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Analysis of the authors' experience over the last 10 years has indicated that excellent pain control has rarely been obtained by thalamic relay nucleus stimulation in patients with thalamic pain. In the present study, 11 patients with thalamic pain were treated by chronic stimulation of the precentral gyrus. In eight patients (73%), the stimulation system was internalized since excellent pain control was achieved during a 1-week test period of precentral gyrus stimulation. In contrast, no clear effect was noted or the original pain was even exacerbated by postcentral gyrus stimulation. The effect of precentral stimulation was unchanged in five patients (45%) for follow-up periods of more than 2 years. In the remaining three patients, the effect decreased gradually over several months. This outcome was significantly better than that obtained in an earlier series tested by the authors with thalamic relay nucleus stimulation (p < 0.05). The pain inhibition usually occurred at intensities below the threshold for production of muscle contraction (pulse duration 0.1 to 0.5 msec, intensity 3 to 8 V). When good pain inhibition was achieved, the patients reported a slight tingling or mild vibration sensation during stimulation projected in the same area of distribution as their pain. The authors discuss the possibility that, in deafferentation pain, sensory neurons below the level of deafferentation cannot exert their normal inhibitory influences toward deafferented nociceptive neurons because of the development of aberrant connections. Thus, while stimulation of the first- to third-order sensory neurons at the level of the thalamic relay nucleus or below cannot bring about good pain inhibition in patients with thalamic pain, activation of hypothetical fourth-order sensory neurons through precentral stimulation may be able to inhibit deafferented nociceptive neurons within the cortex. None of the patients developed either observable or electroencephalographic seizure activity.

The latest (4th) edition of the World Health Organization Classification of Head and Neck tumours has recently been published with a number of significant changes across all tumour sites. In particular, there has been a major attempt to simplify classifications and to use defining criteria which can be used globally in all situations, avoiding wherever possible the use of complex molecular techniques which may not be affordable or widely available. This review summarises the changes in Chapter 8: Odontogenic and maxillofacial bone lesions. The most significant change is the re-introduction of the classification of the odontogenic cysts, restoring this books status as the only text which classifies and defines the full range of lesions of the odontogenic tissues. The consensus group considered carefully the terminology of lesions and were concerned to ensure that the names used properly reflected the best evidence regarding the true nature of specific entities. For this reason, this new edition restores the odontogenic keratocyst and calcifying odontogenic cyst to the classification of odontogenic cysts and rejects the previous terminology (keratocystic odontogenic tumour and calcifying cystic odontogenic tumour) which were intended to suggest that they are true neoplasms. New entities which have been introduced include the sclerosing odontogenic carcinoma and primordial odontogenic tumour. In addition, some previously poorly defined lesions have been removed, including the ameloblastic fibrodentinoma, ameloblastic fibro-odontoma, which are probably developing odontomas, and the odontoameloblastoma, which is not regarded as an entity. Finally, the terminology “cemento” has been restored to cemento-ossifying fibroma and cemento-osseous dysplasias, to properly reflect that they are of odontogenic origin and are found in the tooth-bearing areas of the jaws.

These findings suggest that auto-transplantation of bone marrow mesenchymal stem cells is a novel option for periodontal tissue regeneration.

The present concept favours that all variants have a common origin: a hyperplastic/hypertrophic lobe (or aberrant lobe) of the sublingual, submandibular or parotid salivary gland, exerting pressure upon the cortex of the mandible by the respective gland, leading to focal atrophy or resorption of the bone. The bone depressions take years to develop, appearing radiographically not until the 5th to 6th decades.

Head and neck squamous cell carcinoma (HNSCC) is one of the most common types of human cancer. Typically, HNSCC cells show persistent invasion that frequently leads to local recurrence and distant lymphatic metastasis. However, molecular mechanisms associated with the invasion and metastasis of HNSCC remain poorly understood. Here, we identified periostin as an invasion-promoting factor in HNSCC by comparing the gene expression profiles between parent HNSCC cells and a highly invasive clone. Indeed, periostin overexpression promoted invasion and anchorage-independent growth both in vitro and in vivo in HNSCC cells. Moreover, periostin-overexpressing cells spontaneously metastasized to cervical lymph nodes and to the lung through their aggressive invasiveness in an orthotopic mouse model of HNSCC. Interestingly, periostin was highly expressed in HNSCCs in comparison with normal tissues, and the level of periostin expression was well correlated with the invasiveness of HNSCC cases. In summary, these findings suggest that periostin plays an important role in the invasion and anchorage-independent growth of HNSCC. (Cancer Res 2006; 66(14): 6928-35)

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