Oral Pathology I: Etiopathogenesis & Diagnosis

• Etiopathogenesis refers to the origin of a disease.
• Pathogenesis explains how a disease develops.

Oral Pathology I Course Description

• Oral Pathology I is a semester-long, theoretical-practical course.
• It helps students form diagnostic hypotheses for mucosal lesions, odontogenic infections, and significant syndromic malformations affecting the maxillofacial region.
• Students will learn to suggest complementary exams and treatments based on scientific evidence and current protocols.
• The teaching method includes expository and participatory classes, flipped classroom techniques, and problem-based learning.
• Assessment includes tests, partial exams, presentations, seminars, research reports, practical activity reports, critical reading, and case analysis.

Learning Outcomes

• Students will be able to formulate diagnostic hypotheses for lesions, infections, and malformations in the maxillofacial area.
• They will also be able to recommend necessary tests and treatments based on available scientific evidence and protocols.

Evaluations and Grading

• Final exams comprehensively cover all content taught up to the exam date.
• Students can take a final recovery exam to replace one of the regular final exam scores.
• Partial evaluations include assessments, discussions, assignments, etc., during practical sessions.
• A minimum passing grade of 60% is required.
• Absence from evaluations or failure to submit work on time results in a grade of 1.0 (as per Pregrade Teaching Regulations, Article 29).
• Assessment weighting is as follows:
• Final Exam 1: 15%
• Final Exam 2: 20%
• Final Exam 3: 35%
• Partial Grade 1: 10%
• Partial Grade 2: 10%
• Partial Grade 3: 10%

Passing Requirements

• Minimum attendance is required.
• 75% for theoretical classes.
• 90% for practical sessions.
• A final grade of 4.0 or higher must be achieved.
• Students caught cheating on an academic evaluation will immediately fail that evaluation, with no possibility of replacement, even with a make-up exam (according to Pregrade Teaching Regulations, Article 29); cell phones are prohibited during examinations.

Course Topics

• Malformations of the maxillofacial region
• Odontogenic infections and their complications include bone paroxysm
• Head and neck cysts
• Odontogenic tumors
• Non-odontogenic osseous lesions

Required Bibliography

• Neville, B. (2009). Oral and Maxillofacial Pathology. United States: Elsevier (3rd edition).

Recommended Bibliography

• Sapp, J.P., Eversole, L.R. (2005). Contemporary Oral and Maxillofacial Pathology. Spain. Mosby (2nd edition).

Additional Resources

• Consult indexed journals such as:
• Oral Medicine Oral Surgery Oral Pathology Oral Radiology
• Journal of Oral Pathology
• Journal of the American Dental Association
• Journal of Dental Research.
• Medicina Oral.
• Access journals via EBSCOHOST database at the USS.

Anomalies in Tooth Development

• Focus on alterations in number, size, shape, and eruption of teeth.
• These anomalies can result from both internal (intrinsic) and external (environmental) factors.
• Genetic, epigenetic, nutritional, and environmental factors are involved.

Presentation Topics

• Alterations in Number:*
  • Anodontia and Pseudoanodontia
  • Supernumerary teeth
• Alterations in Size:*
  • Microdontia
  • Macrodontia
• Alterations in Shape:*
  • Fusion
  • Gemination
  • Concrescence
  • Dilaceration
  • Dens invaginatus
  • Dens evaginatus
  • Enamel pearls
  • Supernumerary roots
  • Taurodontism
• Alterations in Eruption:*
  • Premature eruption
  • Delayed eruption
  • Retained teeth

Anomalies of the teeth

• These are the Categories of Anomalies:*
• Changes in Number
• Changes in Size
• Changes in Shape
• Changes in Eruption
• Changes in Enamel
• Changes in Dentin

Alterations in Number

• Can be caused by either too many or too few teeth (total or partial)
• Hipodoncia: fewer than 6 missing teeth
• Oligodoncia: More than 6 missing teeth
• Reasons:*
• Occurs Idiopathically ( cause is unknown)
• Associated with syndromes

Anodoncia

• The absence of one or more teeth
  • Total: is rare and generally associated with a syndrome (DEH).
  • Partial: is common, usually affecting the last tooth in each series (3rd molars, lateral incisors, and 2nd premolars).

Agenesis

• Refers to the congenital absence of a tooth (either deciduous or permanent).
• It is due to the absence of the tooth germ itself.

Affects

• Hypodontia primarily affects the permanent dentition.
• It is frequently linked to microdontia.
• Some instances of hypodontia result from genetic mutations; however, the causes remain unclear in other instances with various syndromes.

Pseudoanodoncia

• Occurs when teeth erupt at an incorrect angle

Ectodermal Dysplasia

• It represents a group of hereditary conditions affecting two or more ectodermal derivatives
• The degree of ectodermal dysplasia can result in changes/lack of development of skin, hair, nails, teeth and sweat glands.
• Absence of sweat glands leads to heat intolerance
• Sparse and thin hair, including reduced eyebrow and eyelash density.
• Periorbital skin with hyperpigmentation, decrease in middle and lower facial thirds, prominent lips; Hyposalivation.
• Nails are brittle and Dystrophic
• Hipo or oligodontia, with conic crowns.

Oligodontia

• It is associated with ectodermal dysplasia.

Supernumerary Teeth

• Refers to an extra tooth or teeth beyond the normal dental count.
• More common in the upper jaw (90% of cases).
• Frequently occur between the central incisors (mesiodens), followed by the 4th molar (paramolar) and premolars.
• The morphology can be normal or rudimentary.
• Usually singular, but can be multiple when associated with syndromes like Gardner's Syndrome or Cleidocranial Dysplasia.

Supernumerary can be Associated with

• Gardner's Syndrome (AD 5q21).
• Fibromas in skin.
• Epidermoid cysts.
• Multiple Osteomas.
• Intestinal polyposis turns into cancer.
  • Mesiodens
  • Multiple Osteomas
• Can also be associated with cleidocranial dysplasia (AD 6p21).
  • Cranial deformities like brachycephaly and flattened nasal bridge.
  • Clavicle abnormalities such as aplasia or hypoplasia.
  • Dental issues include impacted and extra teeth.

Alterations in Size

• Differences in tooth size compared to the normal, categorized as macro (large) or microdontia (small).
• They can involve one or multiple teeth.
  • Can be local
  • Can be systemic ( pituitary alterations)

Microdontia

• Generalised: can occur in pituitary dwarfism.
• Relative: when the bones are larger than average
• More common
• Typically affects lateral incisors and third molars.

Macrodontia

• Generalised: found in pituitary gigantism
• Regional/Localized: found in the cases of hemifacial hypertrophy
• Less common
• Only affect the root by causing rizomegalia,

Alterations in Shape

• A variety of changes in tooth shape
• These lead to taurodontism.

Fusión

• Involves the joining of two tooth germs.
• The joining is partial or complete with a crown
• Clinically, fused teeth appear to be missing one crown.
• The enamel, dentin, cementum, and pulp may be involved.
• The root canals may be either joined or separate.
• The cause is unknown. But it is a mix of etiologies.

Gemination

• It's the division or attempted division of one germ into 2 teeth.
• Generally effects the anterior teeth.
• Clinically it can confuse with fusion
• Affects decidous and permanent teeth.
• Can either be total or partial to cause the appearance of 2 completely individual teeth.
• Etiology is unknown. It is a mix of etiologies
• It can be caused by trauma or hereditary factors

Concrescence

• It occurs when the roots of one or more normally formed teeth are fused by cementum
• A type of fusion that occurs after root development is complete
• Caused by Trauma
• Commonly Affects Two Adjacent Teeth
• Usually the 2nd and 3rd Molars
• Hyper cementosis can result in concrescence

Dilaceration

• It is an abnormal sharp curve or bend in a tooth root
• Sometimes due to trauma during developed teeth.
• It can also be because of tortuous movements during eruption

Dens Invaginatus

• Deep pocket in enamel, depth is variable (can go to dentine/ pulp tissue).
• Can be in ILS and ICS
• Difficult to observe clinically because it might not always be vissible.
• Can rapidly develop pulpitis pulp necrosis.

Dens Evaginatus

• A tooth with abnormality, a cusp that protrudes the surface.
• Often the pm, ics, ils: talon cusp
• Can disrupt with the teeth erruption
• Sometimes the pulpa horn can protrude.

Enamel Pearls

• Are projections of enamel in atypical regions
• Differentiation of ameloblasts from rest of the heitwigs root.
• At the levels of the cervix/ root
• 1-3mm; can lead to periodontitis.

Extra Roots: Supernumerary Roots

• The tooth has roots more than usual.
• Generally in PMi and 3Mi.
• Implicates need foe endodontisc and exodontia

Taurodontism

• The chamber is elongated towards the apex.
• Crowns are rectangular
• Alteration with lack of Hertwig sheet
• Connected to klinefelter and down syntheses

The chronological eruption

• Chart for the timing of supernumerary and normal teeth.

Eruptions can be

• Premature
• Retarded
• impacted

Premature

• Is Rara
• Occurs if exodontic of teeth fall prematurly because of trauma or infection.

Lateness of Eruption

• If teeth 75% root formation hasn't occurred
• Can be due to hormonal influences

Impaction

• Rarely in temporals
• Normally in 2M
• In 3MI, Caninios, Pms, Ils/ Ics
• A possible cause is a lack if space
• Other contributing factors are Trauma , Systemic disorders