Cellular and biological factors involved in healing wounds and burns and treatment options in tissue engineering.

Severe traumatic wounds and burns have a high chance of mortality and can leave survivors with many functional disabilities and cosmetic problems, including scars. The healing process requires a harmonious interplay of various cells and growth factors. Different structures of the skin house numerous cells, matrix components and growth factors. Any disturbance in the balance between these components can impair the healing process. The function of cells and growth factors can be manipulated and facilitated to aid tissue repair. In the current review, the authors focus on the importance of the skin microenvironment, the pathophysiology of various types of burns, mechanisms and factors involved in skin repair and wound healing and regeneration of the skin using tissue engineering approaches.

Wounds and ulcers, especially burn wounds, are major causes of morbidity and mortality and pose a significant burden for individuals and societies. The skin has numerous structures that play important roles in wound healing via cells and growth factors. Tissue engineering and regenerative medicine represent a rather new field that focuses on manipulating cells and growth factors, aiming to facilitate repair and regeneration of injured tissues and organs. This review focuses on different burn injuries that can result in nonhealing wounds, provides an overview of several cells and growth factors that are involved in the healing process of the skin and introduces various strategies practiced in tissue engineering with regard to cutaneous wound healing.

Specific patterns of vital sign fluctuations predict infection and enable sepsis diagnosis in pediatric burn patients.

Early recognition of the clinical signs of bloodstream infection in pediatric burn patients is key to improving survival rates in the burn unit. The objective of this study was to propose a simple scoring criteria that used readily available temperature, heart rate (HR) and mean arterial pressure (MAP) data to accurately predict bloodstream infection in pediatric burn patients. A retrospective chart review included 100 patients admitted to the pediatric burn unit for >20% total body surface area (TBSA) burn injuries. Each patient had multiple blood culture tests, and each test was treated as a separate and independent "infection event" for analysis. The time at each blood culture draw was time 0 for that event, and temperature, HR and MAP data was collected for 24 hours after the blood culture was drawn. "Infection events" included in this study had at least six complete sets of temperature, HR and MAP data entries. Median temperature, HR and MAP, as well as mean fever spikes, HR spikes and MAP dips, were compared between infection group (positive blood cultures) and control group (negative blood cultures). These vital sign fluctuations were evaluated individually and as a combination of all three as timely predictors of bloodstream infection. In addition, we tested the prediction of Gram-negative bacteria versus Gram-positive or fungi present in blood cultures. Patients in the infection group had significantly higher median temperatures (p<0.001), mean fever spikes (p<0.001) and mean HR spikes (p<0.001), compared to the control group. Using the combination scoring criteria to predict bloodstream infection, the strongest predictive values in the 24-hour timeframe had high sensitivity (93%) and specificity (81%). The predictive test metric based on vital sign spikes predicted Gram-negative bacteria, but with limited sensitivity (57%) and specificity (44%). A simple scoring criteria using a combination of fever spikes, HR spikes and MAP dips predicted bloodstream infection in pediatric burn patients, and can be feasibly implemented in routine clinical care. There is also potential to use the predictive metric to detect a few select organisms based on vital signs, however further work is necessary to enhance accuracy to levels that would allow consideration for clinical use.

Burn Specific Health Scale - Brief - Brazil and International Classification of Functioning, Disability and Health in Burn Patients.

With better burn trauma survival rates, quality of life and functionality have become important outcomes in the evaluation of burn patients. The objective of this study was to evaluate the quality of life of burn survivors using the Burn Specific Health Scale-Brief-Br and their function and health using the International Classification of Functioning Disability and Health (ICF) in order to assess whether there is a correlation in the results obtained between the two instruments. A cross-sectional study with 80 burn patients who underwent outpatient follow-up was completed. Quality of life was assessed using the BSHS-B-Br, an instrument translated and validated in Brazilian Portuguese. Based on ICF category concepts, a data collection tool was used with "yes" and "no" answers. A "yes" answer represented the "8" qualifier, indicating a problem without a specific order of magnitude. Both instruments were self-applied in standardized conditions without complications during the process. Results were analyzed through Spearman's rank correlation coefficients. The BSHS-B-Br had an average score of 127.12 (SD ± 23.03). The correlation was moderate between the total BSHS-B-Br score and the answers of ICF for body functions (r = -.53; P < .001) and environmental factors (r = -.50; P < .001). It was weak for body structures (r = -.47; P < .001) and for activities and participation (r = -.43; P < .001). This study found a moderate correlation between the results of the Burn Specific Health Scale - Brief - Brazil and the International Classification of Functioning, Disability and Health for burn patients showing that both instruments provide complementary information about burned patients.

Activity Impairment, Work Status, and Work Productivity Loss in Adults 5-7 Years After Burn Injuries.

An important aspect of the rehabilitation of burn patients is social participation, including daily activities and work. Detailed information on long-term activity impairment and employment is scarce. Therefore, we investigated activity impairment, work status, and work productivity loss in adults 5-7 years following burn injuries, and investigated associations with burn-specific health-related quality of life (HRQL) domains. Adult participants completed the Work Productivity and Activity Impairment General Health questionnaire and the Burn Specific Health Scale-brief (BSHS-B) 5-7 years post-burn. Outcomes were compared between participants with mild/intermediate and severe burns (>20% total body surface area burned). Seventy-six (36%) of the 213 participants experienced some degree of activity impairment due to burn-related problems 5-7 years post-burn. Seventy percent of the population was employed; 12% of them experienced work productivity loss due to burn-related problems. Nineteen percent reported changes in their work situation (partly) because of the burn injury. A higher proportion of participants with severe burns had activity impairments (56% vs 29%; P = .001) and work productivity loss (26% vs 8%; P < .001) compared to participants with mild/intermediate burns. Activity impairment and work productivity loss were both associated with burn-related work problems and lower mood, measured with the BSHS-B. In conclusion, a substantial part of the study population experienced activity impairment and work productivity loss, was unemployed, and/or reported changes in their work situation due to their injury. Particularly patients with severe burns reported productivity loss and had lower employment rates. This subscribes the importance of addressing work-related functioning in the rehabilitation of burn patients.

A Cross-sectional Survey of Health Professionals Across Australia and New Zealand to Determine What Outcome Measures Are Important From a Clinical Perspective Post Hand Burn Injury.

Outcome measures are used in healthcare to evaluate clinical practice, measure efficiencies and to determine the quality of health care provided. The Burns Trauma Rehabilitation: Allied Health Practice Guidelines advocates for the collection of outcome measures post burn injuries across different time points. These guidelines recommend multiple tools which can be utilized when measuring outcomes post burn injuries. The aim of this study was to gather information from specialist clinicians regarding their clinical practice and the outcome measurement tools used post hand burn injuries. This cross-sectional study used a survey design to collect data at one given point in time across a sample population. A total of 43 clinical specialists allied health professionals responded to the survey. Respondents indicated that their patients considered hand dexterity was the most important outcome. Three months post burn injury was the most common timepoint for measurement (n = 31, 72.1%) followed by six months (n = 27, 62.8%). Patient report of hand function (n = 42, 97.7%) and observation (n = 41, 95.3%) were the most frequently reported assessment methods. The Jamar Dynamometer (n = 40, 93%), goniometer (n = 39, 90.7%) and pinch gauge (n = 36, 83.7) were the most frequency cited assessment tools. The findings of this study suggest that clinical specialist allied health collect some outcome measures in their routine practice. Based on the respondent's perceptions of barriers when using outcome measures and lack of reliable/validated tools to measure hand burn outcomes, there is a need for further studies in this area.

Respiratory Characteristics in Patients With Major Burn Injury and Smoke Inhalation.

This study aimed to evaluate pulmonary function measurements and respiratory muscle parameters in patients with major burn injury and smoke inhalation. The inclusion criteria included patients who were diagnosed with a smoke inhalation burn or a major burn of more than 20% of total body surface area (TBSA). All subjects underwent a pulmonary function test, respiratory muscle strength test, peak cough flow and fluoroscopic diaphragmatic movement measurement, and 6-minute walk test before starting pulmonary rehabilitation. Evaluations were conducted on the 88th day after the injury, the average time of admission to the Department of the Rehabilitation Medicine for burn rehabilitation after the completion of the acute treatment. The average degree of burns of the total 67 patients was 34.6% TBSA. All parameters in the patient group were significantly lower than the healthy controls, and a mild restrictive pattern of impairment with a reduction in diffusing capacity and more reduced expiratory muscle, than inspiratory muscle strength were observed. Peak cough flow, respiratory muscle strength, and forced vital capacity in the patient group with inhalation burn were significantly lower than in those without inhalation burn. The conditions of the majority of patients with major burn and inhalation injury were consistent with restrictive impairment and significant reduction in diffusion capacity. The patients had expiratory muscle weakness, decreased diaphragmatic movement, and exercise capacity impairment.

Validation of PROMIS-29 domain scores among adult burn survivors: A National Institute on Disability, Independent Living, and Rehabilitation Research Burn Model System Study.

BACKGROUND: Patient-reported outcomes are important for understanding recovery after burn injury, benchmarking service delivery and measuring the impact of interventions. Patient-Reported Outcomes Measurement Information System (PROMIS)-29 domains have been validated for use among diverse populations though not among burn survivors. The purpose of this study was to examine validity and reliability of PROMIS-29 scores in this population. METHODS: The PROMIS-29 scores of physical function, anxiety, depression, fatigue, sleep disturbance, ability to participate in social roles, and pain interference were evaluated for validity and reliability in adult burn survivors. Unidimensionality, floor and ceiling effects, internal consistency, and reliability were examined. Differential item functioning was used to examine bias with respect to demographic and injury characteristics. Correlations with measures of related constructs (Community Integration Questionnaire, Satisfaction with Life Scale, Post-Traumatic Stress Checklist-Civilian, and Veteran's Rand-12) and known-group differences were examined. RESULTS: Eight hundred and seventy-six burn survivors with moderate to severe injury from 6 months to 20 years postburn provided responses on PROMIS-29 domains. Participants' ages ranged from 18 years to 93 years at time of assessment; mean years since injury was 3.4. All PROMIS domain scores showed high internal consistency (Cronbach's α = 0.87-0.97). There was a large ceiling effect on ability to participate in social roles (39.7%) and physical function (43.3%). One-factor confirmatory factor analyses supported unidimensionality (all comparative fit indices >0.95). We found no statistically significant bias (differential item functioning). Reliability was high (>0.9) across trait levels for all domains except sleep, which reached moderate reliability (>0.85). All known-group differences by demographic and clinical characteristics were in the hypothesized direction and magnitude except burn size categories. CONCLUSION: The results provide strong evidence for reliability and validity of PROMIS-29 domain scores among adult burn survivors. Reliability of the extreme scores could be increased and the ceiling effects reduced by administering PROMIS-43, which includes six items per domain, or by administering by computerized adaptive testing. LEVEL OF EVIDENCE: Diagnostic Test or Criteria, level III.

The Effect of Betulin Diphosphate in Wound Dressings of Bacterial Cellulose-ZnO NPs on Platelet Aggregation and the Activity of Oxidoreductases Regulated by NAD(P)+/NAD(P)H-Balance in Burns on Rats.

The inhibition of platelet aggregation, and the activity of oxidoreductases and microhemocirculation in a burn wound on the treatment of burns with wound dressings based on bacterial nanocellulose (BC)-zinc oxide nanoparticles (ZnO NPs)-betulin diphosphate (BDP) were studied. The control of the treatment by BC-ZnO NPs-BDP on burned rats by the noninvasive DLF method showed an increase in perfusion and the respiratory component in wavelet spectra, characterizing an improvement in oxygen saturation in the wound. The study on the volunteers' blood found the inhibition of ADP-induced platelet aggregation by 30-90%. Disaggregation depends on the dose under the action of the ionized form of BDP and ZnO NPs-BDP in a phosphate buffer; it was reversible and had two waves. It was shown on rats that the specific activity of LDHreverse and LDHdirect (control-intact animals) on day 21 of treatment increased by 11-38% and 23%, respectively. The LDHreverse/LDHdirect ratio increased at BC-ZnO NPs-BDP treatment, which characterizes efficient NAD+ regeneration. AlDH activity increased significantly in the first 10 days by 70-170%, reflecting the effectiveness of the enzyme and NAD+ in utilizing toxic aldehydes at this stage of burn disease. The activities of GR and G6PDH using NADP(H) were increased with BC-ZnO NPs-BDP treatment.

Carotid smooth muscle contractility changes after severe burn.

Severe burns result in cardiovascular dysfunction, but responses in the peripheral vasculature are unclear. We hypothesize that severe burns disturb arterial contractility through acute changes in adrenergic and cholinergic receptor function. To address this, we investigated the changes in carotid artery contractility and relaxation following a severe burn. Thirty-four adult Sprague-Dawley male rats received a 40% total body surface area (TBSA) scald burn and fluid resuscitation using the Parkland formula. Control animals received sham burn procedure. Animals were serially euthanized between 6 h and 14 days after burn and endothelium-intact common carotid arteries were used for ex vivo force/relaxation measurements. At 6 h after burn, carotid arteries from burned animals demonstrated a > 50% decrease in cumulative dose-responses to norepinephrine (p < 0.05) and to 10-7 M angiotensin II (p < 0.05). Notably, pre-constricted carotid arteries also demonstrated reduced relaxation responses to acetylcholine (p < 0.05) 6 h after burn, but not to sodium nitroprusside. Histologic examination of cross-sectional planes revealed significant increases in carotid artery wall thickness in burned rats at 6 h versus 3 days, with increased collagen expression in tunica media at 3 days (p < 0.05). Carotid artery dysfunction occurs within 6 h after severe burn, demonstrating decreased sensitivity to adrenergic- and angiotensin II-induced vasoconstriction and acetylcholine-induced relaxation.

The Impact of Ambient Temperature Control Across Various Care Settings on Outcomes in Burn Patients: A Review Article.

Ambient/room temperature settings in burn treatment areas vary greatly due to a lack of evidence-based guidelines to direct care. While it is generally understood that ambient/room temperature impacts patient body temperature and metabolism, the ideal settings for optimizing patient outcomes are unclear. The literature assessing this topic is scarce, with many of the articles having significant limitations. We aim to summarize the current evidence for ambient/room temperature control, to address gaps in current reviews addressing this topic, and to elucidate topics requiring further research. PubMed and Google Scholar databases were queried for studies which evaluated the effect of the ambient/room temperature on burn patient core body temperature, patient metabolism, and outcomes among those treated in trauma bays, burn ICUs, and operating rooms. Although existing literature lacks sufficient patient outcome data regarding specific ambient/room temperatures, we highlight physiological processes that are impacted by changes in room temperatures in an effort to describe strategies that can allow for improved patient core body temperature control and outcomes in burn care settings.

Keratin-Alginate Sponges Support Healing of Partial-Thickness Burns.

Deep partial-thickness burns damage most of the dermis and can cause severe pain, scarring, and mortality if left untreated. This study serves to evaluate the effectiveness of crosslinked keratin-alginate composite sponges as dermal substitutes for deep partial-thickness burns. Crosslinked keratin-alginate sponges were tested for the ability to support human dermal fibroblasts in vitro and to support the closure and healing of partial-thickness burn wounds in Sus scrofa pigs. Keratin-alginate composite sponges supported the enhanced proliferation of human dermal fibroblasts compared to alginate-only sponges and exhibited decreased contraction in vitro when compared to keratin only sponges. As dermal substitutes in vivo, the sponges supported the expression of keratin 14, alpha-smooth muscle actin, and collagen IV within wound sites, comparable to collagen sponges. Keratin-alginate composite sponges supported the regeneration of basement membranes in the wounds more than in collagen-treated wounds and non-grafted controls, suggesting the subsequent development of pathological scar tissues may be minimized. Results from this study indicate that crosslinked keratin-alginate sponges are suitable alternative dermal substitutes for clinical applications in wound healing and skin regeneration.

Use of 816 Consecutive Burn Wound Biopsies to Inform a Histologic Algorithm for Burn Depth Categorization.

Burn experts are only 77% accurate when subjectively assessing burn depth, leaving almost a quarter of patients to undergo unnecessary surgery or conversely suffer a delay in treatment. To aid clinicians in burn depth assessment (BDA), new technologies are being studied with machine learning algorithms calibrated to histologic standards. Our group has iteratively created a theoretical burn biopsy algorithm (BBA) based on histologic analysis, and subsequently informed it with the largest burn wound biopsy repository in the literature. Here, we sought to report that process. This was an IRB-approved, prospective, multicenter study. A BBA was created a priori and refined in an iterative manner. Patients with burn wounds assessed by burn experts as requiring excision and autograft underwent 4 mm biopsies procured every 25 cm2. Serial still photos were obtained at enrollment and at excision intraoperatively. Burn biopsies were histologically assessed for presence/absence of epidermis, papillary dermis, reticular dermis, and proportion of necrotic adnexal structures by a dermatopathologist using H&E with whole slide scanning. First degree and superficial second degree were considered to be burn wounds likely to have healed without surgery, while deep second- and third-degree burns were considered unlikely to heal by 21 days. Biopsy pathology results were correlated with still photos by five burn experts for consensus of final burn depth diagnosis. Sixty-six subjects were enrolled with 117 wounds and 816 biopsies. The BBA was used to categorize subjects' wounds into four categories: 7% of burns were categorized as first degree, 13% as superficial second degree, 43% as deep second degree, and 37% as third degree. Therefore, 20% of burn wounds were incorrectly judged as needing excision and grafting by the clinical team as per the BBA. As H&E is unable to assess the viability of papillary and reticular dermis, with time our team came to appreciate the greater importance of adnexal structure necrosis over dermal appearance in assessing healing potential. Our study demonstrates that a BBA with objective histologic criteria can be used to categorize BDA with clinical misclassification rates consistent with past literature. This study serves as the largest analysis of burn biopsies by modern day burn experts and the first to define histologic parameters for BDA.

Methodology and applicability of the human contact burn injury model: A systematic review.

The contact burn injury model is an experimental contact thermode-based physiological pain model primarily applied in research of drug efficacy in humans. The employment of the contact burn injury model across studies has been inconsistent regarding essential methodological variables, challenging the validity of the model. This systematic review analyzes methodologies, outcomes, and research applications of the contact burn injury model. Based on these results, we propose an improved contact burn injury testing paradigm. A literature search was conducted (15-JUL-2020) using PubMed, EMBASE, Web of Science, and Google Scholar. Sixty-four studies were included. The contact burn injury model induced consistent levels of primary and secondary hyperalgesia. However, the analyses revealed variations in the methodology of the contact burn injury heating paradigm and the post-burn application of test stimuli. The contact burn injury model had limited testing sensitivity in demonstrating analgesic efficacy. There was a weak correlation between experimental and clinical pain intensity variables. The data analysis was limited by the methodological heterogenicity of the different studies and a high risk of bias across the studies. In conclusion, although the contact burn injury model provides robust hyperalgesia, it has limited efficacy in testing analgesic drug response. Recommendations for future use of the model are being provided, but further research is needed to improve the sensitivity of the contact burn injury method. The protocol for this review has been published in PROSPERO (ID: CRD42019133734).

Thermoregulatory Responses with Size-matched Simulated Torso or Limb Skin Grafts.

PURPOSE: This study aimed to test the hypothesis that a simulated burn injury on the torso will be no more or less detrimental to core temperature control than on the limbs during uncompensable exercise-heat stress. METHODS: Nine nonburned individuals (7 men, 2 women) completed the protocol. On separate occasions, burn injuries of identical surface area (0.45 ± 0.08 m2 or 24.4% ± 4.4% of total body surface area) were simulated on the torso or the arms/legs using an absorbent, vapor-impermeable material that impedes sweat evaporation in those regions. Participants performed 60 min of treadmill walking at 5.3 km·h-1 and a 4.1% ± 0.8% grade, targeting 6 W·kg-1 of metabolic heat production in 40.1°C ± 0.2°C and 19.6% ± 0.6% relative humidity conditions. Rectal temperature, heart rate, and perceptual responses were measured. RESULTS: Rectal temperature increased to a similar extent with simulated injuries on the torso and limbs (condition-by-time interaction, P = 0.86), with a final rectal temperature 0.9°C ± 0.3°C above baseline in both conditions. No differences in heart rate, perceived exertion, or thermal sensation were observed between conditions (condition-by-time interactions, P ≥ 0.50). CONCLUSIONS: During uncompensable exercise-heat stress, sized-matched simulated burn injuries on the torso or limbs evoke comparable core temperature, heart rate, and perceptual responses, suggesting that the risk of exertional heat illness in such environmental conditions is independent of injury location.

Negative-pressure wound therapy in skin grafts: A systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Although skin grafts are widely used in reconstruction of large skin defect and complex wounds, many factors lead to suboptimal graft take. Negative-pressure wound therapy (NPWT) reportedly increases the graft take rates when added to skin grafting, but a summary analysis of the data of randomized controlled trials has yet to be performed. We conducted this systematic review and meta-analysis of randomized controlled trials to compare the effectiveness and safety of NPWT and non-NPWT for patients with skin grafts. METHODS: We searched PubMed, Embase, Cochrane Library, and CNKI for relevant trials based on predetermined eligibility criteria from database establishment to February 2020. Two reviewers screened citations and extracted data independently. The quality of the included studies was evaluated according to the Cochrane Handbook, whereas statistical heterogeneity was assessed using chi-square tests and I2 statistics. Review Manager 5.3 was used for statistical analysis. RESULTS: Ten randomized controlled trials with 488 patients who underwent NPWT or non-NPWT were included. Compared with non-NPWT, NPWT yielded an improved the percentage of graft take, a reduction in days from grafting to discharge, with lower relative risk of re-operation, and no increased relative risk of adverse event. Further, the subgroup analysis showed an improved the percentage of graft take in negative pressure of 80 mmHg, and no improved the percentage of graft take in negative pressure of 125 mmHg. CONCLUSION: NPWT is more effective than non-NPWT for the integration of skin grafts, and the negative pressure of 80 mmHg can be recommended. Data on adverse events and negative pressure are, however, limited. A better understanding of complications after NPWT and the ideal negative pressure for the integration of skin grafts is imperative.

Development of a Topical Insulin Polymeric Nanoformulation for Skin Burn Regeneration: An Experimental Approach.

Insulin is a peptide hormone with many physiological functions, besides its use in diabetes treatment. An important role of insulin is related to the wound healing process-however, insulin itself is too sensitive to the external environment requiring the protective of a nanocarrier. Polymer-based nanoparticles can protect, deliver, and retain the protein in the target area. This study aims to produce and characterize a topical treatment for wound healing consisting of insulin-loaded poly-DL-lactide/glycolide (PLGA) nanoparticles. Insulin-loaded nanoparticles present a mean size of approximately 500 nm and neutral surface charge. Spherical shaped nanoparticles are observed by scanning electron microscopy and confirmed by atomic force microscopy. SDS-PAGE and circular dichroism analysis demonstrated that insulin preserved its integrity and secondary structure after the encapsulation process. In vitro release studies suggested a controlled release profile. Safety of the formulation was confirmed using cell lines, and cell viability was concentration and time-dependent. Preliminary safety in vivo assays also revealed promising results.

The Use of Visible-Light Hyperspectral Imaging in Evaluating Burn Wounds: A Case Report.

Burn depth is a critical factor in determining the healing potential of a burn as the extent of injury ultimately guides overall treatment. Visible-Light Hyperspectral Imaging is an FDA-approved, noninvasive, and noncontrast imaging technology that uses light waves within the visible spectrum to evaluate skin and superficial soft tissue perfusion. In this case report, visible-light hyperspectral imaging was used to evaluate a 37-year-old male who presented to the Emergency Department with a thermal burn of the trunk, back, and right upper extremity. Images were taken at initial evaluation, 6 hours postinjury, and again during daily dressing changes until hospital day 5 when the patient underwent surgical debridement. In this patient, operative treatment was postponed until 89.7 hours postinjury, at which point the clinical examination showed clear visual demarcation in regions of irreversible damage. Comparatively, visible-light hyperspectral imaging analysis of the permanently injured tissue demonstrated acute but varying changes in both oxygenated hemoglobin and deoxygenated hemoglobin at the time of initial evaluation. The most dramatic change in tissue oxygenation occurred between 6.5 and 39.3 hours, demonstrating visible-light hyperspectral imaging's ability to detect significant differences in oxygenation values between areas of second-degree superficial burns and areas of second-degree deep and third-degree burns in the acute period. The data suggest that the utilization of visible-light hyperspectral imaging in this 6.5- to 39.3-hour window may help predict final burn depth before clinical assessment, potentially allowing for surgical intervention within the first 48 hours following injury.

The development of a tool to predict temperature-exposure of incinerated teeth using colourimetric and hydroxyapatite crystal size data.

This study presents a novel tool to predict temperature-exposure of incinerated pig teeth as a proxy for understanding impacts of fire on human teeth. Previous studies on the estimation of temperature-exposure of skeletal elements have been limited to that of heat-exposed bone. This predictive tool was developed using a multinomial regression model of colourimetric and hydroxyapatite crystal size variables using data obtained from unheated pig teeth and teeth incinerated at 300 °C, 600 °C, 800 °C and 1000 °C. An additional variable based on the observed appearance of the tooth was included in the tool. This enables the tooth to be classified as definitely burnt (600 °C-1000 °C) or uncertain (27 °C/300 °C). As a result, the model predicting the temperature-exposure of the incinerated teeth had an accuracy of 95%. This tool is a holistic, robust and reliable approach to estimate temperature of heat-exposed pig teeth, with high accuracy, and may act as a valuable proxy to estimate heat exposure for human teeth in forensic casework.