L14, Dentition, Clavicle, Humerus

What is the dental formula for deciduous teeth?

2.1.0.2

What is the dental formula for permanent teeth?

2.1.2.3

How many deciduous teeth are there?

20 total teeth

How many permanent teeth are there?

32 total teeth

What is the short hand for deciduous incisor teeth?

i1, i2

What is the short hand for permanent incisor teeth?

I1, I2

What is the short hand for deciduous canines?

c

What is the short hand for permanent canines?

C

What is the short hand for deciduous premolars?

P1, P2 (or P3, P4)

What is the short hand for permanent premolars?

m1, m2

What is the short hand for permanent molars?

M1, M2, M3

What are the identifying factors for indidivual teeth?

type: deciduous or permanent

arcade: maxillary or mandibular

class: incisor, canine, premolar, or molar

Features of Incisors

anterior-most teeth

chisel-shaped, spatulate

single root

maxillary: broader crown, conical root

mandibular: narrower crown, mesiodistally pinched root

What are the different osteological variants for incisors?

shovel-shaped incisors

agenesis of lateral incisor

peg-shaped incisors

midline diastema

incisor twinning

features of canines

anterior teeth (1)

unicuspid (one cusp)

single root

Maxillary: broader shoulders, squat appearance, conical root

Mandibular: narrower shoulders, taller, pinched root

How to recognizes deiduous teeth?

• Smaller!

• Crowns have thinner enamel

• Yellowish appearance (dentine)

• Crowns more bulbous

  • Bulges out about cementoenamel junction more prominently

• Thinner shorter roots in anterior teeth

• Molar roots more divergent

features of premolars

bicuspid (two cusps)

often single root, but with deep grooves. some may have divergent roots

shorter, squatter crown

Maxillary: two cusps similar in size, can have divergent roots

Mandibular: buccal cusp much larger than lingual cusp, single root

What are some osteological variants of premolars?

odontome, divergent roots (only maxillary)

features of molars

largest teeth in mouth

multiple roots (M3 roots may fuse)

3+ cusps (for crushing and grinding)

Maxillary: 4 cusps, 3 roots, rhomboid

Mandibular: 5 cusps, 2 roots, rectangular/symmetrical

What are the osteological variants of molars?

carabelli’s cusp (maxillary only), parastyle (maxillary only), protostylid (mandibular only), peg-shaped thrid molar, enamel pearl, enamel extension

What are some enamel defects?

linear enamel hypoplasia, amelogenesis imperfecta

What is malocculsion?

often referred to as a "bad bite," means your upper and lower teeth don't align properly when you close your mouth

could be due to displacement, crowding, or rotation

What dental modifications exist?

dental filing, dental inlays and filing, dental avulsion

What is the pectoral girdle?

bone complex composed of clavicle and scapula

it provides support and articulation for the upper limb

anchors a variety of muscles essential for locomotion of the upper limb

provides a plateform/struct for movement of upper limb

What are the 3 major joints of the pectoral girdle?

1. Sternoclavicular joint

   • Clavicular notch of sternum

   • Sternal end of clavicle

2. Acromioclavicular joint

   • Acromial facet of clavicle

   • Acromion process of scapula

3. Glenohumeral joint

   • Glenoid fossa of scapula

   • Humeral head

features of clavicle

paired long bone

articulates with scapula, R1, and sternum

serves as strut between scapula and sternum

only horizontal long bone

no medullary cavity

What type of ossification centers does the clavicle have?

Both intramembranous and endochondral

• Acromial end ossifies

  intramembranously

• Sternal end ossifies endochondrally

One of last bones to finish ossifying ~21-25 years

What type of joint is the sternoclavicular joint?

saddle joint, diarthroses (allows movement in sagittal and coronal planes)

joint is between clavicular notch of sternum, sternal end of the clavicle, and costal cartilage of Rib 1

What is the origin of the subclavius muscle (depresses the lateral clavicle, protects the brachial plexus)?

subclavian sulcus

What type of joint is the acromioclavicular joint?

plane joint, diarthroses

Joint is between acromial facet of clavicle and acromion process of the scapula

acts as a strut to help movement with scapula and result in greater degree of arm rotation

What is the attachment for the conoid ligament (attaches to the scapula)?

conoid tubercle

What is the attchment for trapezoid ligament (attaches to the scapula)?

trapezoid line

Which two ligaments connect the clavicle to the bony shoulder blade?

1. Conoid ligament:

   • Conoid tubercle (clavicle)

   • Coracoid process (scapula)

2. Trapezoid ligament:

   • Trapezoid line (clavicle)

   • Coracoid process (scapula)

How is the clavicle most commonly fractured?

It is the most commonly fracture bone, usually via a direct blow or transmitted force from falling on arm.