Developmental Defects

Question 1

4th week of development

Answer 1

Development of central face begins

Question 2

6-7th weeks of development

Answer 2

• medial nasal process mergers with maxillary process of 1st branchial arch
• 7th week = bilateral projections emerge forming palatal shelves which are vertical, as mandible grows the tongue drops and the palatal shelves rotate to be horizontal

Question 3

8th Week

Answer 3

shelves proliferate and fuse in the midline with the anterior fusing first the progressing back

Question 4

Cleft Lip

Answer 4

defective fusion of the medial nasal processes with the maxillary process

Question 5

Cleft Palate

Answer 5

defective fusion of the palatal shelves

Question 6

What is the odds of cleft palate/lip?

Answer 6

• 1 in 700 live births
• 1.5 times higher in Asians and 3.6 per 1000 live births in Native Americans
• M:F = 1.5:1
• isolated CP is more common in females

Question 7

% of cases that are CP & CL?

Answer 7

45%

Question 8

% of cases that are CP?

Answer 8

30%

Question 9

% of cases that are CL?

Answer 9

25%

Question 10

Cause of CL & CP?

Answer 10

• a genetic mutation in the fibroblast growth factor

- complex trait with a multifactorial etiology

Question 11

% of CL that is unilateral and on what side?

Answer 11

70% occur on left side

Question 12

Lateral Facial Cleft

Answer 12

lack of fusion of maxillary and mandibular processes; occurs from commissure to the ear

Question 13

Oblique Facial Cleft

Answer 13

very rare, associated with cleft palate; extends from the upper lip to the eye

Question 14

Median Cleft of the Upper Lip

Answer 14

very rare, failure of fusion of the medial nasal processes;

Question 15

Commissural Lip Pit

Answer 15

• mucosal invaginations at the corner of the mouth
• common, 10-20% of adults
• have a higher prevalence of preauricular pits
• no treatment necessary unless infected (surgical excision)

Question 16

Paramedian Lip Pits

Answer 16

• rare, congenital invaginations (or bump) of the median lower lip that are usually bilateral symmetric fistulas
• occurs in median lower lip
• autosomal dominant traits associated with cleft lip and/or palate
• seen in ver der Woude or Popliteal Pyterygium syndrome
• no treatment needed

Question 17

Double Lip

Answer 17

• redundant fold of tissue on the inside of the lip
• usually congenital but can be acquired
• associated with Ascher Syndrome (double lip, blepharochalasis (droopy eyelids), non toxic thyroid enlargement)

Question 18

Fordyce Granules

Answer 18

• ectopic (in abnormal position) sebaceous glands on the oral mucosa
• on the buccal mucosa or lateral position of the vermilion on upper lip, could be on genital mucosa
• common, 80% of adults
• present as multiple yellow or white papules
• no treatment needed

Question 19

Leukoedema

Answer 19

• common 70-80% of adult blacks and 50% black children

- milk white diffuse mucosa with folded or wrinkled surface that disappears when stretched

Question 20

Microglossia

Answer 20

• very rare
• small tongue
• associated with: oromandibular-limb hypogenesis syndromes, hypodactylia (absence of digits), hypomelia (incomplete part or all of limb), and situs inversus (mirror positioning of internal organs)

Question 21

Macroglossia

Answer 21

• large tongue
• congenital/hereditary association: vascular malformations, hemihyperplasia (enlargement of onside of body), Cretinism, Beckwith-Wiedemann syndrome, Down syndrome
• acquired: amyloidosis, myxedema, acromegaly, angioedema, tumors

Question 22

Lingual Thyroid

Answer 22

• ectopic thyroid gland
• at the junction of the anterior 2/3 and posterior 1/3, site of developing foramen cecum in midline
• 4-7 more frequent in females, 70% of cases this is only thyroid tissue
• May need surgical removal or repositioning
• symptoms usually develop during puberty, pregnancy or menopause

Question 23

Lingual Tonsil

Answer 23

• relatively common, possible enlarged but benign tonsil
• tonsil on the tongue
• may need to remove if biopsy is positive

Question 24

Tonsillar Enlargement

Answer 24

• common, enlarged tonsils

- may have tonsiliths (calcifications that form on crypts of palatal tonsils)

Question 25

Fissured Tongue

Answer 25

- common 2-5% of population, fissures on tongue - association: geographic tongue (many have both conditions), component of Melkersson-Rosenthal syndrome - no treatment necessary

Question 26

Hairy Tongue

Answer 26

- accumulation of keratin on the filiform papilla on dorsum of the tongue - black and brown from pigment producing bacteria - association: smoking, antibiotics, poor oral hygiene, oxidizing mouth rinses

Question 27

Geographic Tongue

Answer 27

- common, 1-3% of population, benign condition due to atrophy of the filiform papillae - have well demarcated zones of erythema (redness) with white borders on the anterior 2/3 of the tongue - Female to Male ratio = 2:1 - comes and goes in a few days but could burn if eating spicy things

Question 28

Varicosities (Varices)

Answer 28

- common in older people > 60 yo. - abnormally dilated and tortuous veins that can occur in the sublingual vein, lips, and buccal mucosa, presents as blue/purple nodule - usually don't need treatment but sometimes need to biopsied to confirm

Question 29

Caliber-Persistent Artery

Answer 29

- common vascular anomaly in which a large caliber artery extends into the underlying submucosa without a reduction in diameter, common in older adults - occurs on the lip and shows as a linear elevation that is pale or blueish, can be seen pulsing - no treatment necessary but can be easily popped and bleed

Question 30

Exostoses

Answer 30

- common localized bony protuberances that comes from the cortical plate (roof or bottom of mouth) - most often seen in adults - buccal exostoses are on facial aspect of max. and mand. alveolar ridge - palatal exostoses (palatal tubercules) are on lingual aspect of max. - solitary exostoses are under free gingiva or skin grafts

Question 31

Torus Palatinus

Answer 31

- common, 20-35% of population, exostosis that occurs in the palatal vault in the midline that can increase in size throughout life - no treatment needed but can become irritated and need fixing - female to male ration 2:1 - flat torus = broad base and smooth surface - spindle torus = midline ridge along that palatal raphe - nodular torus = multiple protuberances that may coalesce forming grooves - lobular torus = lobular mass that may come from a single base

Question 32

Torus Mandibularis

Answer 32

- common exostosis that develops along the lingual portion of the mandible - appears above mylohyoid in premolar region, it's bilateral - more common in Asisans and Inuit - has correlation with bruxism (teeth grinding) - only need treatment if getting dentures in that area

Question 33

Stafne Defect

Answer 33

- asymptomatic radiolucent lesions near the angle of the mandible that shows a concavity caused by submandibular gland