Exploring the feasibility of smartphone cameras for 3D modelling of bite patterns in forensic dental identification.

The field of bitemark analysis involves examining physical alterations in a medium resulting from contact with teeth and other oral structures. Various techniques, such as 2D and 3D imaging, have been developed in recent decades to ensure precise analysis of bitemarks. This study assessed the precision of using a smartphone camera to generate 3D models of bitemark patterns. A 3D model of the bite mark pattern was created using 3Shape TRIOSTM and a smartphone camera combined with monoscopic photogrammetry. The mesiodistal dimensions of the anterior teeth were measured using Rapidform Explorer and OrtogOnBlender, and the collected data were analyzed using IBM® SPSS® Statistics version 23.0. The mean mesiodistal dimension of the anterior teeth, as measured on the 3D model from 3Shape TRIOSTM and smartphone cameras, was found to be 6.95 ± 0.7667 mm and 6.94 ± 0.7639 mm, respectively. Statistical analysis revealed no significant difference between the two measurement methods, p > 0.05. The outcomes derived from this study unequivocally illustrate that a smartphone camera possessing the specific parameters detailed in this study can create a 3D representation of bite patterns with an accuracy level on par with the outputs of a 3D intraoral camera. These findings underscore the promising trajectory of merging smartphone cameras and monoscopic photogrammetry techniques, positioning them as a budget-friendly avenue for 3D bitemark analysis. Notably, the monoscopic photogrammetry methodology assumes substantial significance within forensic odontology due to its capacity for precise 3D reconstructions and the preservation of critical measurement data.

Bitemarks and 3D scanner: An objective comparison for bitemarks. A pilot study.

The marks left by the bite of a subject (bitemark) represent an unequivocal character, being useful in identifying the possible perpetrator of a crime. To date, the analysis of bitemarks is mainly based on the direct vision of photographic finds and on the visual comparison with the teeth of the hypothetically responsible person. However, the bitemark also retains three-dimensional characteristics detectable with a 3D scanner. In this pilot study, an innovative method of bitemark analysis, utilizing a three-dimensional scanner and some software, will be introduced, enabling a quantitative comparison of bitemarks and their corresponding human dentitions. For this purpose, 10 complete plaster models (human dentitions) of 10 adult subjects were used to make 20 experimental bitemarks on dentistry wax. All materials were individually scanned with the iTero® 3D scanner and reworked with MeshMixer software. A visual analysis of the characteristics and a computerized analysis with the CloudCompare software were also performed. Study showed a different trend of the distribution curves of the points which were obtained comparing the human dentition and coincident and non-coincident bitemarks. Current results support that the intraoral 3D scanner allows the fast record and the preservation of the three-dimensional characteristics of the bitemarks, and it allows computerized analyses to be carried out.

Management of Human Bites in a Rural Kenyan Setting: A Plastic Surgeon's 8-Year Experience.

INTRODUCTION: The treatment of human bites is a common issue facing healthcare practitioners in the developing countries of Sub-Saharan Africa where it has been noted as a growing public health concern. Generally, the desired outcomes from surgical management are healing, function, and aesthetics. We share our 8-year experience at Kapsowar Hospital in Kenya with the presentation, management, and outcome of human bites. We are uniquely situated to do so given the prevalence of human biting in our community and the full-time presence of a plastic surgeon at our institution. To the best of our knowledge, this study is the first to present human bite surgical management by a plastic surgeon certified by the American Board of Surgery working full-time on the African continent. METHODS: A retrospective chart review was conducted on all patients who presented to the operating theater at Kapsowar Hospital with a human bite between 2013-2021. After identification of eligible patients, charts were reviewed assessing parameters including age, gender, timing from injury to presentation at hospital, localization of bite, severity of facial wounds using Lackmann's classification, surgical procedure(s), postoperative complications, surgical revisions, antibiotics administered, and circumstance of incident. Data were analyzed using SPSS 29.0.0.0. RESULTS: Forty-four patients were identified. Seventeen (38.6%) were female and 27 (61.4%) were male. Thirty-one patients had facial bites and 13 patients had bites to other parts of the body. Of facial bites, 70.3% resulted in amputation of the affected part while 29.7% were lacerations. Using Lackmann's classification for facial bite severity, IIIA bites (complete avulsion) were most common for both males (9) and females (7). Females comprised 68.4% of total lip bite victims. Bites to the extremity were associated with late presentation and infection. We report a salvage rate of 85.7% for infected digits. CONCLUSIONS: Compared with most other studies on human bites, our patient population presents with a higher rate of avulsive lip injuries, most commonly among women. Our postoperative infection rate is lower than many others reported in the literature. Satisfactory cosmetic outcome with low risk of infection can be achieved by following well-established principles of wound healing and tension-free closure.

Presentation and treatment of animal and human bite injuries at a Swiss tertiary emergency department: a cross-sectional study.

BACKGROUND: Animal and human bite injuries are a relevant health problem worldwide. With the increasing number of pets, bite injuries are becoming more frequent. Previous studies on animal and human bite injuries in Switzerland were completed several years ago. The aim of the present study was to provide a detailed overview of patients with bite injuries admitted to a tertiary emergency department in Switzerland in terms of demographics, injury patterns and treatment strategies. METHODS: A 9-year cross-sectional analysis of patients presenting to the emergency department of Bern University Hospital in the period January 2013 to December 2021 following an animal or human bite injury. RESULTS: A total of 829 patients with bite injuries were identified, including 70 for postexposure prophylaxis only. Their median age was 39 (IQR 27-54) years and 53.6% were female. Most patients were bitten by a dog (44.3%), followed by cats (31.5%) and humans (15.2%). Most bite injuries were mild (80.2%); severe injuries were mainly found in dog bites (28.3%). Most patients were treated within six hours after human (80.9%) or dog (61.6%) bites; after cat bites, patients often presented with a delay (74.5%) and signs of infection (73.6%). Human bite wounds were superficial in the majority of cases (95.7%), rarely showed signs of infection (5.2%) at the time of presentation and hospitalisation was never required. CONCLUSIONS: Our study provides a detailed overview of patients admitted to an emergency department of a tertiary Swiss University Hospital after an animal or human bite. In summary, bite injuries are common among patients who present to the emergency department. Therefore, primary and emergency care clinicians should be familiar with these injuries and their treatment strategies. The high risk of infection, particularly in cat bites, may warrant surgical debridement in the initial treatment of these patients. Prophylactic antibiotic therapy and close follow-up examinations are recommended in most cases.

Chondro-Cutaneous Autograft for Reconstruction of the Nasal Ala After a Human Bite.

BACKGROUND The nasal ala is a paired structural subunit of the nose that is functionally important in the maintenance of the nasal valve. It consists of 3 anatomically distinct layers: skin, cartilage, and mucosa, all of which need to be restored in reconstructive surgeries to maintain nasal patency. When multiple layers are involved in a defect, the reconstruction requires combining procedures to replace each layer. CASE REPORT We describe a peculiar case of a 58-year-old man with a full-thickness loss of substance of the right nasal ala due to a human bite. The patient came to our hospital after an altercation with another man who bit his nose off. He was initially seen at a smaller regional hospital that did not have a plastic surgery department and was soon after transferred to our facility due to the complexity of the case. To reduce the risk of infection, the patient was treated with a complete course of intravenous antibiotic therapy and the wound was medicated daily with antiseptic solutions. The loss of substance was reconstructed with a composed graft from the auricle concha and the melolabial flap. CONCLUSIONS Defects of the nasal ala are challenging to reconstruct, given its complex 3-dimensional structure. The successful repair of these defects provides aesthetic symmetry and preserves nasal function. A wide variety of reconstructive options have been utilized in many nasal reconstruction cases and have been documented. The combination of a chondro-cutaneous graft from the auricular concha and a melolabial flap graft allowed a good result without local or systemic complications.

Alterações dimensionais em marcas de mordidas humanas simuladas em alimentos: estudo in vitro / Dimensional changes in simulated human bite marks on food: in vitro study

Objetivo: avaliar alterações dimensionais em marcas de mordidas simuladas em um tipo de queijo e de goiabada com o decorrer do tempo. Materiais e Métodos: mordidas foram simuladas em 20 amostras-padrão formato retangular nas medidas 30 x 60 mm e espessura de 20 mm de queijo tipo muçarela (n=10) e goiabada (n=10) com a utilização de um manequim odontológico montado em oclusão normal e acoplado à máquina universal de ensaios mecânicos. Amostras foram mantidas em superfície de vidro em ambiente com temperatura e umidade controladas seguida da aferição das distâncias intercaninas das marcas a cada hora com auxílio de paquímetro digital, durante 120 horas de experimentação. A temperatura e umidade mantiveram-se constantes durante todo período. As medidas obtidas foram estatisticamente analisadas por meio dos testes de Friedman, de Wilcoxon, coeficiente de correlação de Spearman e a partir da análise de regressão linear simples. O nível de significância adotado foi de 5%. Resultados: os alimentos testados mantiveram o padrão das medidas lineares nas primeiras quatro horas (p>0,05). Após esse período, ocorreu uma deformação progressiva, levando ao aumento significativo das medidas (p<0,05). Conclusão: a marca de mordida em queijo tipo muçarela e goiabada apresentou-se dimensionalmente estável nas primeiras quatro horas, pós mordida. Após esse período, as marcas já não apresentaram características favoráveis para serem utilizadas como registro para fins de comparação.

Objective: to evaluate dimensional changes in simulated bite marks in a type of cheese and guava paste over time. Materials and Methods: Bites were simulated on 20 standard rectangular samples. in the measures 30 x 60 mm and thickness of 20 mm of mozzarella cheese (n=10) and guava paste (n=10) using a dental manikin mounted on normal occlusion and coupled to the universal mechanical testing machine. The samples were kept on a glass surface in an environment with controlled temperature and humidity , followed by the measurement of intercanine distances of the marks, every hour, with the aid of a caliper digital, during 120 hours of experimentation. The temperature and humidity remained constant throughout the period. The measurements obtained were statistically analyzed using the Friedman, Wilcoxon, Spearman's correlation coefficient and from the linear regression analysis simple (IBM SPSS. 21.0, 2012, Armonk, NY: IBM Corp.). The level of significance adopted was 5%. Results: the foods tested maintained the pattern of linear measurements in the first four hours (p>0.05). After this period, a progressive deformation occurred, leading to the significant increase in measurements (p<0.05). Conclusion: the bite mark in mozzarella cheese and guava paste it was dimensionally stable in the first four hours, post-bite. After this period, brands no longer have favorable characteristics to be used as a record for comparison purposes.

The "hypopigmented" bitemark: a clinical and histologic appraisal.

So-called "hypopigmented" bitemark patterns, commonly seen but not limited to dark skinned individuals, can be of value in forensic investigations. The process of aging bitemarks observed on skin is controversial and without guidelines. This report analyzes tissue obtained from the site of a hypopigmented bitemark using special histochemical stains for the identification of melanin pigment, and a panel of immunohistochemical markers to aid in the aging process. Histologic evaluation clearly showed that cellular changes in the hypopigmented area were indicative of wound healing that had taken place over a period of time. This validates the hypothesis that a hypopigmented bitemark is an indication of a wound inflicted some days previously. These findings have value in forensic investigations, particularly in cases of suspected long-term physical abuse.

3D Bitemark Analysis in Forensic Odontology Utilizing a Smartphone Camera and Open-Source Monoscopic Photogrammetry Surface Scanning

Abstract Bitemark analysis is a challenging procedure in the field of criminal case investigation. The unique characteristics of dentition are used to find the best match between the existing patterned injury and the suspected perpetrator in bitemark identification. Bitemark analysis accuracy can be influenced by various factors, including biting pressure, tooth morphology, skin elasticity, dental cast duplication, timing, and image quality. This review article discusses the potential of a smartphone camera as an alternative method for 3D bitemark analysis. Bitemark evidence on human skin and food should be immediately recorded or duplicated to retrieve long-lasting proof, allowing for a sufficient examination period. Various studies utilizing two-dimensional (2D) and three-dimensional (3D) technologies have been developed to obtain an adequate bitemark analysis. 3D imaging technology provides accurate and precise analysis. However, the currently available method using an intraoral scanner (IOS) requires high-cost specialized equipment and a well-trained operator. The numerous advantages of monoscopic photogrammetry may lead to a novel method of 3D bitemark analysis in forensic odontology. Smartphone cameras and monoscopic photogrammetry methodology could lead to a novel method of 3D bitemark analysis with an efficient cost and readily available equipment.

Using a V-Y Advance Flap for Alar Rim Defect After Human Bite: A Case Report.

A human bite is a traumatic injury that often occurs in the recipient's nasal area. In this report, we describe the case of a 38-year-old man who was bitten by his roommate and sustained an alar rim defect. After reviewing the literature and professional recommendations for managing human bite wounds in the nasal area, we found both were unclear as to whether it is best to implement primary reconstruction or to defer reconstruction to a later date. We utilized a V-Y flap for secondary reconstruction in our patient.

Bite wounds to the hand - a review.

Bite wounds occur as a result of bite by an animal or a human. They are relatively frequent due to the growing number of pets living with people, as well as from inadequate human-animal interactions. The knowledge of most surgeons about the management of these injuries is relatively outdated, whereas the current literature points to important changes in this field. The article presents several aspects concerning epidemiology, classification, bacteriology, and characteristics of bite wounds to the hand. Based on the actual literature, detailed rules for the management of these injuries are described. This information may prove useful in the daily practice of surgeons and doctors at emergency departments who are frequently faced with bite wounds.

Forensic microbiology and bite marks: a systematic review.

The forensic role of microbiology in bite mark analysis as evidence in a court of law has not yet been explored, as the analysis of bite marks is mostly morphology-based. The aim of this systematic review is to investigate if the analysis of the oral microbiota may be helpful as a complementary forensic tool. Articles were searched on the PubMed database, using predefined data fields and keywords. The final selection included a total of 6 papers (out of 42). Our results indicated that the Streptococcus genus is a key player in the analysis of bite mark microbiology from a forensic perspective and its genomic analysis may facilitate the association of a bite mark to the perpetrator. However, much more research is still needed before this forensic strategy can be applied in real scenarios. There is a need to optimize and standardize the methods of microbiome analysis and to determine several factors that may influence the results, such as the frequency of bacterial genotypes in the human population and the temporal stability of the oral microbiome on human skin.

[A human bite wound caused a severe life threatening infection]. / Een mensenbeet met desastreuze gevolgen.

Within 24 hours after a human bite trauma, a 34-year-old male patient became septic and ended up at an intensive care unit. The combination of a local damage of the skin or mucosa, aggressive micro-organisms, local host factors, and some bad luck resulted in necrotizing fasciitis for this patient. This is a very rapid progressive infection which can spread via fat tissue and the muscle fascia. The occurrence of extensive necrosis releases a lot of cytokines and acute-phase proteins, resulting in a systemic reaction. The consequential vasodilatation makes it necessary for the heart to pump harder in order to maintain the circular volume. The patient will soon become septic and hemodynamically unstable. This can also lead to multiple organ failure with potentially fatal consequences. Because necrotizing fasciitis can be caused by commensal bacteria, even young healthy patients are at risk for this invasive life threatening disease. Early recognition of the clinical manifestations can prevent a fatal outcome.

Nasal Reconstruction: Reconstruction of a Nasal Tip, Columella and Middle Crura Defect After Human Bite with a Turn Down Flap Associated With Conchal Graft and Interpolated Melolabial Flap.

ABSTRACT: Nasal reconstruction is one of the most difficult procedures in plastic surgery due to its complex anatomy and function. A 31-year male was sent to our evaluation after an acquired nasal defect caused by a human bite 2 years before. The defect encompassed the nasal tip, columella, and both middle crura. After a detailed evaluation, the inner lining was reconstructed with a turndown flap of the released scar. In the same operative time, a shaped conchal cartilage graft was anchored to the remnants of both lateral crura and covered with a melolabial interpolated flap. Division, debulking, and final in setting of the flap was done after 5 weeks. Although simple steps were used, a good aesthetic reconstruction was achieved with minimal donor site morbidity.This case proves that a good planning is a cornerstone of a good reconstruction.

Biting the hand that feeds you: Management of human and animal bites.

Bites from animal and humans represent a very small proportion of all the patients presenting to emergency departments, However, they require prompt medical and surgical intervention in order to minimise the risk of infection, that may lead to limb and life-threatening complications. In this review article we synthesise the existing literature for treatment of human and animal bites and offer practical considerations when managing bite injuries.

[Infections of the hand and forearm]. / Infektionen der Hand und des Unterarms.

Infections of the hand and forearm are a frequently seen surgical emergency of the hand. Patients of all age groups are affected and underlying systemic diseases are risk factors. Posttraumatic causes are the leading cause of infections. This includes cuts and stab wounds, animal and human bites but often also minor injuries. Due to the anatomical peculiarities of the hand, rapid progression of initially inconspicuous infections can occur resulting in functional limitations. If an infection is suspected, a symptom-oriented evaluation by a hand surgeon should be performed. This includes a detailed patient history, clinical examination, laboratory analyses and imaging. This is followed by the development of an individualized and interdisciplinary treatment concept with the aim of achieving the shortest possible rehabilitation period. The treatment includes surgical cleansing of the infection, accompanied by antibiotic treatment taking the expected possible spectrum of pathogens into account. Cephalosporins and aminopenicillins in combination with beta-lactamase inhibitors are the antibiotics of first choice. Follow-up treatment includes early functional exercise under the guidance of a hand therapist to minimize postinfectious restrictions in the range of motion and to enable occupational rehabilitation. In rare cases, fulminant necrotizing infections with resulting skin and soft tissue defects can occur. In these cases, secondary plastic reconstruction is usually required after cleansing of the infection.

A systematic review of 3D scanners and computer assisted analyzes of bite marks: searching for improved analysis methods during the Covid-19 pandemic.

The global Covid-19 pandemic has forced forensic dentists to improve infection control methods. This search investigated the practical utilization of different 3D scanners to record and to analyze bite marks in the skin- and inanimate objects with this aim in mind. A systematic review of the literature using keywords like "human bite mark", "bite mark analyzes", "3D analyzes", "3D scanning", "forensic odontology", and "forensic dentistry" was performed in three scientific databases: MEDLINEOvid®, Pubmed® and Google Scholar. The initial search yielded 263 full-text articles, of which 15 were considered eligible and current within the last 10 years. 3D scanners and computer-assisted human bite mark analyzes showed potential advantages and can be effectively used in forensic odontology on skin and inanimate objects. These technologies minimize the number of people being exposed to pathogens, simplify the chain of evidence, facilitate immediate information exchange between the team members and enable the virtual presentation of the expert witnesses in a court of law.

An approach to a repeated self-biting tongue injury in a toddler.

BACKGROUND: Children with tongue injuries often visit the pediatric emergency department. The vast majority of cases can be conservatively treated, while some injuries require operative repair. The aim of this article was to demonstrate a "back-to-basics" approach to a refractory bifid tongue injury in a toddler. CASE DESCRIPTION: A 1-year-old toddler with a tongue injury was unsuccessfully treated three times within a week by a surgeon in another specialty; all reconstructions were mucosal only. The case was then referred to our maxillofacial unit for proper management. On examination, the recurrent injury seemed to occur because of the patient's self-biting habit. We performed the fourth reconstruction of the tongue muscles and mucosa, and because of no dental prosthetic laboratory available in our hospital, we used transparent adhesive drapes fixed by resorbable sutures to cover the patient's anterior teeth instead of bite guards. The toddler was fed via a nasogastric tube for 1 week under 2-day antibiotic prophylaxis and routine oral care. The patient was discharged without any complications 1 week later. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The causes of repeated orofacial injuries should be identified and require particular attention to establish a proper treatment. For intraoral injuries in pediatric patients, self-biting habits should not be overlooked. The application of materials in an operating theater can help the treating clinicians improve the treatment outcomes.

[Infections of the Hand after Bite Injuries]. / Infektionen an der Hand nach Bissverletzungen.

Bite injuries are common. Along with the resulting complications, they represent approximately 1-2 % of all emergency department visits. In over 75 %, the hands are affected. In Northern Europe, bites and subsequent infections are mainly caused by dogs and cats but also by humans.Up to 40 % of all hand infections are caused to bite injuries. Due to the multiple and complex compartments as well as the low soft tissue coverage of functionally relevant structures, even the smallest and most superficial bite injuries of the hand lead to infections. Any bite injury to the hand may subsequently may result in a fulminant infection and, rarely, even death.The spectrum of pathogens from the oral flora of the biting animal or person is diverse and includes aerobic and anaerobic bacterial strains. Bite injuries represent a major challenge for both the injured person and the attending physician. The rate of complications has been shown to increase with delayed medical consultation, lack of medical care and inadequate wound care. In this review, we discuss the types and complications of bite wounds, their potential risk of infection, their pathogen spectrum and appearance, and their effective treatment.

Emergency amputation necessitated within 24 hours by a human bite: a case report.

We herein review and analyze the diagnosis, treatment, and outcome of a severe infection caused by a human bite. A 68-year-old man was bitten on the forearm by a 3-year-old child. Rapid progression of infection, severe local and systemic poisoning, and diverse clinical manifestations were observed at presentation. Based on the medical history, physical signs, imaging examinations (X-ray films, color Doppler ultrasound, and computed tomography), laboratory examinations, and multidisciplinary consultation, the patient was diagnosed with gas gangrene or gas gangrene-like changes. Twenty-four hours after the injury, an emergency amputation was performed (open amputation with wound closure after 1 week). After the operation, the patient was sent to the intensive care unit for isolation and further anti-infection and anti-shock treatments. His condition gradually improved after treatment and he was discharged without further complications. Bacteriological and pathological examinations indicated Aeromonas hydrophila infection leading to extensive necrotizing fasciitis of the limb and severe systemic poisoning. In addition, pre-existing myelodysplastic syndrome progressing to acute myeloid leukemia was identified as a possible predisposing factor. Human bites can cause serious infections requiring timely treatment, particularly in patients with predisposing comorbidities.

Human bite wounds as a portal of entry for infective endocarditis and purulent pericarditis: a very rare association.

Human bites are an infrequent cause of emergency department visits and hospital admissions. There are rarely published cases of complicated infection, such as infective endocarditis. We present a rare case of a patient with acute infective endocarditis in a healthy native valve and purulent pericarditis from a human bite. A 40-year-old man with obesity suffered deep human bites by an adult woman, with two deep lesions in the anterior thorax and one superficial lesion in the upper abdomen and admitted in intensive care unit with septic shock and a persistent aortic murmur. Echocardiography described evidence of vegetation, perforation and severe regurgitation of aortic valve. Scanner described moderate pericardial effusion. Cardiac surgery was performed, with evidence of purulent pericardial effusion after pericardiotomy, and subsequently aortic valve replacement with a 25 mm bioprosthesis. The patient showed positive progress.