Does a surgery first approach to orthognathic treatment of class III skeletal relations result in a shorter duration of treatment? A systematic review.

The objective of this study was to review the evidence relating to treatment duration and the surgery first approach (SFA) in managing class III skeletal discrepancies to determine whether there is sufficient evidence to show that it results in a shorter duration of treatment compared to a conventional orthodontics first approach (OFA). Analytical and observational studies that compared both approaches and recorded treatment duration as an outcome were included. MEDLINE, EMBASE, CENTRAL and Dental Oral Sciences Source databases were searched along with a review of reference lists. Risk of bias was assessed using the Risk of Bias in Non-randomised Studies of Interventions (ROBINS-I) tool. Eleven observational studies met the inclusion criteria. No experimental studies were identified. The SFA was reported to have a shorter duration of treatment in all studies. All included studies showed a significant risk of bias, particularly in relation to selection of participants, allocation to groups and in the measurement of treatment duration. There is no quality evidence to suggest that using a surgery first approach to orthognathic treatment of class III skeletal patterns results in a shorter duration of treatment.

Neurocognitive function and schizophrenia-proneness in individuals dependent on ketamine, on high potency cannabis ('skunk') or on cocaine.

BACKGROUND: Ketamine, psychostimulants and cannabis have all been associated with psychotic phenomena but no study has directly compared users of these drugs. AIMS: The aim of this study was to assess schizophrenia proneness and neurocognitive function in individuals dependent upon ketamine, cannabis and cocaine. METHOD: 130 volunteers - 29 'skunk' users, 22 cocaine users, 21 ketamine users, along with 28 'recreational' poly-drug users and 30 drug-naïve controls - were assessed on the Schizophrenia Proneness Instrument, Adult version (SPI-A). They were specifically asked to rate symptoms when not under the acute influence of a psychoactive drug. RESULTS: Ketamine and skunk users manifested the greatest attentional and cognitive disturbances. The symptom profile of the dependent ketamine users was very similar to that of prodromal individuals who transitioned to psychosis. CONCLUSIONS: Given the recent rapid rise in use of high potency cannabis and of ketamine, these findings are important and clinicians should be careful to rule out the effects of persistent drug use, especially in users of ketamine or skunk, when assessing an individual's risk of psychosis. A longitudinal study is needed to differentiate which basic symptoms persist following abstention from ketamine and skunk.

In and out of the K-hole: a comparison of the acute and residual effects of ketamine in frequent and infrequent ketamine users.

AIMS: Ketamine, a non-competitive NMDA receptor antagonist, produces acute impairments of working, episodic and semantic memory along with psychotogenic and dissociative effects when a single dose is given to healthy volunteers. In recreational users, Curran & Morgan (2000) showed that ketamine produced the same acute effects but that 3 days after ingestion, ketamine users showed persisting memory impairment and elevated psychotogenic symptoms compared with controls. To explore whether such persisting effects reflect chronic effects of ketamine use, the present study compared frequent with infrequent users of ketamine on the night of drug use and again 3 days later. DESIGN AND PARTICIPANTS: Eighteen frequent and 19 infrequent ketamine users were assessed on each test day on a range of cognitive tasks tapping memory and attentional function and on subjective scales (schizotypal symptomatology, dissociation, mood). FINDINGS: Groups were broadly matched for polydrug use apart from ketamine which frequent users took significantly more often and in larger quantities than infrequent users. Acute effects on day 0 replicated previous findings. On day 3 frequent users showed significant impairments on tasks tapping episodic and semantic memory but there was no evidence of persisting dissociative or schizotypal symptoms. CONCLUSION: These findings indicate that frequent use of ketamine produces long-lasting impairments in episodic memory and aspects of retrieval from semantic memory. Such effects accord with animal evidence of the effects of NMDA receptor blockade on memory. Those using, or contemplating using ketamine should be informed of these persisting, detrimental effects of the drug upon human memory.

Autistic children's ability to interpret faces: a research note.

Ten autistic children were compared with 10 non-autistic children matched for chronological age and performance IQ on two tests of finding the odd face out of a set of photographs of faces, two tests of labelling photographs of faces, and a test of labelling photographs of common objects. The autistic children were significantly worse than the non-autistic children at finding the odd person out and the odd facial expression of emotion out, and at labelling facial expressions of emotion. They did no worse than the non-autistic children at labelling upside down faces or at labelling objects. The results, which replicate the findings of Hobson (J. Child Psychol, Psychiat. 27, 321-342, 671-680, 1986; Communication, 20, 12-17, 1986) are consistent with other evidence for a specific perceptual abnormality in at least some children with autism, the nature of which is discussed.