Standards and Accreditation: ABFO, DVI, ISO

The American Board of Forensic Odontology was founded in 1976 under the umbrella of the American Academy of Forensic Sciences. It grants the title Diplomate to dentists who demonstrate appropriate training and pass a written and practical examination. As of the mid-2020s approximately 400 Diplomates practice worldwide, the majority in the United States. ABFO certification is not required to testify as a forensic odontologist in most jurisdictions, but courts treat it as strong evidence of qualification and some jurisdictions have moved to require it.

The ABFO publishes guidelines covering dental identification methods, bite-mark investigation procedures, mass-disaster response, the role of the dental expert, and report writing standards. These are living documents, revised after significant scientific developments or formal review. The guidelines carry no statutory force, but an expert who departs from them without documented justification is exposed to direct challenge: courts regularly ask whether a practitioner's methodology departs from the guidance of their own certifying body.

• Guidelines for Bite Mark Analysis: the most contested document, revised significantly in 2016. Specifies collection protocol for injury documentation, comparison procedures, and the restricted conclusion language.
• Guidelines for Dental Identification: covers antemortem record collection, postmortem examination, comparison criteria, and the documentation required for a formal identification conclusion.
• ABFO No. 2 Scale: a standardised measurement scale for bite-mark photography that allows proportional comparison. Became controversial when a single practitioner claimed to use a modified version with idiosyncratic results.
• Diplomate certification requirements: currently require a dental degree, relevant postgraduate training, a minimum number of supervised casework cases across different case types, and passage of both written and practical examinations.

The National Academy of Sciences 2009 report, 'Strengthening Forensic Science in the United States', concluded that bite-mark analysis lacked sufficient scientific foundation and that the discipline needed to demonstrate its validity through properly designed studies. Seven years later the President's Council of Advisors on Science and Technology issued an even sharper assessment: bite-mark analysis had not been shown to be foundationally valid as a method for identifying an individual from a bite mark on skin. PCAST recommended that courts require a demonstration of validity before admitting testimony, and cited the lack of systematic error-rate data as a central problem.

The ABFO responded in 2016 with guideline revisions that, while contested internally, made several concrete changes. The revisions restrict bite-mark conclusion language: the 'identification' tier is removed as an available conclusion for bite-mark comparisons; examiners are directed to conclude at most 'consistent with' or 'cannot be excluded'. Independent second-examiner review using a blind procedure became a formal recommendation. The guidelines also acknowledged that human skin is not a reliable recording medium and that the assumption of dental uniqueness had not been empirically validated for bite-mark work.

Disaster Victim Identification is the process of establishing the identity of victims in mass-casualty events, including aircraft crashes, tsunamis, earthquakes, and terrorist attacks. INTERPOL published the first international DVI guidelines in 1984, following the Korean Air Lines Flight 007 disaster. The current edition runs to several hundred pages and covers operational structure, evidence collection, identification methods, and reconciliation procedures across many disciplines.

Dental identification is one of the three primary identification methods under INTERPOL DVI, alongside fingerprints and DNA. The Pink Form (Dental Identification Form) is the structured document on which both the antemortem record and the postmortem dental findings are recorded. The form is deliberately identical in structure for both sides so that a third party, or an automated comparison tool, can assess concordance without interpreting idiosyncratic notation.

A key feature of the DVI dental protocol is the mandatory independent confirmation before a positive identification is finalised. The first odontologist records their findings and conclusion on the Pink Form. A second odontologist, who has not seen the first conclusion, reviews the same forms independently. Only if both reach a positive identification is the match entered on the Reconciliation Form and the case declared identified. This embedded blind verification is operationally enforced rather than aspirational.

ISO 17025:2017, 'General requirements for the competence of testing and calibration laboratories', is the primary international standard for forensic laboratory accreditation. National accreditation bodies (UKAS in the United Kingdom, A2LA and ANAB in the United States, NATA in Australia, among others) assess forensic laboratories against this standard. When dental comparison is included in a laboratory's scope, the accreditation assessment covers those activities.

• Method validation: the laboratory must document that its comparison method has been validated for its intended purpose. For dental identification this includes a defined minimum number of concordant features and a protocol for handling unexplained discordances.
• Measurement traceability: equipment used for comparison (imaging systems, measurement tools, photographic scales) must be calibrated against traceable standards. This applies directly to photographic documentation of bite marks and dental models.
• Proficiency testing: the laboratory must participate in external proficiency testing programmes and document the results. Consistent poor performance triggers a non-conformance requiring corrective action.
• Blind verification: the requirement for an independent second review is embedded in the standard's requirement for quality controls on technical output. A laboratory that sends all cases to a single examiner without independent review cannot demonstrate adequate quality control.
• Documentation and chain of custody: all evidence items must be logged, their handling recorded, and the examination record preserved in a form that supports court testimony. The standard's requirements here mirror the chain-of-custody requirements in criminal procedure.

The ABFO's framework is American, but every jurisdiction with an active forensic odontology community has its own professional and regulatory structure. The picture outside the United States shows both convergence on core principles and genuine local variation.

In England and Wales, the Forensic Science Regulator (now placed on a statutory footing by the Forensic Science Regulator Act 2021) publishes Codes of Practice and Conduct that apply to forensic science activities used in criminal proceedings. Bite-mark comparison is explicitly listed among disciplines that require validation evidence before use. The FSR codes align closely with ISO 17025 but add specific requirements around reporting, impartiality, and court disclosure that go beyond the ISO standard.

Australia's NATA accreditation system for forensic laboratories operates under the same ISO 17025 framework. The Australian and New Zealand Forensic Science Society (ANZFSS) provides professional standards and guidance that inform NATA assessments. In Canada, the Forensic Science Service providers (provincial and federal) also operate under ISO 17025 accreditation, and their guidelines on dental comparison have been influenced both by ABFO standards and by successive Canadian judicial admissibility decisions.

The ABFO guideline reforms of 2016 and the ISO 17025 accreditation requirements together represent a significant tightening of what is required to practice forensic odontology to a defensible standard. But gaps remain that the standards themselves identify as open.

• Validation studies for bite-mark comparison: the PCAST report identified the absence of large-scale, properly designed foundational validity studies as the central gap. Such studies, with known-ground-truth cases and blinded examiner populations, are still limited in number and scale.
• Agreed minimum feature threshold: dental identification has an informal consensus around the number of concordant features needed for a positive identification conclusion, but no universally agreed numeric threshold exists. ABFO guidelines describe qualitative criteria; quantitative thresholds supported by empirical data are still an open research question.
• Digital comparison tools: computational methods for dental comparison in DVI settings (image matching, automated feature extraction) are in active development. ISO 17025 accreditation will need to cover validation requirements for these tools as they enter operational use.
• International harmonisation: the ABFO, INTERPOL DVI, and national forensic regulators each operate with different governance structures and update cycles. Cross-jurisdictional cases can encounter different standards for what constitutes an acceptable comparison, which creates inconsistency in transnational DVI and criminal matters.

The direction of reform is consistent: greater standardisation, external validation, mandatory proficiency testing, and restricted conclusion language where foundational validity has not been established. Progress from the pre-2009 position to the post-2016 framework is real, but the open questions listed above remain unresolved.