Developmental Disturbance Of Jaw

Question 1

What is agnathia?

Answer 1

Agnathia is a lethal anomaly characterised by hypoplasia or absence of the mandible with abnormally positioned ears having an autosomal recessive mode of inheritance. -Shafer

Question 2

Common type of agnathia of maxilla?

Answer 2

Only a portion of jaw is missing.

In the case of maxilla,

• one maxillary process
• premaxilla

Question 3

Common type of agnathia of mandible?

Answer 3

Partial absence of mandible

• only the condyle
• entire ramus
• bilateral agenesis of the condyle and of the rami also has been reported.

Question 4

How is the deformation of the ear related to agnathia ?

Answer 4

In case of unilateral absence of the mandibular ramus, it is not unusual for the ear to be deformed or absence as well.

It is probably due to failure of migration of neural crest mesenchyme into the maxillary prominence at the fourth to fifth week of gestation.

Question 5

Occurrence of agnathia?

Answer 5

The prevalence is unknown and less than 10 cased are described.

Question 6

Prognosis of agnathia?

Answer 6

The prognosis is very poor and considered to be lethal.

Question 7

What is micrognathia?

Answer 7

Micrognathia literally means a small jaw, and either the maxilla or the mandible may be affected.

Question 8

Types of micrognathia?

Answer 8

1. True micrognathia

2. Pseudo micrognathia

Question 9

What is pseudo micrognathia?

Answer 9

Many cases of apparent/pseudo micrognathia are not due to an abnormally small jaw in terms of absolute size, but rather to an abnormal positioning or an abnorma relation of one jaw to the other or to the skull, which produce the illusion of micrognathia.

Question 10

Classification of true micrognathia?

Answer 10

True micrognathia may be classified as

• congenital
• acquired

Question 11

Etiology of congenital micrognathia?

Answer 11

The etiology is unknown, although in many instances it is associated with other congenital abnormalities, including congenital heart disease and the Pierre Robin syndrome.

Question 12

Described the gross of micrognathia of maxilla?

Answer 12

Micrognathia of the maxilla frequently occurs due to deficiency in the premaxillary area, and patient with this deformity appear to have the middle third of the face retracted.

Question 13

Cause and affect of maxilary micrognathia?

Answer 13

Although it has been suggested that mouth-breathing is a cause of maxillary micrognathia, it is more likely that the micrognathia may be one of the predisposing factors in mouth breathing, owing to the associated maldevelopment of the nasal and nasopharyngeal structures.

Question 14

Reasons of pseudo mandibular micrognathia?

Answer 14

• posterior positioning of the mandible with regard to the skull
• to a steep mandibular angle

Question 15

Cause of true mandibular micrognathia?

Answer 15

Agenesis of the condyles

Question 16

Reasons of acquired type of micrognathia?

Answer 16

-results from disturbance in the area of the temporomandibular joint
Eg-ankylosis of the joint due to trauma, or infection of the mastoid, of the middle ear, or of the joint itself, ondylar ankylosis

Question 17

Clinical appearance of mandibular micrognathia?

Answer 17

• severe retrusion of the chin
• a steep mandibular angle
• a deficient chin button

Question 18

Causes of congenital condition of micrognathia?

Answer 18

• pierre Robin syndrome
• Cate- Manzke syndrome
• Cerebrocostomandibular syndrome
• Cornelia de Lange syndrome
• miller-dieter syndrome
• nagar acrobatically dysostosis
• Schwartz-Jamel-Abergele syndrome
• van boaters-hozay syndrome

Question 19

Intraurine acquired conditions of micrognathia?

Answer 19

• syphilis

- congenital

Question 20

What is macrognathia?

Answer 20

Macrognathia refers to the condition of abnormally large jaws.

Question 21

Causes of macrognathia?

Answer 21

1. Paget’s disease of bone, in which overgrowth of the cranium and maxilla or occasionally the mandible occurs
2. Acromegaly, in which there is progressive enlargement of the mandible owing to hyperpituitarism in the adult
3. Leontiasis ossea, a form of fibrous dysphasia in which there is enlargement of the maxilla

Question 22

Etiology of mandibular protrusion or prognathism

Answer 22

The etiology is unknown,although some cases follow hereditary patterns

Question 23

Causes of macrognathia?

Answer 23

• due to disparity in the size of the maxilla in relation to the mandible or in other cases the mandible is measured larger than normal
• the angle between ramus and the body influence the relation of the mandible to the maxilla as does the actual height of the ramus
• increased height of the ramus
• increased mandibular body length
• increased gonial angle
• anterior positioning of the glenoid fossa
• decreased maxillary length
• posterior positioning of the maxilla in relation to the cranium
• prominent chin button
• varying soft tissue contour

Question 24

Long ramus with prognathism?

Answer 24

• prognathic patient tends to have long rami which from a less steep angle with the body of the mandible
• the length of the ramus in turn may be associated with the growth of the condyle therefore excessive condylar growth predisposes to mandibular prognathism.

Question 25

Treatment of macrognathia?

Answer 25

Ostectomy or resection of a portion of the mandible to decrease its length.

Question 26

What is hemihypertrophy?

Answer 26

Hemihyperplasia is a rare developmental anomaly characterised by asymmetric overgrowth of one or more body parts. Although the condition is known more commonly as hemihypertrophy, it is actually represents a hyperplasia of the tissue rather than a hypertrophy.

Question 27

Malformation syndromes associated with hemihyperplasia?

Answer 27

1. Beckwith- Wiedemann syndrome 2. Neurofibromatosis 3. Klippel-Trenaunay-Weber syndrome 4. Proteus syndrome 5. McCune-Albright syndrome 6. Epidermal nexus syndrome 7. Tripoli/diploid mixologist 8. Langer-Giedion syndrome 9. Multiple exostoses syndrome 10. Olllier syndrome 11. Segmental odontomaxillary dysplasia

Question 28

Hoyme et al (1998) provided an anatomical classification of hemihyperplasia?

Answer 28

1. Complex hemihyperplasia : involvement half of the body (at least one arm and one leg); affected parts may be contralateral or ipsilateral 2. Simple hemihyperplasia : involvement single limb 3. Hemifacial hyperplasia : involvement of one side of the face

Question 29

Etiology of hemihyperplasia?

Answer 29

- cause is unknown but the condition has been variously ascribed to * vascular or lymphatic abnormalities * CNS disturbances * chromosomal abnormalities

Question 30

Clinical features of facial hemihypertrophy?

Answer 30

- exhibit an enlargement which is confined to one side of the body - unilateral macroglossia - premature development, and eruption as well as an increased size of dentition

Question 31

Occurrence of hemihypertrophy?

Answer 31

- familial occurrence - females are affected somewhat more frequently than males (63% vs 37%) - equal involvement of the right and left side

Question 32

Oral manifestation of hemihypertrophy?

Answer 32

* The dentition of the hypertrophic side, abnormal - crown size, root size - crown shape, root shape - rate of development * permanent teeth on the affected side are often enlarged although not exceeding a 50% increase in size. * rapidly developed and erupt * premature shedding of the deciduous teeth * enlarged mandible and maxilla, being wider and thicker sometimes with an altered trabecular pattern. * tongue show a bizarre picture of enlargement and contralateral displacement * buccal mucosa appears velvety and may seem to hang in soft, pendulous folds on the affected side.

Question 33

Histologic features of facial hemihypertrophy?

Answer 33

True muscular hypertrophy was not found.

Question 34

Treatment of hemihypertrophy?

Answer 34

No specific treatment for this condition other than attempts at cosmetic repair. Cosmetic surgery is advised after cessation of growth Periodic abdominal ultrasound / MRI is recommended to rue out tumours .

Question 35

Differential diagnosis of facial hemihypertrophy?

Answer 35

-there are certain disease of the jaws such as NEUROFIBROMATOSIS and FIBROUS DYSPLASIA of the jaws, that may give the clinical appearance of facial hemihypertrophy but these can usually be differentiated readily by the lack of effect on tooth size and rate of eruption.

Question 36

What is the other name of facial hemiatrophy?

Answer 36

- Parry-Romberg syndrome

Question 37

What is parry-Romberg syndrome?

Answer 37

Parry-Romberg syndrome or facial hemiatrophy consists of slowly progressive atrophy of the soft tissue of essentially half the face, which is characterised by progressive wasting of subcutaneous fat, sometimes accompanied by atrophy of skin, cartilage, bone and muscle.

Question 38

Parry-Romberg syndrome gross?

Answer 38

Although the atrophy is usually confined to one side of the face and cranium, it may occasionally spread to the neck and one side of the body and it is accompanied usually by COLATERAL JACKSONIAN EPILEPSY, TRIGEMINAL NEURALGIA, and changes in the eyes and hair.

Question 39

Parry-Romberg syndrome may be a form of............... why?

Answer 39

Localised scleroderma because the presence of antinuclear antibodies in his serum

Question 40

Occurance of hemifacial atrophy?

Answer 40

- rare condition | - occurs sporadically although some familial distribution has been found

Question 41

Etiology of parry-Romberg syndrome?

Answer 41

1. According Wartenburg - the primary factor to be a cerebral disturbance leading to increased and unregulated activity of sympathetic nervous system, which in turn produced the localised atrophy through its trophic functions conducted by way of sensory trunks of the trigeminal nerve. 2. According to other - extraction of teeth, oral trauma, infection and genetic factors can be a cause. 3. According to Poswillo - Poswillo attributed the development of facial deformities to the disruption of the stapedial artery.

Question 42

Clinical features of hemifacial atrophy?

Answer 42

- painless cleft, the ‘coup de sabre’, near the midline of the face or forehead. This marks the boundary between normal and strophic tissue. - atrophy of the skin, subcutaneous tissue, muscle, bones, cartilage, alveolar bone and soft palate on that side of the face - hemiatrophy of the tongue - ipsilateral salivary gland - hemiatrophy unilateral involvement of the ear, larynx, eosophagus, diaphragm, kidney, and brain

Question 43

Occurance of hemiatrophy ?

Answer 43

Female : male = 3:2 - slight predilection for the left side - appears in the first or second decade of life

Question 44

Differential diagnosis of facial hemiatrophy?

Answer 44

Post-traumatic fat atrophy, hemifacial microsomia, Goldenhar’s syndrome and partial lipodystrophy

Question 45

Oral manifestation?

Answer 45

- incomplete root formation - delayed eruption - severe facial asymmetry resulting on difficult in mastication - hemiatrophy of the tongue and lips

Question 46

Treatment and prognosis of hemifacial atrophy?

Answer 46

- No treatment - disease will be progressive for a period of several years and then remain unchanged for the remainder of the patients life.