What is the main purpose of miniplates in orthodontic practice?

 # What is the main purpose of miniplates in orthodontic practice?

A. To manage skeletal discrepancy without dental adverse effects 

B. To serve as an alternative anchorage system for mini-implants 

C. To withstand torsional force 

D. To anchor soft tissue to root apices

The correct answer is: A. To manage skeletal discrepancy without dental adverse effects. 

Miniplates are an alternative form of orthodontic TADs. They are anchored on skeletal bone using monocortical titanium screws and are indicated for orthopaedic traction to manage skeletal discrepancy without dental adverse effects. They can also be used as an alternative anchorage system when mini-implant insertion is unsatisfactory. While miniplates can be used as an alternative anchorage system, their primary purpose is not specifically to serve as an alternative to mini-implants.

Unlike mini-implants, miniplates can resist various types of force applications and have a lower failure rate. They are able to withstand force with a magnitude of 400–500 g. Additionally, the portion of a miniplate covered by soft tissue can be anchored apically to root apices, helping to avoid potential root damage and reduce soft tissue irritation.

Skeletal class II growth pattern 18 years old Female

 # Mr. Baburam Bhattarai brought his two children one female and one male for dental checkup. The female was 18-years-old & the male was 12 years old. Both had a skeletal class II growth pattern. The growth modification can be done only for the following: 

A. Only in male 

B. Only in female 

C. In both the male & female 

D. Cannot be done 

The correct answer is A. Only in Male.

Though the chronological age may be misleading and the status of growth has to be evaluated through CVM stages, growth modulation is possible in 12 year males and it's not possible in 18 year females. 

Test done when midline diastema and high frenal attachment is present

 # Prachanda, a 20-year-old boy went to his dentist with a complaint of spacing between his upper central incisors. On examination there was presence of mid line diastema. There was a high frenal attachment. Which test will the dentist do to confirm it?

 A. Montoux test 

B. Cotton test 

C. Ganong’s test 

D. Blanch test

The correct answer is D. Blanch Test.

To confirm the high frenal attachment in the presence of a midline diastema, the dentist would perform the Blanch test. This test involves lifting the lip and pulling it outward. If blanching (whitening) occurs in the soft tissue palatal to or between the central incisors, it indicates a high labial frenum attachment. Therefore, the correct answer is D. Blanch test.

Lesions within the basal ganglia produce the following signs except:

 # Lesions within the basal ganglia produce the following signs except: 

A. Hypotonia 

B. Tremor 

C. Hemiballisumus 

D. Athetosis

Lesions within the basal ganglia can lead to various motor disturbances. Let's analyze the given signs:

1. Hypotonia: This refers to reduced muscle tone or decreased resistance to passive movement. It is associated with basal ganglia dysfunction.

2. Tremor: Tremors are rhythmic, involuntary movements. Basal ganglia lesions can indeed cause tremors.

3. Hemiballismus: Hemiballismus is characterized by sudden, wild, and flinging movements of one side of the body. It specifically results from damage to the subthalamic nucleus within the basal ganglia.

4. Athetosis: Athetosis involves slow, writhing, and twisting movements, often affecting the hands and fingers. It is also associated with basal ganglia dysfunction.

Given the options, the sign that is not directly associated with basal ganglia lesions is Hypotonia. Hypotonia is more commonly related to other brain regions or spinal cord abnormalities.

Remember, basal ganglia play a crucial role in motor control, coordination, and movement regulation. Any disruption in this area can lead to various motor symptoms. 

Perfusion of oxygen supply in a free flap can be correctly estimated by:

 # Perfusion of oxygen supply in a free flap can be correctly estimated by:

a) Pulse oximetry 

b) Laser Doppler flowmetry 

c) Prick test 

d) Fluroscopy

The correct answer is B. Laser doppler flowmetry.

Let's go through each option:

a) Pulse oximetry: Pulse oximetry measures the oxygen saturation of hemoglobin in arterial blood non-invasively. However, it may not provide an accurate estimation of oxygen supply in a free flap because it only measures the oxygen saturation of blood and does not directly assess tissue perfusion. While it can indicate overall oxygenation status, it may not reflect the oxygen supply to a specific tissue like a free flap.

b) Laser Doppler flowmetry: Laser Doppler flowmetry is a non-invasive technique used to measure tissue perfusion by detecting the movement of red blood cells. It can provide real-time information about blood flow in the microcirculation of tissues, including free flaps. Therefore, it is often used to monitor the perfusion of oxygen supply in free flaps during surgery and postoperative care. This option is correct because it directly assesses tissue perfusion, which is crucial for evaluating the viability of free flaps.

c) Prick test: A prick test, also known as a pinprick test, is typically used to assess sensory nerve function by evaluating the patient's ability to perceive pain or touch in a specific area. It is not a suitable method for estimating oxygen supply in a free flap. While changes in sensation may indicate compromised blood flow to the flap, the prick test itself does not directly measure tissue perfusion or oxygen supply.

d) Fluoroscopy: Fluoroscopy is a medical imaging technique that uses a continuous X-ray beam to create real-time moving images of the internal structures of a patient. While fluoroscopy can provide valuable information about blood flow and vascular anatomy, it is not commonly used to estimate oxygen supply in free flaps. Fluoroscopy is more often utilized for guiding interventional procedures or diagnosing vascular issues but is not specifically tailored for assessing tissue perfusion in free flaps.

Hence, Laser Doppler flowmetry is the correct choice for estimating the perfusion of oxygen supply in a free flap as it directly measures tissue perfusion and is commonly used in clinical practice for this purpose.

The teeth most likely to be transposed are:

 # The teeth most likely to be transposed are:

A. Mandibular Premolars and maxillary incisors

B. Maxillary premolars and mandibular incisors

C.  Maxillary molars and canines

D. Mandibular molars and canines

The correct answer is B. Maxillary premolars and mandibular incisors.

Transposition is a rare positional interchange of two adjacent teeth. It occurs with a prevalence of approximately 0.3% and equally affects males and females. The teeth most likely to be transposed

are mandibular incisors and maxillary premolars, and this usually occurs as a consequence of ectopic eruption. There appears to be a genetic component to this problem. In the early mixed dentition years, transposition can develop when distally directed eruption of the permanent mandibular lateral incisor leads to loss of the primary mandibular canine and primary first molar. If left untreated, this can result in a true transposition of the permanent lateral incisor and canine.

The first material used for orthodontic TADs was:

 # The first material used for orthodontic TADs was:

A. Titanium

B. Stainless Steel 

C. Vitallium

D. Nickel - Chromium

The correct answer is C. Vitallium.

To date, three types of materials have been used for orthodontic TADs: titanium alloy, stainless steel

and vitallium. Vitallium was the first material used for orthodontic TADs. However, due to undesirable biocompatibility and a higher failure rate, vitallium was gradually replaced by titanium alloy. Stainless steel is also used for orthodontic mini-implants and recent evidence indicates that the success rate is similar between titanium alloy and stainless steel mini-implants. Nowadays, due to high biocompatibility of titanium, orthodontic TADs made of titanium alloy are most frequently used in clinical practice.

Reference: Clinical Insertion Techniques of Orthodontic Temporary Anchorage Devices, Wiley Blackwell