Joints
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45669 bone maxillofacial mandible face cheek orbit frontal sinus teeth maxilla nasal bone concha zygomatic bone dx fracture of the mandible fracture of the left condyle TMJ skull CT scan Courtesy Ashley Davidoff MD 5star
2. Definition
PAGE 2 – Definition
| Definition |
|---|
| The facial bones are a set of 14 irregular bones forming the structural framework of the face, supporting the eyes, nose, and mouth, and enabling essential functions such as chewing, breathing, facial expression, and speech. |
| Core Attributes | Description |
|---|---|
| Structure | 14 bones including paired maxillae, zygomatics, nasals, lacrimals, palatines, inferior nasal conchae; and unpaired vomer and mandible. |
| Function | Support sensory organs, participate in respiration, digestion, communication, and facial identity. |
| Common Diseases | Facial fractures, cleft palate, cellulitis, sinusitis, neoplasms. |
| Diagnosis | Physical exam, facial X-ray, CT scan, MRI if soft tissue or nerve involvement. |
| Treatment | Fracture stabilization, surgical correction, antibiotic therapy, tumor resection as appropriate. |
3. Anatomy
PAGE 3 – Applied Anatomy and Diagnostic Approach
Table 1 – U-SSPCT–C Structural Anatomy of the Facial Bones (with Connections)
| Attribute | Details |
|---|---|
| Units (U) | – Maxilla (2) – Zygomatic (2) – Nasal (2) – Lacrimal (2) – Palatine (2) – Inferior nasal conchae (2) – Vomer (1) – Mandible (1) |
| Size | Maxilla spans ~5 cm transversely; mandible varies by sex/age; nasal bones ~2–3 cm vertically |
| Shape | Irregular bones with curves, ridges, sinuses, foramina, and processes |
| Position | Inferior and anterior to the cranium; surrounds the orbits, nose, and mouth |
| Character | Thin-walled, complex bone structures that interlock tightly, yet allow for articulation and muscular movement |
| Time (Development and Aging) | – Maxilla and mandible begin ossifying during fetal life – Craniofacial growth continues into late adolescence – Sutures fuse gradually; fontanelles close by age 2 |
| Connections | – Arterial Supply: Facial artery, maxillary artery, infraorbital artery, mental artery – Venous Drainage: Facial vein, retromandibular vein, deep facial vein – Lymphatics: Submandibular, submental, parotid (preauricular) nodes – Nerves: CN V2 (maxilla), CN V3 (mandible), CN VII (motor to facial muscles) – Joints: Temporomandibular joint (mandible), sutures with adjacent cranial bones – Ligaments: Sphenomandibular, stylomandibular, temporomandibular – Tendons: Masseter, temporalis, buccinator attachments on maxilla and mandible |
4. Disease and Diagnosis
PAGE 4 – Clinical Diagnosis
Clinical Signs and Symptoms
| Symptom | Implication |
|---|---|
| Facial asymmetry or flattening | Fracture, congenital defect, tumor |
| Numbness (infraorbital, mental) | Injury to CN V2 or V3 |
| Malocclusion | Mandibular or maxillary fracture |
| Trismus | Mandibular fracture, infection |
| Epistaxis | Nasal or midface trauma |
| Diplopia | Orbital fracture or entrapment of extraocular muscles |
Imaging Modalities
| Modality | Use | Indication |
|---|---|---|
| CT (facial bones) | Gold standard for fractures, 3D planning | All trauma, deformity, surgery |
| MRI | Soft tissue, nerve evaluation | Tumors, infections, CN deficits |
| Waters view (X-ray) | Midface and sinuses | Screening or follow-up |
| Panoramic X-ray (OPG) | Mandible and dentition | Fractures, pre-dental surgery |
Laboratory Tests
| Test | Purpose | When Used |
|---|---|---|
| CBC | Detect anemia, infection | Trauma, cellulitis |
| ESR/CRP | Inflammatory markers | Suspected osteomyelitis |
| Calcium, Vit D | Bone metabolism | Fragility or delayed healing |
| Cultures | Identify infective source | Abscess or infected fracture |
Other Diagnostic Tools
| Tool | Use | When Used |
|---|---|---|
| Intraoral occlusion exam | Mandible/maxilla alignment | Trauma evaluation |
| Sensory testing | CN V branches | Post-traumatic nerve injury |
| Biopsy | Identify neoplastic or infectious pathology | Tumor or lesion evaluation |
| Dental evaluation | Occlusion, fracture, pre-op | Trauma or surgery planning |
5. History and Culture
PAGE 5 – History, Culture, and Art
1. History of Anatomy
| Topic | Details |
|---|---|
| Anatomical drawings | Early depictions in Egyptian and Greco-Roman art show detailed facial features |
| Vesalius’ contributions | Provided landmark illustrations of skull and facial bones |
| Surgical dissection | Advanced during Renaissance; modern anatomy validated with imaging |
2. History of Physiology
| Topic | Details |
|---|---|
| Mastication mechanics | Role of maxilla and mandible long understood |
| Airflow and speech | Nasal and oral cavities key to phonation and breathing |
| Expression | Muscles of facial expression mapped alongside their bony attachments |
3. History of Diagnosis
| Topic | Details |
|---|---|
| Facial symmetry checks | Ancient practice in trauma and birth defect screening |
| X-ray era | Enabled internal visualization for fractures |
| CT/MRI | Brought high-precision craniofacial diagnosis into modern use |
4. History of Imaging
| Topic | Details |
|---|---|
| Waters view | Standard for maxillary sinus and orbital floor |
| 3D CT | Essential in trauma and reconstructive planning |
| MRI | Crucial for evaluating soft tissues and nerve pathways |
5. History of Laboratory Testing
| Topic | Details |
|---|---|
| Infection workup | ESR/CRP, CBC routinely used for facial cellulitis and abscess |
| Bone metabolism | Calcium and vitamin D added to delayed healing evaluations |
| Biopsy techniques | Incorporated into facial tumor diagnostics in 20th century |
6. History of Therapies
| Topic | Details |
|---|---|
| Mandibular wiring | Used since early surgery to stabilize fractures |
| Midface repair | Advanced during wartime reconstruction (WWI & WWII) |
| Cleft repair and orthognathic surgery | Refined in the late 20th century |
7. Cultural Meaning
| Topic | Details |
|---|---|
| Face as identity | Facial bones define individuality and are central to self-recognition |
| Beauty standards | Symmetry of facial bones central to cultural ideals |
| Social stigma | Deformities historically carried unjust burden; now addressable via surgery |
8. Artistic Representations
| Topic | Details |
|---|---|
| Classical art | Ideal facial structure defined in sculpture and portraiture |
| Ritual masks | Symbolize identity and spirit in tribal and theatrical settings |
| Medical illustrations | Facial skeletons featured in Renaissance anatomy art and modern atlases |
9. Notable Figures
| Name | Contribution |
|---|---|
| Sir Harold Gillies | Father of modern facial plastic and reconstructive surgery |
| Charles Bell | Described facial muscles and their expression |
| Paul Tessier | Advanced craniofacial surgical techniques |
10. Quotes
| Quote | Attribution |
|---|---|
| “Every face tells a story.” | Anonymous |
| “The face is the mirror of the mind.” | Cicero |
| “A smile is the universal welcome.” | Max Eastman |
7. MCQ's
PAGE 6 – MCQs
Basic Science MCQ 1
Which bone forms the anterior portion of the hard palate?
A. Zygomatic
B. Maxilla
C. Palatine
D. Vomer
Correct Answer Table
| Answer | Explanation |
|---|---|
| B. Maxilla | The palatine process of the maxilla forms the anterior two-thirds of the hard palate. |
Incorrect Answers Table
| Option | Why Incorrect |
|---|---|
| A. Zygomatic | Forms cheek and part of orbit, not palate. |
| C. Palatine | Forms posterior one-third of hard palate. |
| D. Vomer | Contributes to nasal septum, not palate. |
Basic Science MCQ 2
Which facial bone is the only movable one?
A. Maxilla
B. Zygomatic
C. Mandible
D. Nasal
Correct Answer Table
| Answer | Explanation |
|---|---|
| C. Mandible | It articulates with the temporal bone via the TMJ, allowing movement. |
Incorrect Answers Table
| Option | Why Incorrect |
|---|---|
| A. Maxilla | Fused to skull. |
| B. Zygomatic | Immobile cheekbone. |
| D. Nasal | Small and fixed. |
Clinical MCQ 1
A patient with cheek numbness after trauma likely injured which nerve?
A. CN V1
B. CN V2
C. CN V3
D. CN VII
Correct Answer Table
| Answer | Explanation |
|---|---|
| B. CN V2 | The infraorbital nerve (branch of V2) supplies the midface and cheek. |
Incorrect Answers Table
| Option | Why Incorrect |
|---|---|
| A. CN V1 | Supplies forehead and upper orbit. |
| C. CN V3 | Supplies lower jaw and chin. |
| D. CN VII | Motor to facial muscles; not sensory. |
Clinical MCQ 2
Trismus is most commonly associated with pathology involving which bone?
A. Zygomatic
B. Mandible
C. Nasal
D. Maxilla
Correct Answer Table
| Answer | Explanation |
|---|---|
| B. Mandible | Trismus results from spasm or injury to muscles attached to the mandible. |
Incorrect Answers Table
| Option | Why Incorrect |
|---|---|
| A. Zygomatic | Not directly involved in jaw motion. |
| C. Nasal | No role in mastication. |
| D. Maxilla | Stationary bone; trismus not typically caused by maxillary pathology. |
Radiologic MCQ 1
Best modality for evaluating an orbital floor fracture?
A. MRI
B. Panoramic X-ray
C. CT
D. X-ray (lateral skull)
Correct Answer Table
| Answer | Explanation |
|---|---|
| C. CT | Provides high-resolution bone detail; essential in orbital trauma. |
Incorrect Answers Table
| Option | Why Incorrect |
|---|---|
| A. MRI | Excellent for soft tissue but poor bone detail. |
| B. Panoramic X-ray | For mandible and dentition, not orbits. |
| D. Lateral skull X-ray | Not detailed enough for orbital floor. |
Radiologic MCQ 2
Which view best shows the paranasal sinuses?
A. Waters view
B. PA skull
C. Lateral skull
D. Submentovertex
Correct Answer Table
| Answer | Explanation |
|---|---|
| A. Waters view | Specifically designed to evaluate maxillary sinuses and orbital rims. |
Incorrect Answers Table
| Option | Why Incorrect |
|---|---|
| B. PA skull | More general overview. |
| C. Lateral skull | Poor sinus visualization. |
| D. Submentovertex | Shows skull base, not sinuses well. |
Radiologic MCQ 3
CT shows a fracture at the frontozygomatic suture. Which bone is involved?
A. Maxilla
B. Zygomatic
C. Palatine
D. Vomer
Correct Answer Table
| Answer | Explanation |
|---|---|
| B. Zygomatic | Articulates with frontal bone at the frontozygomatic suture. |
Incorrect Answers Table
| Option | Why Incorrect |
|---|---|
| A. Maxilla | Forms upper jaw, not lateral orbital wall. |
| C. Palatine | Forms posterior palate. |
| D. Vomer | Forms part of nasal septum. |
8. Memory Image
PAGE 7 – MEMORY IMAGE
| Caption | Interpretation |
|---|---|
| The Scaffold of Expression | AI-generated metaphor of the face as a skeletal scaffold overlaid with emotion wires and chewing gears. It illustrates the facial bones as rigid supports for dynamic function. Courtesy: Ashley Davidoff MD, TheCommonVein.com (140550.facialbones) |
| Symbolic Element | Meaning |
|---|---|
| Scaffold frame | Facial bone structure |
| Gears | Chewing mechanisms (TMJ, mandible) |
| Threads/wires | Facial muscles and expressions |
| Mask faceplate | Identity, communication, and humanity |