Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology

Pragmatics versus contrarians: how does one resolve their differences with respect to oral cancer screening?

Mark W. Lingen — 2010-03-01

With an annual incidence of nearly 600,000 cases, oral and pharyngeal squamous cell carcinoma is the sixth most common malignancy in the world today. The American Cancer Society (ACS) estimates there will be over 35,000 new cases in the United States in 2010, with nearly 8,000 deaths from the disease. When focusing specifically on the oral cavity, it is estimated there will be over 23,000 new cases and more than 5,300 deaths. Despite advances in therapy, long-term survival for patients with oral cavity cancers has remained largely unchanged. Several factors contribute to this poor outcome. First, oral cancer is often diagnosed in an advanced stage. The 5-year survival rate of early stage disease is approximately 80%, while the survival drops to about 20% for late stage disease. Second, as a result of field cancerization, the development of multiple primary tumors has a major impact on survival. Among patients with early stage disease, second primary tumors are the most common cause of treatment failure and death. Therefore, in order to improve outcomes, a comprehensive treatment plan must include both early detection and secondary prevention.

The wrong emperor

Ken M. Hargreaves, Alan Law — 2010-03-01

Science rarely progresses in a smooth or linear fashion with an enthusiastic and broad appreciation of newly developed hypotheses. In Thomas Kuhn's classic work, The Structure of Scientific Revolutions, he notes that “the reception of a new paradigm often necessitates a redefinition of the corresponding science. Some old problems may be relegated to another science or declared entirely 'unscientific.' Others that were previously nonexistent or trivial may, with a new paradigm, become the very archetypes of significant scientific achievement. The normal-scientific tradition that emerges from a scientific revolution is not only incompatible but often actually incommensurable with that which has gone before.” This conflict in the development of new paradigms is not restricted to the development of the atomic theory or cosmology. Even in dentistry, scientists often display a reluctance to consider new theories.

In reply

Larz Spångberg — 2010-03-01

It is with interest I read the response to my Editorial by Drs. Hargreaves and Law, because they just express the take-home lesson from Hans Christian Andersen's fairy tale: “the cloth is so light and fine that it looks invisible to anyone who is too stupid and incompetent to appreciate quality.”

Presence of oral lesions in leprosy patients does not imply involvement by Mycobacterium leprae

2010-01-07

Leprosy is still an important public health problem in many countries. The spectrum of clinical manifestations is extremely broad and depends on different degrees of cell-mediated immunity to the bacillus. The frequency of leprotic oral mucosal involvement is a controversial topic in the literature, varying from the complete absence of lesions to 57.5%. Many lesions frequently observed in the oral mucosa of normal individuals or with other illnesses can also involve the oral mucosa of leprosy patients. In such a case, a biopsy is essential of any lesion whose diagnosis is doubtful, because none is pathognomic of leprosy. We decided to conduct a cross-sectional study in patients with varied clinical forms of leprosy, with the objective of verifying the frequency of lesions of the oral mucosa through clinical and histopathologic examinations.

Rapidly progressing mass of anterior mandible following a dental extraction

A. Fasanmade, M. Pring, J. Pawade, P. Guest, C. Bell — 2010-03-01

A 75-year-old woman was referred to the department of oral and maxillofacial surgery for extraction of a lone standing symptomatic mandibular right canine tooth. Clinically, the tooth was mobile (grade II). The associated free gingiva demonstrated erythema and gingival recession. There was no discharging sinus, mass, or other clinically evident soft tissue pathology noted. A periapical radiograph () showed no secondary caries of this restored tooth, although there was evidence of mesial and distal bone loss with an intact dental lamina, consistent with chronic periodontal bone loss.

Risk factors associated with injury to the inferior alveolar and lingual nerves following third molar surgery—revisited

2010-01-25

Objective: Earlier reports, including a preliminary study within our unit, have shown that the surgeon's experience is one of the most influential factors in determining the likelihood of both permanent inferior alveolar nerve (IAN) and lingual nerve (LN) paresthesia, following third molar surgery. The effect of this and other factors influencing such prevalence are assessed in this study.Study design: This prospective study involved 3236 patients who underwent surgical removal of impacted third molars. Patients' demographics and radiological parameters were recorded along with the grade of the treating surgeon. The prevalence of inferior alveolar and lingual nerves paresthesia at 1 month, 6 months, and 18 to 24 months postoperatively were also traced.Results: At 1 month postoperatively, the incidence of IAN paresthesia was 1.5% and the LN was 1.8%. These figures decreased over time and 18 to 24 months postoperatively, the incidence of permanent dysfunction of the IAN was 0.6% and LN was 1.1%. With regard to inferior alveolar nerve paresthesia, risk factors included the patient's age (26-30 years), horizontally impacted teeth, close radiographic proximity to the inferior alveolar canal (IAC), and treatment by trainee surgeons. With regard to the lingual nerve, risk factors included male patients, distoangular impactions, close radiographic proximity to the IAC, and treatment by trainee surgeons.Conclusion: One of the main risk factors of developing permanent sensory dysfunction in the distribution of these nerves is related to the surgical skills/experience of the operator. Other factors are associated with the type of impaction and the radiographic proximity of the tooth to the inferior alveolar nerve. Such long-term complications can affect the patient's quality of life; the impact on profession, education, and research is unknown.

A comparison of stresses in implantation for grafted and plate-and-screw mandible reconstruction

Tomohisa Nagasao, Junpei Miyamoto, Tamotsu Tamaki, Hiromasa Kawana — 2010-01-25

Objective: During oral rehabilitation by dental implantation for mandibles reconstructed with plate and screws, intensified stresses can develop at the implant-bone interfaces and fixation screw–bone interfaces that might cause complications at these interfaces. The present study aims to evaluate the stresses occurring at these sites using the finite element method.Study design: Ten computer-aided design models simulating 10 mandibles were produced and were termed normal models. Simulation surgery was performed on these normal models, where parts of the models were removed and replaced by fibula or reconstruction plates plus screws. Depending on the replaced part (body [B] or body and symphysis [BS]) and the reconstruction materials (fibula [Fib] or reconstruction plate [Plate]), the modified models were termed B-Fib, B-Plate, BS-Fib, and BS-Plate models, respectively. For each model, an implant was embedded in the first molar region. Stresses occurring at the implant-bone interfaces and fixation screw–bone interfaces on mastication were calculated using the finite element method and compared among the model groups.Results: The stresses at the implant-bone interfaces showed no statistically significant differences among the 5 model groups. With the B-Plate and BS-Plate models, stresses at the fixation screw–bone interfaces were nearly twice as intense as those at the implant-bone interfaces.Conclusion: If it is allowed that complication risks correlate with stresses, fixation screws are more subject to failure than implants in performing implantation for mandibles reconstructed with a plate and fixation screws. Therefore, the fixation screws deserve special attention in performing oral rehabilitation for such patients.

Scar less: a review of methods of scar reduction at sites of peripheral nerve repair

Wei Cheong Ngeow — 2010-03-01

Scar formation is important for normal wound healing but proliferation of scar tissue from the epineurium in response to a nerve injury will result in impediment to the regenerating axons that need to traverse the repaired site. This article reviews the events that occur after peripheral nerve transection and the challenges that need to be addressed to reduce scarring in order to improve nerve regeneration.

Abdominal fat harvest technique and its uses in maxillofacial surgery

Dennis J. Kantanen, James J. Closmann, Henry H. Rowshan — 2010-01-11

Abdominal fat harvest and augmentation to the maxillofacial region is a relatively inexpensive, safe, and readily available procedure. The use of abdominal fat free transfer has been well documented for cosmetic, trauma, and temporomandibular joint reconstruction. Fat is the closest we have to an ideal filler, it is readily available and inexpensive, it is autologous and therefore lacks a host immune response, it is safe and noncarcinogenic, and it is easily acquired with a minimally invasive procedure. Abdominal fat donor site is the most commonly used owing to ease of access and availability of fat stores. Complications are rare and easily managed in the office. Free abdominal fat harvest is a predictable surgical technique that allows the maxillofacial surgeon access to autologous graft material that is ideal for multiple facial procedures.

Bone healing with an in situ–formed bioresorbable polyethylene glycol hydrogel membrane in rabbit calvarial defects

2010-01-11

Objectives: The aims of this study were to test whether or not the application of an in situ–formed synthetic polyethylene glycol hydrogel (PEG) used as a biodegradable membrane for guided bone regeneration with a variety of graft materials and ambient oxygen or hyperbaric oxygen (HBO) environments would result in enhanced bone regeneration, and to observe the histologic and histomorphometric aspects of bone healing of the calvarial defects with and without a PEG membrane.Study design: Thirty adult, skeletally mature, male New Zealand white rabbits were randomly divided into 3 groups of 10 animals each. Bilateral 15-mm-diameter critical-size defects were created in the parietal bones of each animal. Group 1 served as a control with unfilled bilateral calvarial defects, group 2 had bilateral calvarial defects filled with morcelized autogenous calvarial bone, and group 3 had bilateral calvarial defects filled with a biphasic calcium phosphate ceramic. One of the calvarial defects was randomly protected with a PEG resorbable liquid membrane in each animal. Five animals from each group underwent a course of HBO treatment (2.4 ATA 100% oxygen for 90 minutes 5 days a week for 4 weeks) and the other 5 served as control and did not receive any supplemental oxygen (normobaric). The animals were killed 6 weeks after their surgery, and their parietal bones were harvested. The specimens were analyzed with microscopic computerized tomography (microCT) scans and histomorphometrics.Results: The unfilled normobaric control bony defects did not heal, proving the critical-size nature of these defects. The presence of autogenous bone or bone ceramic in the defects increased the bone volume fraction and bone mineral density of the defects (P < .001). The presence of a membrane in the ungrafted and autogenous bone grafted defects resulted in a decrease in the corrected bone volume fraction (P = .002) but not in the bone ceramic grafted defects (P = .580). Bony healing of defects where the membrane was unsupported was compromised; the membrane did not maintain the desired bone regeneration volume with the unfilled and autogenous bone grafted groups. The PEG resorbable liquid membrane worked best with the bone ceramic material. HBO did not ameliorate the healing of the autogenous bone graft or ceramic filled defects in the 6-week time period of this study.Conclusions: Although the PEG resorbable liquid membrane is easy to use and forms an occlusive layer, caution is recommended when using the membrane over an unsupported defect. HBO did not ameliorate bony healing with the membrane at the early 6-week time point. The authors recommend future assessment with HBO at the 12-week time point.

Auricular cartilage grafting in arthroplasty of the temporomandibular joint: a retrospective clinical follow-up

Börje Svensson, Karin Wennerblom, Ragnar Adell — 2010-03-01

Objective: The aim of this study was to evaluate TMJ arthroplasty with auricular cartilage grafts in patients with osteoarthritis, refractory to previous surgical and nonsurgical treatment.Study design: Twenty-three TMJs in 18 patients where arthroplasty with auricular cartilage grafts had been performed were evaluated. Sixteen joints in 12 patients with grafts still in position were followed. TMJ pain at mandibular function, TMJ tenderness and mouth opening ability (MIO) were evaluated.Results: The grafts had to be removed from 7 TMJs (30%), all of which had been subject to previous surgery. In the 16 joints with grafts still in position a significant (P < .001) reduction of pain at mandibular function was found and MIO had increased significantly (P = .015).Conclusions: TMJ arthroplasty with auricular cartilage grafts can reduce pain and improve mandibular function in patients with osteoarthritis. The method seems to be less favorable in patients where previous TMJ surgery has been performed.

Reconstruction of maxillectomy defects using deep circumflex iliac artery–based composite free flap

Amresh S. Baliarsing, Vinay V. Kumar, Neelima A. Malik, Dilip Kumar B. — 2010-03-01

Reconstruction of maxillectomy defects is a challenging endeavor, and various methods have been described to rehabilitate these defects, out of which composite free tissue transfer has an established role in reconstruction of the maxillary defects. The deep circumflex iliac artery (DCIA) flap has distinct advantages regarding the volume and length of the bone in reconstruction. The contour of the iliac bone is similar to the maxilla and provides good esthetic result. Good volume of bone allows placement of osseointegrated implant for dental rehabilitation. We present 8 cases of maxilla reconstruction using DCIA flap (3 osteocutaneous and 5 osseous flaps) for benign and malignant pathologies of the maxilla. DCIA flap is difficult to harvest, has variable anatomy, and needs meticulous planning for optimum result.

Sinus bone graft using new alloplastic bone graft material (Osteon)—II: clinical evaluation

Ji-Hyun Bae, Young-Kyun Kim, Su-Gwan Kim, Pil-Young Yun, Jae-Seung Kim — 2010-03-01

Objectives: The objective of this study was to clinically evaluate the use of Osteon as a sinus bone graft material and to measure the loss of sinus bone graft volume and marginal bone loss around the implants.Study design: Thirty-two implants were placed in 16 patients after maxillary sinus bone grafting. In 7 patients, maxillary sinus bone graft was performed first and 15 implants were placed after 4 months; in 9 patients, 17 implants were placed simultaneously with maxillary sinus bone grafting. Based on medical records and radiographs, intraoperative and postoperative complications were examined, and at 1 year after the placement of the upper fixture, the success rate of implants, peri-implant soft tissue condition, and the marginal bone loss were evaluated. Additionally, the sinus bone graft volume loss was evaluated by comparing the residual alveolar bone height of the preoperative maxillary sinus floor with that immediately after the operation and after 1 year.Results: Regarding intraoperative complications, perforation of the maxillary sinus membrane occurred in 6 cases (37.5%), and after surgery maxillary sinusitis developed in 2 cases. During the healing period, 1 implant failed in osseointegration. At the last follow-up observation, none of cases showed marginal bone loss of >1 mm and a 96.9% success rate was seen. The follow-up observation period after placement of the superstructure was 12-30 months (average 15). Between the simultaneous placement group and the delayed placement group, marginal bone loss showed no statistically significant difference (P = .455). In the entire patient group, the volume of sinus bone graft loss did not correlate with marginal bone loss (P = .568). Preoperative alveolar bone height was 0.8-8.8 mm (mean 4.64), postoperative alveolar bone height was 12-21.8 mm (mean 17.67), and the alveolar bone height 1 year after the operation was 11.2-20.8 mm (mean 16.78). Between the group with perforation of the maxillary sinus membrane and the group without, no difference in marginal bone loss was observed (P = .628). Additionally, no difference in the volume of sinus bone graft resorption between the two groups was observed (P = .970).Conclusion: It was concluded that Osteon is suitable for use in sinus graft application.

A biomechanical analysis of titanium miniplates used for treatment of mandibular symphyseal fractures with the finite element method

Baohui Ji, Chun Wang, Lei Liu, Jie Long, Weidong Tian, Hang Wang — 2010-03-01

Objective: This study aimed to evaluate the stress distribution and stress shielding effect of titanium miniplates used for the treatment of symphyseal fractures using finite element (FE) analysis.Study design: Two 3-D FE models of symphyseal fractured mandibles reduced by technique 1, reduction with a single miniplate, and technique 2, reduction with 2 miniplates, respectively, were developed. Three basic loading conditions were simulated.Results: The ratios of stress shielding of miniplates were different. Ratios of the lower miniplates in technique 2 were much higher than the upper miniplates and the miniplates in technique 1 during all conditions, and that value of the lower miniplate gained a maximum value of 83.34% during left unilateral molar clenching. The stress areas were concentrated on the central section of the miniplates. However, the stress distribution varied with masticatory conditions.Conclusion: The study demonstrated that miniplate stress distribution and stress shielding effect ratio were affected not only by the way in which the mandible was loaded but also by the number of the miniplates fixing the fracture.

Severe dental malocclusion: a rare and insidious complication of mandibular advancement devices for obstructive sleep apnea syndrome treatment

Max Hugentobler, Paolo Scolozzi — 2010-03-01

Objectives: Severe dental malocclusion resulting from mandibular advancement devices (MADs) for obstructive sleep apnea syndrome (OSAS) is extremely rare. Reporting of such situations is therefore useful for clinicians managing OSAS.Study design: We report the unusual cases of 4 patients who developed a severe circular dental open bite related to the use of a MAD. These bite changes were related to molar extrusion in two patients, whereas in the other two patients no obvious etiology was found.Results: In all patients, the MAD was immediately discontinued as early as the malocclusion was detected and continuous positive airway pressure proposed.Conclusion: Mandibular advancement devices may be associated with a severe dental malocclusion. Failure to recognize and promptly treat this complication may lead to irreversible dentoskeletal changes. Therefore, follow-up to survey dental occlusion is mandatory in all patients wearing a MAD.

Neurogenic temporomandibular joint dislocation treated with botulinum toxin: report of 4 cases

2010-03-01

Many patients suffer recurrent episodes of temporomandibular joint (TMJ) dislocation due to an excess of muscle contraction or spasticity in the depressor muscles of the jaw. The manual repositioning using the Nelaton maneuver is the first treatment. Occasionally, it may be necessary to use sedation or general anesthesia to achieve the desired muscle relaxation. In case of recurrence, surgical treatment is indicated. One nonsurgical method of treatment is the local infiltration of botulinum toxin type A. We present 4 cases of recurrent TMJ dislocation in patients suffering from conditions of neurologic origin, with considerable motor deterioration, treated with local infiltration of botulinum toxin type A. In conclusion, the injection of botulinum toxin type A is an effective method in cases of neurogenic TMJ dislocation, with low morbididty and side effects, improving patients' quality of life.

Effect of low-level laser therapy (GaAlAs) on bone regeneration in midpalatal anterior suture after surgically assisted rapid maxillary expansion

2010-03-01

Objective: The aim of this study was to evaluate the effects of laser therapy on bone regeneration in the midpalatal anterior suture (MPAS) after surgically assisted rapid maxillary expansion (SARME).Methods: Thirteen patients aged between 18 and 33 years old with maxillary transverse deficiency (≥7.0 mm) were evaluated. All patients underwent subtotal Le Fort I osteotomy with separation of the pterygomaxillary suture with the use of Hyrax expander, and were divided into 2 groups: control group (n = 6) and laser group (n = 7). A GaAlAs laser (P = 100 mW, λ = 830 nm, Ø = 0.06 cm2) was used. The laser was applied in 8 treatment sessions with intervals of 48 hours. Each treatment session consisted of laser applications, per point (E = 8.4J, ED = 140J/cm2), at 3 points on the MPAS, and total dose of E = 25.2 J, ED = 420 J/cm2. Digital radiographs were taken before the surgical procedure and at 1-, 2-, 3-, 4-, and 7-month follow-up visits. Optical density analysis of the regenerated bone was performed using Adobe Photoshop 8.0 software.Results: Bone regeneration associated with the use of laser after SARME showed a statistically significant difference. A higher mineralization rate was found in the laser group (26.3%, P < .001) than the control group.Conclusion: Low-level laser irradiation (GaAlAs) accelerates bone regeneration in MPAS after SARME. However, the optical density measurements after 7 months of follow-up were lower in comparison with the preoperative measurements.

Jaw bone changes in rats after treatment with zoledronate and pamidronate

2010-01-11

Objective: The aim of this study was to histopathologically evaluate the effects of pamidronate and zoledronate on the mandible in an animal model.Study design: Sixty female Sprague-Dawley rats were used in this study. Animals were divided into 6 groups (10 per group): control-1 (C1), injected with saline solution for 6 weeks; zoledronate-1 (ZA1), injected with zoledronate for 6 weeks; pamidronate-1 (PA1), injected with pamidronate for 6 weeks; control-2 (C2), injected with saline solution for 8 weeks; zoledronate-2 (ZA2), injected with zoledronate for 8 weeks; and pamidronate-2 (PA2), injected with pamidronate for 8 weeks. No dental procedures were performed on the animals. Rats were killed 2 days after the end of drug therapy, and the posterior and anterior mandible and femur of each rat were evaluated histopathologically.Results: Histological examination revealed inflammation limited to the posterior mandible of the ZA2 and PA2 groups; the anterior mandible and femur were not affected. Soft tissue necrosis was evident in one rat in the ZA2 group.Conclusion: Specific, bisphosphonate-asociated inflammatory bony and soft tissue changes were observed in the mandible, suggesting that these drugs may set the stage for altered healing associated with the development of bisphosphonate-related osteonecrosis of the jaw.

Susceptibility of Candida albicans to photodynamic therapy in a murine model of oral candidosis

2010-01-11

Objective: In vivo studies of antimicrobial PDT in animal models of oral candidosis are scarce and the association of porphyrin and LED light has not been evaluated for in vivo photoinactivation of Candida. In this study the effectiveness of photodynamic therapy (PDT) on the inactivation of Candida albicans in vivo was evaluated.Study design: Seventy-one 6-week-old female Swiss mice were immunosuppressed, provided tetracycline to their drinking water, then orally swabbed with a suspension of C. albicans (107 CFU/mL). Four days after oral inoculation, PDT was performed on the dorsum of the tongue after topical administration of Photogem at 400, 500, or 1000 mg/L and followed 30 minutes later by illumination with LED light (305 J/cm2) at 455 or 630 nm (n = 5 each). After swabbing to recover yeast from the tongue, the number of surviving yeast cells was determined (CFU/mL) and analyzed by ANOVA and Holm-Sidak tests (P < .05). Animals were humanely killed, and the tongues surgically removed and processed for histological evaluation of presence of yeast and inflammatory reaction.Results: PDT resulted in a significant reduction in C. albicans recovered from the tongue (P < .001) when compared with mice from the positive control group. There was no difference between the concentrations of Photogem and LED light wavelengths used. Histological evaluation of the tongue revealed that PDT causes no significant adverse effects to the local mucosa.Conclusion: PDT promoted significant reduction in the viability of C. albicans biofilm without harming the tongue tissue.

Pilot study on recurrent aphthous stomatitis (RAS): a randomized placebo-controlled trial for the comparative therapeutic effects of systemic prednisone and systemic montelukast in subjects unresponsive to topical therapy

F. Femiano, C. Buonaiuto, F. Gombos, A. Lanza, N. Cirillo — 2009-11-19

Background: Recurrent aphthous stomatitis (RAS) is characterized by recurrent painful oral ulcers whose etiology remains largely unknown. Numerous therapeutic protocols have been tried so far, but effectiveness remains an issue.Objective: To test a new drug for patients with recurrent oral aphthae nonresponsive to local corticosteroid therapy, we compared the therapeutic effectiveness and adverse effects of systemic prednisone and systemic montelukast in a placebo-controlled trial.Study design: Sixty patients suffering from minor RAS for ≥6 months were studied and randomly assigned to 3 groups of 20 each in a double-blind study. Patients of group A took 25 mg prednisone orally daily for 15 days, 12.5 mg daily for 15 days, 6.25 mg daily for 15 days, then 6.25 mg on alternate days for 15 days. Patients of group B took 10 mg montelukast orally every evening and then on alternate days for the second month. Patients of group C took 100 mg cellulose (placebo) by mouth daily for the first month and on alternate days for the second month. Outcomes assessed were days til pain cessation, days to ulcer healing, and number of aphthae occurring during the follow-up period.Results: Both prednisone and montelukast were effective in reducing the number of lesions and improving pain relief and ulcer healing when compared with placebo. Prednisone was more effective than montelukast in pain cessation (P < .0001) and in accelerating ulcer healing (P < .0001). However, adverse drug reactions recorded during the entire trial were more common in the prednisone group compared with montelukast (10%) and placebo (10%).Conclusions: These data suggest that the effectiveness of systemic montelukast is similar to that of systemic prednisone in patients with RAS. The lack of serious side effects makes montelukast a candidate drug to use in cases of RAS where pharmacologic therapy for long periods is needed.

Seroprevalence of anti-HCV among patients with oral lichen planus in Southern Taiwan

Liang-Ho Lin, Shin-Yu Lu, Sheng-Nan Lu — 2010-01-25

A possible association between oral lichen planus (OLP) and hepatitis C virus (HCV) infection has been documented in certain populations such as Japan and Southern Europe; however, the issue remains controversial. The aim of this study was to investigate the prevalence of HCV antibodies among patients with OLP in Southern Taiwan, and to assess the possible association between OLP and HCV infection. All patients enrolled in the study sought care at a hospital dental clinic. Serum samples of 104 patients with OLP and 100 controls with healthy oral mucosa, whose age and gender were matched, were respectively screened for anti-HCV antibodies by the microparticle enzyme immunoassay (AxSYM HCV version 3.0). The prevalence of HCV infection was 22.1% in the study group (23 of 104 OLP patients) and 2% in the control group (2 of 100 control subjects) respectively (P < .001). Eleven of 23 HCV-infected OLP patients (47.8%) were unaware of their HCV infection status in the study. A positive association between OLP and HCV in Southern Taiwan exists, suggesting that routine HCV infection testing of patients with OLP in Southern Taiwan should be considered.

Injection of botulinum toxin type A (BOTOX) into trigger zone of trigeminal neuralgia as a means to control pain

Wei Cheong Ngeow, Rekha Nair — 2010-03-01

This article illustrates a case of persistent trigeminal neuralgia in a medically compromised 65-year-old female who did not respond to pharmacotherapy. She had undergone several peripheral neurectomies as well as a failed right posterior fossa exploration that resulted in a cerebrospinal fluid leak. Persistent pain over the right external nasal area and right mental region was relieved for several hours after daily injections of bupivacaine. A trial of a single dose of 100 units of botulinum toxin type A (BOTOX) diluted in 2.5 mL saline was injected into the external nasal trigger zone (60 units) and to the mental nerve region (40 units). She achieved complete pain relief in the external nasal region for 5 months. Pain recurred and the site was again injected with 100 units of botulinum toxin type A (BOTOX). Pain relief at the mental region was partial. This was finally controlled with peripheral neurectomy. The patient was pain free with a maintenance dose of 200 mg carbamazepine daily for about 1 year, after which she elected to undergo stereotactic gamma knife radiosurgery when pain recurred at the external nasal region.

Association between metabolic control and oral health in adolescents with type 1 diabetes mellitus

2010-03-01

Objectives: The aim of this study was to evaluate the association between metabolic control and oral health of adolescents with type 1 diabetes mellitus (DM1).Study design: A case-control epidemiologic study was performed on adolescents allocated between 2 groups: DM1 group composed of 51 with DM1, and control group composed of 51 without diabetes. In the DM1 group, metabolic control data were observed (glycosylated hemoglobin (GHb) and capillary glucose), whereby GHb ≤8.0% was considered to indicate good metabolic control (DM1-A) and >8.0% poor metabolic control (DM1-B). Oral mucosal abnormalites, Community Periodontal Index (CPI), and decayed, missing, and filled (DMF) index were documented. Salivary flow was evaluated by means of stimulated saliva collection (SSFR).Results: Glycosylated hemoglobin values of ≤8.0% (DM1-A) were observed in 17 (24%) and >8.0% (DM1-B) in 34 (76%) of the subjects. The average DMF indexes were 1.5 (control) and 3.3 (DM1-group) (P ≤ .05). The average CPIs were 0.2 (control), 1.4 (DM1-A), and 2.0 (DM1-B) (P ≤ .05). Average SSFRs were 0.997 (DM1-A), 0.903 (DM1-B), and 1.224 (control) mL/min.Conclusions: Oral health of adolescents with DM1 was impaired regardless of metabolic control.

Tumor-induced osteomalacia associated with a maxillofacial tumor producing fibroblast growth factor 23: report of a case and review of the literature

2010-03-01

Tumor-induced osteomalacia (TIO) is a rare acquired paraneoplastic disease characterized by renal phosphate wasting and hypophosphatemia. Recently, it was reported that tumors associated with TIO produce fibroblast growth factor (FGF) 23, identified as the last member of the FGF family and of which excessive action causes several hypophosphatemic diseases whereas deficient FGF23 activity results in hyperphosphatemic tumoral calcinosis. In this case, although it was difficult to locate the associated tumor, an abnormal mass in the left maxilla was detected by imaging. The tumor was removed by partial resection of the left maxillary alveolar region. Thereafter, serum level of FGF23 rapidly decreased, hypophosphatemia improved, and the clinical symptoms greatly improved. Histopathologic diagnosis of the tumor was phosphaturic mesenchymal tumor, mixed connective tissue variant. Immunohistochemical findings confirmed that the removed tumor produced FGF23. These results indicate that development of osteomalacia in this patient was related to the maxillary tumor, which overexpressed FGF23.

Successful treatment of periodontal mucormycosis: report of a case and literature review

2010-03-01

Mucormycosis is an aggressive and potentially devastating fungal infection which typically manifests in pulmonary, rhinocerebral, or disseminated forms in patients with hematologic malignancy. Mucormycosis confined to the periodontium is uncommon, and to our knowledge only 6 cases have been reported in the English-language literature. This case report describes a patient with acute leukemia and periodontal mucormycosis. Calcofluor fluorescence microscopy is also proposed as a method for establishing a prompt diagnosis and guiding extent of intraoperative surgical debridement.

Oral myiasis caused by Cochliomyia hominivorax treated nonsurgically with nitrofurazone: report of 2 cases

2010-03-01

Accidental oral myiasis are caused by ingestion of fly's eggs or direct oviposition over a compromised area of the host. Here the authors report 2 cases of accidental oral myiasis caused by direct oviposition over an edentulous area in the first patient and in the periodontium in the second patient. Both cases were treated successfully with topical applications of nitrofurazone during a 3-day period. No surgical procedures were required. Flushing the wound with nitrofurazone caused the maggots to endure a liquid-filled anaerobic environment. Healing was uneventful in the 2 cases presented and no adverse reactions were observed during the treatment after 2 months of follow-up. The maggots of both patients were identified as Cochliomyia hominivorax.

Parathyroid hormone–related peptide (PTHrP), parathyroid hormone/parathyroid hormone–related peptide receptor 1 (PTHR1), and MSX1 protein are expressed in central and peripheral giant cell granulomas of the jaws

2010-01-11

Objective: Parathyroid hormone–related peptide (PTHrP) binds to the parathyroid hormone receptor type 1 (PTHR1), which results in the activation of pathways in osteoblasts that promote osteoclastogenesis through the RANK/RANKL system. RANK/RANKL expression has been shown in central giant cell granuloma of the jaws but PTHrP/PTHR1 has not. MSX1 protein is a classical transcription regulator which promotes cell proliferation and inhibits cell differentiation by inhibiting master genes in tissues such as bone and muscle. It has been implicated in the pathogenesis of cherubism, and its expression has been reported in a single central giant cell granuloma (CGCG) case. We aimed, therefore, to study the expression of those proteins by the different cellular populations of central and peripheral giant cell granulomas (PGCGs) of the jaws.Study design: Twenty cases of CGCG and 20 cases of PGCG of the jaws were retrospectively examined by immunohistochemistry for the percentage of positively staining cells to antibodies for PTHrP, PTHR1, and MSX1, using a semiquantitative method.Results: In both CGCG and PGCG of the jaws, PTHrP and PTHR1 were abundantly expressed by type I multinucleated giant cells (MGC) and mononucleated stromal cells (MSC) with vesicular nuclei, whereas type II MGC and MSC with pyknotic nuclei expressed those proteins to a lesser extent. In both CGCG and PGCG of the jaws, MSX1 was abundantly expressed by type I MGC and MSC but type II MGC did not express it. A statistically significant difference (P < .05) was observed between CGCG and PGCG in the expression of PTHrP in type II MGC and MSC with pyknotic nuclei and in the expression of PTHR1 in type II MGC.Conclusions: We suggest that in CGCG and PGCG of the jaws, PTHrP-positive immature osteoblasts activate PTHR1-positive mature osteoblasts to produce RANKL which interacts with RANK on the PTHrP/PTHR1-positive osteoclast-precursor cells found in abundance in the stroma of giant cell lesions and induces osteoclastogenesis through the classic pathway. Cells of the jawbones, the periodontal ligament, or the dental follicle, originating from the neural crest, may be involved in the pathogenesis of giant cell lesions of the jaws. Further study is required for these suggestions to be proved.

Immunohistochemical expression of E-cadherin and β-catenin in ameloblastomas and tooth germs

2010-03-01

Objective: The aim was to analyze the expression of E-cadherin and β-catenin in ameloblastomas and tooth germs to determine their roles in cell differentiation processes and invasiveness compared with odontogenesis.Study design: Twenty-one ameloblastoma cases (16 solid and 5 unicystic tumors) and 5 tooth germs were submitted to the immunohistochemical detection of E-cadherin and β-catenin. Immunoreactivity was evaluated using descriptive and semiquantitative analysis, investigating the location and intensity of staining. The Fisher exact test was performed, and P values of <.05 were considered to indicate statistical significance.Results: There was no statistically significant difference in the expression of E-cadherin and β-catenin between solid and unicystic ameloblastomas (P = .59; P = .63; respectively). The same was found when comparing solid and unicystic ameloblastomas with the tooth germs for both E-cadherin (P = .53; P = .44; respectively) and β-catenin (P = .12; P = .16; respectively). Nuclear staining of β-catenin was observed in only 4 cases (3 solid and 1 unicystic tumor).Conclusion: The results showed no differences in the expression of E-cadherin or β-catenin between tooth germs and solid and unicystic ameloblastomas. The expression of these molecules seems mainly to be related to the process of cell differentiation.

Clinical analysis of Castleman disease (hyaline vascular type) in parotid and neck region

2009-12-07

Objective: The aim of this study was to analyze a single institution's experience in clinical diagnosis, treatment, and prognosis of Castleman disease (hyaline vascular type) in the parotid and neck region.Study design: From 2004 to 2008, a total of 10 consecutive patients with Castleman disease (hyaline vascular type) in the parotid and neck region underwent surgery were included in this retrospective study. The preoperative examinations, clinical diagnosis, surgical treatment, and prognosis were recorded and analyzed.Results: Of the 10 patients, 4 were males and 6 female; their age ranged from 13 to 54 years with a mean of 26.6 years. The lesion occurred in the parotid region in 3 patients, in the neck region in 5 patients, and in both the parotid and neck regions in 2 patients. Their course of disease ranged from 3 months to 48 months with a mean of 12.5 months; 70% of the patients (7 out of 10) had a course of disease of <12 months. The patients always had no obvious complaint, and the laboratory examinations were almost within the normal limits. Magnetic resonance imaging/angiography were valuable on clinical diagnosis and differential diagnosis. All patients underwent surgical removal of the masses completely. During the follow-up period, which ranged from 9 months to 60 months with a mean of 38.9 months, no recurrence of the lesion occurred, and the quality of life of each patient was good.Conclusions: Castleman disease (hyaline vascular type) in the parotid and neck region is rare, with clinical manifestation and physical examination the same as benign lesions. There is no specific indication in the laboratory tests and imaging examinations; however, magnetic resonance imaging/angiography has potential value on clinical diagnosis and differential diagnosis. Surgical resection is the choice of treatment with good prognosis.

Distinctive clinical and microscopic features of squamous cell carcinoma of oral cavity and lip

2010-03-01

Objective: This study was undertaken to gain insight into the distinctive features of squamous cell carcinoma of the lip (LSCC) and oral cavity (OCSCC).Study design: A total of 37 cases of LSCC and 54 of OCSCC were compared regarding clinical and microscopic findings.Results: Predominance of head and neck TNM stages (HNTNM) T1-T2 in LSCC and T3-T4 in OCSCC was observed. A significant percentage (33.3%) of patients with OCSCC at HNTNM T1-T2 presented cervical lymph node metastasis and 18.75% died, whereas lymph node metastasis was absent and no patient died with LSCC at HNTNM T1-T2. LSCC demonstrated a higher number of cases with intense peritumoral inflammatory infiltrate compared with OCSCC. The analysis of the proliferative index demonstrated a significantly higher percentage of PCNA+ and Ki-67+ cells in OCSCC compared with LSCC.Conclusion: Our results suggest that OCSCC and LSCC demonstrate distinct clinical and microscopic characteristics that reflect different biologic behavior and prognosis.

Clinical and radiologic findings of synovial chondromatosis affecting the temporomandibular joint

Juanhong Meng, Chuanbin Guo, Biao Yi, Yanping Zhao, Haiyan Luo, Xuchen Ma — 2010-01-25

Objectives: Our aim was to study the clinical and radiologic findings of synovial chondromatosis (SC) affecting the temporomandibular joint (TMJ) and provide references for diagnosis and treatment.Study design: Twenty patients confirmed as SC histopathologically were included in the investigation. Nineteen cases were treated with arthrotomy and 1 case with arthroscopy. The clinical manifestations, radiographic findings, histopathologic features, surgical treatment, and differential diagnosis were combined to study this disease. The SC features of TMJ on magnetic resonance (MR) images were summarized on proton density–weighted (PD) and T2-weighted images.Results: Synovial chondromatosis of TMJ occurred more often in women and on the right. Symptoms included preauricular pain, swelling, limitation of mouth opening, crepitations, and deviation on opening. The detection rate of calcified loose bodies was 30% on conventional radiographs and 53.3% on computerized tomography. Multiple small ring-like or tubular signals could be seen on PD and T2-weighted MR images. SC mainly affected the superior joint space; it could involve the inferior space when a perforated or deformed disc was present. SC could extend into intracranial fossa, infratemporal fossa, and lateral pytergoid muscle.Conclusions: The characteristic ring-like signals could be found on MR images of the patients with SC of TMJ. This lesion should be differentially diagnosed with TMJ disorders and preauricular masses. Considering its recurrence and the different behavior of SC in different patients, various treatment strategies should be considered.

Correlations between seven panoramic radiomorphometric indices and bone mineral density in postmenopausal women

2010-03-01

Objectives: The aim was to test for correlations of 7 panoramic radiomorphometric indices with lumbar spine and hip bone mineral densities (BMDs) and to test the accuracy of these indices for predicting osteoporosis and a T-score ≤−2.0.Study design: Mandibular cortical indices, simple visual estimations of cortical widths, mental and antegonial indices, antegonial depth, gonial and antegonial angles, and BMD were measured in 351 postmenopausal women.Results: Associations were demonstrated between BMDs, qualitative indices, and cortical measurements. In the case of severely eroded mandibular cortices, the odds ratio (OR) for osteoporosis (according to the World Health Organization criteria) was 4.82 and the OR for a T-score ≤−2.0, the threshold to begin treatment, was 10.87. In the case of very thin mandibular cortices, the ORs were 8.02 and 5.46 for osteoporosis and a T-score ≤−2.0, respectively. The mental index cutoff for osteoporosis was 3.15 mm.Conclusions: Antegonial indices and gonial angles cannot be used as osteoporosis predictors. The most accurate indices were the mental index, mandibular cortical index, and visual estimation of cortical width.

An evaluation of microbiologic contamination on a phosphor plate system: is weekly gas sterilization enough?

2010-01-11

Objective: This study was performed to determine: 1) the rate and source of microbiologic contamination of photostimulable phosphor plates (PSP) in a predoctoral clinic; and 2) whether a combination of weekly gas sterilization and barrier protocols can prevent contamination of PSP plates.Methods: Fifty plates in clinical use and 25 gas-sterilized control plates were selected for examination. The PSP plates were pressed onto blood agar medium and incubated at 37°C. The number, size, distribution, and variety of resulting colonies were noted. To test whether these bacteria could have come from oral sources, 17 colonies were selected for culture on Mitis-Salivarius (M-S) agar. Those colonies that grew on the M-S agar were Gram stained.Results: Twenty-eight test plates (56%) exhibited growth of bacterial colonies on blood agar. Seventeen of those bacterial colonies were selected for growth on M-S agar, and 13 (76.47%) showed growth, 69% of them gram positive.Conclusion: Our results indicate reinforcing standard precautions of infection control for intraoral radiography, and that gas sterilization of plates after each day's clinical use is a potential solution.

Diagnostic accuracy of proximal caries by digital radiographs: an in vivo and in vitro comparative study

Gang Li, Xin-min Qu, Yan Chen, Jie Zhang, Zu-yan Zhang, Xu-chen Ma — 2010-01-25

Objectives: The aim of this study was to evaluate if the diagnostic accuracy of proximal dental caries in digital radiographs was similar when obtained in in vivo and in vitro conditions.Study design: Thirty-nine noncavitated teeth were collected from 11 subjects who had part of upper or lower jaws excised owing to cyst or neoplasm. Before operation, radiographs of the teeth involved were taken with the digital imaging system Digora Optime (Soredex, Helsinki, Finland), and after operation, the same extracted teeth were mounted in plaster blocks and exposed with the same digital imaging system. The teeth were subsequently sectioned for histologic validation of the lesions. Six observers evaluated all of the radiographs according to a 5-category scale. Receiver operating characteristic analysis was performed. Repeated-measure analysis of variance was used for the statistical analysis.Results: There were no significant differences between digital radiographs taken in in vivo and in vitro conditions for diagnosis of proximal dental caries (P = .286).Conclusion: Detection accuracy of proximal dental caries obtained from an in vitro study can be considered to be representative of diagnostic accuracy of proximal dental caries obtained in the real clinical situation.

Prevalence of mucosal abnormalities of the maxillary sinus and their relationship to dental disease in panoramic radiography: results from the Health 2000 Health Examination Survey

2010-03-01

Background: Mucosal thickening and mucosal antral cyst (MAC) in the maxillary sinus are incidental findings in panoramic radiographs.Methods: The study sample consisted of 5021 participants in a nationally representative Health 2000 Health Examination Survey using panoramic radiography.Results: The prevalence of mucosal thickening was 12% and of MACs 7%, both being twice as frequent in men as in women. Mucosal thickening was most common in the 40- to 49-year age group, whereas MACs were most often seen in younger age groups. Pathologic dental findings and root canal treatments were significantly associated with mucosal thickening but not with MACs. The odds ratios of vertical infrabony pockets were 5.2-fold compared with edentulous.Conclusion: This nationally representative study indicates that dental infections are etiologic for antral mucosal thickening, but not for MACs.

Computed tomography findings in radiation-induced osteosarcoma of the jaws

Ziyang Shao, Yu He, Lizhen Wang, Haisheng Hu, Huimin Shi — 2010-03-01

Objective: The objective of this study was to report the CT appearances of radiation-induced jaw osteosarcomas (RIJOS) following therapeutic irradiation.Study design: The CT studies of 7 subjects with RIJOS were reviewed retrospectively.Results: RIJOS developed at 3 to 14 years following radiotherapy. Four patients had tumors in the maxilla and 3 in the mandible. Five tumors were osteoblastic, with 1 osteolytic and 1 mixed lesions. Osteoid tumor matrix mineralization was identified in 6 subjects. Periosteal reaction was demonstrated in 6 cases. All subjects showed a soft tissue extension component beyond the area of bone destruction.Conclusion: CT is a useful tool to identify RIJOS and plays an important role in preoperative assessment of the extent of the tumor.

The metaplastic variant of Warthin tumor of the parotid gland: dynamic multislice computerized tomography and magnetic resonance imaging findings with histopathologic correlation in a case

Hasan Yerli, Suat Avcı, Erdinc Aydin, Ünser Arıkan — 2009-12-07

Metaplastic Warthin tumor is a rarely seen subtype of Warthin tumor. It can resemble squamous carcinomas histopathologically, because it contains atypical squamous cells on the necrotic surface. Making a diagnosis can become easier by knowing this entity of Warthin tumor well and by correlating the radiologic findings with pathology. In this case presentation, imaging features of a metaplastic Warthin tumor are presented together with its histopathologic findings. When a solid mass with peripheral enhancing cystic-necrotic component and well defined contour and capsule that shows early enhancement and washout is identified with imaging methods in parotid gland, metaplastic Warthin tumor should be indicated in the differential diagnosis before the histopathologic evaluation.

A case of malignant fibrous histiocytoma of the maxillary sinus

2010-03-01

Malignant fibrous histiocytoma (MFH) is recognized as one of the most common soft tissue sarcomas arising in late adulthood. Most MFHs arise from the extremities and the retroperitoneum, thus the incidence of head and neck MFH is relatively low. Because of its rare incidence, there are very few reports focusing on the imaging features of MFH arising in the maxillary sinus. A case of MFH of the maxillary sinus in a 67-year-old male patient is reported including imaging and pathological features.

Efficacy of combining a buccal infiltration with an inferior alveolar nerve block for mandibular molars with irreversible pulpitis

2010-03-01

Objective: The aim of this study was to assess the efficacy of inferior alveolar nerve (IAN) block combined with buccal infiltration for mandibular molars with irreversible pulpitis.Methodology: Eighty-four patients were randomly assigned to 3 groups of 28 patients each. Lidocaine 2% with 1:80,000 epinephrine was used for all injections. Group I patients received an IAN block with 1.8 mL of anesthetic. Group II patients received an IAN block using 3.6 mL. Group III patients received 1.8 mL as an IAN block and 1.8 mL as a buccal infiltration. A visual analogue scale was used to rate pain before anesthesia and discomfort experienced before and during access cavity preparation. Data were analyzed by chi-square, ANOVA, Kruskal-Wallis, and Mann-Whitney tests.Results: The success rates for groups I to III were 14.8%, 39.3%, and 65.4%, respectively. Group III had significantly better anesthesia compared with group I (P < .05).Conclusion: Combining an IAN block and a buccal infiltration injection provided more effective anesthesia in mandibular molars with irreversible pulpitis. However, some cases may still require further anesthesia to prevent pain during endodontic treatment.

Distribution of Porphyromonas gingivalis fimA genotypes in primary endodontic infections

Isabela N. Rôças, José F. Siqueira — 2010-03-01

Objective: Long fimbriae (FimA) are important virulence factors of Porphyromonas gingivalis. Based on the diversity of the fimA gene, this species is classified into 6 genotypes. This study surveyed samples from primary endodontic infections for the presence of these P. gingivalis fimA variants.Study design: Genomic DNA isolated from samples taken from 25 root canals of teeth with chronic apical periodontitis and 25 aspirates from acute apical abscess was used as template in polymerase chain reaction (PCR) assays directed toward the detection of the different P. gingivalis fimA genotypes.Results: Porphyromonas gingivalis was detected by a 16S rRNA gene-based PCR in 36% of the total number of cases sampled (44% of chronic apical periodontitis and 28% of abscess aspirates). In cases of chronic apical periodontitis, P. gingivalis variant type IV was the most prevalent (24%), followed by types I (20%), II (16%), and III (8%). In acute abscess samples, variant type II was the most prevalent (12%), followed by types III and IV (8% of each) and type I (4%). Combinations of up to 3 different genotypes were detected in a few cases. No single fimA genotype variant or combination thereof was significantly associated with symptoms. Overall, fimA types IV (16%), II (14%), and I (12%) were the most prevalent.Conclusions: Findings demonstrated that different P. gingivalis fimA genotypes can be present in primary endodontic infections.

Comparison of the cleaning efficacy of a new apical negative pressure irrigating system with conventional irrigation needles in the root canals

2010-03-01

Objectives: This study evaluated the efficacy of EndoVac system in comparison with that of a conventional needle irrigation method when the root canals were enlarged to various sizes.Study design: Sixty-nine single-rooted teeth were divided into 3 groups according to the root canal irrigation system (24G and 30G needle and EndoVac). Each group was divided into 3 subgroups according to the MAF size (#25, #40, and #60). Four-micron-thick serial sections were prepared at 1.5 and 3.5 mm from the apical level and photographs were taken for the analysis. The influence of the irrigation system and apical size was evaluated using a 1-way ANOVA test and Tukey's test (P < .05).Results: At both levels, significant differences were detected between EndoVac system and conventional needle irrigation in removing debris (P < .05). The relationship between the MAF size and irrigation efficacy was found to have a positive relationship (P < .05).Conclusions: EndoVac left significantly less debris behind than the conventional needle irrigation methods. Although all 3 irrigation methods resulted in clean root canals because the percentage occupied by remaining debris was very low in our specimens, larger apical instrumentation seemed to improve apical root canal debridement.

Comparative evaluation of rotary ProTaper, Profile, and conventional stepback technique on reduction in Enterococcus faecalis colony-forming units and vertical root fracture resistance of root canals

Mamta Singla, Vivek Aggarwal, Ajay Logani, Naseem Shah — 2010-03-01

Objective: The purpose of this in vitro study was to evaluate the effect of various root canal instrumentation techniques with different instrument tapers on cleaning efficacy and resultant vertical root fracture (VRF) strength of the roots.Study design: Fifty human mandibular first premolar roots were enlarged to ISO size 20, inoculated with Enterococcus faecalis [ATCC2912] for 72 hours and divided into 5 groups: group I: prepared with .02 taper hand instruments ISO size 40; group II: Profile .04 taper size 40; group III: Profile .06 taper size 40; group IV: ProTaper size F4; and group V (control group) further divided into: Va: with bacterial inoculation and no mechanical instrumentation; and Group Vb: neither bacterial inoculation nor mechanical instrumentation. Cleaning efficacy was evaluated in terms of reduction of colony forming units (CFUs). The VRF strength was evaluated using D11 spreader as wedge in an Instron testing machine.Results: Root canals instrumented with ProTaper and 6% Profile instruments showed maximum reduction in CFUs, with statistically insignificant difference between them. The VRF resistance decreased in all instrumented groups. The difference of VRF between 2% and 4% taper Profile groups was statistically insignificant (P = .195). One-way analysis of variance showed that canals instrumented with ProTaper F4 showed maximum reduction in VRF resistance compared with control uninstrumented group.Conclusions: Profile 6% taper instruments offer the advantage of maximum debridement without significant reduction in root fracture resistance.

An improved model of 3-dimensional finite element analysis of mechanical behavior of endodontic instruments

Valérie Chevalier, Reza Arbab-Chirani, Shabnam Arbab-Chirani, Sylvain Calloch — 2010-03-01

Objectives: The aim of this study was to develop a numeric method to study the mechanical behavior of an endodontic instrument during different loading paths and to demonstrate the importance of the behavior model in the finite element results.Study design: A numeric study of an endodontic instrument was carried out. At first, the geometry was meshed with a finite element code. Then, 3 among the most representative loadings in clinical use, i.e., bending, torsion, and nonproportional bending-torsion, were studied. Each of them was simulated by setting 3 different behaviors: elasticity, elastoplasticity, and an ad hoc model for the superelasticity.Results: The simulations with nonproportional bending-torsion loading showed that the mechanical behavior of Ni-Ti shape memory alloy was strongly affected by change in the loading direction. Elastic and elastoplastic models were unable to consider this feature of Ni-Ti behavior. Only a superelastic model taking into account the effects of nonproportional loading proved to respect this crucial point.Conclusion: To realize valid simulations of the mechanical behavior of Ni-Ti instruments during different mechanical loading paths, it is necessary to use an ad hoc mechanical behavior model.

Cytotoxicity evaluation of endosequence root repair material

Amer Z. AlAnezi, Jin Jiang, Kamran E. Safavi, Larz S.W. Spangberg, Qiang Zhu — 2010-03-01

Objective: The purpose of this study was to evaluate the cytotoxicity of EndoSequence Root Repair Material (Brasseler USA, Savannah, GA) and compare it with gray and white MTA.Study design: Samples of 2 mg freshly mixed or set gray MTA (GMTA), white MTA (WMTA), EndoSequence Root Repair Material (ERRM), and AH26 were eluted with 300, 600, and 1,000 μL cell culture medium for 24 and 72 hours. L929 cells were seeded into 96-well plates at 3 × 104 cells/well and incubated with 100 μL elute from each elute group. Cells cultured only with culture medium served as negative control. AH26 was used as positive control. After 24 hours' incubation, cell cytotoxicity was evaluated by MTT assay. Cell viability was calculated as percentage of the control group. The results were analyzed with 1-way analysis of variance.Results: For both set and fresh samples, there were no significant cell viability differences among GMTA, WMTA, and ERRM. Cell viability in the AH26 group was less than in all of the other 3 materials.Conclusion: This study suggests that ERRM may have cell viability similar to GMTA and WMTA in both set and fresh conditions.

A comparative evaluation of postobturation apical seal following intracanal irrigation with maleic acid and EDTA: a dye leakage under vacuum study

Nidambur Vasudev Ballal, Mala Kundabala, Kadengodlu Seetharama Bhat — 2010-03-01

Objective: The aim of the study was to evaluate the postobturation apical seal following irrigation with 7% maleic acid (MA) or 17% EDTA using dye leakage under vacuum method.Study design: Seventy single-rooted human anterior teeth were subjected to root canal instrumentation. Based on the final irrigating solution used, samples were divided into 3 groups: (1) 17% EDTA + 2.5% NaOCl, (2) 7% MA + 2.5% NaOCl, (3) 0.9% saline. Then samples were obturated and placed in 2% rhodamine B dye solution under vacuum pressure for 30 minutes and allowed to remain in the dye for 7 days. Samples were then longitudinally split and examined for dye leakage under stereomicroscope. Data were analyzed using the Kruskal-Wallis test.Results: MA showed the least apical leakage compared with EDTA and saline. Saline showed maximum leakage.Conclusion: Final irrigation with 7% MA improved the postobturation apical seal compared with 17% EDTA.

Comparison of cyclic fatigue resistance of used and new RaCe instruments

Cumhur Aydin, Ugur Inan, Yasar M. Tunca — 2010-03-01

Objective: The aim of this study was to evaluate cyclic fatigue resistance of used and new RaCe rotary nickel-titanium instruments.Study design: Forty RaCe (FKG Dentaire, La-Chaux-de-Fonds, Switzerland) instruments of sizes 30/.06, 30/.02, 25/.04, and 25/.02 were selected and divided into 2 groups: group A = 20 new instruments; group B = 20 used instruments. In group B, each instrument was used for shaping 5 curved molar root canals. Cyclic fatigue testing of new and used instruments was performed using a device that allowed the instruments to rotate freely inside a stainless steel artificial canal. Data were analyzed using t test to determine any statistical significance between used and new instruments of the same file size.Results: For all sizes, new instruments were more resistant to failure then the used ones (P < .05). A reduction in lifespan was observed ranging from 18% (30/.06) to 51% (25/.02).Conclusion: The results showed that clinical use significantly reduced cyclic fatigue resistance of RaCe rotary instruments compared with new ones.

Mineral trioxide aggregate stimulates macrophages and mast cells to release neutrophil chemotactic factors: role of IL-1β, MIP-2 and LTB4

2010-03-01

Objective: In the present study, the role of macrophages and mast cells in mineral trioxide aggregate (MTA)-induced release of neutrophil chemotactic factor was investigated.Study design: MTA suspension (50 mg/mL) was plated over inserts on macrophages or mast cells for 90 minutes. Untreated cells served as controls. Cells were washed and cultured for 90 minutes in RPMI without the stimuli. Macrophages and mast cell supernatants were injected intraperitoneally (0.5 mL/cavity), and neutrophil migration was assessed 6 hours later. In some experiments, cells were incubated for 30 minutes with dexamethasone (DEX, 10 μM/well), BWA4C (BW, 100 μM/well) or U75302 (U75, 10 μM/well). The concentration of Leukotriene B4 (LTB4) in the cell-free supernatant from mast cells and macrophage culture was measured by ELISA.Results: Supernatants from MTA-stimulated macrophages and mast cells caused neutrophil migration. The release of neutrophil chemotactic factor by macrophages and mast cells was significantly inhibited by DEX, BW, or U75. Macrophages and mast cells expressed mRNA for interleukin-1 (IL-1)β and macrophage inflammatory protein-2 (MIP-2) and the pretreatment of macrophages and mast cells with DEX, BW, or U75 significantly altered IL-1β and MIP-2 mRNA expression. LTB4 was detected in the MTA-stimulated macrophage supernatant but not mast cells.Conclusions: MTA-induces the release of neutrophil chemotactic factor substances from macrophages and mast cells with participation of IL-1β, MIP-2, and LTB4.

2010-03-01

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2010-03-01

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Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology

Pragmatics versus contrarians: how does one resolve their differences with respect to oral cancer screening?

The wrong emperor

In reply

Presence of oral lesions in leprosy patients does not imply involvement by Mycobacterium leprae

Rapidly progressing mass of anterior mandible following a dental extraction

Risk factors associated with injury to the inferior alveolar and lingual nerves following third molar surgery—revisited

A comparison of stresses in implantation for grafted and plate-and-screw mandible reconstruction

Scar less: a review of methods of scar reduction at sites of peripheral nerve repair

Abdominal fat harvest technique and its uses in maxillofacial surgery

Bone healing with an in situ–formed bioresorbable polyethylene glycol hydrogel membrane in rabbit calvarial defects

Auricular cartilage grafting in arthroplasty of the temporomandibular joint: a retrospective clinical follow-up

Reconstruction of maxillectomy defects using deep circumflex iliac artery–based composite free flap

Sinus bone graft using new alloplastic bone graft material (Osteon)—II: clinical evaluation

A biomechanical analysis of titanium miniplates used for treatment of mandibular symphyseal fractures with the finite element method

Severe dental malocclusion: a rare and insidious complication of mandibular advancement devices for obstructive sleep apnea syndrome treatment

Neurogenic temporomandibular joint dislocation treated with botulinum toxin: report of 4 cases

Effect of low-level laser therapy (GaAlAs) on bone regeneration in midpalatal anterior suture after surgically assisted rapid maxillary expansion

Jaw bone changes in rats after treatment with zoledronate and pamidronate

Susceptibility of Candida albicans to photodynamic therapy in a murine model of oral candidosis

Pilot study on recurrent aphthous stomatitis (RAS): a randomized placebo-controlled trial for the comparative therapeutic effects of systemic prednisone and systemic montelukast in subjects unresponsive to topical therapy

Seroprevalence of anti-HCV among patients with oral lichen planus in Southern Taiwan

Injection of botulinum toxin type A (BOTOX) into trigger zone of trigeminal neuralgia as a means to control pain

Association between metabolic control and oral health in adolescents with type 1 diabetes mellitus

Tumor-induced osteomalacia associated with a maxillofacial tumor producing fibroblast growth factor 23: report of a case and review of the literature

Successful treatment of periodontal mucormycosis: report of a case and literature review

Oral myiasis caused by Cochliomyia hominivorax treated nonsurgically with nitrofurazone: report of 2 cases

Parathyroid hormone–related peptide (PTHrP), parathyroid hormone/parathyroid hormone–related peptide receptor 1 (PTHR1), and MSX1 protein are expressed in central and peripheral giant cell granulomas of the jaws

Immunohistochemical expression of E-cadherin and β-catenin in ameloblastomas and tooth germs

Clinical analysis of Castleman disease (hyaline vascular type) in parotid and neck region

Distinctive clinical and microscopic features of squamous cell carcinoma of oral cavity and lip

Clinical and radiologic findings of synovial chondromatosis affecting the temporomandibular joint

Correlations between seven panoramic radiomorphometric indices and bone mineral density in postmenopausal women

An evaluation of microbiologic contamination on a phosphor plate system: is weekly gas sterilization enough?

Diagnostic accuracy of proximal caries by digital radiographs: an in vivo and in vitro comparative study

Prevalence of mucosal abnormalities of the maxillary sinus and their relationship to dental disease in panoramic radiography: results from the Health 2000 Health Examination Survey

Computed tomography findings in radiation-induced osteosarcoma of the jaws

The metaplastic variant of Warthin tumor of the parotid gland: dynamic multislice computerized tomography and magnetic resonance imaging findings with histopathologic correlation in a case

A case of malignant fibrous histiocytoma of the maxillary sinus

Efficacy of combining a buccal infiltration with an inferior alveolar nerve block for mandibular molars with irreversible pulpitis

Distribution of Porphyromonas gingivalis fimA genotypes in primary endodontic infections

Comparison of the cleaning efficacy of a new apical negative pressure irrigating system with conventional irrigation needles in the root canals

Comparative evaluation of rotary ProTaper, Profile, and conventional stepback technique on reduction in Enterococcus faecalis colony-forming units and vertical root fracture resistance of root canals

An improved model of 3-dimensional finite element analysis of mechanical behavior of endodontic instruments

Cytotoxicity evaluation of endosequence root repair material

A comparative evaluation of postobturation apical seal following intracanal irrigation with maleic acid and EDTA: a dye leakage under vacuum study

Comparison of cyclic fatigue resistance of used and new RaCe instruments

Mineral trioxide aggregate stimulates macrophages and mast cells to release neutrophil chemotactic factors: role of IL-1β, MIP-2 and LTB4

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