Peri-articular bone formation involving the temporomandibular joint: a narrative summary and Delphi consensus of a new classification system.

Heterotopic ossification (HO) is defined as 'bone where it does not belong'. Given the historical variety of nomenclature and eponyms, there is significant confusion about the etiology, pathogenesis, classification, and treatment of HO related to the temporomandibular joint (TMJ). The existing classifications for TMJ HO have shortcomings: they relate to specific populations, use differing imaging studies and demographic data, do not universally include alloplastic/autologous replacements, are based variously on radiological and/or clinical presentations that cannot always be combined, and were largely developed to assist oral and maxillofacial surgeons in surgical management. These deficiencies make it problematic to compare studies, draw valid conclusions, and pursue research. The aim of this study was to develop a new, more inclusive classification for TMJ HO. Currently available classifications were evaluated and a Delphi-type system used to build consensus from clinicians and researchers to develop a new system. Fourteen unique classifications for TMJ ankylosis/HO were identified. In light of the biological specifics related to heterotopic calcification of extracellular matrix versus heterotopic formation of actual bone, the group recommends a more unambiguous term - peri-articular bone formation - and proposes a new classification. This will help clinicians and researchers to study, describe, and manage various types of ectopic bone associated with the TMJ.

Which comorbid conditions and risk factors affect the outcome of and progression to total temporomandibular joint replacement?

Surgery is an effective modality to reduce pain and increase range of motion (ROM) in TMJ disorders. The aim of this study was to determine which comorbidities and risk factors affect outcomes and progression to total joint replacement (TJR). A retrospective cohort study of patients who underwent TJR between 2000- 2018 at MGH was conducted. Primary outcome was successful vs unsuccessful surgery. Success was defined as pain score ≤ 4 and ROM ≥ 30 mm; failure was defined as lack of either or both. Secondary outcome was differences between patients undergoing TJR only (group A) and those undergoing multiple surgeries progressing to TJR (group B). 99 patients (82 females, 17 males) were included. Mean follow-up was 4.1 years; mean age at first surgery was 34.2 (range 14-71) years. Unsuccessful outcomes were associated with high preoperative pain, low preoperative ROM, and higher number of surgeries. Male sex favored successful outcome. 75.0% group A and 47.6% group B had successful outcome. Group B had more females, higher postoperative pain, lower postoperative ROM, and used more opioids compared to group A. High preoperative pain, low preoperative ROM, and more surgeries were associated with poorer outcomes and frequent opioid use.

Persistent effects of underground longwall coal mining on freshwater wetland hydrology.

More than half of global wetlands have been lost because of anthropogenic disturbance, with the trend of decline continuing in the 21st century. While much of this loss relates to changes in surface flows, groundwater is also critical to sustaining wetland hydrology. Underground longwall mines extract coal seams, in turn fracturing the overlying stratigraphy, influencing aquifer connectivity and affecting surface flows via subsidence disturbance. Crucially, this subterranean disturbance may disrupt the hydrological processes that sustain freshwater wetlands at the surface. Here we present a new designed empirical study that compares the persistence of soil moisture after a rainfall event in wetlands subject to underground longwall coal mining to that in unmined reference wetlands. Accelerated Failure Time models showed that mined wetlands were persistently drier, retained water for shorter durations and exhibited less spatial differentiation than unmined wetlands. This quantitative evidence of severe, persistent hydrological change following resource extraction reinforces earlier observations and has important implications for biodiversity and provision of ecosystem services to a large urban population. If Ecologically Sustainable Development (ESD) outcomes and effective deployment of the mitigation hierarchy are to be achieved in line with current legislative and policy paradigms, our results highlight the need for more emphasis on impact avoidance and minimisation than restoration or offsetting to protect water and biodiversity values. Given severe constraints on restoration success, greater emphasis on avoidance in mine design and approval processes offers realistic opportunities for an improved balance between sustaining irreplaceable public assets and short-term benefits from non-renewable resource extraction.

Detecting state changes for ecosystem conservation with long-term monitoring of species composition.

Effective conservation requires an understanding not only of contemporary vegetation distributions in the landscape, but also cognizance of vegetation transitions over time with the goal of maintaining persistence of all states within the landscape. Using a state and transition model framework, we investigated temporal transitions over 31 years in species composition among five upland swamp vegetation communities in southeastern Australia. We applied fuzzy clustering to document transitions across communities; evaluated the resilience and resistance of communities to change; and explored the relationship between ecosystem states and major environmental factors posited to structure the system. We also evaluated the predictive ability of an established vegetation dynamics model. We found that community composition remained stable or underwent reversible or directional transitions depending on the vegetation type. Wetter communities (Ti-tree thicket and Cyperoid heath) were more stable (i.e., resistant) while drier communities showed a greater propensity to transition (i.e., had lower resistance) under the observed disturbance regime (low variance fire intervals). The resilience of drier communities differed under this regime, with Banksia thicket showing reversible compositional change, while Restioid heath and Sedgeland showed directional change. In accord with an established conceptual model, we found that communities were distributed along a hydrological gradient. In addition, vegetation structure, along with light penetration to ground level, differentiated communities. However, internal dynamics of drier communities were complex: differences in fire regime (penultimate fire interval in 2014 and number of fires since 1965) were unable to predict differences in community membership among sites. Aspects of the fire regime are expected to be more important predictors if fire intervals vary more strongly among sites in the future. Fuzzy clustering of compositional data allows managers to track community transitions over time and facilitates planned interventions for conservation purposes.

Major conservation policy issues for biodiversity in Oceania.

Oceania is a diverse region encompassing Australia, Melanesia, Micronesia, New Zealand, and Polynesia, and it contains six of the world's 39 hotspots of diversity. It has a poor record for extinctions, particularly for birds on islands and mammals. Major causes include habitat loss and degradation, invasive species, and overexploitation. We identified six major threatening processes (habitat loss and degradation, invasive species, climate change, overexploitation, pollution, and disease) based on a comprehensive review of the literature and for each developed a set of conservation policies. Many policies reflect the urgent need to deal with the effects of burgeoning human populations (expected to increase significantly in the region) on biodiversity. There is considerable difference in resources for conservation, including people and available scientific information, which are heavily biased toward more developed countries in Oceania. Most scientific publications analyzed for four threats (habitat loss, invasive species, overexploitation, and pollution) are from developed countries: 88.6% of Web of Science publications were from Australia (53.7%), New Zealand (24.3%), and Hawaiian Islands (10.5%). Many island states have limited resources or expertise. Even countries that do (e.g., Australia, New Zealand) have ongoing and emerging significant challenges, particularly with the interactive effects of climate change. Oceania will require the implementation of effective policies for conservation if the region's poor record on extinctions is not to continue.

Assessment of contact allergens by dissociation of irritant and sensitizing properties.

The human organotypic skin explant culture (hOSEC) model is a promising alternative in vitro model for screening contact allergens. In this model, the chemical-induced migration of Langerhans cells (LCs) out of the epidermis, evaluated after a 24-h exposure period, is used as a measure of sensitizer potential. As skin irritants can also induce LC migration it is essential that concentrations of test chemicals are used that are not even weakly irritant. Using the hOSEC irritation model chemicals are classified as weak irritants if they are toxic after a 48-h exposure period. Toxicity is determined by methyl green-pyronine (MGP) staining of hOSEC. We studied three frequently used non-sensitizing skin irritants and six potent or frequent human sensitizers in a dose-response. A complete discrimination between non-sensitizers and contact sensitizers was obtained for the chemicals tested when the concentrations used were lower than the weak irritant concentrations. Frequency of positive allergen reactions in patch test of human populations correlated with the difference between weak irritant concentrations and the lowest concentration inducing significant LC migration. Sensitizer potency correlated with chemical irritancy as determined by keratinocyte death. For the compounds tested, the hOSEC model predicted allergenicity in humans better than the guinea pig maximization test and the mouse local lymph node assay.

Craniofacial skeletal deviations following in utero exposure to the anticonvulsant phenytoin: monotherapy and polytherapy.

OBJECTIVE: To identify and quantify the craniofacial effects from prenatal exposure to phenytoin monotherapy and polytherapy using cephalometric, hand-wrist, and panoramic radiographs and to determine if such deviations persist with age. DESIGN: Craniofacial structures of 28 anticonvulsant-exposed individuals were evaluated using 20 landmarks in lateral cephalometric radiographs and 19 landmarks in frontal cephalometric radiographs. Skeletal maturity was assessed using hand-wrist radiographs. Dental maturity and the presence of dental anomalies were evaluated using panoramic radiographs. Eleven individuals were re-evaluated 7 years later, on average, to determine the persistence of any measured deviations. SETTING AND SAMPLE POPULATION: Department of Growth and Development, Harvard School of Dental Medicine and Massachusetts General Hospital. Patients were recruited from several sources. OUTCOME MEASURE: The evaluated dimensions included linear, angular, and proportional measures. RESULTS: The most common deviations were decreased height and length of the maxilla, decreased length of the posterior cranial base, length of the mandible, cranial width and level of the cribriform plate, and a decrease in the Wits Appraisal assessment. The deviations were more significant in the polytherapy-exposed individuals than in the monotherapyexposed individuals. These deviations, especially in the maxilla, persisted with age as revealed in a re-evaluation of 11 individuals. CONCLUSION: The craniofacial skeletal findings among individuals exposed in utero to phenytoin monotherapy or phenytoin polytherapy, when considered in aggregate, suggest a mild pattern of maxillary hypoplasia that becomes more pronounced with age.

Effect of orthognathic surgery on the temporomandibular joint in patients with anterior open bite.

This study examined the prevalence of temporomandibular joint (TMJ) signs and symptoms in patients with anterior open bite. The influence of orthognathic surgery on the TMJ in these patients and the interaction of occlusal and psychologic variables on the presence and/or persistence of pain was studied. A retrospective survey of 83 patients with an anterior open bite who underwent orthognathic surgery was carried out. Records were examined for the prevalence of abnormal TMJ signs and symptoms, including pain. A survey was mailed to these patients that consisted of: (1) the TMJ Scale, (2) the Symptom Checklist 90 (SCL90), (3) the Spielberger State-Trait Anxiety Inventory (STAI), and (4) a visual analog scale on which patients indicated their degree of satisfaction with the procedure. Thirty-seven (42%) patients responded to the survey, and 13 (15%) also attended a clinical and radiographic examination. Multiple regression analysis was used for statistical analysis of the factors contributing to the presence and/or persistence of pain. In the preoperative group, the prevalence of pain was 32%, dysfunction 40%, and limitation of opening 7%. Age and gender were significantly associated with the presence of pain. The overall prevalence of abnormal TMJ signs and symptoms was not significantly different after orthognathic surgery. An abnormal psychologic profile was the most significant factor associated with the presence and/or persistence of pain. It is concluded that that the prevalence of temporomandibular disorders in anterior open bite patients increases with age, is significantly higher in females, and is not influenced by other occlusal variables. Furthermore, orthognathic surgery does not significantly influence temporomandibular disorders in patients with anterior open bite. Female patients, particularly those with an abnormal psychologic profile, are at a higher risk of persistent postoperative TMJ pain.

Chronic neurogenic facial pain: lack of response to intravenous phentolamine.

AIMS: Chronic neurogenic facial pain is commonly resistant to treatment and is often the source of significant patient morbidity. Adrenergic mechanisms are postulated to play a role in producing this type of pain, and adrenergic blocking agents are frequently used in clinical practice for pain control therapy. The analgesic effectiveness of an adrenergic blocking agent, intravenous phentolamine, was compared to saline and intravenous lidocaine in the present study using a single-blind protocol in patients with chronic neurogenic facial pain. METHODS: Thirty patients were studied whose common clinical features included pain for more than 6 months, unilateral trigeminal distribution, constant dysesthesia, and no evidence of pathology or known etiology. Phentolamine (30 mg), lidocaine (100 mg), and saline were each infused over periods of 5 to 10 minutes. Pain ratings were assessed every 4 minutes throughout each study period using a 10-point pain intensity scale. RESULTS: No patient reported subjective improvement of pain during or immediately following phentolamine or saline infusions alone. Sixteen of the 30 patients reported decreased pain following lidocaine infusion. In the majority of the patients, the duration of lidocaine analgesia was less than 30 minutes; however, some patients reported decreased pain for a longer time. CONCLUSION: The results do not support an adrenergic mechanism for chronic neurogenic facial pain. The response to lidocaine, a nonadrenergic, membrane-stabilizing agent, suggests that it may have clinical effectiveness in certain neurogenic facial pain patients.

Percutaneous stereotactic differential radiofrequency thermal rhizotomy for the treatment of trigeminal neuralgia.

PURPOSE: The purpose of this study was to evaluate the effectiveness of radiofrequency thermal rhizotomy (RTR) for trigeminal neuralgia, after failure of pharmacological management. PATIENTS AND METHODS: Two hundred fifteen patients underwent RTR from 1991 to 1996 and were prospectively evaluated. These patients were characterized by age, sex, side of the face, and division(s) involved. Patients were evaluated for pain relief, recurrence requiring or not requiring reoperation, and the type and rate of complications. They were followed-up by serial clinical evaluation and telephone interview. Patients were categorized into groups: 1) Successful result: excellent, good pain relief; and 2) Unsuccessful result: fair, poor, or no pain relief. The RTR group was compared with historical controls. Follow-up ranged from 9 to 68 months (mean, 32 months) and results were evaluated at early and long-term follow-up. RESULTS: At early follow-up (defined as immediately postoperatively to 6 months), pain relief of excellent or good quality (successful result) occurred in 198 of 215 patients (92%). Fair or poor or no pain relief (unsuccessful result) occurred in 17 (8%) patients. At long-term follow-up (>6 months to 68 months), recurrence of pain that required reoperation occurred in 24 patients (11%) and recurrence of pain that did not require reoperation (medically managed) occurred in 34 patients (16%). Dysesthesia developed in 18 patients (8%); seven patients (3%) had dysesthesia alone (medically managed) and 11 patients (5%) had dysesthesia with recurrence of pain (medically or surgically managed). "Anesthesia/analgesia dolorosa" developed in four patients (1.8%) and was medically managed. At long-term follow-up, 83% of patients had good to excellent pain relief (successful result). There were no mortalities, no significant morbidity, and a low rate of minor complications. CONCLUSION: With the use of this specific diagnostic approach and management algorithm, patients with trigeminal neuralgia can be successfully managed.

Prenatal anticonvulsant drug exposure: teratogenic effect on the dentition.

Prenatal exposure to anticonvulsant medication has been shown to cause craniofacial dysmorphology, prenatal growth retardation, hypoplastic nails and phalanges, and visceral abnormalities. In this study we examined maxillary and mandibular stone dental casts (45) and panoramic radiographs (39) from 45 individuals with ages 4.5 to 22.0 years for changes in mesiodistal crown size of deciduous and permanent teeth, and the presence of dental anomalies. These individuals had been exposed prenatally to antiepileptic drugs (AEDs). Mesiodistal crown diameters were measured from the dental casts and converted into standard scores (Z), using published normative data from the University of Michigan Longitudinal Craniofacial Growth Series. A significant increase in mesiodistal crown dimensions of the posterior maxillary teeth was observed, specifically in primary molars and their permanent premolar successors, as well as permanent molars. Changes in tooth size were more common in females than in males. Dental maturity, assessed using the panoramic radiographs, was equal to chronologic age. An increased frequency of hypodontia was the only notable dental anomaly.

New syndrome? Prominent, constricted ears with malformed condyle of the mandible.

We report on several relatives in 5 generations of one family with prominence of the ears, with a marked constriction at the junction between the lower and middle thirds of the pinna. Computerized tomography and radiographs in the propositus and his affected father showed abnormalities of the condyle of the mandible. The propositus had more severe changes in the condyle with microstomia and reduced range of motion of the mandible in the temporomandibular joint. There was no hearing loss or abnormalities of the bones of the middle ear.

Posttraumatic gustatory neuralgia: a clinical model of trigeminal neuropathic pain.

Six cases are reported in which the primary complaint was episodic, recurrent facial pain that was triggered by a taste stimulus. The pain first occurred days to weeks after head and neck surgery. Patients reported that a food stimulus placed in the mouth evoked episodic, electric shock-like pain in a preauricular location on the surgical side. The smell of food or, less reliably, emotional excitement could also trigger pain. Mandibular movement did not evoke the pain, and between lancinating attacks there was either no pain or only mild discomfort. Following an episode of pain, there was a refractory period during which the pain could not be elicited. Physical examination demonstrated a preauricular sensory loss of variable distribution. No abnormal sweating or vasomotor findings were clinically apparent. No odontogenic, muscular, salivary gland, neurologic, or psychologic pathology was found to explain the clinical symptoms. The pain was not relieved with standard doses of anticonvulsants that are commonly used to treat trigeminal neuralgia. The duration of the recurrent pain symptoms in this group was 8 to 132 months without remission. Gustatory neuralgia may be a discrete syndrome that results from abnormal interactions between salivary efferent fibers and trigeminal sensory afferent fibers in the injured auriculotemporal nerve. The unique features of the disorder make it a potentially useful clinical model for the investigation of autonomic/sensory interactions in neuropathic pain.

The incidence of pain in the muscles of mastication in patients with fibromyalgia.

This study recognizes the high incidence of temporomandibular symptoms in a group of patients with documented fibromyalgia. Findings indicate that the diagnosis and treatment of temporomandibular disorders and fibromyalgia have many similarities.