Risk of inferior alveolar nerve injury with coronectomy vs surgical extraction of mandibular third molars-A comparison of two techniques and review of the literature.

The removal of mandibular third molar teeth is one of the most common oral surgical procedures. In a significant number of patients, it carries a degree of associated morbidity, including damage to the inferior alveolar nerve (IAN). For this reason, practitioners desire the most up-to-date guidance on the most appropriate technique, informed by the best available evidence that will produce the lowest incidence of iatrogenic complications. The aim of this study was to perform a systematic review comparing the effect of coronectomy vs complete surgical extraction of mandibular third molar teeth on the risk of IAN injury and other complications in adults. Studies were identified through Embase (1980-2016) and Ovid MEDLINE (1946-2016) database searches. Search terms included coronectomy, partial root removal, deliberate vital root retention, odontectomy, surgical removal, surgical extraction, complete tooth extraction and extract. Limits of the study included humans, English language and randomised controlled trials (RCTs). Only RCTs comparing IAN damage associated with surgical extraction of mandibular third molars vs coronectomy were included. From our database searches, we identified two unique RCTs matching the inclusion criteria. Both evaluated patients who had specific radiographic signs of intimate relationships with the IAN. Upon detailed analysis, the studies were noted to exhibit a high risk of bias in many categories, thereby rendering their results inconclusive. Although evidence from two RCTs suggests that coronectomy can reduce the risk of IAN injury compared to surgical removal of high-risk mandibular third molars, the quality of evidence is insufficient to provide definitive conclusions regarding the preferred technique.

Characterising the variations in ethnic skin colours: a new calibrated data base for human skin.

BACKGROUND: Accurate skin colour measurements are important for numerous medical applications including the diagnosis and treatment of cutaneous disorders and the provision of maxillofacial soft tissue prostheses. METHODS: In this study, we obtained accurate skin colour measurements from four different ethnic groups (Caucasian, Chinese, Kurdish, Thai) and at four different body locations (Forehead, cheek, inner arm, back of hand) with a view of establishing a new skin colour database for medical and cosmetic applications. Skin colours are measured using a spectrophotometer and converted to a device-independent standard colour appearance space (CIELAB) where skin colour is expressed as values along the three dimensions: Lightness L*, Redness a* and Yellowness b*. Skin colour differences and variation are then evaluated as a function of ethnicity and body location. RESULTS: We report three main results: (1) When plotted in a standard colour appearance space (CIELAB), skin colour distributions for the four ethnic groups overlap significantly, although there are systematic mean differences. Between ethnicities, the most significant skin colour differences occur along the yellowness dimension, with Thai skin exhibiting the highest yellowness (b*) value and Caucasian skin the lowest value. Facial redness (a*) is invariant across the four ethnic groups. (2) Between different body locations, there are significant variations in redness (a*), with the forehead showing the highest redness value and the inner arm the lowest. (3) The colour gamut is smallest in the Chinese sample and largest in the Caucasian sample, with the Chinese gamut lying entirely the Caucasian gamut. Similarly, the largest variability in skin tones is found in the Caucasian group, and the smallest in the Chinese group. CONCLUSION: Broadly speaking, skin colour variation can be explained by two main factors: individual differences in lightness and yellowness are mostly due to ethnicity, whereas differences in redness are primarily due to different body locations. Variations in lightness are more idiosyncratic probably reflecting the large influence of environmental factors such as exposure to sun.

Evidence-based outcomes following inferior alveolar and lingual nerve injury and repair: a systematic review.

The inferior alveolar nerve (IAN) and lingual (LN) are susceptible to iatrogenic surgical damage. Systematically review recent clinical evidence regarding IAN/LN repair methods and to develop updated guidelines for managing injury. Recent publications on IAN/LN microsurgical repair from Medline, Embase and Cochrane Library databases were screened by title/abstract. Main texts were appraised for exclusion criteria: no treatment performed or results provided, poor/lacking procedural description, cohort <3 patients. Of 366 retrieved papers, 27 were suitable for final analysis. Treatment type for injured IANs/LNs depended on injury type, injury timing, neurosensory disturbances and intra-operative findings. Best functional nerve recovery occurred after direct apposition and suturing if nerve ending gaps were <10 mm; larger gaps required nerve grafting (sural/greater auricular nerve). Timing of microneurosurgical repair after injury remains debated. Most authors recommend surgery when neurosensory deficit shows no improvement 90 days post-diagnosis. Nerve transection diagnosed intra-operatively should be repaired in situ; minor nerve injury repair can be delayed. No consensus exists regarding optimal methods and timing for IAN/LN repair. We suggest a schematic guideline for treating IAN/LN injury, based on the most current evidence. We acknowledge that additional RCTs are required to provide definitive confirmation of optimal treatment approaches.

Can masticatory electromyography be normalised to submaximal bite force?

The combination of bite force and jaw muscle electromyography (EMG) provides an insight into the performance of the stomatognathic system, especially in relation to dynamic movement tasks. Literature has extensively investigated possible methods for normalising EMG data encapsulating many different approaches. However, bite force literature trends towards normalising EMG to a maximal voluntary contraction (MVC), which could be difficult for ageing populations or those with poor dental health or limiting conditions such as temporomandibular disorder. The objectives of this study were to (i) determine whether jaw-closing muscle activity is linearly correlated with incremental submaximal and maximal bite force levels and (ii) assess whether normalising maximal and submaximal muscle activity to that produced when performing a low submaximal bite force (20 N) improves repeatability of EMG values. Thirty healthy adults (15 men, 15 women; mean age 21 ± 1·2 years) had bite force measurements obtained using a custom-made button strain gauge load cell. Masseter and anterior temporalis muscle activities were collected bilaterally using surface EMG sensors whilst participants performed maximal biting and three levels of submaximal biting. Furthermore, a small group (n = 4 females) were retested for reliability purposes. Coefficients of variation and intra-class correlation coefficients showed markedly improved reliability when EMG data were normalised compared to non-normalised. This study shows that jaw muscle EMG may be successfully normalised to a very low bite force. This may open possibilities for comparisons between at-risk sample groups that may otherwise find it difficult to produce maximal bite force values.

Evidence of frequent dosing errors in paediatrics and intervention to reduce such prescribing errors.

WHAT IS KNOWN AND OBJECTIVE: Drug prescribing is an essential part of inpatient care, and prescription errors/omissions have the potential to lead to disastrous consequences. Paediatric inpatient prescribing is particularly sensitive to error due to the weight-adjusted dosing of many medications prescribed in the acute setting. Previous studies have described a high incidence of error in adult drug chart completion, although no studies to date have assessed the error seen in the paediatric setting or accuracy of weight-adjusted dosing. Our objective was to determine the degree of error seen in paediatric drug prescribing for patients admitted under the care of oral and maxillofacial surgery and to explore practical and accessible methods through which error can be reduced. METHODS: We retrospectively evaluated inpatient drug charts to assess the prescribing practices seen for patients admitted under the care of oral and maxillofacial surgery in an NHS children's hospital and compared these findings against established hospital standards. The study also examined the distribution and variability of weight-adjusted dose prescribing in an attempt to set targets for auditing improvements following the implementation of changes. RESULTS AND DISCUSSION: Prescriptions were completed by a combination of doctors from maxillofacial and anaesthetic teams, with similar error rates seen in both specialties. 13% of drug charts contained one or more errors in frequency prescribing. For weight-adjusted drugs, a median under-dosage of -5·4% was noted, with an IQR of -12 to -0·6. Our study has confirmed that errors are common both in the manual completion of paediatric prescription charts and in the calculation of weight-adjusted doses. WHAT IS NEW AND CONCLUSION: We conclude that inaccuracies in prescription chart completion are a frequent occurrence and that dosage and frequency-prescribing errors may potentially act synergistically to create a significant disparity between the recommended and actual amount of drug that is delivered. Our study demonstrates a clear bias towards under-prescribing weight-adjusted doses which may be contributing to reduced efficacy of analgesia, among other drugs. Simple methods can be implemented on a specialty basis to improve the accuracy of both drug chart completion and weight-adjusted dosing.

Clinical medical sciences for undergraduate dental students in the United Kingdom and Ireland - a curriculum.

The technical aspects of dentistry need to be practised with insight into the spectrum of human diseases and illnesses and how these impact upon individuals and society. Application of this insight is critical to decision-making related to the planning and delivery of safe and appropriate patient-centred healthcare tailored to the needs of the individual. Provision for the necessary training is included in undergraduate programmes, but in the United Kingdom and Ireland there is considerable variation between centres without common outcomes. In 2009 representatives from 17 undergraduate dental schools in the United Kingdom and Ireland agreed to move towards a common, shared approach to meet their own immediate needs and that might also be of value to others in keeping with the Bologna Process. To provide a clear identity the term 'Clinical Medical Sciences in Dentistry' was agreed in preference to other names such as 'Human Disease' or 'Medicine and Surgery'. The group was challenged to define consensus outcomes. Contemporary dental education documents informed, but did not drive the process. The consensus curriculum for undergraduate Clinical Medical Sciences in Dentistry teaching agreed by the participating centres is reported. Many of the issues are generic and it includes elements that are likely to be applicable to others. This document will act as a focus for a more unified approach to the outcomes required by graduates of the participating centres and act as a catalyst for future developments that ultimately aim to enhance the quality of patient care.

Use of YouTube™ as a self-directed learning resource in oral surgery among undergraduate dental students: a cross-sectional descriptive study.

This cross-sectional descriptive study was done to assess the use and effectiveness of YouTube™ as a learning resource for oral surgery by fourth and final-year dental students at a single university. A study-specific survey was distributed to fourth (n=83) and final-year (n=86) dental students during a six-week period. In total, 122 (72%) responded. Most (n=82, 67%) used YouTube™ as study material, and 50 (41%) stated that the videos had influenced their practice. Generally, the quality was rated as good, and YouTube™ was a popular and influential learning resource. However, the material was not always consistent with that of the curriculum, and students should use it with caution as there is no quality assurance with respect to educational content or learning outcomes. Institutions should provide recorded learning material and teach students skills in the critical appraisal of contemporary teaching materials such as open-resource videos.

Sarcoidosis presenting as an isolated facial swelling--an unexpected diagnosis?

UNLABELLED: Sarcoidosis is a rare chronic granulomatous disease of unknown aetiology that primarily affects individuals between 30 and 50 years of age. It is usually characterized by the presence of non-caseating, granulomatous, epithelioid tissue at the sites affected with involvement of lymphoid tissue. Sarcoidosis confined to lymph nodes, salivary glands and other tissue in the head and neck is uncommon and usually indicative of a more generalized systemic process. Within the differential diagnosis of isolated masses associated with the head and neck, sarcoidosis is indeed rare. We report a case of systemic sarcoidosis presenting as a small localized facial swelling. The report illustrates that other symptoms, albeit mild, may direct the clinician to a provisional diagnosis of generalized sarcoidosis. CLINICAL RELEVANCE: Within the differential diagnosis of isolated facial swellings, sarcoidosis is extremely uncommon. However, clinicians should consider the diagnosis, especially in the presence of other, albeit mild, symptoms.

High-plasticity mesenchymal stem cells isolated from adult-retained primary teeth and autogenous adult tooth pulp--A potential source for regenerative therapies?

PURPOSE: The objective of this study was to compare the growth rate, morphology, immunohistology and plasticity of autogenous adult-retained SHEDs (arSHEDs) and adult dental pulp stem cells (DPSCs) obtained from the same donor. METHODS: Expression of the mesenchymal stem cell markers CD44, CD90, CD105, caspase-3 and GAPDH were assessed using RT-PCR. Caspase-3 and CD44 were also evaluated at the protein level by western blotting of cell lysates. Plasticity of DPSCs and arSHEDs were tested by culture in adipogenic, chondrogenic, osteogenic and Schwann cells induction media. RESULTS: DPSCs and arSHEDs were isolated by explant culturing and were similarly positive for growth rate and all tested markers. Furthermore, DPSCs and arSHEDs could be driven to adipocyte, chondrocyte, osteocyte and Schwann cells lineages thus indicating similar plasticity as precursor cells. CONCLUSION: This study demonstrates the similarities between DPSCs and arSHEDs in a unique situation, where both stem cells (SC) types were obtained from a single patient and thus represent an alternative source of SC's for tissue engineering and regeneration.

The influence of age and the level of arterial blood pressure on the changes in forearm blood flow resulting from sudden alterations in local vascular transmural pressure.

Forearm blood flow was measured by venous occlusion plethysmography in normotensive subjects of various ages and in patients with treated or untreated hypertension. Brief exposure of one forearm to pressures below atmospheric was used to study the transient local changes in arterial inflow which occurred with changes in transmural pressure induced in this way. The increase in initial arterial inflow with such an exposure to suction in a group of young normotensive women was only slightly reduced in two groups of older women. However, a group of subjects with untreated hypertension showed a significantly smaller initial inflow during the suction. There was some indication that adequate treatment of high blood pressure might reverse this effect.

Revolution vs status quo? Non-intervention strategy of asymptomatic third molars causes harm.

The Faculty of Dental Surgery of the Royal College of Surgeons of England has prompted the National Institute for Health and Care Excellence to urgently re-assess the TA1 guidance on extractions of wisdom teeth and highlighted required amendments to the present version in light of published evidence concerning the harm caused by wisdom tooth retention. This article seeks to address the recent concerns relating the increasing frequency of distal-cervical caries in lower second molar teeth when associated with asymptomatic partially erupted mesial or horizontal impacted mandibular third molars. Such acute angle impactions are classified as partially erupted when one of the third molar cusps breached the epithelial attachment of the distal aspect of the second molar, thus prevents the formation of a gingival seal. At its earliest stage the wisdom tooth appears clinically absent or unerupted, yet histologically the architecture of the gingival epithelium has been disrupted allowing ingress of microbes, demineralisation and succeeding cavitation to take place on the distal aspect of the second molar. We hope to highlight the difficulties faced in addressing this growing clinical problem and encourage clinicians to re-evaluate their own caries risk assessment and caries prevention strategy in relation to mesial and horizontal third molar extractions.

Effect of iron concentration and growth rate on the expression of protein G in Pseudomonas aeruginosa.

Protein G of Pseudomonas aeruginosa was found to be strongly induced by iron and repressed by iron restriction in chemically defined medium (CDM). Expression in batch culture was influenced by phase of growth and in iron limited continuous culture by the doubling time. We suggest that protein G may constitute a low-affinity iron uptake system.

Ectopic neural activity from myelinated afferent fibres in the lingual nerve of the ferret following three types of injury.

Sensory disturbances following nerve injury may result from abnormal neural activity initiated at the injury site. We have studied the activity generated in the lingual nerve after three types of injury which may have variable potentials for the initiation of sensory disturbances. We have also compared the results with those found after damage to the inferior alveolar nerve, another branch of the trigeminal nerve, to determine whether differences in nerve fibre type or location affect the level of abnormal activity. In anaesthetised adult male ferrets the left lingual nerve was either ligated and cut distally, chronically constricted, or sectioned and allowed to regenerate. Following recovery periods of 3 days-6 months, single unit electrophysiological recordings were made from central to the injury site. After all three types of injury, some of the damaged axons at the injury site developed spontaneous activity (up to 36% of units) and mechanical sensitivity (up to 35% of units). There were significantly fewer spontaneously active units after ligation than after the other two types of injury but the level of mechanical sensitivity was not significantly different between the three types of injury. There was a significant increase in the spontaneous activity between 3 weeks and later recovery periods following both ligation and section injuries, and this late increase was not seen in our previous studies on the inferior alveolar nerve. Differences in the time-course of ectopic activity in adjacent branches of the trigeminal nerve suggest that the fibre types or anatomical relationships affect the outcome of injury.

Sympathectomy does not affect the early ectopic discharge from myelinated fibres in ferret inferior alveolar nerve neuromas.

Ectopic neural activity from damaged axons is thought to contribute to the development of sensory disorders following nerve injury. Here we have studied the role of sympathetic fibres in the generation or potentiation of this abnormal activity by determining the effect of predegenerating these fibres. Twelve adult ferrets were used in the study and six of them underwent sympathectomy by removal of the left superior cervical ganglion. Electrophysiological recordings were made from myelinated axons in fine filaments dissected from the inferior alveolar nerve, 3 days after it had been ligated further distally, and the level of spontaneous activity and mechanical sensitivity was determined. There was no significant difference between the level or characteristics of spontaneous activity, or the level of mechanical sensitivity, in the two groups of animals. We conclude that, in this animal model, the absence of sympathetic nerve fibres does not affect the development or characteristics of ectopic neural activity in the early period following nerve injury.

Geographical variations in rates of ophthalmic surgery.

AIMS/BACKGROUND: Geographical variations in health care are common. There is, however, no simple explanation for why they arise. Variations in rates of ophthalmic surgery in the population aged 65 and over were investigated, with the aim of determining their cause. METHODS: Routine data sources were used to obtain the 1991-2 age and sex standardised rates for English health districts with an ophthalmic unit. Weighted least squares regression was used to study the relation between these rates and various factors describing the population and the provision of care. RESULTS: Surgery rates varied more than threefold. High rates of surgery were associated with high throughput and bed numbers (both p < 0.001), high proportions of day case surgery (p < 0.001), long waiting lists (p < 0.001), and a high number of theatre sessions (p = 0.002). Conversely, a high percentage of emergency admissions was associated with lower rates of surgery (p = 0.004). These six variables accounted for 58% of the variation. CONCLUSION: Geographical variations were found to exist, less than two thirds being explained by differences in the provision of care. The remaining variation may partly be attributed to private practice and the lack of consensus for many ophthalmic procedures (the 'surgical signature'), including a lowering of the threshold for surgery. These findings have implications for the planning of ophthalmic services.

Drug interactions in general dental practice--considerations for the dental practitioner.

The aim of this article is to explore the diverse and complex nature of pharmacological drug-drug interactions in the general dental practice setting. Using published NHS statistics, this article will highlight medications for common medical conditions that could interact with frequently prescribed drugs by the general dental practitioner.

Interventions for the prevention of dry socket: an evidence-based update.

This paper reviews the latest evidence for local and systemic interventions for the prevention of alveolar osteitis (dry socket). Dry socket is a painful and common post-operative complication following exodontia. Any interventions for the prevention of dry socket could reduce both its incidence and help avoid this painful complication. Prophylactic measures proposed in the literature are discussed. Furthermore, this article discusses both the clinical and histological stages of a normal healing socket.

Treatment of the edentulous atrophic maxilla using zygomatic implants: evaluation of survival rates over 5-10 years.

The aim of this retrospective observational cohort study was to analyse and report the 5-10-year survival rates of endosseous zygomatic implants used in the rehabilitation of the atrophic maxilla. Forty-three consecutive zygomatic implant placements in 25 patients were evaluated over a 5-10-year period. All zygomatic implant surgery was carried out under general anaesthesia. Nobel Biocare zygomatic machined-surface implants were used, and placement was undertaken using the modified sinus slot method. The main outcome measures and determinants for success were survival of the restored implants and the proportion of originally planned prostheses delivered to patients. Of the 25 patients treated, 12 were male and 13 were female; 19 were non-smokers, and the mean age at time of surgery was 64 years. Patients were treatment-planned for implant-retained bridgework, a removable prosthesis retained by fixed cast gold or milled titanium beams, or magnet-retained removable prostheses. A combination of zygomatic and conventional implants was used in all but one patient. In this study it was shown that the overall success rate for zygomatic implants was 86%, with six of the implants either failing to integrate or requiring removal due to persistent infection associated with the maxillary sinus. All patients received their planned prosthesis, although in six cases the method of retention required modification. This study illustrates that zygomatic implants are a successful and important treatment option when trying to restore the atrophic maxilla, with the potential to avoid additional augmentation/grafting procedures and resulting in a high long-term success rate.

Evidence for anti-inflammatory and putative analgesic effects of a monoclonal antibody to calcitonin gene-related peptide.

BACKGROUND: Calcitonin gene-related peptide (CGRP) is a powerful pro-inflammatory mediator thought to play a significant role in the development of inflammation and pain. We investigated the role of CGRP in trigeminal inflammatory pain by determining the ability of a monoclonal antibody to CGRP to modify central Fos expression in response to stimulation of the inflamed ferret tooth pulp. We also assessed the effect of the antibody on pulpal inflammation. METHODS: Ten adult ferrets were prepared under anaesthesia to allow stimulation of the upper and lower left canine pulps, recording from the digastric muscle and intravenous injections at subsequent experiments. In all animals, pulpal inflammation was induced by introducing human caries into a deep buccal cavity. Four days later animals were treated intravenously with either CGRP antibody (n=5) or vehicle (n=5). After a further 2 days animals were re-anaesthetised and the tooth pulps stimulated at 10 times jaw-opening reflex threshold. Brainstems and tooth pulps were processed immunohistochemically for Fos and the common leucocyte marker CD45, respectively. RESULTS: Fos was expressed in ipsilateral trigeminal subnuclei caudalis (Vc) and oralis (Vo). Significantly fewer Fos-positive nuclei were present within Vc of CGRP antibody-treated animals (p=0.003 vs vehicle-treated). Mean percentage area of staining for CD45 was significantly less in antibody-treated animals (p=0.04 vs vehicle-treated). CONCLUSIONS: This is the first direct evidence that sequestration of CGRP has anti-inflammatory and putative analgesic effects. Previous studies using this Fos model have demonstrated that it is able to predict clinical analgesic efficacy. Thus these data indicate that this antibody may have analgesic effects in dental pain and other types of inflammatory-mediated transmission, and suggest that this is in part due to peripheral anti-inflammatory effects.