Experimental analysis about the evaluation of tungsten carbide-bur, piezoelectric and laser osteotomies.

AIM: Osteotomies are performed in oral surgery with five kinds of cutting instruments: 1) burs (Tungsten carbide cylindric burs), 2-3) ultrasound Piezosurgery (type I and II), 4-5) and lasers (Er:YAG; Er,Cr:YSGG). This study compares the quality of cutting of every single instruments, evaluating accuracy (length, thickness, depth and morphology), velocity (number of passages and time) and entity of damage. METHODS: In vitro experiments with ten osteotomies were performed on one-hundred of cow ribs with each instrument. In vivo surgery was performed on New Zealand white rabbit: two osteotomies are made with all instruments on the mandible and on the shinbone, totalizing four osteotomies for each instrument. Samples are processed to be evaluated through histological exam at stereo microscopy. DISCUSSION: Results show a statistically significant variability on "thickness" (p value=0.001), "time" (p value=0.001), "depth" and penetration speed (p-value=0.001; p-value=0.001) and the "number of passages" (p-value=0.001). No differences have been observed in "length" (p-value=0.078). Histological analysis reveals that osteotomy performed with laser and Piezosurgery II generates major damage to osteocytes near cutting surfaces. CONCLUSIONS: Currently, purchase and management elevated costs, minor versatility of use, and long training times for equipments such as Piezosurgery and laser limit their general use, but remain advantageous in case of risky interventions near noble structures. Choice of device depends on experience maturated by operator in time, characteristics of operation and patient's clinical conditions.

Reduction of precocious peri-implant resorption cone.

AIM: After implant-insertion, bone tissue, newly-formed on peri-implant crest, undergoes to a mild marginal osseous readjustment due to build-up of inflammatory cell tissue (ICT). The present study verifies the possibility to limit bone resorption by placing implant fixtures 0.5 mm outside cortical bone edge. METHODS: A clinically-controlled randomized study on 100 implants has been performed to compare early resorption process of implant fixtures placed 0.5 mm outside cortical bone edge with implant-fixtures inserted according to juxtacortical bone conventional protocols. RESULTS: After 6 months, bone implant level was higher with emersion approach (-1.01±0.54 mm, mean±SD) than with submerged treatment (-1.56±0.5 mm) (P<0.001). CONCLUSIONS: Factors to achieve an excellent result at mean-long term seem to be very good, even though the latter have to be confirmed by follow-up.

Evaluation of quality of life in patients with total or partial edentulism treated with computer-assisted implantology.

AIM: The study deals with a preliminary analysis that compares quality of life of a randomized sample of patients with total or partial edentulism rehabilitated through conventional implantology or computer-assisted implantology. METHODS: The first group was treated with conventional implantology, while the second group was treated with NobelGuide™ computer-assisted implantology. every patient has filled up a questionnaire about quality of life in presurgical period (sf-361), in postsurgical period (sf-361; tiq2) and about the gratification after prosthetic treatment. the questionnaire has evaluated physical, general and psycho-emotive health parameter. RESULTS: SF-36 has demonstrated an improvement in quality of life after computer-assisted surgery. tiq has revealed that patients symptoms in post-surgical week were inferior in quality and in quantity in NobelGuide™ technique. gratification questionnaire has demonstrated that quality of life improvement matches patient full satisfaction after the treatment. CONCLUSIONS: NobelGuide™ protocol improves physical health after implantology with positive reflections on psycho-emotive health. furthermore prefabricated temporary prostheses reduces treatment time and patient discomfort.

Lingual frenectomy: a comparison between the conventional surgical and laser procedure.

AIM: Ankyloglossia, commonly known as tongue-tie, is a congenital oral anomaly characterized by a short lingual frenulum that may contribute to feeding, speech and mechanical problems. The purpose of this study is to compare the advantages of laser vis-à-vis conventional frenectomy in both intra- and post-surgical phases. METHODS: This study took into consideration two patients, who were respectively 9 and 10-year-old. The first one underwent a common surgical procedure. A Nd:Yap laser device with a micropulsed wavelength of 1340 nm and power of 8 watts was used for the second. The postsurgical discomfort and healing characteristics were evaluated. RESULTS: The results indicated that the Nd:Yap laser has the following advantages when compared to the conventional frenectomy: 1) soft tissue cutting was efficient, with no bleeding, giving a clear operative field; 2) there was no need to use sutures; 3) the surgery was less time-consuming; 4) there was no postsurgical infection and no need for analgesics or antibiotics; 5) wound contraction and scarring were decreased or eliminated; 6) despite the initial slowness of the healing process, the complete and final recovery was faster. CONCLUSIONS: Considering the above elements, it is possible to assert that the laser frenectomy has a series of unquestionable advantages if compared to the conventional surgical technique.

NobelGuide™ influence in the perception of postoperative pain.

AIM: The aim of this study was to evaluate the perception of pain after Computer-aided-implantology Implant Surgery (NobelGuideTM, Nobel Biocare, Göteborg, Sweden) compared to the conventional implant surgery. METHODS: Eighteen patients from dental and maxillo-facial clinic of Policlinico G. B. Rossi (Verona, Italy) have been recruited: 9 were treated with the NobelGuide™ Technique, and 9 with the conventional one (approved by Local Ethical Committee) After the operation, painkillers (Ibuprofene tablets of 400 mg) were prescribed to the patients. Patients were asked to answer a questionnaire during the postoperative days and to report on the Visual Analogue Scale form (VAS), the intensity of pain and the number of painkillers used. RESULTS: The VAS mean one day after the operation (peak of maximum pain) was 47.22 for the conventional technique, and 12.77 for the NobelGuide™ technique, and also the number of painkillers assumed is smaller for the NobelGuide™ technique. The 5th day after the operation all the patients treated with the NobelGuide™ Technique stopped painkillers and nobody felt pain, while the patients treated with the conventional technique felt more pain and for a longer period. They also took painkillers until the 7th day. CONCLUSIONS: Pain is minor and disappears more quickly with the Nobelguide™ Implant Surgery compared with the conventional surgical technique. Nobelguide™ Implant Surgery can reduce hospitalization improving the compliance of odontophobic patients towards implant therapy.

Aneurysmal bone cyst of the nasal bone: case report.

The aneurysmal bone cyst (ABC) is a solitary, expansile, non-neoplastic bone lesion, described as a distinct clinicopathological entity by Jaffe and Lichtenstein. We report a case of an ABC arising from the nasal bone in a adult male patient treated with complete surgical excision.

Tongue flap to treat a severe case of Miescher's cheilitis granulomatosa.

Miescher's cheilitis granulomatosa is the monosymptomatic form of Melkersson-Rosenthal Syndrome. Severe macrocheilitis often causes a functional and esthetical impairment of the lip. Conservative treatment represents the first option to face this rare disease. Unfortunately, medical treatment is often ineffective without any significant result as far as swelling and disfigurement are concerned. Reductive cheiloplasty is indicated in all those patients who have failed to respond to medical treatment. Excision of excess tissue may be obtained by means of several surgical techniques. We report a case of a 55-year-old man affected by severe granulomatous cheilitis refractory to any medical treatment and then treated with the use of tongue flap for the reconstruction of the excised lower lip.

How to improve retromandibular transmasseteric anteroparotid approach for mandibular condylar fractures: our clinical experience.

Fractures of the mandibular condyle are common and account for 25-35% of all mandibular fractures reported in the literature. Even with the development of a consensus on the preference for open reduction and internal fixation of these fractures, the clinician is still faced with a dilemma concerning the optimal approach to the ramus-condyle unit. Limited access and injury to the facial nerve are the most common problems. The most commonly used extraoral approaches are the submandibular, retromandibular and preauricular methods. In this study, we propose a modified cosmetic preauricular incision with a short end in the neck, to improve the transmasseteric anteroparotid (TMAP) approach previously described by Wilson et al. in 2005. We retrospectively analysed 13 patients treated in our department for mandibular condylar fractures. Post-operative complications, occlusal status, interincisal opening and joint tenderness were evaluated at 3 months after surgery. The wider skin incision described here provides a convenient approach for open reduction and rigid internal fixation, and good results were obtained. The follow-up ranged from 6 to 40 months.

Early c-Jun N-terminal kinase-dependent phosphorylation of activating transcription factor-2 is associated with degeneration of retinal ganglion cells.

Neuron death due to deprivation of target-derived neurotrophic factors depends on protein synthesis regulated by transcription factor activity. We investigated the content and phosphorylation of activating transcription factor 2 (ATF-2) in axon-damaged retinal ganglion cells of neonatal rats. In the retina of neonatal rats, the ATF-2 protein is predominantly located in the nucleus of the ganglion cells. A gradual loss of the immunoreactivity for ATF-2 occurred after explantation. ATF-2 is phosphorylated early after explantation, with a peak within 3 hours, preceding the peak of cell death that occurs at 18 hours. Both the phosphorylation of ATF-2 and ganglion cell death were blocked by treatment with an inhibitor of c-Jun N-terminal kinase (JNK), whereas an inhibitor of p38 reduced only slightly the rate of ganglion cell death with no effect upon phosphorylation of ATF-2. Inhibitors of phosphatidyl inositol 3 kinase (PI-3K), protein kinase C (PKC) or extracellular regulated kinase (ERK) had no effect. Finally, the inhibitor of JNK blocked the upregulation of both c-Jun and Hrk in the GCL after retinal explantation. The data show that phosphorylation of ATF-2 by JNK is associated with retinal ganglion cell death after axon damage.

Application of multiplex single nucleotide primer extension (mSNuPE) to the identification of bacteria: the Burkholderia cepacia complex case.

Burkholderia cepacia complex (BCC) is characterized by a complex taxonomy constituted by seventeen closely related species of both biotechnological and clinical importance. Several molecular methods have been developed to accurately identify BCC species but simpler and effective strategies for BCC classification are still needed. A single nucleotide primer extension (SNuPE) assay using gyrB as a target gene was developed to identify bacteria belonging to the B. cepacia (BCC) complex. This technique allows the successful detection and distinction of single nucleotide polymorphisms (SNPs) and is effectively applied in routine medical diagnosis since it permits to analyze routinely many samples in a few times. Seven SNuPE primers were designed analyzing the conserved regions of the BCC gyrB sequences currently available in databases. The specificity of the assay was evaluated using reference strains of some BCC species. Data obtained enabled to discriminate bacteria belonging to the species B. multivorans, B. cenocepacia (including bacteria belonging to recA lineages III-A, III-C, and III-D), B. vietnamiensis, B. dolosa, B. ambifaria, B. anthina and B. pyrrocinia. Conversely, identification failed for B. cepacia, B. cenocepacia III-B and B. stabilis. This study demonstrates the efficacy of SNuPE technique for the identification of bacteria characterized by a complex taxonomical organization as BCC bacteria.

RecA gene sequence and Multilocus Sequence Typing for species-level resolution of Burkholderia cepacia complex isolates.

AIM: To identify, by means of recA sequencing and multilocus sequence typing (MLST), Burkholderia cepacia complex (BCC) isolates of environmental and clinical origin, which failed to be identified by recA RFLP and species-specific PCR. METHODS AND RESULTS: By using recA sequence-based identification, 17 out of 26 BCC isolates were resolved at the level of species and lineage (ten Burkholderia cenocepacia IIIB, two Burkholderia arboris and five Burkholderia lata). By using MLST method, 24 BCC isolates were identified. MLST confirmed recA sequence results, and, furthermore, enabled to identify isolates of the BCC5 group, and showed relatedness with Burkholderia contaminans for one of the two isolates not identified. CONCLUSIONS: recA sequence-based identification allowed to resolve, at the level of species and lineage, 65.4%, of the BCC isolates examined, whilst MLST increased this percentage to 88.5%. SIGNIFICANCE AND IMPACT OF THE STUDY: BCC isolates previously not resolved by recA RFLP and species-specific PCR were successfully identified by means of recA sequencing and MLST, which represent the most appropriate methods to identify difficult strains for epidemiological purposes and cystic fibrosis patients management.

Vascularized fibula flap reconstruction of the mandible in bisphosphonate-related osteonecrosis.

AIMS: To point out the feasibility of microsurgical reconstruction of the mandible in patients with bisphosphonate-related osteonecrosis (BRONJ). METHODS: Seven patients with extensive mandibular osteonecrosis underwent subtotal mandibulectomy and immediate reconstruction with a free fibula flap. They were six women and one man aged 49-72 years. The mean size of the bone and oral mucosa defects were 18.5 and 22.5 cm(2) respectively. RESULTS: The mean time of surgical intervention was 12 h. All flaps survived and the postoperative course was uneventful. Oral feeding was resumed 14 days after surgery in all cases. The donor legs healed without complications. The pathology report confirmed the diagnosis of BRONJ in all patients. Normal bone was detected at the resection margins in six out of seven patients. Patients were followed-up at intervals of 3 months. After a median follow-up time of 23 months, no clinical and radiographic evidence of recurrent BRONJ were detected in six patients. One patient with osteomyelitis at the resection margins had signs of recurrent BRONJ 6 months after surgery. The overall curative rate of the population was 86%. CONCLUSIONS: Despite the limited number of patients studied so far, our data show that mandible reconstruction with the fibula flap is feasible and does not influence the natural course of the primary disease in BRONJ-resected patients.

Nodular fasciitis of the face: aesthetic considerations.

Nodular fasciitis is an uncommon tumor-like fibroblastic proliferation that occurs rarely in the head and neck region. A new case of nodular fasciitis occurring in the cheek of a 56-year-old woman is reported. The case was characterized by dental trauma preceding the appearance of the lesion (extraction of tooth 35). Histologically, the lesion consisted of proliferating fibroblasts and myofibroblasts presenting clinically as a rapidly growing subcutaneous nodule. A conservative surgical excision with curettage is the treatment of choice, and the lesion usually does not exhibit a tendency to recur. The clinical relevance of this condition relies on the fact that both the disorder and its surgical treatment may cause tissue distortion resulting in aesthetic compromise. Furthermore, it needs to be differentiated from malignancy due to its very rapid growth, its rich cellularity, and its high mitotic activity. Both of these aspects, i.e. aesthetic implications and differential diagnosis, have been discussed.

The role of purinergic P2X7 receptors in the inflammation and fibrosis of unilateral ureteral obstruction in mice.

Receptors of the P2X7 type have been demonstrated in granulocytes, monocytes/macrophages, B and T lymphocytes, and have been involved in several cellular mechanisms including those related to inflammation and immunological response. This study attempted to investigate the role of these receptors on the inflammatory and fibrogenic response in the kidneys of unilateral ureteral obstruction (UUO), by using P2X7 knockout mice (-/-). C57Bl6 mice were submitted to left UUO and killed after 7 and 14 days. Histopathology using hematoxylin-eosin, periodic-acid Schiff and Sirius-red staining, immunohistochemistry for macrophages, myofibroblasts, transforming growth factor-beta (TGF-beta)1 and P2X7, and immunofluorescence for apoptotic cells (terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick-end labeling) were performed. Protocols were as follows: (1) control; (2) sham; (3) control P2X7 (-/-); (4) sham P2X7 (-/-); (5) UUO wild type (WT); (6) UUO P2X7 (-/-). Myofibroblasts and Sirius-red staining were significantly lower in UUO P2X7 (-/-) mice at days 7 and 14, compared to UUO WT. Kidneys from UUO P2X7 (-/-) mice showed reduced number of inflammatory cells at day 14 but not at day 7, compared to UUO WT. TGF-beta1 was less in UUO P2X7 (-/-) mice at days 7 and 14 when compared to UUO WT. Macrophage infiltration and tubular apoptosis were lower in UUO P2X7 (-/-) at day 14 but not at day 7, compared to UUO WT. P2X7 was expressed only in tubular epithelial cells at day 7 of UUO WT mice. These findings constitute the first evidence that P2X7 receptors are implicated in macrophage infiltration, collagen deposition and apoptosis in response to ureteral obstruction in mice.

Carcinogen metabolism, DNA damage repair and oral head and neck squamocellular carcinoma (HNSCC). A review.

Head and neck squamocellular carcinoma (HNSCC) has now become the 6th most common cancer among men in the developed world and affects the oral cavity, salivary glands, larynx and pharynx. Tobacco chewing, alcohol consumption and last but not least, smoking seem to be the most important risk factors. In particular in non-drinkers, smoke increases the relative risk (RR) of developing HNSCC of the oral cavity and pharynx from 2 to 20 fold; especially in the oral cavity, the association between alcohol and smoke could have a multiplier effect. Cancer arises from damage to DNA of genes located at various points of the short (p) and long (q) arms of a number of chromosomes, caused by exposure to various carcinogens. Thus, the carcinogenic process requires continuous exposure to environmental carcinogens (i.e., longstanding history of smoking and drinking), an increased susceptibility to carcinogens (induced by xenobiotic metabolizing enzyme polymorphism) and an impaired DNA repair capacity (both inherited and acquired). Our purpose in this paper is to review advances in the understanding of the role of the European or Caucasian genetic aberrations that affect carcinogen metabolism and DNA repair genes in oral HNSCC development: we consider that those abnormalities will be useful in assessing individuals at risk.

Modulation of the expression of the transcription factor Max in rat retinal ganglion cells by a recombinant adeno-associated viral vector.

Exclusion of the transcription factor Max from the nucleus of retinal ganglion cells is an early, caspase-independent event of programmed cell death following damage to the optic axons. To test whether the loss of nuclear Max leads to a reduction in neuroprotection, we developed a procedure to overexpress Max protein in rat retinal tissue in vivo. A recombinant adeno-associated viral vector (rAAV) containing the max gene was constructed, and its efficiency was confirmed by transduction of HEK-293 cells. Retinal ganglion cells were accessed in vivo through intravitreal injections of the vector in rats. Overexpression of Max in ganglion cells was detected by immunohistochemistry at 2 weeks following rAAV injection. In retinal explants, the preparation of which causes damage to the optic axons, Max immunoreactivity was increased after 30 h in vitro, and correlated with the preservation of a healthy morphology in ganglion cells. The data show that the rAAV vector efficiently expresses Max in mammalian retinal ganglion cells, and support the hypothesis that the Max protein plays a protective role for retinal neurons.

Modulation of the expression of the transcription factor Max in rat retinal ganglion cells by a recombinant adeno-associated viral vector

Exclusion of the transcription factor Max from the nucleus of retinal ganglion cells is an early, caspase-independent event of programmed cell death following damage to the optic axons. To test whether the loss of nuclear Max leads to a reduction in neuroprotection, we developed a procedure to overexpress Max protein in rat retinal tissue in vivo. A recombinant adeno-associated viral vector (rAAV) containing the max gene was constructed, and its efficiency was confirmed by transduction of HEK-293 cells. Retinal ganglion cells were accessed in vivo through intravitreal injections of the vector in rats. Overexpression of Max in ganglion cells was detected by immunohistochemistry at 2 weeks following rAAV injection. In retinal explants, the preparation of which causes damage to the optic axons, Max immunoreactivity was increased after 30 h in vitro, and correlated with the preservation of a healthy morphology in ganglion cells. The data show that the rAAV vector efficiently expresses Max in mammalian retinal ganglion cells, and support the hypothesis that the Max protein plays a protective role for retinal neurons.

Functional rehabilitation of the atrophic mandible and maxilla with fibula flaps and implant-supported prosthesis.

Historically, nonvascularized bone grafts have been the standard treatment for severe mandibular and maxillary atrophy, followed by immediate or delayed implant placement. Extreme atrophy is an unfavorable biological and mechanical location for nonvascularized autologous bone transplants. The authors present the results of a multidisciplinary treatment protocol for rehabilitation of extreme mandibular and maxillary atrophy by use of the vascularized fibular flap. This protocol includes bone augmentation, implant surgery, soft-tissue management, and prosthetic restoration. Since 1993, 18 patients with a mean age of 47.5 years presented with extreme mandibular and/or maxillary atrophy and underwent alveolar crest augmentation with vascularized fibular flaps. Bone healing was achieved in 17 of the 18 patients. Seventy-three osteointegrated implants were inserted in 12 of 17 fibular flaps. Altogether, 62 implants were loaded and 11 dental prostheses were made. Average follow-up of the loaded implants was 41 months. The success rate of loaded implants was 100 percent. The authors strongly recommend the use of the fibular bone flap when dealing with extreme atrophy of the mandible and maxilla and suggest the protocol outlined in this review.

Combined effect of vestibular and craniomandibular disorders on postural behaviour.

A correlation has been reported in the dental literature between temporomandibular disorders and musculoskeletal abnormalities, however, the question whether they modify body postural sway remains controversial. In the present investigation, the Craniomandibular Index was used to evaluate the clinical extension of temporomandibular joint dysfunction and related problems in 40 patients with normal vestibular function and in 42 patients with peripheral vestibular disorders. Balance function was assessed by static posturography and body sway area was measured in two conditions: i) eye open, and g) eye closed. Data were compared to those of 40 healthy subjects. Postural control showed a significantly different behaviour between groups with an increase in average body sway in patients with craniomandibular disorders as opposed to controls (p < 0.005). Although the involvement of the stomatognathic apparatus was not quantitatively different in the two groups of patients, those also presenting a peripheral vestibular disorder exhibited greater average body sway than patients with only craniomandibular disorders (p < 0.005). The latter showed a greater average body sway than controls only in the trial with eyes closed (p < 0.05). The results demonstrated that craniomandibular alterations could produce moderate postural instability in patients with a normal vestibular function. Conversely, their association with peripheral vestibular disorders becomes a real challenge to the upright quiet stance probably due to a negative effect of somatosensory origin on the vestibulo-spinal reflex impairment.

Lining the mouth floor with prelaminated fascio-mucosal free flaps: clinical experience.

Soft-tissue defects of the mouth floor need thin, foldable, and pliable tissues able to preserve local anatomy as well as chewing, phonation, and deglutition. The oral mucosa is made of a stratified, nonkeratinized, epithelium-secreting mucus, which lubricates the oral cavity and facilitates tongue movements. No flap exists that can reproduce the physiology of the oral mucosa better than the oral mucosa itself. Prefabrication of mucosal flaps may represent the best solution. Therefore, 10 consecutive cases of mouth floor cancer were treated with prelamination of the fascia antibrachialis with mucosal grafts obtained from the healthy cheek, and with subsequent transplantation 3 weeks later. A significant increase in mucosal graft surface was seen in all cases, with a mean size twice the original. All flaps healed uneventfully. Follow-up time ranged between 2-60 months (average, 26.6 months). Morphological and functional results were excellent. Tongue motility, speech intelligibility, and swallowing were reestablished in all treated cases. Mucosal prelamination of the forearm fascia is feasible and allows physiological reconstruction of oral cavity defects up to 6 x 4 cm.