A new classification system of trifid mandibular canal derived from Malaysian population.

BACKGROUND: The purpose of this study was to identify and classify the anatomic variation of mandibular canal among Malaysians of three ethnicities. MATERIALS AND METHODS: The courses of the mandibular canal in 202 cone-beam computed tomography scanned images of healthy Malaysians were evaluated, and trifid mandibular canal (TMC) when present, were recorded and studied in detail by categorizing them to a new classification (comprising of 12 types). The diameter and length of canals were also measured, and their shape determined. RESULTS: Trifid mandibular canals were observed in 12 (5.9%) subjects or 16 (4.0%) hemi-mandibles. There were 10 obvious categories out the 12 types of TMCs listed. All TMCs (except one) were observed in patients older than 30 years. The prevalence according to ethnicity was 6 in Malays, 5 in Chinese and 1 in Indian. Four (33.3%) patients had bilateral TMCs, which was not seen in the Indian subject. More than half (56.3%) of the accessory canals were located above the main mandibular canal. Their mean diameter was 1.32 mm and 1.26 mm for the first and second accessory canal, and the corresponding lengths were 20.42 mm and 21.60 mm, respectively. Most (62.5%) canals had irregularly shaped lumen; there were more irregularly shaped canals in the second accessory canal than the first branch. None of the second accessory canal was oval (in shape). CONCLUSIONS: This new classification can be applied for the variations in the branching pattern, length and shape of TMCs for better clinical description.

[Sampling Survey of the Relationship Between Acute Mountain Sickness and Mental Health of Officers and soldiers].

Objective: To sample survey the relationship between acute mountain sickness and mental health of officers and soldiers, so as to provide theoretical direction for the psychological prevent and counsel of them. Methods: In May 2017, 61 officers and soldiers were selectedas subject investigated, and divided to AMS group included 35 persons and non-AMS group included 26 persons according to the finding of theAMS symptom division point table, then used symptom self-testing tableto test and evaluate the mental health of them. Results: The AMS group showed significantly higher scores on the psychological parameters such as omatization, interpersonal sensitivity, depression, anxiety, phobicanxiety, parnoid ideation and so on (105.20±13.82, 1.37±0.26, 1.14±0.21, 1.16±0.19, 1.16±0.18, 1.06±0.11, 1.10±0.17, 1.22±0.19, P<0.05) . Conclusion: The mental factors of omatization, interpersonal sensitivity, depression, anxiety, phobic anxiety, parnoid ideation and so on had great influence on AMS, we should pay attention to these factors and carry on mental intervention, and enhance anti-stress ability of individual, to ensure the successful completion of plateau military mission.

[Association between hypertension and serum microRNA21 and microRNA133a in ocean seamen].

OBJECTIVE: To investigate the prevalence of hypertension in ocean seamen and major influencing factors, as well as the association between hypertension and serum microRNA21 and microRNA133a. METHODS: Health examination and a questionnaire survey were performed for 780 ocean seamen who underwent physical examination in an international travel healthcare center in Fujian, China from January to June, 2014. TaqMan RT-qPCR was used to measure the serum levels of microRNA21 and microRNA133a in seamen with hypertension. RESULTS: The prevalence of hypertension differed significantly between the ocean seamen with different ages, education levels, marital status, body mass index (BMI) values, drinking frequencies, and numbers of sailing years (P<0.05). The prevalence rate of hypertension in the ocean seamen increased with the increasing drinking frequency (χ(2)=9.02, P<0.05) , decreased with the increase in degree of education (χ(2)=11.578, P<0.05) , and increased with the increase in the number of sailing years (χ(2)=28.06, P<0.05). The hypertensive ocean seamen had significantly higher expression levels of microRNA21 and MicroRNA133a than the healthy ocean seamen (microRNA21: 7.87±5.46 vs 1.03±0.80, P<0.05; MicroRNA133a: 7.45±1.94 vs 4.52±1.15, P<0.05). The multivariate analysis showed that a high level of microRNA21 (OR=1.61, 95% CI: 1.22~2.11) , a high level of microRNA133a (OR=1.52, 95% CI: 1.24~1.87) , drinking (OR=1.64, 95% CI: 1.08~2.50) , overweight based on BMI (OR=1.18, 95%CI: 1.07~1.30) , and many sailing years (OR=2.89, 95% CI: 1.14~7.30) were risk factors for hypertension. CONCLUSION: The prevention and treatment of hypertension in ocean seamen should be enhanced. Excessive drinking should be controlled, and sailing time should be arranged reasonably. The microRNA21 and microRNA133a may be associated with the development and progression of hypertension in ocean seamen.

[A survey of mental health status in armored vehicle crew].

OBJECTIVE: To investigate the mental health status in armored vehicle crew (commanders, gunners, and drivers) , to know the level of mental health in them, and to provide educational intervention. METHODS: In April 2009, 120 male armored vehicle crew with >2 driving years were enrolled as battle group, and 70 male persons within the same age group who were not engaged in armored vehicle operation were enrolled as control group. The Symptom Checklist-90 (SCL-90) was used to evaluate the mental status of the 180 subjects. RESULTS: Compared with the control group, the battle group showed significantly higher scores on the subscales of obsessive-compulsive symptom, interpersonal sensitivity, depression, anxiety, phobic anxiety, and paranoid ideation (t=2.323, 3.250, 3.158, 2.712, 2.391, and 2.137, all P<0.05) , as well as significantly higher total score, number of positive items, and average score of positive symptoms (t=4.128, 4.357, and 4.632, all P<0.05). In the battle group, the scores on the subscales of somatization, obsessive-compulsive symptom, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, psychoticism, and additional items, total score, number of positive items, and average score of positive symptoms were significantly lower than the military reference values (t=4.364, 5.127, 5.280, 3.783, 7.012, 5.361, 4.369, 6.167, 6.476, 3.558, 6.357, 4.379, and 6.763, all P<0.05). CONCLUSION: A survey should be performed on the mental health status of armored vehicle crew, including obsessive-compulsive symptom, interpersonal sensitivity, depression, and anxiety. Mental health service for the crew should be enhanced to improve their psychological quality.

Quantification of the dental morphology of orangutans.

Orangutans are believed to have close biological affinities to humans. Teeth being the hardest tissue provide useful information on primate evolution. Furthermore, knowledge of the pulp chamber and root canal morphology is important for dental treatment. A female Bornean orangutan and a Sumatran male orangutan skull were available for this study. Both of their dentitions, comprising 50 teeth, were scanned employing the cone-beam computed tomography for both metrical and nonmetrical analyses. Measurements included tooth and crown length, root length, enamel covered crown height, root canal length (posterior teeth), length of pulpal space (anterior teeth), and root canal width. Nonmetrical parameters included number of canals per root, number of foramina in each root, and root canal morphology according to Vertucci's classification. It was found that the enamel covered crown height was the longest in the upper central incisors although the canine was the longest amongst the anterior teeth. Both the upper premolars were three-rooted while the lower second premolar of the Sumatran orangutan was two-rooted, with two foramina. The mandibular lateral incisors of the Bornean orangutan were longer than the central incisors, a feature similar to humans. In addition, secondary dentine deposition was noticed, a feature consistent with aged humans.

Contour analysis of an implant--soft tissue interface.

BACKGROUND AND OBJECTIVE: Studies of peri-implant soft tissue on in vivo models are commonly based on histological sections prepared using undecalcified or 'fracture' techniques. These techniques require the cutting or removal of implant during the specimen preparation process. The aim of this study is to explore a new impression technique that does not require any cutting or removal of implant for contour analysis of soft tissue around four types of titanium (Ti) surface roughness using an in vitro three-dimensional oral mucosal model (3D OMM). METHODS: The 3D OMM was constructed by co-culturing a keratinocyte cell line TR146 and human oral fibroblasts on to an acellular dermis scaffold. On the fourth day, a Ti disk was placed into the model. Four types of Ti surface topographies, i.e. polished, machined, sandblasted and anodized were tested. After 10 d of culture, the specimens were processed based on undecalcified (ground sectioning), electropolishing and impression techniques for contour analysis of the implant-soft tissue interface. RESULTS: Under light microscopic examination of the ground and electropolishing sections, it was found that the cell line-based oral mucosa formed a peri-implant-like epithelium attachment on to all four types of Ti surfaces. In contour analysis, the most common contour observed between the cell line-based oral mucosa and Ti surface was at an angle ranging between 45° and 90°. CONCLUSION: The in vitro cell line-based 3D OMM formed a peri-implant-like epithelium at the implant-soft tissue interface. The contour of the implant-soft tissue interface for the four types of Ti surface was not significantly different.

Tissue-engineered oral mucosa.

Advances in tissue engineering have permitted the three-dimensional (3D) reconstruction of human oral mucosa for various in vivo and in vitro applications. Tissue-engineered oral mucosa have been further optimized in recent years for clinical applications as a suitable graft material for intra-oral and extra-oral repair and treatment of soft-tissue defects. Novel 3D in vitro models of oral diseases such as cancer, Candida, and bacterial invasion have been developed as alternatives to animal models for investigation of disease phenomena, their progression, and treatment, including evaluation of drug delivery systems. The introduction of 3D oral mucosal reconstructs has had a significant impact on the approaches to biocompatibility evaluation of dental materials and oral healthcare products as well as the study of implant-soft tissue interfaces. This review article discusses the recent advances in tissue engineering and applications of tissue-engineered human oral mucosa.

A review of histomorphometric analysis techniques for assessing implant-soft tissue interface.

The success of dental implant treatment depends on the healing of both hard and soft tissues. While osseointegration provides initial success, the biological seal of the peri-implant soft tissue is crucial for maintaining the long term success of implants. Most studies of the biological seal of peri-implant tissues are based on animal or monolayer cell culture models. To understand the mechanisms of soft tissue attachment and the factors affecting the integrity of the soft tissue around the implants, it is essential to obtain good quality histological sections for microscopic examination. The nature of the specimens, however, which consist of both metal implant and soft peri-implant tissues, poses difficulties in preparing the specimens for histomorphometric analysis of the implant-soft tissue interface. We review various methods that have been used for the implant-tissue interface investigation with particular focus on the soft tissue. The different methods are classified and the advantages and limitations of the different techniques are highlighted.

Numbness of the ear following inferior alveolar nerve block: the forgotten complication.

This article presents a distant complication in the auricle following the administration of a standard inferior alveolar nerve block. The patient experienced profound numbness of the auricle on the ipsilateral side of the injection that lasted for about an hour following unintended injection to the auriculotemporal nerve.

Avoiding Osteoradionecrosis - The Dental Surgeo's Nightmaren.

Osteoradionecrosis is a severe debilitating complication; it may occur from radiotherapy to the bones. It is a dental surgeon's nightmare as it may be long standing and difficult to manage. Osteoradionecrosis is characterised by hypoxia, hypocellularity and hypovascularity of the affected tissue. This paper reviews osteoradionecrosis in relation to dental treatment.

Clinicopathologic study of odontogenic keratocysts in Singapore and Malaysia.

This was a retrospective study of odontogenic keratocysts in people from the Singapore-Malaysian region. The purpose of this study was to present the clinicopathologic features of odontogenic keratocysts in the Oriental population and to compare these data with those from other reported studies. Biopsy records from 1981 to 1992 of 61 cases of odontogenic keratocysts from patients in Malaysia and Singapore showed that 42.6% of patients were female and 57.4% of patients were male. Among patients with cysts, 75.4% were Chinese, 6.6% were Malays, 9.8% were Indians and 8.2% were other ethnic groups. The mean age of these patients was 26.98 +/- 15.38 years with a peak incidence occurring in the second to fourth decades. The location of the lesions was more often in the mandible (65.5%) than the maxilla (31.0%). There was a marked predilection for lesions to occur in the posterior mandible. Histologically, 90.2% of the cysts were lined with a para-keratinized stratified squamous epithelium while only 3.3% of the cysts were lined with orthokeratinized stratified squamous epithelium. Mixed para-keratinized and orthokeratinized epithelial linings were observed in 4 cases (6.5%). The cyst linings were mainly uninflamed (95.1%). Inflammation of the cyst wall was found in 42 cases (68.8%). Twelve (19.7%) cases contained keratin in the lumen. A satellite cyst was observed in only 6 cases (9.8%). In conclusion, most clinical and histological features seen in this study were similar to those found for Caucasians. The only clinical feature that was different was the peak age incidence, that ranged from the second to fourth decades, with an absence of a second peak. Odontogenic keratocysts presenting at the site of the dentigerous cyst were observed in 7 cases (11.5%).

Red man syndrome during administration of prophylactic antibiotic against infective endocarditis.

Red man syndrome (RMS) is the occurrence flushing, pruritus, chest pain, muscle spasm or hypotension during vancomycin infusion. It usually happens as a result of rapid infusion of the drug but may also occur after slow administration. The frequency and severity of this phenomenon diminish with repeated administration of vancomycin. A case is presented whereby RMS occurred while prophylactic antibiotic against infective endocarditis was administered.

Making your own retrograde carrier.

One of the problems faced by manufacturers is the difficulty in constructing a robust and reliable, angled applicator tip. This can be overcome by handmaking your own retrograde carrier. The applicator tip may be bent to about 50 degrees and, if a kink occurs while bending the tip, it can be replaced easily by a new modified needle. Because the wire used is flexible, it can adapt to the bend without a problem. Narrower carriers can also be made using a 20-G needle, perhaps more suitable for retrograde fillings of molar apices. Because the carrier is designed to be used once only, the problems of it being difficult to load and liable to blockages should not arise.

Familial cases of missing mandibular incisor: three case presentations.

Hypodontia is the congenital absence of one or more teeth because of agenesis. The most commonly missing teeth are the third molars, the maxillary lateral incisors and the second premolars. Cases are presented of three patients with a missing mandibular incisor.

Understanding the dental need and care during pregnancy: a review.

This paper reviews the oral and dental lesions that are seen during pregnancy. Trimester approach should be adopted in the management of the pregnant patients. A good dental preventive programme is essential. The significance of prescribing fluoride supplements and the use of dental radiography during pregnancy is also briefly reviewed.