Jens Ove Andreasen, 1935-2020 Father of Dental Traumatology.

The life and professional contributions to dental traumatology of Dr. Jens Ove Andreasen are described in terms of his research, writing, teaching, and leadership.

A preclinical dental trauma teaching module.

A dental trauma exercise using the anterior segment of a sheep mandible as a model has been incorporated into the undergraduate dental programme at the University of Adelaide since 2011. Students are required to replant a simulated tooth avulsion, reposition a laterally luxated tooth injury and then apply a flexible splint consisting of 40 lb fishing nylon attached with a resin-modified glass ionomer cement, GC Fuji Ortho LC. The exercise concludes with the simple removal of the splint with a spoon excavator. The acrylic mounted formalin-fixed sheep mandible is reusable, which has obvious economic and practical advantages.

Healing responses following transverse root fracture: a historical review and case reports showing healing with (a) calcified tissue and (b) dense fibrous connective tissue.

BACKGROUND: The understanding and management of transverse intra-alveolar root fractures has evolved to its current high level of sophistication and clinical success from foundations laid down by histological studies as early as the mid-nineteenth century. SIGNIFICANCE: The aim of the review was to highlight those earlier histological reports and studies that have contributed to the current understanding of the biological processes involved in the healing of transverse root fractures. Healing of a transverse root fracture by calcified tissue was demonstrated histologically by Howe in 1926, while Boulger in 1928 showed the two other patterns of root fracture healing, namely the interposition of fibrous connective tissue and the interposition of bone and periodontal ligament around both fractured segments. Other major histological reports around that time came from members of the so-called 'The Vienna group of Illinois', who had a significant influence in the development of oral biology worldwide. Other important reports and an experimental study emanated from Germany and Switzerland in the late 30s and early 40s, followed in the 1950s and early 1960s by histological material principally from Sweden, Denmark, France, the USA and Britain. Jens Andreasen and Erik Hjörting-Hansen's landmark paper in 1967 included new histological reports and a classification of healing responses following transverse root fractures. The expansion of knowledge related to root fractures since that time has been exponential, with major contributions from Scandinavia and several other countries. CASE REPORTS: Accompanying the historical review are two case reports with histology of root fracture healing by (a) calcified tissue and (b) dense fibrous connective tissue. The role of the pulp and the periodontal ligament in the repair process is described and the clinical significance discussed with particular emphasis to diagnosis and orthodontic management.

Micro-CT Evaluation of Spontaneous Apexification of an Immature Tooth following Trauma.

This case reports on the micro-computerised tomography (CT) images of a periapical calcified dome following spontaneous apexification as a subsequence of trauma. An immature, maxillary central incisor was found to be non-vital one month following trauma. The tooth had minimal signs of structural damage; however, there was radiographic evidence of spontaneous apexification. The tooth suffered a second traumatic episode two years later and was decoronated to facilitate bone retention during osseous development. The patient presented with swelling and pain 36 months later, and the tooth root was extracted. The root was embedded in resin, and cross-sectional images were obtained using micro-CT. Analysis of the images provided insight into the structure of the calcified dome that formed following the first traumatic injury.

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth.

Avulsion of permanent teeth is one of the most serious dental injuries, and a prompt and correct emergency management is very important for the prognosis. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the task group. The guidelines represent the current best evidence and practice based on literature research and professionals' opinion. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of avulsed permanent teeth.

Herpes Zoster and association with pulp necrosis and development of apical periodontitis - a review and presentation of two case reports.

The varicella zoster virus as an aetiological agent for endodontic disease is not a well-recognised entity despite several published case reports. While advances in DNA molecular analysis techniques (PCR) have contributed to the current understanding of the potential role of the varicella zoster virus in the initiation and progression of endodontic disease, a review indicates a need for ongoing research. Case reports are presented of two female patients with a history of herpes zoster who developed pulp necrosis, with one patient progressing to apical periodontitis. Both patients received non-surgical endodontic therapy, followed by intra-coronal bleaching in one of the patients due to tooth discolouration which developed during the prodromal and acute phases of the herpes zoster infection. Clinical and radiographic examinations at 23 and 22 years, respectively, showed the affected teeth to be retained in an asymptomatic and aesthetically satisfactory state with no radiographic evidence of apical pathosis.

A comparative diagnostic assessment of anterior tooth and bone status using panoramic and periapical radiography.

AIMS: The aim of the present study was to compare diagnostic assessments of anterior tooth and bone status in a randomised cohort of pre-orthodontic patients using panoramic and periapical radiographs. METHOD: Four hundred and forty-four cases with matched periapical and panoramic radiographs were examined by three observers. Two were final-year postgraduate endodontic students and the other, a final-year Honours degree dental student. Multi-rater Kappa values were used to assess the reliability of the observers, with a value of 1 equating to complete agreement. RESULTS: With the exception of endodontic Class 1 and 2 palatal invaginations, reliability exceeded 0.95 for all three observers. An assessment of the graduate endodontic students revealed only a marginal increase in the kappa values. Statistical analysis (p < 0.05) determined that developmental anomalies or tooth/bone pathoses were more reliably detected by observers using periapical radiographs compared with panoramic films. This finding has relevance given the likelihood of anterior dental trauma among young children. CONCLUSION: While there have been considerable improvements in the quality of dental panoramic radiography, the present study indicated that a reliable pre-orthodontic or post-trauma diagnostic assessment should include both panoramic and intra-oral radiographs.

Reprint of: Jens Ove Andreasen, 1935-2020 Father of Dental Traumatology.

The life and professional contributions to dental traumatology of Dr Jens Ove Andreasen are described in terms of his research, writing, teaching, and leadership.

Dentinal dysplasia type 1: A 3D micro-computed tomographic study of enamel, dentine and root canal morphology.

Dentine dysplasia type 1 is a rare and complex dental anomaly. Our aim was to conduct a morphometric assessment of a dentinal dysplasia type 1c (DD1c) caries-free mandibular second molar, extracted due to symptomatic apical periodontitis. Controls consisted of five intact mandibular second molars. Micro-computed tomography analysis showed that the DD1c volume % for enamel, dentine/cementum and pulp chamber fell in the 0.36th, 99.97th and 0.09th percentiles of the control teeth (P < 0.01). It also revealed an extremely complicated root canal system in the DD1c tooth with a varying degree of dentine mineralisation and aberrant dentine deposition in the pulp chamber. A crack extending from the external tooth surface to the pulp chamber was identified as a potential site for microbial invasion. Clinical implications include preventive measures and early intervention in reversible pulpitis. Conclusion: Micro-CT imaging can be useful in establishing post-extraction diagnosis of cracks and phenomic characterisation of tooth anomalies.

Sequelae to trauma to immature maxillary central incisors: a case report.

This case report highlights (i) a rare example of spontaneous apexification despite pulp necrosis and periradicular pathosis, and (ii) pulpal necrosis and periapical pathosis following secondary trauma. The initial trauma occurred in a seven-year-old female who received secondary trauma 4 years later. The diagnosis and management of both maxillary central incisors as well as follow-up assessments for both immature and mature teeth subjected to trauma is discussed.

Guidelines for the Management of Traumatic Dental Injuries: 2. Avulsion of Permanent Teeth.

Avulsion of permanent teeth is one of the most serious dental injuries, and a prompt and correct emergency management is very important for the prognosis. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the task group. The guidelines represent the current best evidence and practice based on literature research and professionals' opinion. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate orurgent care of avulsed permanent teeth.

Evaluation of Hydroxyl Radical Diffusion and Acidified Thiourea as a Scavenger during Intracoronal Bleaching.

INTRODUCTION: The diffusion of hydroxyl radicals in intracoronal bleaching is associated with a risk of invasive cervical resorption. The use of acidified thiourea has been recommended as a scavenger of residual radicals generated during intracoronal bleaching. The aims of this study were to quantify hydroxyl radical diffusion to external root surfaces after intracoronal bleaching with commonly used materials and to evaluate the effect of using acidified thiourea with hydrogen peroxide (H2O2) on hydroxyl radical diffusion. METHODS: Eighty-two human premolars were prepared, stained, root filled, and allocated to experimental and control groups as follows: group 1: sodium perborate (SP) and water (n = 21), group 2: H2O2 (n = 21), group 3: acidified thiourea and H2O2 (n = 21), group 4: neutral thiourea and H2O2 (n = 10), control group 1: negative control (water) (n = 10), and control group 2: positive control (SP and H2O2) (n = 10). Materials were placed into the pulp chamber, sealed, and placed in 5 mmol/L terephthalic acid at 37°C for 48 hours. Hydroxyl radicals were quantified using a fluorescence microplate reader and high-performance liquid chromatography with fluorescence detection. RESULTS: The H2O2 and SP mixture resulted in the greatest hydroxyl radical diffusion and was significantly greater than SP and water (P < .05) and H2O2 (P < .05). The addition of acidified thiourea resulted in higher radical diffusion, whereas the addition of neutral thiourea resulted in lower diffusion than H2O2 alone. CONCLUSIONS: The SP and water mixture resulted in the lowest hydroxyl radical diffusion, and the H2O2 and SP mixture resulted in the greatest. Although the addition of acidified thiourea to H2O2 did not reduce radicals detected, the addition of neutral thiourea had a positive effect.

Guidelines for the Management of Traumatic Dental Injuries: 2. Avulsion of Permanent Teeth.

Avulsion of permanent teeth is one of the most serious dental injuries, and a prompt and correct emergency management is very important for the prognosis. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the task group. The guidelines represent the current best evidence and practice based on literature research and professionals' opinion. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate orurgent care of avulsed permanent teeth.

Inaugural Geoffrey Heithersay oration in endodontics and oral biology.

Smiles are often a reflection of dental health, and as such provide great satisfaction to a dental practitioner who has successfully managed complex dental problems such as malformed, malpositioned or traumatically damaged teeth. A biological approach to the management of the pulpal and periodontal responses to dental trauma has been made possible by cumulative research, and application of this knowledge will enhance successful treatment.

Central giant cell granuloma.

Central giant cell granuloma, a fibro-osseous lesion, is more commonly found in the mandible and mainly in children and young adults. The lesion, which has a greater incidence in females, may be uni or multilocular. On the basis of clinical, radiological and histologic features, central giant cell granulomas can be classified as "non-aggressive" or "aggressive". Management involves surgical removal and in most cases the dentition can be maintained. Three cases of central giant cell granuloma are reported and they illustrate clinical features of the lesion, how differential diagnosis can be assisted by ORAD (a special software program), treatment, and the importance of recall examinations.

An evidence-based appraisal of splinting luxated, avulsed and root-fractured teeth.

The evidence-based methodology involves framing a well defined PICO (problem, intervention, comparison and outcome) question related to a clinical problem and then comprehensively searching for the evidence, which is evaluated to appraise the value of the treatment intervention. For this systematic review of splinting of teeth that have been luxated, avulsed or root-fractured, the clinical PICO question is (P) what are splinting intervention decisions for luxated, avulsed and root-fractured teeth (I) considering that the splinting intervention choice may include (i) no splinting, (ii) rigid or functional splinting for the different types of trauma and (iii) different durations of the splinting period (C) when comparing these splinting choices for the different types of trauma and their effect on (O) healing outcomes for the teeth. A keyword search of PubMed was used. Reference lists from identified articles and dental traumatology texts were also appraised. The inclusion criterion for this review was either a multivariate analysis or controlled stratified analyses as many variables have the potential to confound the assessment and evaluation of healing outcomes for teeth that have been luxated, avulsed or root-fractured. A positive statistical test is not proof of a causal conclusion, as a positive statistical relationship can arise by chance, and so this review also appraises animal studies that reportedly explain biological mechanisms that relate to healing outcomes of splinted teeth. The clinical studies were ranked using the 'Centre of Evidence-based Medicine' categorization (levels 1-5). All 12 clinical studies selected were ranked as level 4. The studies generally indicate that the prognosis is determined by the type of injury rather than factors associated with splinting. The results indicate that the types of splint and the fixation period are generally not significant variables when related to healing outcomes. This appraisal identified difficulties in the design of animal experimentation to correctly simulate some dental injuries. Some of the studies employed rigid splinting techniques, which are not representative of current recommendations. Recommended splinting treatment protocols for teeth that have been luxated, avulsed or root-fractured teeth are formulated on the strength of research evidence. Despite the ranking of these studies in this appraisal as low levels of evidence, these recommendations should be considered 'best practice', a core philosophy of evidence-based dentistry.