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Purpose: The aim of this study was to evaluate mental nerve regeneration in rats after a crush lesion by using a polymeric membrane functionalized with nerve growth factor (NGF)., Materials and Methods: To evaluate the regeneration 1 month after the lesion, electrophysiological recordings of afferent neurograms were associated with a histologic analysis of neurons soma in the trigeminal ganglion using a retrograde fluorescent tracer. Three animal groups were used: uninjured rats (TEM), injured control rats without membrane (CONT), and injured rats with membrane containing NGF., Results: One month after the crush injury, an early regeneration was observed independently of exogenous NGF. However, in comparison with the level recorded before the lesion, the afferent activity was decreased by 28.5% in the CONT group, whereas it was increased by 30.8% in the NGF group. In comparison with the TEM group, a decrease in the mean number of labeled neurons was observed in the CONT group, whereas no significant difference was found after 1 month of NGF treatment., Conclusion: The exogenous application of NGF using a polymeric membrane improves mental nerve regeneration after a crush lesion.

Exogenous neurotrophic factors, delivered by various systems, are used to improve nerve regeneration. This study tested the effectiveness of a polymeric membrane loaded with Nerve Growth Factor (NGF) on mental nerve regeneration after a crush injury in rats. We tested NGF application, known to play a role in afferent fiber repair in dental neurobiology, to see if it could improve the regeneration. Afferent neurogram recordings and histological analyses of the trigeminal ganglion neurons were performed. One month after the crush injury, early regeneration was observed independently of exogenous NGF. However, as compared with the activity level recorded before the injury, the afferent activity was reduced by 28.5% without NGF, and the mean number of labeled neurons decreased. With NGF, activity was increased by 30.8%, with no significant histological difference compared with animals without lesions. NGF application through a polymeric membrane can influence degenerative and/or regenerative processes after a crush injury.

Based on its anatomical relationships, the lateral pterygoid muscle is strongly linked with the temporomandibular joint (TMJ). It plays a major role in mastication. Embryological, histological, and anatomical knowledge define the lateral pterygoid muscle as a single muscle with a penniform structure. The various results of electromyographic (EMG) studies describe a complex physiology with a chronological contraction of the layers during the masticatory cycle. The sequential contraction of the layers of the lateral pterygoid muscle is the result of a selective neuronal activation induced by the masticatory Central Pattern Generator (mCPG). This neurophysiological theory highlights the essential role of the reticular formation in oral motor control. The sensitivity of those neurological structures to chronic emotional stress is one of the possible explanations for the appearance of oral parafunctions accompanied by a modification of pain perception and a disorganized muscular activation, determining factors in temporomandibular disorders.

Purpose: The aim of this study was to evaluate the prevalence of neurosensory disturbances (NSDs) of the inferior alveolar nerve after dental procedures., Materials and Methods: A retrospective study of patient complaints for transient and permanent NSDs was achieved by means of a 10-year follow-up of claims to a national practitioner insurance company. Claims for 3 different dental procedures were analyzed from 157,292 contracts of insurance recorded during this period., Results: Three hundred eighty-two complaints of NSDs were recorded with 75 permanent injuries (19.6%). The incidence of endodontic treatment and surgical procedures in NSDs cases were 35.3% and 61.5%, respectively, and the prevalence of third molar removals in permanent loss of sensation was 46.6%., Conclusion: Impacted third molar removal appears to be the main etiology of permanent inferior alveolar nerve sensory deficiency, but endodontic treatments are often implicated and implant placement procedures can cause severe nerve injuries.

This article describes the case of a 78-year-old patient whose mandibular fracture was treated with miniplate osteosynthesis. After initial treatment, panoramic radiography revealed a fracture of the miniplate, and at follow-up, a loosening of the replacement plate. For the dental practitioner, this clinical case highlights the importance of panoramic radiography and occlusal analysis and stabilization for diagnosis of mandibular fracture, evaluation of miniplate fracture and treatment, especially in the absence of trauma.

Inferior alveolar nerve (IAN) damage can occur in trauma, cyst enucleation, sagittal split osteotomy or third molar removal, and the consequences are a loss of sensation to the mandibular teeth, gingiva and lower lip. Because of its anatomical position in a bony canal, IAN suture is rarely evoked. The aim of this study was to demonstrate the reality of IAN regeneration by using electrophysiological and histological methods after experimental section and suture of this nerve in rabbits. Nine adult female animals were used for the experiments. Six months after section and suturing using 10.0 nylon with a conventional technique, electrical stimulation of the nerve was performed to record electrophysiological activity. Each rabbit was its own reference. In each case, an action potential was recorded after microsurgical repair and definitively suppressed by section of the nerve. Morphometric analysis showed a decrease in the number of nerve fibers in the operated nerve versus the control nerve. The histological study showed an increase in nerve fibers with a cross-sectional area of 19-36 and 37-73 micro m(2) and a decrease in the smaller fibers (2-4 and 5-7 micro m(2)). This preliminary study confirms the possibility of nerve regeneration in rabbits 6 months after section and conventional suturing.

We report a case of giant-cell granuloma located in the maxilla of a 9-year-old child. The pathogenesis of giant-cell reparative granuloma (GCRG) remains obscure. Radiological features are variable. Radiolucency or well or ill-defined uni-or multilocular aspects with trabeculations can be observed. Symptoms of compression on the adjacent tooth's root and pathology findings confirm the diagnosis. Curettage is effective and recurrence is rare.

Purpose: In this retrospective study, we analyzed immediate and late mandibular fractures after impacted lower third molar surgery., Patients and Methods: One hundred fifty oral and maxillofacial surgeons in the north of- France were questioned about their experience with intraoperative and late mandibular fracture after third molar surgery. Cases were examined clinically and radiographically., Results: Thirty-seven fractures were reported in about 750,000 extractions (incidence of 0.0049%). Only 27 cases could be precisely described: 17 intraoperative and 10 late fractures. The patients were 19 to 75 years of age, with an average age of 37 years for intraoperative fractures and 47 years for late fractures. All grades of tooth impaction were included. Only 2 patients did not have full dentition., Conclusions: The major incidence of immediate and late mandible fractures occurs in patients older than over 25 years. Men may be more likely to have late fractures (8 of 10 cases)., (Copyright 2002 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 60:163-165, 2002)

Chemotherapy administered during childhood may induce dental abnormalities, such as acquired amelogenesis imperfecta, microdontia, hypodontia and altered root morphology. The magnitude of the defect varies according to the cytotoxic agents, the duration of their use and the stage of tooth development at the time of chemotherapy. Patients who received high-dose chemotherapy before the age of 5 are particularly concerned. The dental supervision of these children is based upon three orthopantomograms: the first one has to be performed before starting chemotherapy and will be used as a reference; the second is done soon after the drug therapy in order to evaluate the first consequences; the third is performed after the eruption of all permanent teeth (age 12-13 in average) in order to determine the dental abnormalities. In case of hypodontia, orthodontic treatment must be considered, but it is necessary to take into account the fact that it may increase the risk of root resorption. Preventive dental care is important for these children. It involves meticulous oral hygiene and frequent dental visits to assess and maintain dental health.

In our study we used M.R. sectional imaging in the axial and coronal planes to investigate three alveolar nerve anaesthesia techniques: Gow Gates, Akinosi and Classical techniques. Furthermore, anatomic sections were made using cadaveric specimens in axial and coronal planes to visualize anatomical relations of the anaesthetic drug. The present study showed the more or less important and quick spreading of the anaesthetic drug through the infra temporal area depending on the anaesthesia technique. Possible incidents are also discussed.

A prospective study about the development of the mandibular second right molar, has been performed with 17 chemotherapy treated children in the Paediatric Oncology department of the Centre Oscar-Lambret (Lille). Our method is based upon the measure of the crown or root length for different periods: periods with or without chemotherapy. These measurements have been performed every 6 months for 18 months with orthopantomograms. We notice for both the crown and the root: a significant difference in growing speed between periods with an without chemotherapy; a speeding up of the mineralization at the end of the treatment rejoining the average figures of a healthy test population.

A prospective comparative study of the alveolar bone resorption after teeth extraction was achieved in a series of 79 patients in order to analyze macroscopically the possible consequences of radiotherapy and chemotherapy on the toothless edges. After quarterly coronal and sagittal X-rays for two years, this study enhances quite a similar vertical resorption for the radiation and chemotherapy-treated patients as well as for the witness patients. The alveolar bone resorption progression also appears unaltered by anti cancerous treatments. In both cases, a resorption stabilisation can be clearly seen after 6 months according to dental extractions. The vertical alveolar bone resorption is more important in incisor and canine regions. The anti cancerous treatments may not have significant disastrous consequences as far as available bone amount is concerned, on a post prosthetic restoration.

A prospective study of mandibular alveolar bone resorption has been achieved on 49 patients with upper aerodigestive tract tumor and treated by radiation therapy and/or a chemotherapy, on 30 patients who were not treated. All these patients were subjected to dental extractions followed by X rays in coronal and sagittal view, during at least one year, at the rate of one X ray every three months. The comparative study enabled to show a quite similar resorption for the two population, a slightly more important resorption on incisor and canine regions, and a stopping of the resorption about five months later according to dental extractions. Radiation therapy and chemotherapy (therapeutic doses) may not have significant influence on alveolar bone resorption after dental extractions.