analog scale was also given to each participant to be completed once daily at approximately the same time as the surgery time until day 7 after the surgery. Data collected were analyzed using SPSS version 23. Results: Sixty participants who consented to third molar surgery took part in this study. Five participants were lost to follow-up. There were slightly more males (50.9%) than females (49.1%). Nineteen participants in this study had moderate dental anxiety (34.5%) and 6 participants (11%) had severe dental anxiety with more females having moderate-to-severe dental anxiety. The correlation between pain perception at different days and dental anxiety was not significant (P > 0.05). Conclusion: Preoperative dental anxiety may not significantly influence pain perception after third molar surgery.

RésuméContexte: L'extraction chirurgicale de la troisième molaire incluse est souvent accompagnée d'un gonflement, d'une difficulté à ouvrir la bouche et de douleurs. La douleur est la morbidité post-chirurgicale la plus courante associée à la chirurgie de la troisième molaire. C'est un facteur important qui détermine la façon dont les patients perçoivent la guérison après une chirurgie de la troisième molaire. Il est rapporté que l'anxiété dentaire a une influence sur le seuil de douleur des patients. Objectif: Pour déterminer si l'anxiété dentaire préopératoire a un rôle significatif sur la perception de la douleur postopératoire après une chirurgie de la troisième molaire. Méthodes: Soixante patients adultes nécessitant l'extraction des troisièmes molaires incluses sous anesthésie locale ont été inclus dans cette étude de recherche. Un Modified Dental Anxiety Scale Questionnaire a été administré à chaque participant dans la salle d'attente avant la chirurgie. Le Visual Analogue Scale (VAS) a également été donnée à chaque patient à compléter une fois par jour à peu près au même moment que l'heure de la chirurgie jusqu'au jour 7 après la chirurgie. Les données obtenues ont été analysées à l'aide de la version 23 de SPSS. Résultats: Soixante patients ayant consenti à une chirurgie de la troisième molaire ont participé à cette étude. Cinq patients ont été perdus de vue. Il y avait un peu plus d'hommes (50,9%) que de femmes (49,1%). Dix-neuf patients avaient une anxiété dentaire modérée (34,5%) et 6 (11%) une anxiété dentaire sévère, un plus grand nombre de femmes ayant une anxiété dentaire modérée à sévère. La corrélation entre la perception de la douleur à différents jours et l'anxiété dentaire n'était pas significative (P> 0,05). Conclusion: L'anxiété dentaire préopératoire peut ne pas avoir d'effet significatif sur la perception de la douleur après une chirurgie de la troisième molaire.

Characterization of the Cellular Reaction to a Collagen-Based Matrix: An In Vivo Histological and Histomorphometrical Analysis.

The permeability and inflammatory tissue reaction to Mucomaix® matrix (MM), a non- cross-linked collagen-based matrix was evaluated in both ex vivo and in vivo settings. Liquid platelet rich fibrin (PRF), a blood concentrate system, was used to assess its capacity to absorb human proteins and interact with blood cells ex vivo. In the in vivo aspect, 12 Wister rats had MM implanted subcutaneously, whereas another 12 rats (control) were sham-operated without biomaterial implantation. On days 3, 15 and 30, explantation was completed (four rats per time-point) to evaluate the tissue reactions to the matrix. Data collected were statistically analyzed using analysis of variance (ANOVA) and Tukey multiple comparisons tests (GraphPad Prism 8). The matrix absorbed the liquid PRF in the ex vivo study. Day 3 post-implantation revealed mild tissue inflammatory reaction with presence of mononuclear cells in the implantation site and on the biomaterial surface (mostly CD68-positive macrophages). The control group at this stage had more mononuclear cells than the test group. From day 15, multinucleated giant cells (MNGCs) were seen in the implantation site and the outer third of the matrix with marked increase on day 30 and spread to the matrix core. The presence of these CD68-positive MNGCs was associated with significant matrix vascularization. The matrix degraded significantly over the study period, but its core was still visible as of day 30 post-implantation. The high permeability and fast degradation properties of MM were highlighted.

Serum levels of 25-hydroxy-vitamin D in patients with oral squamous cell carcinoma: Making a case for chemoprevention.

OBJECTIVES: Serum level of vitamin D has been used as a predictor for cancer development. We intend to measure the baseline vitamin D level in patients with oral squamous cell carcinoma (OSCC) and to compare same with non-cancer controls to determine any association. MATERIALS AND METHODS: Patients with OSCC presenting to our clinics were included in this study. Their baseline serum vitamin D levels were measured prior to cancer treatment after obtaining their consents. These patients were then matched with at least 2 cancer-free subjects to serve as controls and whose serum vitamin D levels were also measured. The serum vitamin D levels obtained for the two groups were then categorized into normal (>35 ng/ml), mild deficiency (25-35 ng/ml), moderate deficiency (12.5-25 ng/ml), and severe deficiency (<12.5 ng/ml). The data were analyzed statistically and the two groups compared. RESULTS: A total of 51 patients with OSCC (Male 22 [43%] and female 29 [57%]) and 113 cancer-free controls (Male 36 [31.86%] and female 77 [68.14%]) were included in the study. The commonest site for OSCC was the tongue, accounting for 45% of the cancer cases. Mean age for cancer patients was 59.33 years ±12.54 and 49.24 years ±15.79 for the control. Among the OSCC patients, 74.51% had moderate to severe vitamin D deficiencies, whereas only 20.35% had a moderate deficiency in the control group with no severe deficiency. CONCLUSION: Logistic regression analysis shows a positive association between vitamin D deficiency and OSCC risk especially in levels below 25 ng/ml. This further corroborates the assertion that vitamin D deficiency may be a useful indicator of OSCC. It may, therefore, be necessary to routinely prescribe vitamin D supplements to subjects with moderate to severe deficiencies in order to decrease the chances of OSCC development.

Evaluation of Tumour Associated Macrophages and Angiogenesis in Ameloblastoma.

INTRODUCTION: Ameloblastoma is a locally invasive odontogenic neoplasm that has a high recurrence rate. The invasion of adjacent tissue is supported by angiogenesis stimulated by Tumour-Associated Macrophages (TAMs). TAMs are macrophages modified in the milieu of the tumour microenvironment and have very weak or no ability to present antigens. Thus, there is collaboration between the tumour and the tumour microenvironment to maintain tumour enlargement. TAMs exist as the classically activated M1 macrophages that possess antitumour activity and the otherwise activated M2 macrophages that support tumour invasion and metastasis. AIM: To investigate the relative expression and topography of TAMs and CD34 in ameloblastoma in order to assess their affiliation and effect on tumour growth. MATERIALS AND METHODS: Forty-six Formalin Fixed Paraffin Embedded (FFPE) blocks of ameloblastoma were processed for Abcam Mouse monoclonal Anti-CCR7 antibody, Abcam Rabbit polyclonal Anti-CD206 antibody and Dako Mouse monoclonal Anti-CD34 antibody QBEnd-10. Cytoplasmic/membrane brown staining was taken as positive for all antibodies. The relative percentage of TAMs was classified as: <5%, 5-25%, 25-50% and >50%. TAMs related Microvessel Density (MVD) was evaluated as the mean of the three-recorded values. Cases with no CD34+ vessels adjacent to the TAMs region had MVD score of 0. Simple descriptive statistics was applied. RESULTS: Macrophages adjacent to peri-tumour islands were marked by CD206 and CCR7 and we noted negligible intra-tumour presence of positive macrophages. The percentage of positive CCR7 immune cells was greater than that for CD206 in 38 (82.6%) cases, approximately equal to CD206 in 6 (13%) cases, and the CD206 expression was more than CCR7 in only 2 (4.3%) cases. In 34 (73.9%) cases, the area of MVD did not overlap with the region of TAMs but in 4 (8.7%) cases (where MVD overlapped TAM1), the average MVD score was 20. CONCLUSION: The relative percentage of TAM1 exceeds TAM2 in peri-tumoural areas of ameloblastoma, conferring anti-angiogenic and hence anti-tumour activity on the tumour.

Tumor-associated macrophages, angiogenesis, and tumor cell migration in oral squamous cell carcinoma.

OBJECTIVE: To investigate the relationship between tumor-associated macrophages (TAMs), neovascularization, and tumor cell migration in oral squamous cell carcinoma (OSCC) of an African subpopulation. MATERIALS AND METHODS: Twenty OSCC paraffin blocks underwent immunohistochemistry to TAM1 (CCR7), TAM2 (CD206), Twist, E-cadherin, N-cadherin, and CD34. The relative percentage of CCR7 + and CD206 + cells to overall immune cell population was calculated for three high power fields and an average was taken. TAM-related microvessel density (MVD) was determined as the mean of the three recorded values. Cases that had no CD34 + vessels adjacent to the TAMs region were regarded as having an MVD score of 0. RESULTS: Ten cases (50%) expressed greater CCR7 activity than CD206, seven cases (35%) expressed approximately equal activity of CCR7 and CD206, while three cases (15%) expressed greater activity of CD206 than CCR7. Twist expression was strong in some cases with strong N-cadherin and weak E-cadherin, but the expression of Twist was not consistently high in all cases that expressed strong N-cadherin and weak E-cadherin. CONCLUSIONS: TAMs distribution suggested antitumor activity and the potential for tumor metastasis was only partly due to Twist-mediated epithelial-mesenchymal transition.

The utility of azan trichrome staining in Ameloblastoma.

BACKGROUND: It is occasionally difficult to distinguish the stellate reticulum-like region of ameloblastoma from the fibrous connective tissue stroma. This difficulty is further pronounced in the plexiform variant of ameloblastoma that has very sparse fibrous connective tissue. AIM: To test the utility of Azan trichrome stain in marking tumour regions and the peri-tumour environment of ameloblastoma. MATERIALS AND METHODS: Sections were prepared for 18 formalin fixed paraffin-embedded blocks of ameloblastoma cases and stained with Azan trichrome stain according to the manufacturer's specification. RESULTS AND CONCLUSIONS: The tumour areas were stained mostly brown, with the ameloblasts mainly marked as deep brown while the stellate reticulum-like region was light brown. The structures in the peri-tumour region were marked with different shades of blue. Azan trichrome staining was able to distinguish between the fibrous connective tissue and the stellate reticulum-like areas in 100% of the cases.

Relative expression of α-smooth muscle actin and matrix metalloproteinases-2 in ameloblastoma of a black African sub-population.

BACKGROUND: Ameloblastoma although a benign odontogenic tumor, is locally invasive. The abundant presence of myofibroblasts (marked by α-smooth muscle actin [α-SMA]) in the stroma and expression of matrix metalloproteinase-2 (MMP-2) in the neoplastic or stromal cells have been linked with the tumor's ability for both local and distant spread. We aim to estimate the relative expression of α-SMA and MMP-2 in ameloblastoma from a black African subgroup to gauge their relative potential for enhancing local invasiveness and hence, their prospects as possible chemotherapeutic targets. MATERIALS AND METHODS: Twenty-five formalin-fixed paraffin-embedded blocks of ameloblastoma cases from Nigeria were prepared for antibody processing to α-SMA (Dako Monoclonal Mouse Anti-Human α-SMA antibody clone 1A4) and MMP-2 (Abcam Mouse Monoclonal Anti-MMP-2 antibody [CA-4001/CA719E3C] ab3158). The score for percentage positivity of the tumor cells and the score for staining intensities were then multiplied in order to generate an immunoreactive score. RESULTS: α-smooth muscle actin was only expressed in the fibrous connective tissues adjacent to the tumor islands while MMP-2 was expressed in the ameloblasts, stellate reticulum, and the connective tissues in varying proportions. All the variants analyzed expressed α-SMA mildly or moderately, except for the follicular variant that either did not express α-SMA or expressed it mildly. The highest number of strong immunoreactivity to MMP-2 in the ameloblast region was found in the plexiform variant. CONCLUSION: Chemotherapeutic targeting of both molecules may, therefore, be a vital step in the control of local ameloblastoma invasiveness.

PTCH-1 and MDM2 expression in ameloblastoma from a West African sub-population: implication for chemotherapeutics.

INTRODUCTION: Ameloblastoma is a slow growing, painless odontogenic swelling which can attain sizes that result in severe deformities of the craniofacial complex. It is the most commonly encountered odontogenic tumor in Nigeria. Surgical intervention is currently the method of treatment; however identification of altered molecular pathways may inform chemotherapeutic potential. The Protein Patched homolog 1 (PTCH-1) is overexpressed in ameloblastoma. Also, mutation in the MDM2 gene can reduce the tumor suppressor function of p53 and promote ameloblastoma growth. No study however has characterized the molecular profile of African cases of ameloblastoma with a view to developing chemotherapeutic alternatives. The objective was to characterize the PTCH-1 genetic profile of Ameloblastoma in Nigerian patients as a first step in investigating its potential for chemotherapeutic intervention. METHODS: Twenty-eight FFPE blocks of ameloblastoma cases from Nigerian patients were prepared for antibody processing to PTCH-1 (Polyclonal Anti-PTCH antibody ab39266) and MDM2 (Monoclonal Anti-MDM2 antibody (2A10) ab16895). Cytoplasmic brown staining was considered as positive for PTCH while nuclear staining was positive for MDM2. RESULTS: Moderate and strong expressions for PTCH in ameloblast and stellate reticulum were 78.6% and 60.7% respectively. Only 3 (10.7%) cases expressed MDM2. CONCLUSION: The importance of our study is that it supports, in theory, anti-PTCH/SHH chemotherapeutics for Nigerian ameloblastoma cases and also infers the possible additional use of anti-p53 agents.

High-Temperature Sintering of Xenogeneic Bone Substitutes Leads to Increased Multinucleated Giant Cell Formation: In Vivo and Preliminary Clinical Results.

The present preclinical and clinical study assessed the inflammatory response to a high-temperature-treated xenogeneic material (Bego-Oss) and the effects of this material on the occurrence of multinucleated giant cells, implantation bed vascularization, and regenerative potential. After evaluation of the material characteristics via scanning electron microscopy, subcutaneous implantation in CD-1 mice was used to assess the inflammatory response to the material for up to 60 days. The clinical aspects of this study involved the use of human bone specimens 6 months after sinus augmentation. Established histologic and histomorphometric analysis methods were applied. After implantation, the material was well integrated into both species without any adverse reactions. Material-induced multinucleated giant cells were observed in both species and were associated with enhanced vascularization. These results revealed the high heat treatment led to an increase in the inflammatory tissue response to the biomaterial, and a combined increase in multinucleated giant cell formation. Further clarification of the differentiation of the multinucleated giant cells toward so-called osteoclast-like cells or foreign-body giant cells is needed to relate these cells to the physicochemical composition of the material.

Pattern of midface trauma with associated concomitant injuries in a nigerian referral centre.

AIM: The aim of this study was to determine the pattern of midface trauma with associated concomitant injuries seen in our environment. METHODOLOGY: This was a prospective analysis of trauma patients with midfacial injuries presenting at a referral center in South West Nigeria. In addition to socio-demographic data, the following information was also obtained: Mechanism of injuries, type of midfacial injuries, concomitant/associated injuries and treatment. RESULTS: A total of 101 patients with midfacial injuries were involved. They were made up of 85 males and 16 females. The 20-29 year age group was mostly affected (44.6%) and the most common cause of midface injuries was road traffic accident (91.1%). The zygoma was fractured more than any other midfacial bone (46.0%). A total of 144 associated injuries were recorded among these patients, head and ocular injuries accounted for 49 (34%) and 35 (24.3%) respectively. The patients were mostly treated conservatively or by closed reduction. CONCLUSION: The rate of head and ocular injuries among patients with midfacial injury was high. Knowledge of these associated injuries provides useful strategies for patient care and prevention of further complications. A multidisciplinary approach is important for optimum management of these patients.

Implantation of silicon dioxide-based nanocrystalline hydroxyapatite and pure phase beta-tricalciumphosphate bone substitute granules in caprine muscle tissue does not induce new bone formation.

BACKGROUND: Osteoinductive bone substitutes are defined by their ability to induce new bone formation even at heterotopic implantation sites. The present study was designed to analyze the potential osteoinductivity of two different bone substitute materials in caprine muscle tissue. MATERIALS AND METHODS: One gram each of either a porous beta-tricalcium phosphate (ß-TCP) or an hydroxyapatite/silicon dioxide (HA/SiO2)-based nanocrystalline bone substitute material was implanted in several muscle pouches of goats. The biomaterials were explanted at 29, 91 and 181 days after implantation. Conventional histology and special histochemical stains were performed to detect osteoblast precursor cells as well as mineralized and unmineralized bone matrix. RESULTS: Both materials underwent cellular degradation in which tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells and TRAP-negative multinucleated giant cells were involved. The ß-TCP was completely resorbed within the observation period, whereas some granules of the HA-groups were still detectable after 180 days. Neither osteoblasts, osteoblast precursor cells nor extracellular bone matrix were found within the implantation bed of any of the analyzed biomaterials at any of the observed time points. CONCLUSIONS: This study showed that ß-TCP underwent a faster degradation than the HA-based material. The lack of osteoinductivity for both materials might be due to their granular shape, as osteoinductivity in goat muscle has been mainly attributed to cylindrical or disc-shaped bone substitute materials. This hypothesis however requires further investigation to systematically analyze various materials with comparable characteristics in the same experimental setting.

Squamous cell carcinoma of the oral cavity and the oropharynx in patients less than 40 years of age: a 20-year analysis.

BACKGROUND: Squamous cell carcinoma mainly afflicts patients older than 40 years of age however, few cases are seen in younger patients. The aim of this study therefore was to determine the incidence of squamous cell carcinoma of the oral cavity and oropharynx in patients less than 40 years of age with a view to assessing the prognosis over a period of time. METHODS: This was a 20 years retrospective review of patients who were histologically diagnosed with squamous cell carcinoma of the oral cavity and the oropharynx at the Department of Cranio-Maxillo-Facial Surgery of the Hannover Medical School, Germany and had not received treatment anywhere else. Records of these patients were analysed for age and sex distribution, tumour staging and differentiation, location, treatment given, recurrences and metastasis, time between diagnosis and death or last contact with patient, and possible cause of death. Comparisons were also made with patients older than 40 years of age. RESULTS AND DISCUSSION: A total of 977 patients treated for squamous cell carcinoma of the oral cavity and the oropharynx in the 20-year period of this study were included. Thirty eight (3.9 %) of the overall patient population were under 40 years of age. Among these, 30 (78.9%) were males and 8 (21.1%) were females. The incidence was highest in the 30-39 year age group accounting for 31 (81.6%) of the 38 patients. The moderately differentiated carcinoma was commonest (24; 63.2%). The floor of the mouth had the highest number of tumours (15; 39.5%), but none was seen in the oropharynx. Surgery alone was the main stay of treatment given to 26 (68.4%) patients. At the end of the study period, 13 (34.2%) patients had died of the tumour and the 5-year survival rate was 66.2%. In the older patient group (>40 years), 42.7% died from the tumour and the 5-year survival rate was 57.6%. CONCLUSION: The results from the present study showed that young adults may have a better prognosis especially in terms of long term overall survival from oral and oropharyngeal carcinoma.