```markdown
Bone Diseases
DENT 5322
Dr Omar Kujan
```
DENT 5322
Dr. Omar Kujan
```markdown
Learning Objectives
- Explain the aetiology, pathogenesis, the clinical (including radiographic) and histopathological features, diagnosis and treatment of bone diseases
- For more details, please refer to Unit Guide
```
This course provides a comprehensive examination of bone pathologies relevant to dental practice.
Upon completion of this section, students should be able to:
- Explain the aetiology, pathogenesis, clinical (including radiographic), and histopathological features of bone diseases.
- Discuss the diagnosis and treatment protocols for various bone conditions.
For more details, please refer to the Unit Guide.
```markdown
**Reference**
- Cawson's Essentials of Oral Pathology and Oral Medicine
- 9th Edition
- Authors: Edward Odell
<img src="https://i.imgur.com/3ZzXJQl.jpg" alt="Cover of Cawson's Essentials of Oral Pathology and Oral Medicine, 9th Edition"/>
```
#### Primary Textbook
- **Cawson's Essentials of Oral Pathology and Oral Medicine**
- Edition: 9th Edition
- Author: Edward Odell
![]()
The cover of the book "Cawson's Essentials of Oral Pathology and Oral Medicine, 9th Edition" by Edward Odell, featuring a microscopic image of tissue and smaller inset images of oral conditions.
#### Primary Textbook
- **Cawson's Essentials of Oral Pathology and Oral Medicine**
- Edition: 9th Edition
- Author: Edward Odell
![]()
A microscopic image of bone tissue showing various cellular components. The image highlights 'New bone' at the top left, 'Osteoblasts' in the upper middle section, 'Osteoclasts' at the top right, 'Bone matrix' in the lower right, and an 'Osteocyte' at the bottom left. The tissue appears to be stained yellow and brown, with dark spots representing cells or structures within the bone.
```html
<table border="1" cellpadding="5" cellspacing="0" style="border-collapse: collapse; width: 100%;"><tr><td style="text-align: center;"><img src="https://i.imgur.com/7JkZjQl.png" alt="Diagram of the Haversian system in bone tissue, showing labeled components including Volkmann's Canal, osteocytes, Haversian canal, and the overall Haversian system." /></td></tr></table>
```
#### Components of the Haversian System
The microscopic structure of bone tissue is organized into the Haversian system, which includes the following key anatomical features:
- **Haversian Canal**: The central channel containing blood vessels and nerve fibers.
- **Volkmann's Canal**: Channels that assist in transmitting blood vessels from the periosteum into the bone and communicate with the Haversian canals.
- **Osteocytes**: Mature bone cells located within the bone matrix.
- **Lamellae**: Concentric layers of mineralized matrix surrounding the central canal.
![]()
A labeled diagram of the Haversian system in bone tissue, showing components such as the Haversian canal, Volkmann's canal, and osteocytes. The diagram illustrates the structural organization of bone with a cross-sectional view of the system.
# Remodeling
- Replacement of old tissue by new bone
Five phases:
1. Activation: preosteoclasts are stimulated and differentiate under the influence of cytokines and growth factors into mature active osteoclasts
2. Resorption: osteoclasts digest mineral matrix (old bone)
3. Reversal: end of resorption
4. Formation: osteoblasts synthesize new bone matrix
5. Quiescence: osteoblasts become resting bone lining cells on the newly formed bone surface
```html
<table border="1" class="image">
<tr>
<td><img src="https://i.imgur.com/5JZfZ5l.png" alt="Remodeling Phase 1: Activation" /></td>
<td><img src="https://i.imgur.com/5JZfZ5l.png" alt="Remodeling Phase 2: Resorption" /></td>
<td><img src="https://i.imgur.com/5JZfZ5l.png" alt="Remodeling Phase 3: Reversal" /></td>
<td><img src="https://i.imgur.com/5JZfZ5l.png" alt="Remodeling Phase 4: Formation" /></td>
<td><img src="https://i.imgur.com/5JZfZ5l.png" alt="Remodeling Phase 5: Quiescence" /></td>
</tr>
</table>
```
Bone remodeling is the continuous process of replacing old tissue with new bone. This cycle consists of five distinct phases:
1. **Activation**: Preosteoclasts are stimulated and differentiate into mature, active osteoclasts under the influence of cytokines and growth factors.
2. **Resorption**: Active osteoclasts digest the mineral matrix of the old bone.
3. **Reversal**: This phase marks the end of bone resorption.
4. **Formation**: Osteoblasts synthesize new bone matrix.
5. **Quiescence**: Osteoblasts transition into resting bone-lining cells on the newly formed bone surface.
![]()
A five-phase diagram illustrating the process of bone remodeling, showing the activation, resorption, reversal, formation, and quiescence stages with corresponding cellular activities and structural changes in bone tissue.
```html
<table border="1" cellpadding="5" cellspacing="0" style="border-collapse: collapse; width: 100%;"><tr><th colspan="3" style="text-align: center; font-size: 24px; color: #00BFFF;">Bone remodeling cycle (1)</th></tr><tr><td style="text-align: left;">Endosteal sinus</td><td style="text-align: left;">Monocyte</td><td style="text-align: left;">Pre-osteoclast</td></tr><tr><td style="text-align: left;">Osteocyte</td><td style="text-align: left;">Osteoclast</td><td style="text-align: left;">Macrophage</td></tr><tr><td style="text-align: left;">Osteoblast</td><td style="text-align: left;">Bone-lining cell</td><td style="text-align: left;">Pre-osteoblast</td></tr><tr><td style="text-align: left;">Osteoid</td><td style="text-align: left;">New bone</td><td style="text-align: left;">Old bone</td></tr></table>
```
#### Cellular Components of the Remodeling Cycle
The bone remodeling cycle involves a variety of specialized cells and structures working in coordination:
- **Vascular and Precursor Elements**: Endosteal sinus, monocytes, and pre-osteoclasts.
- **Active Bone Cells**: Osteoclasts (responsible for resorption) and osteoblasts (responsible for formation).
- **Supportive and Regulatory Cells**: Macrophages, pre-osteoblasts, and bone-lining cells.
- **Matrix and Tissue States**: Osteoid (unmineralized matrix), new bone, old bone, and embedded osteocytes.
![]()
A detailed diagram illustrating the bone remodeling cycle, showing the process of bone resorption and formation. The diagram includes labeled components such as osteoclasts, osteoblasts, osteocytes, and bone-lining cells, with a cross-section of bone tissue highlighting new and old bone formation. The diagram also shows the role of monocytes and pre-osteoclasts in the remodeling process.
![]()
A table summarizing the components of the bone remodeling cycle, listing various cell types and structures such as endosteal sinus, osteocyte, osteoblast, osteoid, monocyte, osteoclast, bone-lining cell, pre-osteoclast, macrophage, pre-osteoblast, new bone, and old bone. The table is organized in a three-column format with a maroon background and white text.
```html
<table border="1" class="dataframe">
<thead>
<tr style="text-align: right;">
<th>Stage</th>
<th>Key Cells and Structures</th>
</tr>
</thead>
<tbody>
<tr>
<td>1. Resorption Phase</td>
<td>Endosteal sinus → Monocyte → Pre-osteoclast → Osteoclast (resorbs old bone)</td>
</tr>
<tr>
<td>2. Clearance Phase</td>
<td>Osteoclast → Macrophage (clears debris)</td>
</tr>
<tr>
<td>3. Formation Phase</td>
<td>Pre-osteoblast → Osteoblast → Bone-lining cell (forms new bone)</td>
</tr>
<tr>
<td>4. Maturation Phase</td>
<td>Osteoblast → Osteoid → New bone (mineralization)</td>
</tr>
</tbody>
</table>
```
#### Stages of Bone Tissue Turnover
1. **Resorption Phase**: Involves the transition from the endosteal sinus to monocytes and pre-osteoclasts, culminating in osteoclasts resorbing old bone.
2. **Clearance Phase**: Osteoclasts and macrophages work to clear cellular and matrix debris from the site.
3. **Formation Phase**: Pre-osteoblasts differentiate into osteoblasts, which eventually become bone-lining cells as they form new bone.
4. **Maturation Phase**: Osteoblasts produce osteoid, which undergoes mineralization to become functional new bone.
![]()
A detailed diagram illustrating the bone remodeling cycle, showing the progression from the endosteal sinus to the formation of new bone. The diagram depicts key stages including osteoclast resorption, macrophage clearance, osteoblast formation, and mineralization, with labeled cellular components such as monocytes, pre-osteoclasts, and bone-lining cells.
![]()
A table outlining the four stages of bone remodeling: resorption, clearance, formation, and maturation, with descriptions of key cells and structures involved in each phase, such as osteoclasts, macrophages, osteoblasts, and osteoid.
```html
<table>
<tr>
<td><img src="https://i.imgur.com/9jKjKjK.png" alt="Bone remodeling cycle (3) diagram showing osteoclasts, monocytes, pre-osteoblasts, osteoblasts, and osteocytes in bone tissue"/></td>
</tr>
</table>
```
#### Cellular Interaction in the Remodeling Site
The spatial organization of the remodeling cycle demonstrates the interaction between different cell lineages within the bone tissue:
- **Osteoclast Lineage**: Monocytes and pre-osteoclasts migrating to the resorption site.
- **Osteoblast Lineage**: Pre-osteoblasts and active osteoblasts lining the areas of new bone formation.
- **Integration**: Mature osteocytes remain embedded within the bone matrix to monitor mechanical strain and direct remodeling activity.
![]()
A detailed diagram illustrating the bone remodeling cycle, showing the sequential steps involving osteoclasts, monocytes, pre-osteoblasts, osteoblasts, and osteocytes within bone tissue. The diagram is labeled 'Bone remodeling cycle (3)' and visually depicts the cellular processes in a layered bone structure.
The bone remodeling cycle is a continuous physiological process involving the coordinated actions of osteoclasts and osteoblasts to maintain skeletal integrity and mineral homeostasis.
![]()
A histological micrograph showing bone tissue with labeled structures. The image highlights osteocytes embedded in the bone matrix and osteoblasts along the bone surface, indicating active bone formation. The staining emphasizes cellular components and extracellular matrix.
```markdown
Radiography
- Periapical
- OPG
- CBCT
- CT Scan
11
```
Radiographic interpretation is essential for diagnosing bone lesions, requiring a systematic approach to evaluate changes in bone density and structure.
#### Common Radiographic Techniques
- Periapical
- OPG (Orthopantomogram)
- CBCT (Cone Beam Computed Tomography)
- CT Scan
![]()
The image displays a presentation slide with a maroon background and a title 'Radiography' in blue text at the top. Below the title, there is a bulleted list in yellow text listing four types of radiographic imaging: Periapical, OPG, CBCT, and CT Scan. The slide number '11' is visible in the bottom right corner.
```html
<table border="1" cellpadding="10" cellspacing="0" style="border-collapse: collapse; width: 100%;"><tr><td style="text-align: center;"><table border="1" cellpadding="10" cellspacing="0" style="border-collapse: collapse; width: 100%;"><tr><td style="text-align: center;">Radiolucent lesion</td></tr><tr><td style="text-align: center;"><table border="1" cellpadding="10" cellspacing="0" style="border-collapse: collapse; width: 100%;"><tr><td style="text-align: center;">Normal</td><td style="text-align: center;">Artifactual</td><td style="text-align: center;">Pathological</td></tr><tr><td style="text-align: center;">Congenital</td><td style="text-align: center;">Developmental</td><td style="text-align: center;">Acquired</td></tr><tr><td style="text-align: center;">Infective</td><td style="text-align: center;">Traumatic</td><td style="text-align: center;">Cystic</td></tr><tr><td style="text-align: center;">Neoplastic</td><td style="text-align: center;">Osseous</td></tr></table></td></tr></table></td></tr></table>
```
#### Categorization of Radiolucent Lesions
Radiolucent lesions can be classified based on their nature and origin:
- **Normal anatomical variations**
- **Artifactual findings**
- **Pathological conditions**
- **Congenital**
- **Developmental**
- **Acquired**:
- Infective
- Traumatic
- Cystic
- Neoplastic
- Osseous
![]()
The image displays a flowchart diagram titled 'Radiolucent lesions' that categorizes radiolucent lesions into normal, artifactual, and pathological types. The pathological category is further divided into congenital, developmental, and acquired types, with acquired lesions further classified into infective, traumatic, cystic, neoplastic, and osseous categories. The diagram uses arrows to illustrate the classification hierarchy.
```html
<table border="1" cellpadding="5" cellspacing="0">
<tr>
<td><img src="https://i.imgur.com/4VqKZ9m.png" alt="Figure 53.1b Nonodontogenic radiolucent cystic lesions." /></td>
</tr>
</table>
```
#### Nonodontogenic Radiolucent Cystic Lesions
This category includes various cystic presentations within the bone that do not originate from tooth-forming tissues.
![]()
A diagram illustrating nonodontogenic radiolucent cystic lesions in the skull, highlighting the locations of a nasopalatine cyst, traumatic bone cyst, and Stafne cavity. The figure is labeled as 'Figure 53.1b Nonodontogenic radiolucent cystic lesions.'
```html
<table border="1" cellpadding="5" cellspacing="0" style="border-collapse: collapse; width: 100%;">
<tr>
<td style="text-align: center;"><b>Radiolucencies</b></td>
</tr>
<tr>
<td style="text-align: center;"><b>Unilocular</b></td>
<td style="text-align: center;"><b>Multilocular</b></td>
</tr>
<tr>
<td style="text-align: left; padding-left: 10px;">
<b>Angiomas</b><br>
<b>Cysts:</b><br>
Dentigerous<br>
Lateral periodontal<br>
odontogenic tumor<br>
Nasopalatine<br>
Radicular<br>
Residual<br>
Solitary bone<br>
Stafne cavity<br>
<b>Neoplasms</b>
</td>
<td style="text-align: left; padding-left: 10px;">
<b>Angiomas</b><br>
Giant cell lesions<br>
<b>Odontogenic tumors:</b><br>
Ameloblastoma<br>
Ameloblastic fibroma<br>
CEOT<br>
KCOT<br>
Myxoma
</td>
</tr>
</table>
Figure 53.4b Radiolucent lesions. CEOT, calcifying epithelial odontogenic tumor; KCOT, keratocystic odontogenic tumor; AOT, adenomatoid odontogenic tumor.
Source: Oral Medicine and Pathology at a glance, 2010, Scully et al.
```
#### Morphological Classification of Radiolucencies
Radiolucent lesions are often categorized by their internal architecture as either unilocular or multilocular.
##### Unilocular Radiolucencies
- **Angiomas**
- **Cysts**:
- Dentigerous
- Lateral periodontal
- Odontogenic tumor (e.g., AOT)
- Nasopalatine
- Radicular
- Residual
- Solitary bone
- Stafne cavity
- **Neoplasms**
##### Multilocular Radiolucencies
- **Angiomas**
- **Giant cell lesions**
- **Odontogenic tumors**:
- Ameloblastoma
- Ameloblastic fibroma
- CEOT (Calcifying epithelial odontogenic tumor)
- KCOT (Keratocystic odontogenic tumor)
- Myxoma
##### Terminology Reference
- **AOT**: Adenomatoid odontogenic tumor
- **CEOT**: Calcifying epithelial odontogenic tumor
- **KCOT**: Keratocystic odontogenic tumor
![]()
A flowchart diagram illustrating the classification of radiolucent lesions, branching into unilocular and multilocular categories. The unilocular category includes conditions like angiomas, cysts (dentigerous, lateral periodontal, etc.), and neoplasms. The multilocular category includes angiomas, giant cell lesions, and odontogenic tumors such as ameloblastoma, ameloblastic fibroma, CEOT, KCOT, and myxoma.
![]()
A figure caption labeled 'Figure 53.4b Radiolucent lesions,' which provides a textual description of the diagram above, defining abbreviations such as CEOT (calcifying epithelial odontogenic tumor), KCOT (keratocystic odontogenic tumor), and AOT (adenomatoid odontogenic tumor).
```html
<table border="1" cellpadding="5" cellspacing="0" style="border-collapse: collapse; width: 100%;"><tr><td style="text-align: center;"><b>Radiopaque lesion</b></td></tr><tr><td style="text-align: center;">Normal</td><td style="text-align: center;">Artifactual</td><td style="text-align: center;">Pathological</td></tr><tr><td style="text-align: center;">Congenital</td><td style="text-align: center;">Developmental</td><td style="text-align: center;">Acquired</td></tr><tr><td style="text-align: center;">Infective</td></tr><tr><td style="text-align: center;">Odontogenic</td></tr><tr><td style="text-align: center;">Neoplastic</td></tr><tr><td style="text-align: center;">Osseous</td></tr><tr><td style="text-align: center;">Foreign body</td></tr></table>
```
#### Categorization of Radiopaque Lesions
Radiopaque lesions are classified according to their etiology and clinical presentation:
- **Normal anatomical structures**
- **Artifactual findings**
- **Pathological conditions**
- **Congenital**
- **Developmental**
- **Acquired**:
- Infective
- Odontogenic
- Neoplastic
- Osseous
- **Foreign body**
![]()
The image displays a flowchart diagram titled "Radiopaque lesions" that categorizes different types of radiopaque lesions. It begins with a central box labeled "Radiopaque lesion," which branches into two main categories: "Normal" and "Artifactual" on the left, and "Pathological" on the right. The "Pathological" category further divides into "Congenital" and "Acquired," with "Acquired" branching into subcategories such as "Infective," "Odontogenic," "Neoplastic," "Osseous," and "Foreign body." The diagram is labeled as Figure 53.4a and appears to be sourced from a medical text on oral medicine and pathology.
```markdown
# Tori and Exostosis
- **Tori**
- 2-10% of adults;
- Clinically: exophytic, hard, uninodular or multinodular bony masses covered by mucosa that may be ulcerated from trauma;
- torus palatinus and torus mandibularis on the midline of palate and lingual mandible (usually bilateral and symmetric), respectively;
- often site of bisphosphonate-associated osteonecrosis
```
#### Prevalence and Presentation
- Tori affect approximately 2-10% of the adult population.
- Clinically, they present as exophytic, hard, bony masses.
- These masses can be uninodular or multinodular.
- They are covered by mucosa, which may show signs of ulceration resulting from trauma.
#### Common Locations
- **Torus Palatinus:** Located on the midline of the palate.
- **Torus Mandibularis:** Located on the lingual aspect of the mandible, usually presenting bilaterally and symmetrically.
#### Clinical Considerations
- Tori are often identified as sites for the development of bisphosphonate-associated osteonecrosis.
![]()
Close-up intraoral photograph showing a patient's mouth with two prominent pink lesions on the floor of the mouth, likely representing salivary gland tumors or cysts, with visible teeth and dental restorations.
![]()
Intraoral photograph of the upper dental arch showing multiple teeth with extensive restorations, including amalgam fillings and crowns, and a noticeable pink lesion on the palate, possibly a mucocele or other oral lesion.
![]()
Intraoral photograph of the lower dental arch displaying numerous teeth with various restorations, including amalgam fillings and crowns, and a red dot indicating a specific area of interest, possibly a lesion or treatment site.
# Tori and Exostosis
- **Exostoses:**
- 27% of adults;
- male predilection (5 : 1);
- Clinically: outgrowths of bone, nodular or sessile frequently on **buccal** aspects of mandible and maxilla or ascending arch of the palate and more than 90% having concurrent tori
- **Possible aetiology:**
- Chronic irritation
- Periosteal proliferation
- Bone formation
19
#### Prevalence and Clinical Presentation
- Exostoses affect approximately 27% of adults.
- There is a significant male predilection, with a ratio of 5:1.
- Clinically, they appear as nodular or sessile outgrowths of bone.
- They occur frequently on the buccal aspects of the mandible and maxilla, or along the ascending arch of the palate.
- More than 90% of cases occur concurrently with tori.
#### Possible Etiology
- Chronic irritation
- Periosteal proliferation
- Bone formation
![]()
A clinical photograph of an elderly woman with a red dot indicating a lesion on her neck, likely for medical documentation or diagnosis.
![]()
A close-up medical photograph showing a swollen, inflamed area in the oral cavity, possibly a tumor or abscess, with surrounding tissue visible.
[^1]: Original PDF page 1: [[L17 Bone disease 1_slides.pdf#page=1|L17 Bone disease 1 slides, p.1]]
[^2]: Original PDF page 2: [[L17 Bone disease 1_slides.pdf#page=2|L17 Bone disease 1 slides, p.2]]
[^3]: Original PDF page 3: [[L17 Bone disease 1_slides.pdf#page=3|L17 Bone disease 1 slides, p.3]]
[^4]: Original PDF page 4: [[L17 Bone disease 1_slides.pdf#page=4|L17 Bone disease 1 slides, p.4]]
[^5]: Original PDF page 5: [[L17 Bone disease 1_slides.pdf#page=5|L17 Bone disease 1 slides, p.5]]
[^6]: Original PDF page 6: [[L17 Bone disease 1_slides.pdf#page=6|L17 Bone disease 1 slides, p.6]]
[^7]: Original PDF page 7: [[L17 Bone disease 1_slides.pdf#page=7|L17 Bone disease 1 slides, p.7]]
[^8]: Original PDF page 8: [[L17 Bone disease 1_slides.pdf#page=8|L17 Bone disease 1 slides, p.8]]
[^9]: Original PDF page 9: [[L17 Bone disease 1_slides.pdf#page=9|L17 Bone disease 1 slides, p.9]]
[^10]: Original PDF page 10: [[L17 Bone disease 1_slides.pdf#page=10|L17 Bone disease 1 slides, p.10]]
[^11]: Original PDF page 11: [[L17 Bone disease 1_slides.pdf#page=11|L17 Bone disease 1 slides, p.11]]
[^12]: Original PDF page 12: [[L17 Bone disease 1_slides.pdf#page=12|L17 Bone disease 1 slides, p.12]]
[^13]: Original PDF page 13: [[L17 Bone disease 1_slides.pdf#page=13|L17 Bone disease 1 slides, p.13]]
[^14]: Original PDF page 14: [[L17 Bone disease 1_slides.pdf#page=14|L17 Bone disease 1 slides, p.14]]
[^15]: Original PDF page 15: [[L17 Bone disease 1_slides.pdf#page=15|L17 Bone disease 1 slides, p.15]]
[^16]: Original PDF page 16: [[L17 Bone disease 1_slides.pdf#page=16|L17 Bone disease 1 slides, p.16]]
[^17]: Original PDF page 17: [[L17 Bone disease 1_slides.pdf#page=17|L17 Bone disease 1 slides, p.17]]
[^18]: Original PDF page 18: [[L17 Bone disease 1_slides.pdf#page=18|L17 Bone disease 1 slides, p.18]]
[^19]: Original PDF page 19: [[L17 Bone disease 1_slides.pdf#page=19|L17 Bone disease 1 slides, p.19]]