Aula - Antropologia Forense - determinando o sexo.

Main ideas, concepts, and lessons (Forensic anthropology: determining sex from human remains)

Purpose of the class

• Explains what forensic anthropology does to help evaluate human remains with the goal of determining biological sex (male vs. female).
• Frames the work as part of legal/forensic medicine.
• Highlights connections with other forensic disciplines, especially forensic odontology (teeth).

Forensic context and information-gathering

• Crime scene evidence matters because it can provide “a lot of information.”
• The lesson emphasizes: the more careful the evaluation, the better, especially when remains are limited.
• Practical limitations may depend on available services:
  • The setting described notes the absence of forensic odontology and botany services.
  • Toxicology support is mentioned as available.

Core protocol: first questions when receiving material

1. Check whether the material is bone, and determine what kind:
   • Human bone
   • Only human bone
   • Mixed with other species
2. Consider the context of the find.
3. If multiple bones may be present, estimate the Minimum Number of Individuals (MNI).
   • Example logic: if at least three bones are present, that can imply at least two individuals (“loophole” example).
4. Build a biological profile, focusing on:
   • Sex
   • Age at death
   • Ancestry
   • Stature
5. Also assess:
   • Whether the individual can be identified
   • Possible pathology
   • Possible trauma
6. Time since death is also important, though this presentation focuses primarily on sex determination.

“Sex vs. gender” clarification

• Gender is social.
• Sex is biological.
• Forensic anthropology uses sex (biological differences), not gender identity.

General approach to sex determination

• Determine sex using anatomical differences and morphological assessment (visual inspection).
• Emphasize collecting as much evidence as possible and combining multiple indicators, since no single trait is perfectly reliable.

How reliable methods are described (approximate effectiveness)

• Pelvis: up to 100%
• Skull: up to 95%
• Long bones of the pelvis: about 90%
• Long bones (general): about 80%

Adult-only limitation and ancestry warning

• Many traits become clearer in adulthood.
• Warns about ancestry-related overlap:
  • Example: traits in an Asian male skull may resemble those in a European female skull.
• Presentation advises assessing ancestry before or alongside sex determination.

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Detailed bullet-point methodology/instructions (sex determination workflow)

1) Start with the material and context

• Confirm whether the remains are:
  • Human bone
  • Only human
  • Or mixed with other species
• Evaluate the context of the find.
• Estimate MNI (minimum number of individuals).
  • Example logic: if there are at least three bones, infer at least two individuals.

2) Build the biological profile (with emphasis on sex)

Record and evaluate:

• Sex
• Age at death
• Ancestry
• Stature
• Also consider:
  • Possibility of individual identification
  • Pathology
  • Trauma
• Consider time since death (even if not the focus here).

3) Use skeletal indicators that are strongest for sex

Prefer traits from highly informative regions:

• Pelvis
• Skull
• Long bones (after pelvis and skull)

4) Pelvis-based sex indicators (primary focus)

Infrapubic angle

• Women: greater than 90°
• Men: usually less than 90°

Pelvic opening shape

• Women: typically wide, described as round
• Men: typically narrow, described as triangular

Sciatic notch

• Women:
  • Larger, wider, shallower
• Men:
  • Narrower, deeper

Thumb-based observation technique (described)

• Insert thumb into the sciatic notch and compare:
  • Female notch appears narrower
  • Male notch appears deeper/clearer

Superimposed/variable traits and cautions

• Pelvic traits may vary gradually, so confounding factors may exist.
• Preauricular groove
  • Usually present (not absent) in men
  • Discussed as being related to pregnancy-related ligament laxity/later strengthening in women (per explanation given).
• Pubis-related evidence
  • Some parts are noted as weak evidence on their own.

5) Pubic angle and index-style measures (quantification examples)

• Angle guideline:
  • Women: > 90°
  • Men: < 80°
• “Index” concept (as described):
  • Wings index: involves “length of the pubis divided by the length of the sphincter * C**” (transcribed as given)
• Threshold-style interpretation:
  • Women: index > 94
  • Men: index < 84
• Public angle recognition thresholds mentioned around values like 84/94 (as stated).

6) Skull-based sex indicators

External occipital protuberance (EOP)

• Women: smooth, barely marked
• Men: prominent, well-defined lines
• Intermediate cases may occur (EOP less distinct in women; more prominent in men).

Forehead configuration

• Women: straighter, more vertical
• Men: more inclined/back-curved

Nasolabial fold / nasal bone junction

• Women: smooth, curved junction
• Men: more projected/coil-like junction

Glabella

• Women: smoother
• Men: more prominent (described as an elongated masculine mark)

Mastoid process (temporal bone)

• Women:
  • Small, less developed, turned outward
• Men:
  • More developed, robust, turned outward
• Orientation guidance mentioned (as described):
  • Turned outwards → suggests sex (per diagram context: male/female)
  • Turned inwards → suggests male sex
  • Turned downwards → indeterminate (recorded as indeterminate sex)

Supraorbital margin

• Women: usually warm (term unclear in transcription)
• Men: more rounded margin

Pattern approach using combined traits

• Example “hyper-feminine” pattern:
  • hyper-feminine EOP + smooth midline glabella + underdeveloped mastoid
• Example “hyper-masculine” pattern:
  • hyper-masculine EOP + prominent masculine glabella + developed mastoid

7) Mandible (jaw) indicators

Bigoniacal angle

• If > 11 cm → suggests male
• If < 9 cm → suggests female

General mandible shape descriptors

• Men: wider, more square, more defined angle
• Women: smoother, narrow (described as more “gullet” in the transcription)

8) Long bone indicators (with measurement cautions)

Femur and humerus

• Femur mentioned generally alongside the humerus.
• Humerus head measurement guideline (as stated):
  • Men: humeral head larger than ~4.5 cm
  • Women: less than ~4.5 cm
  • Another transcribed figure mentions less than 4.

Measurement caution (humerus)

• Avoid a specific error:
  • When measuring humeral head diameter, do not include/approach near the greater tubercle
• The class notes that incorrect line placement can create measurement error.

9) Overall concluding principle

Sex determination is best achieved by:

• Using multiple anatomical indicators
• Considering adult-only limitations
• Considering ancestry
• Applying quantitative thresholds when provided (angles/indices/lengths)

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Sources / speakers featured

• The class speaker (name not clearly preserved in the subtitles)
• Dr. Inácio (explicitly referenced: “That’s Dr. Inácio’s technique.”)