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Notes: The ‘locked-in’ syndrome has not previously been described in the immediate period after open-heart surgery. We describe the case of a patient who remained tetraplegic and mute, but alert, after graft surgery. A brief review of the aetiological factors in the development of this type of stroke after coronary artery bypass is presented.

Notes: summary  A non-invasive protocol was developed to assess tongue and cheek movements during mastication and to evaluate the temporal relationship between mastication and the initiation of pharyngeal swallowing. Typical adults (three males and three females) were monitored during chewing. Miniature pressure transducers were bonded unilaterally to the buccal and lingual surfaces of the first mandibular molar and the buccal surface of the first maxillary molar on each subject's preferred chewing side. Surface electromyography of the ipsilateral masseter muscle was recorded as an indicator of jaw-closing activity. Pressure and electromyography (EMG) recordings were time-linked to simultaneous B-mode ultrasound imaging of the oral cavity using a submental, coronal view aligned with the first mandibular molar. The intervals between peak pressure recorded at each pressure transducer and peak jaw-closing activity for each masticatory cycle were not statistically different [analysis of variance (anova), P=0·9856] and displayed large statistical variation. These intervals were not different at the beginning of the trials (hard biscuit) than they were at the completion of mastication when the cookie had been broken down to a paste/puree consistency bolus. The interval between the last chewing stroke and the initiation of swallowing was 0·92 ± 0·34 s). No significant difference existed among subjects for this time interval (anova, P=0·382).

Notes: Abstract The purpose of this study was to identify the variables that significantly influenced the survival of incisors replanted after extended extraalveolar duration at The Hospital for Sick Children, Toronto, Canada, between June 1988 and December 1993. Survival analysis was used to identify variables that significantly influence the retention of replanted incisor teeth. Survival was defined as the time that elapsed between the replantation of an avulsed incisor and the time it was finally lost. Information on 9 variables was collected for 3H patients (25 males; 13 females) and 52 replanted permanent maxillary incisors. The mean extraalveolar duration for the sample was 123 min. The mean follow-up interval was 942 days (range: 364–2126 days). Incisors replanted with open apices had a significantly decreased survival compared with teeth with mature apices (P=0.04; relative risk 4.2). There was also a significant association between increased survival and obturation of the root canal with gutta-percha and sealer P=0.006 relative risk 10.0). A trend towards improved survival of replanted incisors was found for children older than I 1 years old at the time of replantation (P= 0.09; relative risk 2.8). These results are consistent with previous studies and may assist clinicians and parents in the decision-making process associated with the management of avulsed teeth in children.

Notes: After severe injury to the periodontal ligament (PL), the phenotypes of cells recolonizing root surfaces influence the extent and type of repair processes. In teeth that are replanted following avulsion injury, recolonization of the PL space by osteogenic cells instead of by PL fibroblasts may favor bone formation (i.e. ankylosis) instead of PL regeneration. We consider here that recolonization processes depend in part on the storage conditions of the teeth following avulsion. We used an in vitro cell culture model to assess the effect of storage conditions on immunohistochemical staining of several marker proteins that are expressed by osteogenic cells (osteopontin and alkaline phosphatase) and fibroblasts (α-smooth muscle actin, type III and XII collagens). Prior to cell culture, extracted human premolar teeth were stored in air (“dry”) or in α-MEM (“wet”) for either 30 or 120 min as surrogate conditions for the variations of extra-alveolar tooth storage that may occur following avulsion. Collagenase/trypsin-digested suspensions of PL cells were prepared from the tissue adherent to the extracted root surface. Passage #2 or #3 cultures were immunostained and examined by fluorescence microscopy. For type XII collagen, cells from wet samples displayed perinuclear staining while cells from 30-min dry samples showed only isolated foci. The staining for 120-min dry samples was weak and non-specific. α-Smooth muscle actin was not incorporated into stress fibers in wet samples, whereas dry samples demonstrated prominent stress fibers stained for α-smooth muscle actin. Detached cytoplasmic fragments resembling cell processes that stained for α-smooth muscle actin were abundant in dry samples, indicating the presence of highly contractile cells. The staining for osteopontin was mainly perinuclear but was more intense in dry samples. The focal adhesion pattern of osteopontin staining in 120-min dry samples resembled that of migrating osteogenic cells. The pattern of staining did not vary for type III collagen or alkaline phosphatase, although staining for alkaline phosphatase was more intense in samples stored under dry conditions. We conclude that prolonged extra-alveolar dry storage favors increased in vitro growth of contractile cells expressing osteogenic cell markers while storage in cell culture medium favors growth of cells with the classical phenotype of PL fibroblasts.

Notes: Abstract Dental trauma represents one of the few situations where dentists are called upon to make unscheduled diagnostic and treatment decisions in an area that is outside their routine experience. Since patients who sustain an avulsion present infrequently, except in child-oriented or emergency-based practices, clinicians often make diagnostic and management decisions based upon their previous rare treatment experiences. Clinicians also rely on published guidelines for this aspect of their practice and expect these standards to be up-to-date and based on current research information. None of the current protocols has been tested by a prospective longitudinal outcome study in humans. Nevertheless, current guidelines have become the standard for clinical practice around the world. An effort must be made to develop treatment protocols that are based upon the biological mechanisms that underlie periodontal wound healing.