Assessment of dependence potential and abuse liability of Δ8-tetrahydrocannabinol in mice.

Delta-8-tetrahydrocannabinol (Δ8-THC) is a psychotropic cannabinoid produced in low quantities in the cannabis plant. Refinements in production techniques, paired with the availability of inexpensive cannabidiol substrate, have resulted in Δ8-THC being widely marketed as a quasi-legal, purportedly milder alternative to Δ9-THC. Yet, little research has probed the behavioral and physiological effects of repeated Δ8-THC use. The present study aimed to evaluate the effects of acute and repeated exposure to Δ8-THC. We hypothesized that Δ8-THC produces effects similar to Δ9-THC, including signs of drug tolerance and dependence. Adult male and female C57BL/6J mice were treated acutely with Δ8-THC (6.25-100 mg/kg, i.p.) or vehicle and tested in the tetrad battery to quantify cannabimimetic effects (i.e., catalepsy, antinociception, hypothermia, immobility) as compared with a non-selective synthetic cannabinoid (WIN 55,212-2) and Δ9-THC. As previously reported, Δ8-THC (≥12.5 mg/kg) induced cannabimimetic effects. Pretreatment with the CB1 receptor-selective antagonist rimonabant (3 mg/kg, i.p.) blocked each of these effects. In addition, repeated administration of Δ8-THC (50 mg/kg, s.c.) produced tolerance, as well as cross-tolerance to WIN 55,212-2 (10 mg/kg, s.c.) in tetrad, consistent with downregulated CB1 receptor function. Behavioral signs of physical dependence in the somatic signs, tail suspension, and marble burying assays were also observed following rimonabant-precipitated withdrawal from Δ8-THC (≥10 mg/kg BID for 6 days). Lastly, Δ8-THC produced Δ9-THC-like discriminative stimulus effects in both male and female mice. Together, these findings demonstrate that Δ8-THC produces qualitatively similar effects to Δ9-THC, including risk of drug dependence and abuse liability.

Papillon-Lefèvre syndrome: a review of the literature and report of 4 cases.

This report describes 4 cases of Papillon-Lefèvre syndrome (PLS) affecting 2 Jordanian families with a total of 8 children. In family A, 3 girls out of 6 siblings were affected; and in family B, the eldest of 2 brothers. The patients were between 4 1/2 and 12 years old, and their parents, who are first cousins, were not affected. Diagnosis was determined by history, and clinical, laboratory, and radiographic examinations. All present cases exhibited the typical clinical features of PLS: hyperkeratosis of the palms and soles and the presence of advanced destructive periodontitis resulting in early loss of both the primary and permanent dentitions. In Case 4, cutaneous lesions were noticed at age 6 months and the child was edentulous by the age of 12 years. In all cases, there was a relationship between increased severity of skin lesions and seasonal variations and intensified periodontal destruction. There was an early eruption of the permanent teeth. The teeth were caries-free with no sign of root resorption. Dentists play a significant role in the diagnosis and management of PLS patients.

Solitary maxillary central incisor in the midline associated with systemic disorders.

A single maxillary central incisor in the midline is a rare developmental anomaly. The appearance of a single incisor in place of two teeth may occur as an isolated dental finding that can be related to fusion of two neighboring teeth or to agenesis of a tooth germ. However, the condition has also been reported to occur in association with autosomal dominant holoprosencephaly, growth retardation, and midline developmental defects. This article reports on other systemic defects that can be found in association with a single maxillary central incisor.

Reasons for extraction of permanent teeth in Jordan.

This investigation was carried out to determine the reasons for extraction of permanent teeth in Jordan. A random sample of 200 Jordanian Dentists (1:10) were asked to record reasons for the extraction of permanent teeth during a two week period. Of the 139 dentists responding, only 97 dentists extracted teeth during the study period. A total of 934 teeth were extracted from 582 patients, of these 33.4 per cent were extracted for periodontal disease, and 27.6 per cent because of caries and its sequelae. The study suggests caries and its consequences affected tooth loss throughout life while the rate of tooth loss due to periodontal disease increases with age.

Caries risk in patients with thalassaemia major.

AIM: The aim of this study was to assess the prevalence and distribution of dental caries in subjects with thalassaemia major. DESIGN: Clinical examination for dental caries, diagnosed according to the WHO criteria. PARTICIPANTS: A total of 54 thalassaemic patients, 23 aged 6-9 (14 males and 9 females) and 31 aged 12-18 (17 males and 14 females) were examined. OUTCOME MEASURES: dmft, DMFT and plaque scores. RESULTS: The mean dmft was 6.92 for 6-7 year olds and 4.72 for 8-9 year olds. The DMFT values were 6.57 and 5.95 for ages 12-14 and 15-18, respectively. There was no statistically significant difference in caries prevalence (dmft/DMFT) between gender or between primary and permanent teeth. Only 17.4 per cent of the children aged 6-9 and 21.4 per cent of 12-18 years olds were caries free. The prevalence of dental caries in the thalassaemia patients was considerably higher (22.7 per cent) than that reported in a normal Jordanian sample (DMFT 6.26 vs 4.84). Very few fillings (1.4 per cent of the examined teeth) were observed, indicating a negligible rate of conservative treatment. More than half (61.1 per cent) of the patients had poor oral hygiene (plaque score > or = 2.0). CONCLUSIONS: The need for effective preventive measures, education and dental treatment need to be stressed for this caries risk group.

Talon cusp--clinical significance and management: case reports.

Talon cusp is a rare dental anomaly manifested as an accessory cusplike structure on the tooth crown. This article reports four cases of talon cusp that caused clinical problems related to appearance, occlusal interference, tooth displacement, caries, and tongue irritation. The cases presented were associated with other dental abnormalities, suggesting per se that genetic inheritance may be the causative factor. Clinical and radiographic characteristics of this developmental anomaly and modes of treatment are described.

Delayed eruption of maxillary primary cuspid associated with compound odontoma.

Impaction of primary teeth is very rare especially in the maxillary anterior teeth. A four-year-old male child with the complaint of delayed eruption of right maxillary primary cuspid due to the presence of odontoma is presented.

Unusual nasal foreign body detected on routine dental radiography: case report.

This report describes an unusual nasal foreign body in a 4-year-old boy discovered incidentally in a routine dental radiograph. A small piece of rubber eraser was lodged in the right nasal cavity, causing unilateral nasal obstruction and discharge, sneezing, snoring and breathing difficulty. In this case, discovery of unknown intranasal object was diagnostic for a condition suspected of pathological origin. Dentists may play a significant role in the diagnosis of intranasal foreign objects in children, through careful clinical examination and interpretation of dental radiographs. Early diagnosis is emphasized in order to avoid complications.

Oral manifestations of Ellis-van Creveld syndrome: report of two siblings with unusual dental anomalies.

Ellis-van Creveld syndrome (EvC), also called chondroectodermal dysplasia, is a rare occurrence inherited as an autosomal recessive disease. Despite the fact that oral manifestations play an important role in the diagnosis criteria for EvC, few detailed reports have been published in the dental literature. This articles presents two siblings with EvC, a boy aged 9 years and a girl aged 7 1/2 years, a product of unaffected first cousin parents. The patients manifests: chondrodysplasia of tubular bones resulting in disproportionate dwarfism, polydactyly and syndactyly of hands and feet, severe dystrophic nails, multiple broad labial frenula with abnormal attachments, congenital missing incisors, anomalous teeth, bilateral partial clefts of the alveolar bone, and malocclusion. Other features noted in either cases are: congenital heart defect, median notch of the upper lip, shovel-shaped incisors and taurodontism. Of the unusual dental findings observed in our patients are talon cusp, reduced crown size, supernumerary tooth, and early eruption of teeth. Because half of the cases with EvC have cardiac malformation, dental treatment must be performed under prophylactic antibiotic coverage. Dentists play an important role in early diagnosis and control of dental problem of this condition.

Patulous eustachian tube complicating gastric bypass surgery.

OBJECTIVE: We report the first case in the English literature of a patulous eustachian tube occurring after laparoscopic Roux-en-Y gastric bypass surgery for obesity. METHOD: Case report of a 44-year-old woman who was referred to our ENT clinic complaining of autophonia and bilateral aural fullness. The patient had noticed these symptoms after she had undergone a laparoscopic Roux-en-Y gastric bypass surgery to aid weight loss. RESULT: On the basis of the medical history, clinical examination and immittance measurement (revealing a change in acoustic immittance synchronous with normal breathing in the right ear), a diagnosis of patulous eustachian tube was made, more severe in the right ear than the left. CONCLUSION: We report a case of patulous eustachian tube occurring after laparoscopic gastric bypass surgery for weight loss, which could be considered as one of the possible complications of this surgery. Our patient began to notice the symptoms of patulous eustachian tube after a 20 kg weight loss.

In vitro studies of the effect of a dental explorer on the formation of an artificial carious lesion.

This project deals with in vitro mechanical damage of early carious lesion (enamel lesion) in artificial U-shaped grooves caused by a sharp dental explorer. The lesions were formed in enamel grooves in 3 percent by weight cellulose solution in 0.1 M lactic acid containing 1.08 M KH2PO4 and 1.8 mM CaCl2 buffer to pH 4.28 after two weeks of demineralization. A relatively intact surface layer was observed in all the grooves. Three demineralized grooves were probed with different forces 100 g, 300 g and 500 g. The traumatic damage was assessed by using microradiography. There was no damaging effect in the sound enamel grooves probed with a sharp explorer up to a force of 500 g. Breakdown of the surface layer was assessed in all probed demineralized enamel grooves, converting the white spot lesion with apparently a sound surface layer into a cavity. Explorer penetration into the lesion was found to be strongly related to the force applied. The use of a sharp dental explorer should be reconsidered in examination and diagnosis of early carious lesions in pits and fissures and an alternative technique should be sought.

Bilateral talon cusps on primary central incisors: a case report.

Talon cusp is an uncommon anomaly in the primary dentition. The present report describes a case of bilateral talon cusps on the maxillary primary central incisors of a 17-month-old Jordanian-Arab boy, bringing to seven the total cases reported in the literature. Both central incisors exhibited a sharp prominent accessory cusp on the palatal surface which extended from the cemento-enamel to the incisal edge. The cusp on the right incisor was attached to tooth surface, forming a T-shape crown outline. whereas the cusp on the left incisor projected away from the rest of the crown. The anomalous cusps were a source of tongue irritation and occlusal interference.

Etiology and diagnosis of tooth wear: a literature review and presentation of selected cases.

PURPOSE: This article presents an overview of etiologies associated with tooth wear. MATERIALS AND METHODS: Specific types of wear based on clinical findings and patient history are described. RESULTS: The occurrence and pattern of tooth wear are related to cultural, dietary, occupational, and geographic factors. Examples of tooth wear related to these factors with regional specificity are presented. CONCLUSION: The dental practitioner should recognize the characteristic signs of tooth wear, as they may be the first to discuss the problem with the patient. Management should be based on accurate diagnosis.

Localisation of a gene for prepubertal periodontitis to chromosome 11q14 and identification of a cathepsin C gene mutation.

Prepubertal periodontitis (PPP) is a rare and rapidly progressive disease of young children that results in destruction of the periodontal support of the primary dentition. The condition may occur as part of a recognised syndrome or may occur as an isolated finding. Both autosomal dominant and recessive forms of Mendelian transmission have been reported for PPP. We report a consanguineous Jordanian family with four members affected by PPP in two nuclear sibships. The parents of the affected subjects are first cousins. We have localised a gene of major effect for PPP in this kindred (Zmax=3.55 for D11S901 at theta=0.00) to a 14 cM genetic interval on chromosome 11q14 flanked by D11S916 and D11S1367. This PPP candidate interval overlaps the region of chromosome 11q14 that contains the cathepsin C gene responsible for Papillon-Lefèvre and Haim-Munk syndromes. Sequence analysis of the cathepsin C gene from PPP affected subjects from this Jordanian family indicated that all were homozygous for a missense mutation (1040A-->G) that changes a tyrosine to a cysteine. All four parents were heterozygous carriers of this Tyr347Cys cathepsin C mutation. None of the family members who were heterozygous carriers for this mutation showed any clinical findings of PPP. None of the 50 controls tested were found to have this Tyr347Cys mutation. This is the first reported gene mutation for non-syndromic periodontitis and shows that non-syndromic PPP is an allelic variant of the type IV palmoplantar ectodermal dysplasias.