The juxta-oral organ of Chievitz (organum yuxtaorale) updated: Embryology, anatomy, function and pathology.

BACKGROUND: The Chievitz's organ or juxta-oral organ is a mysterious bilateral structure, phylogenetically preserved, which develops from the mouth epithelium as an invagination that loses connection to it in the prenatal period. It is located laterally to the walls of the oral cavity in an imprecise anatomical location and receives abundant innervation from the buccal nerve. Structurally it consists of non-keratinizing squamous-like neuroepithelial cells surrounded by two layers of connective tissue with nerve fibers and different morphotypes of sensory corpuscles. Its function is completely unknown although based on its rich innervation it is assumed that works as a mechanoreceptor. METHODS: We have performed immunohistochemistry for axonal and Schwann cells, and the putative mechanoproteins ASIC2, TRPV4 and Piezo2 in sections of fetal juxta-oral organ. RESULTS: Intraparenchymatous nerve fibers and sensory corpuscles were observed as well as immunoreactivity for Piezo2 in both nerve fibers and epithelial parenchymatous cells. CONCLUSIONS: We add indirect evidence that the juxtaoral organ is a mechanoreceptor because in addition to its dense innervation, the epithelial cells and sensory nerve fibers display immunoreactivity for the mechanogated ion channel Piezo2. Based on current knowledge, the functional and clinical importance of the juxta-oral organ should be further investigated.

Hand perfusion following radial or ulnar forearm free flap harvest for oral cavity reconstruction: A prospective study.

The radial forearm free flap (RFFF) and ulnar forearm free flap (UFFF) are used in head and neck reconstruction because they provide a thin and pliable skin paddle as well as a long vascular pedicle. However, in spite of several studies showing the safety of the UFFF, the RFFF is more popular among reconstructive surgeons based on concerns about hand ischaemia. A prospective study was designed in which 10 UFFF and 11 RFFF surgeries were performed in 20 patients undergoing oral cavity reconstruction between January 2017 and July 2018. Hand vascular parameters were evaluated preoperatively and postoperatively using Doppler ultrasound and plethysmography. The preoperative and postoperative diameters of the radial and ulnar arteries, and the flow velocities through the remainder of the forearm artery were measured preoperatively and at 3 months postoperative. Additionally, a comparison was performed between the preoperative and postoperative fingertip perfusion values according to impedance plethysmography. The preoperative mean diameter of the radial artery (2.89±0.47mm) was significantly greater than that of the ulnar artery (2.35±0.48mm) at the level of the wrist; however, 3 months after the surgery, the mean diameters of the two arteries did not differ significantly. There were no differences in digital perfusion when a UFFF was used compared with an RFFF.

Management of mandibular condylar fractures in patients with atrophic edentulous mandibles.

INTRODUCTION: Treatment of condylar fractures in patients with atrophic edentulous mandibles is a peculiar field that has been little considered in the literature. The aim of the study was to assess the demographic and clinical variables as well as management and outcome of mandibular condylar fractures in edentulous patients with atrophic mandibles that were treated at several European departments of oral and maxillofacial surgery. METHODS: The data of all patients with fractures of the atrophic edentulous mandible from the involved maxillofacial surgical units across Europe between January 1, 2008, and December 31, 2017. Only patients that were diagnosed with condylar fractures of the edentulous atrophic mandible were included. RESULTS: A total of 52 patients met the inclusion criteria and were included in the study: 79% of patients reported one or more comorbidities. Thirty-four unilateral neck or subcondylar fractures, 9 bilateral neck or subcondylar condylar fractures, 7 unilateral head condylar fractures, and 2 bilateral head condylar fractures were diagnosed. No treatment was performed in 37 cases, whereas in 4 patients a closed treatment was decided, and 11 patients underwent open reduction and internal fixation. Outcome was considered to be satisfying in 48 patients, with no complications. CONCLUSIONS: The golden rule still remains that the diagnosis of a subcondylar or neck fracture in an edentulous patient should constitute an indication for open reduction and internal fixation. However, an appropriate choice of management options has to be individualized on a case by case basis, also depending on the patient consent.

Epidemiology of maxillofacial trauma in the elderly: A European multicenter study.

INTRODUCTION: The progressive aging of European population seems to determine a change in the epidemiology, incidence and etiology of maxillofacial fractures with an increase in the frequency of old patients sustaining craniofacial trauma. The objective of the present study was to assess the demographic variables, causes, and patterns of facial fractures in elderly population (with 70 years or more). MATERIALS AND METHODS: The data from all geriatric patients (70 years or more) with facial fractures between January 1, 2013, and December 31, 2017, were collected. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, etiology, site of facial fractures, synchronous body injuries, Facial Injury Severity Score (FISS). RESULTS: A total of 1334 patients (599 male and 735 female patients) were included in the study. Mean age was 79.3 years, and 66% of patients reported one or more comorbidities. The most frequent cause of injury was fall and zygomatic fractures were the most frequently observed injuries. Falls were associated with a low FISS value (P<.005). Concomitant injuries were observed in 27.3% of patients. Falls were associated with the absence of concomitant injuries. The ninth decade (P<.05) and a high FISS score (P<.005) were associated with concomitant body injuries too. CONCLUSIONS: This study confirms the role of falls in the epidemiology of facial trauma in the elderly, but also highlights the frequency of involvement of females, and the high frequency of zygomatic fractures.

Exhaled breath and oral cavity VOCs as potential biomarkers in oral cancer patients.

Corporal mechanisms attributed to cancer, such as oxidative stress or the action of cytochrome P450 enzymes, seem to be responsible for the generation of a variety of volatile organic compounds (VOCs) that could be used as non-invasive diagnosis biomarkers. The present work presents an attempt to use VOCs from exhaled breath and oral cavity air as biomarkers for oral squamous cell carcinoma (OSCC) patients. A total of 52 breath samples were collected (in 3 L Tedlar bags) from 26 OSCC patients and 26 cancer-free controls. The samples were analyzed using solid-phase microextraction followed by gas chromatography-mass spectrometry detection. Different statistical strategies (e.g., Icoshift, SIMCA, LDA, etc) were used to classify the analytical data. Results revealed that compounds such as undecane, dodecane, decanal, benzaldehyde, 3,7-dimethyl undecane, 4,5-dimethyl nonane, 1-octene, and hexadecane had relevance as possible biomarkers for OSCC. LDA classification with these compounds showed well-defined clusters for patients and controls (non-smokers and smokers). In addition to breath analysis, preliminary studies were carried out to evaluate the possibility of lesion-surrounded air (analyzed OSCC tumors are in the oral cavity) as a source of biomarkers. The oral cavity location of the squamous cell carcinoma tumors constitutes an opportunity to non-invasively collect the air surrounding the lesion. Small quantities (20 ml) of air collected in the oral cavity were analyzed using the above methodology. Results showed that aldehydes present in the oral cavity might constitute potential OSCC biomarkers.

The use of piezoelectric surgery to lateralize the inferior alveolar nerve with simultaneous implant placement and immediate buccal cortical bone repositioning: a prospective clinical study.

A prospective study was conducted to assess a variation of inferior alveolar nerve (IAN) lateralization. This study included 13 patients. An osteotomy was made with a piezoelectric device, and the IAN bundle was moved buccally. Dental implants were then inserted medial to the nerve bundle, and the inner surface of the buccal cortical bone plate was shaped to reduce its thickness. Finally, the bone plate was repositioned to restore the original shape and contour of the mandible. Neurosensory examinations of the lower lip and chin were performed using three tests: light touch, pain, and two-point discrimination. Three months after surgery, the function of the IAN was judged to be completely restored at 11 of the 13 surgical sites. Differences in the tests comparing the operated and non-operated sides were not significant. No implants were lost, and all patients were satisfied with the result. Although IAN lateralization in conjunction with dental implant placement is rarely indicated, the use of a piezoelectric device to perform a buccal osteotomy with final repositioning of the buccal cortical plate over the bony defect contributes to the recovery of the contour and shape of the mandible, without impairment of IAN function.

Carcinoma of the parotid gland: developing prognostic indices.

Prognosis for parotid carcinomas is not-well defined. The authors have developed models that could be useful to define subgroups of patients with differential risks. Clinical and pathological variables, and immunohistochemically studied MMP-7, MMP-9, MT1-MMP, and VEGF proteins were analysed in 42 patients with parotid gland cancer, regarding disease-specific survival and loco-regional recurrence. A prognostic index (PI) was calculated by combining age, disease stage, squamous cell carcinoma histology, and vascular endothelial growth factor immunoexpression. Based on the values of this PI, patients were classified into three groups: 1.89-4.18 (SPI1); 4.2-7 (SPI2), and >7 (SPI3). Corresponding 5-year survival rates for these groups of patients were of 89%, 47%, and 21%, respectively. Regarding loco-regional recurrence three different patient groups were calculated combining three factors: T, N and grade. Differences amongst them were statistically significant and the estimated hazard ratios were 6.4 and 24.2 for intermediate and poor prognosis, respectively, taking the good prognostic group as reference. The authors identified several significant prognostic factors and they propose two PIs for disease-specific survival and for loco-regional recurrence. They allow for the calculation of death risk and recurrence for a given patient, providing a practical system for clinical use.

In vitro engineering of complete autologous oral mucosa equivalents: characterization of a novel scaffold.

BACKGROUND AND OBJECTIVE: Restoration of oral mucosa defects by means of in vitro-cultured equivalents has become a valid alternative in the field of oral and periodontics surgery. Although different techniques have been described, none has been able to provide an equivalent with an autologous scaffold for the epithelium. The purpose of this study was to obtain complete autologous oral mucosa equivalents (CAOME) using the patient's own fibroblasts and plasma and to characterize these equivalents both morphologically and immunohistochemically. MATERIAL AND METHODS: We acquired cell types (keratinocytes and fibroblasts) from the same mucosal samples, which were taken from healthy patients who underwent oral surgery. To construct the CAOME, a small sample of blood was obtained from the patient and subsequently processed to obtain a fibrin glue scaffold. All CAOME thus obtained were stained using the standard hematoxylin and eosin method to study their morphological characteristics. To establish the type of cells in the epithelial layer, CAOME were stained with pancytokeratin AE1/AE3, cytokeratins 5/6 and 13, p-63 and Ki-67. Finally, laminin 5 and collagen IV were used to reveal the presence of a basal membrane. RESULTS: The CAOME featured a monolayer of cube-shaped epithelial cells similar to that found on the basal layer of the oral mucosa. Close to the epithelial layer lay the fibrin and fibroblasts-embedded scaffold. The CAOME was positive to pancytokeratin AE1/AE3, cytokeratin 5/6 and p-63. No reaction was found to cytokeratin 13 and Ki-67. There was staining to laminin 5 but not to collagen IV. CONCLUSIONS: It is possible to engineer a CAOME with an epithelium of basal-like and immature keratinocytes, which could potentially reconstruct in vivo loss of tissue.

Expression of MMP-7 and MT1-MMP in oral squamous cell carcinoma as predictive indicator for tumor invasion and prognosis.

BACKGROUND: Squamous cell carcinoma of the oral cavity is a highly invasive neoplasm that spreads locally and metastasizes to regional lymph nodes. This process involves multiple proteolytic enzymes including matrilysin (MMP-7) and membrane type I-matrix metalloproteinase (MT1-MMP). This study was designed to explore the association between MMP-7 and MT1-MMP in the invasiveness and prognosis of oral squamous cell carcinoma (OSCC). METHODS: About 4-microM, formalin-fixed, paraffin-embedded tissue sections from 69 patients with OSCC were immunohistochemically studied using specific antibodies against MMP-7 and MT1-MMP proteins. Immunostaining was semiquantitatively scored, and results were correlated with histologic and clinical variables including clinical behavior and survival. RESULTS: MMP-7 was observed only in cancer cells, and MT1-MMP in both tumoral tissue and stroma. MMP-7 expression was significantly correlated with lymph node metastasis (P = 0.03; RR = 3.2). MT1-MMP showed a significant association with TIMP-2 (in N+ cases) and p53 expression (P = 0.01). MMP-7 and MT1-MMP displayed a survival relevance, and in multivariate analysis they were independent prognostic indicators, particularly in neck node-positive cases.

Histomorphometric evaluation of guided bone regeneration around implants with SLA surface: an experimental study in beagle dogs.

The aim of this study was to evaluate the efficacy of collagen membranes, either alone or combined with a human demineralized freeze-dried bone allograft (DFDBA) or natural bovine bone graft, in bone defects around dental implants with an SLA (sand-blasted, large grit, acid-etched) surface. The experiments were carried out in three beagle dogs using a split-mouth design. On one side of the jaw, three implants were placed and intra-bony defects were created and covered with a collagen membrane, randomly combined in two of the defects with human DFDBA or inorganic bovine bone graft. A control implant, without membrane covering or defect filling, was also placed. On the other side of the jaw, three implants were placed and the bone defects were treated in a similar fashion, but without membrane covering. The studied variables were the percentage of bone-to-implant contact within the limits of the initial bony defect and percentage of the original bony defect occupied by bone tissue. Although no statistically significant differences were found in this study between the membrane and nonmembrane groups, bone defects augmented with anorganic bovine bone and membranes showed the most promising results from a histological and histomorphometric perspective.

[Intrathecal baclofen for children with chronic pain related to severe spasticity: advantages of tunneling the catheter in the testing phase]. / Baclofeno intratecal en niños con dolor crónico por espasticidad intensa: ventajas de la tunelización del cateter en la fase diagnóstica.

OBJECTIVE: To document the effectiveness and safety of intrathecal baclofen administered through a tunneled catheter during a diagnostic procedure, prior to implantation of a subcutaneous pump, in children with chronic pain due to severe spasticity. METHODS: This was a retrospective study of 6 children with intense chronic pain due to spasticity caused by cerebral palsy or genetic dystonia. Increasing doses of intrathecal baclofen in continuous perfusion through a tunneled catheter were tested. RESULTS: Lumbar intrathecal catheters were tunneled for 48 to 80 hours in 5 males and 1 female aged 8 to 18 years old. Intrathecal baclofen was administered in continuous perfusion up to maximum rates that ranged between 105 and 570 microg/day. For 5 patients the score on the visual analog pain scale (0-10) changed from over 7 to 0 by the end of the test. In 2 patients, side effects of analgesia were noted, specifically sedation, bradycardia, and bradypnea. No serious complications, such as meningitis, spinal abscess, or hematoma, were reported. The families of 4 patients chose to accept implantation of a subcutaneous pump. Pump therapy remained effective and free of complications when checked 23 or 55 months after placement. CONCLUSIONS: Performing a trial of increasing doses of intrathecal baclofen therapy in continuous perfusion through a tunneled catheter facilitated selection of patients for whom chronic administration of intrathecal baclofen is effective and free of complications.

Impaired dental cytodifferentiation in glial cell-line derived growth factor (GDNF) deficient mice.

Glial cell line-derived neurotrophic factor promotes the survival of multiple neuron types in the central and peripheral nervous system. Moreover, it plays a key role in the development of the enteric nervous system and in the kidney organogenesis. Glial cell line-derived neurotrophic factor and their receptors are expressed in the developing tooth as well as in the trigeminal ganglion. However, the precise role of this growth factor in tooth morphogenesis and cell differentiation, or in the development of trigeminal ganglion cells, is still elusive. Using structural and ultrastructural techniques we analyzed in detail the first molar tooth germ of glial cell line-derived neurotrophic factor deficient mice as well as the neuronal density in trigeminal ganglion. The length and width of first molar tooth germ in knockout deficient animals showed no differences in the knockout animals in comparison with age-matched heterozygous or wild-type littermates. Nevertheless, in mice lacking glial cell line-derived neurotrophic factor, both ameloblasts and odontoblasts failed to fully develop and differentiate, and the enamel matrix and predentin layers were absent. On the other hand, the number of trigeminal sensory neurons and the structure of the nerves supplying first molar tooth germ were largely normal. Present results suggest a new non-neuronal role for glial cell line-derived neurotrophic factor in tooth development. Glial cell line-derived neurotrophic factor seems not to be involved in tooth initiation and morphogenesis, whereas it seems essential for cytodifferentiation. Conversely, neither development of trigeminal neuron nor nerve fibers supplying teeth are directly dependent on glial cell line-derived neutrophic factor.

Oral squamous cell carcinoma of the mandibular region: A survival study.

BACKGROUND: Oral squamous cell carcinomas (SCC) of the mandibular region present the lowest survival rates of the whole oral cavity. The purpose of this analysis was to evaluate the prognostic significance of several diagnostic and therapeutic variables in the survival rates of these carcinomas. METHODS: Forty-nine patients with oral cancers were treated by primary site surgery, involving mandibular resection in all cases. Thirty-one patients underwent postoperative adjuvant radiotherapy. RESULTS: Overall mean survival time and 5-year survival rate were 56.5 months and 44%, respectively. Patients in stages III and IV showed a statistically significant (p = .01) lower survival rate than those in stage II, and positive surgical margins had an adverse effect on survival (p = .03). No differences were found between patients treated by marginal or segmental mandibulectomy. CONCLUSIONS: Among the prognostic predictors studied, only the status of the surgical resection margin (odds ratio, 5.7) and tumor stage (III and IV vs II showed odds ratios of 2.1 and 3.6, respectively) affected the prognosis for SCC of the mandibular region. Tumor site was not associated with prognosis but was related with the probability that surgical margins were involved.

Traumatic optic neuropathy. A case report.

A case of visual loss following cranio-maxillofacial trauma is reported. The patient had a sudden partial blindness associated with a fracture of the roof, medial and lateral orbital walls. Access to the orbit was achieved through a transethmoidal approach using the Howarth-Lynch medial incision and resecting the bone fragments which impinged on the optic nerve. The patient had total return of visual acuity, without surgical complications. The role of orbital and optic decompression in the management of patients with traumatic optic neuropathy is discussed. Its indications are controversial and the procedure should be considered only within the context of the specific needs of the individual patient.

Tissue regeneration in bone defects adjacent to endosseous implants: an experimental pilot study.

Extraction socket defects or alveolar ridge defects may limit or restrict placement of implants. The present study assessed the efficacy of inducing bone formation with demineralized freeze-dried bone (DFDB), osteoinduction with hydroxyapatite (HA), and guided bone regeneration with expanded polytetrafluoroethylene (e-PTFE) in bone defects adjacent to endosseous implants in an animal model. Twenty-four implants were placed in the long bones of 3 pigs. After preparation of 24 cylindric acute defects adjacent to the coronal 5 mm of each implant, 18 of the defects were treated by DFDB, HA, or e-PTFE. The 6 remaining defects healed spontaneously with no treatment (controls). In each pig, one tibia received 4 commercially pure titanium screw implants (3.75 mm x 15 mm), while the contralateral tibia received 4 HA-coated cylindric implants (3.25 mm x 15 mm). Bone formation in response to the 3 treatments and control cases was evaluated using computer-assisted densitometric image analysis. The results showed that a higher density of tissue formed under e-PTFE membranes. A significantly greater increase in bone density was noticed in bone defects treated with an e-PTFE membrane vs DFDB (P = 0.04), in e-PTFE vs control sites (P = 0.04), and in defects treated with HA vs DFDB (P = 0.04) in HA-coated implants. In titanium implants the differences observed were not significant. It was also observed that bone regeneration in defects treated with HA differs with the type of implant used (titanium vs HA-coated implants), but such differences were not significant.

Salivary duct carcinoma: an unusual case of long-term evolution.

Salivary duct carcinoma is a highly malignant adenocarcinoma of salivary origin. Its pathologic features are distinct from the other salivary gland tumors and bear a remarkable histologic resemblance to ductal breast carcinoma. The clinical course is rapid and the prognosis is dismal. Aggressive therapy is warranted, including primary tumor resection, cervical neck dissection, and radiotherapy. We present a case of salivary duct carcinoma of parotid origin with a very long-term evolution in clear contrast to its supposed aggressiveness. Tumor cells expressed low- and high-molecular-weight cytokeratins, epithelial membrane antigen, carcinoembryonic antigen, and c-erbB-2 but not estrogen and progesterone receptors, actin, and S-100.

Immunohistochemical localization of neurotrophins and neurotrophin receptors in human and mouse salivary glands.

This study was undertaken to analyze the occurrence of low- (p75) and high-affinity (TrkA, TrkB and TrkC) neurotrophin receptor proteins in human and mouse salivary glands using immunohistochemistry. Furthermore, the presence of neurotrophins was also investigated. The study was carried out on 14 human (4 parotid, 6 submandibular and 4 sublingual glands) and 5 mouse salivary glands, using polyclonal antibodies against Trk proteins. The intensity of immunostaining was calculated automatically and evaluated in arbitrary units of grey levels. In human tissues no immunoreactivity (IR) for the assessed antigens was observed in the serous or mucous acinar cells, although TrkA IR was found in the acini of the submandibular gland. The cells of the intercalated ducts showed p75 IR (sublingual) and TrkA IR (parotid gland). The striated and excretory ducts displayed p75 IR, TrkA IR and TrkC IR in all glands, but TrkB IR was never detected. No neurotrophins were detected. In the mouse glands the ductal cells display IR for p75 (submandibular) and Trks A and C (parotid and submandibular) but not the sublingual gland. Acinar cells of the submandibular gland also show p75 IR. The only neurotrophin found in the mouse salivary glands was NGF (submandibular gland). These results suggest that neurotrophins may be involved in controlling the physiology of epithelial salivary cells.

Bone regeneration after radicular cyst removal with and without guided bone regeneration.

In order to determine the degree of bone regeneration after removal of radicular cysts using guided bone regeneration (GBR), a prospective, controlled and randomized clinical study was performed. Thirty patients with radicular cysts were divided into three groups. One group, the control group (n=10 patients), was treated by enucleation and primary closure. The other two groups were treated by enucleation and primary closure but GBR was used in addition, using a resorbable membrane (n=10) and a nonresorbable membrane (n=10). The membranes were fixed with nonresorbable Memfix System screws. The residual volume and the density of the newly formed tissue was measured by computer-assisted tomography and computer-assisted digital image analysis before enucleation and three and six months postoperatively. No statistical significance was found in density and residual volume between the three treatment groups after six months. These results suggest that GBR using membranes does not contribute to increased bone regeneration.