Simple retraction of maxillary incisors using maxillary molars as anchorage is an example of: PGCEE MDS 2025

 # Simple retraction of maxillary incisors using maxillary molars as anchorage is an example of:  (PGCEE MDS 2025)

a) Simple anchorage 

b) Reciprocal anchorage

c) Stationary anchorage 

d) Intermaxillary anchorage

The correct answer is:

c) Stationary anchorage

Explanation:

Stationary anchorage refers to a type of anchorage where the resistance to unwanted tooth movement is achieved by using teeth that undergo minimal movement, usually due to bodily movement rather than tipping.

• In simple retraction of maxillary incisors using maxillary molars as anchorage, the molars provide resistance while the incisors move posteriorly. The molars remain relatively stable, which characterizes stationary anchorage.
• Other types of anchorage:
  • Simple anchorage – Resistance to movement provided by the PDL of the anchoring teeth.
  • Reciprocal anchorage – Two equal and opposite forces are applied, leading to movement of both units (e.g., space closure between two adjacent teeth).
  • Intermaxillary anchorage – Anchorage derived from teeth in the opposite arch (e.g., elastics from maxillary to mandibular teeth).

Serial extractions are indicated when there is - PGCEE MDS Entrance 2025

 # Serial extractions are indicated when there is -

a) No skeletal discrepancy with dental crowding > 10 mm

b) No skeletal discrepancy with dental crowding between 5 - 7 mm.

c) Skeletal discrepancy >5°

d) Skeletal discrepancy >10° with dental crowding < 5mm

The correct answer is A. No skeletal discrepancy with dental crowding > 10 mm

 Serial extraction is indicated in cases of severe dental crowding. For this reason, it is best used when no skeletal problem exists, and the space discrepancy is large i.e., >10 mm per arch.

If the crowding is severe, little space will remain after the teeth are aligned, which means there will be little tipping and uncontrolled movement of the adjacent teeth into the extraction sites. If the initial space discrepancy is smaller, more residual space must be anticipated.

The commonest teeth involved in transposition are: PGCEE MDS Entrance 2025

 # The commonest teeth involved in transposition are:

a) Maxillary central incisor and lateral incisor

b) Maxillary canine and first premolar

c) Maxillary 1st premolar and 2nd premolar

d) Maxillary canine and Lateral incisor

The correct answer is:

b) Maxillary canine and first premolar

Explanation:

Tooth transposition is a rare developmental anomaly where two adjacent teeth exchange their positions within the dental arch. The most commonly involved teeth in transposition are the maxillary canine and first premolar. This occurs due to disturbances in tooth eruption patterns, genetics, or space constraints in the dental arch.

Other less common transpositions include:

• Maxillary canine and lateral incisor (less frequent but still observed)
• Mandibular canine and lateral incisor (rare)

The free gingival groove is most commonly associated with which tooth? PGCEE MDS Entrance 2025

 # The free gingival groove is most commonly associated with which tooth? 

a) Maxillary canine 

b) Mandibular incisor 

c) Maxillary first molar 

d) Mandibular premolar

The correct answer is:

b) Mandibular incisor

The free gingival groove is a shallow linear depression that demarcates the free gingiva from the attached gingiva. It is more prominent in some individuals and may not always be present. However, when it is visible, it is most commonly associated with the mandibular incisors due to their relatively thin and well-defined gingival anatomy. This aligns with standard dental textbooks like Carranza’s Clinical Periodontology, which highlights the mandibular incisors as a common site for the free gingival groove.

Well aligned deciduous dentition is an indication of: PGCEE MDS Entrance 2025

 # Well aligned deciduous dentition is an indication of:

A. Potential crowding

B. Disto occlusion

C. Mesio occlusion

D. Well aligned permanent teeth

The correct answer is:

A. Potential crowding

Explanation:

• Well-aligned deciduous dentition (primary teeth) with little to no spacing is often a predictor of potential crowding in the permanent dentition.

• Primary teeth are smaller than permanent teeth, and deciduous arches typically exhibit natural spacing ("primate spaces") to accommodate the larger permanent successors. If primary teeth are tightly aligned, it suggests insufficient space for the eruption of larger permanent teeth, increasing the risk of crowding.

• D. Well-aligned permanent teeth is incorrect because spaced (not tightly aligned) primary teeth are actually a better indicator of sufficient arch space for proper alignment of permanent teeth.

• B. Disto-occlusion and C. Mesio-occlusion refer to malocclusions (Class II and Class III bites, respectively) and are unrelated to primary tooth alignment.

Key Takeaway: Tightly aligned primary teeth (lacking spacing) often signal future crowding, as permanent teeth require more space. Spaced primary dentition is ideal for alignment of permanent teeth.

The palate is considered the most appropriate insertion site for miniscrews supporting an intraoral distalizer because it:

 # The palate is considered the most appropriate insertion site for miniscrews supporting an intraoral distalizer because it:

a) is free of dental roots and other anatomical structures

b) does not create a force vector passing coronally to the maxillary arch’s center of resistance

c) takes advantage of bicortical anchorage

d) all of the above

The correct answer is D. All of the above

Explanation:

The palate is an ideal site for miniscrew-supported intraoral distalizers because of the following advantages:

1. Free of dental roots and other anatomical structures (Option a)

   • The mid-palatal region is a safe zone with minimal risk of damaging dental roots or vital structures, making it ideal for miniscrew placement.

2. Does not create a force vector passing coronally to the maxillary arch’s center of resistance (Option b)

   • Placing miniscrews in the palate helps direct force closer to the center of resistance of the maxillary arch, reducing unwanted tipping or extrusion effects.

3. Takes advantage of bicortical anchorage (Option c)

   • The palatal bone is thick and dense, allowing for bicortical engagement (penetration into both the cortical and cancellous bone), which improves primary stability and resistance to failure.

Since all of the statements are true, option d (all of the above) is the correct answer.

Intraoral Class II distalizers have the major disadvantage of:

 # Intraoral Class II distalizers have the major disadvantage of:

a) the need for patient compliance

b) a force vector passing coronally to the maxillary arch’s center of resistance

c) anterior anchorage loss

d) an inability to be used simultaneously with multibracket appliances

The correct answer is:

c) Anterior anchorage loss

Explanation:

Intraoral Class II distalizers, such as the Pendulum appliance, Distal Jet, or Forsus, rely on posterior force application to move the maxillary molars distally. However, a major drawback is anterior anchorage loss, meaning:

As the maxillary molars move distally, the anterior teeth tend to drift forward, leading to proclination of the incisors.

This can compromise the correction of a Class II malocclusion if not properly controlled with anchorage reinforcement.

Why not the other options?

(a) The need for patient compliance → Not true for most fixed distalizers (e.g., Pendulum, Distal Jet), but true for removable appliances like elastics or headgear.

(b) A force vector passing coronally to the maxillary arch’s center of resistance → This is a concern in some cases but not the primary disadvantage.

(d) An inability to be used simultaneously with multibracket appliances → Many distalizers can be used alongside braces (e.g., Forsus, Carriere Motion Appliance).

The Invisalign Palatal expander is directly printed from:

 # The Invisalign Palatal expander is directly printed from:

a) polyamide-12

b) TC-85

c) polymethyl methacrylate

d) thermoplastic polyurethane

The correct answer is A. Polyamide-12.

The Invisalign Palatal Expander (IPE) is 3D-printed directly from Polyamide-12 (PA-12), a biocompatible and durable nylon-based material. This material is widely used in medical applications due to its strength, flexibility, and resistance to wear. PA-12 allows for precise and customized expansion while maintaining patient comfort.

The Invisalign Palatal Expander (IPE) is designed to expand the dentition in increments of:

  # The Invisalign Palatal Expander (IPE) is designed to expand the dentition in increments of:

a) 0.1mm

b) 0.25mm

c) 0.5mm

d) 1mm

The correct answer is B. 0.25 mm.

The Invisalign Palatal Expander (IPE) uses a series of custom-designed, 3D-printed expansion trays to gradually widen the upper arch. It expands the dentition in controlled increments of 0.25mm per adjustment, ensuring a more comfortable and predictable expansion compared to traditional rapid palatal expanders (RPEs).

Following are "essential diagnostic criteria" according to Graber except:

 # Following are "essential diagnostic criteria" according to Graber except:

a) Case history

b) Facial photographs

c) Periapical x-rays

d) Lateral cephalograms

The correct answer is:

d) Lateral cephalograms

Graber's essential diagnostic criteria for orthodontic diagnosis typically include case history, facial photographs, and periapical x-rays. Lateral cephalograms, while useful for orthodontic analysis, are not considered part of the essential diagnostic criteria according to Graber.

In a trauma patient with intraoral bleeding, best way to secure airway is:

 # In a trauma patient with intraoral bleeding, best way to secure airway is:

A. Awake blind intubation

B. Awake fibreoptic intubation

C. Tracheostomy

D. Cricothyroidotomy

The correct answer is:

D. Cricothyroidotomy

Explanation:

In a trauma patient with intraoral bleeding, maintaining a secure airway is critical because blood in the oral cavity can obstruct visualization and aspiration can compromise the airway. Here's why cricothyroidotomy is the best option in this scenario:

1. Challenges with intubation in intraoral bleeding:

• Awake blind intubation (Option A) is highly unreliable due to the inability to visualize the airway and the presence of blood.
• Awake fibreoptic intubation (Option B) may not be feasible in this case because the blood obstructs the fibreoptic scope's view, making the procedure very difficult. 
• Although performing fiber-optic intubation under local anesthesia for achieving successful endotracheal intubation is one of the recommended methods in situations where airway management is difficult, the use of FOB (fiber-optic bronchoscope) is somewhat impractical in patients with maxillofacial trauma. Blood, vomitus, and secretions in the patient’s airway may preclude vision by fiber-optic instruments, and accomplish ing effective local anesthesia in the injured regions is difficult. Furthermore, the patient’s cooperation is essential for such an approach, and this cooperation is not easy to obtain in the trauma patient.

2. Tracheostomy (Option C):

   • While a tracheostomy can secure the airway, it is a more complex and time-consuming procedure than a cricothyroidotomy, making it less ideal in an emergency setting.

3. Cricothyroidotomy (Option D):

   • It is the fastest and most effective way to secure an airway in a patient with significant oral bleeding.
   • It bypasses the upper airway and oral cavity entirely, preventing further complications from blood aspiration.
   • Cricothyroidotomy is generally the procedure of choice in emergency situations where intubation is not feasible or has failed.

Summary:

In an emergency involving trauma with significant intraoral bleeding, cricothyroidotomy is the best and most practical approach for quickly securing the airway and ensuring the patient's survival.

Patients with organ transplants are most frequently infected with:

 # Patients with organ transplants are most frequently infected with:

A. Hepatitis A

B. Hepatitis B

C. CMV

D. EBV

The correct answer is:

C. CMV (Cytomegalovirus)

Explanation:

Cytomegalovirus (CMV) is the most common opportunistic infection in patients with organ transplants. This is because immunosuppressive therapy, which is necessary to prevent organ rejection, compromises the immune system, making the patient more vulnerable to infections.

CMV in transplant patients:

It can cause severe complications, including fever, gastrointestinal disease, pneumonitis, hepatitis, and graft rejection.

Reactivation of latent CMV or primary infection (from donor tissue or environmental exposure) is common.

Other options:

Hepatitis A: Rarely an issue in transplant patients since it does not become chronic and typically resolves without major complications.

Hepatitis B: Can cause complications in transplant patients, but it is less frequent than CMV. Pre-transplant screening and antiviral prophylaxis help manage the risk.

EBV (Epstein-Barr Virus): Can cause post-transplant lymphoproliferative disorder (PTLD), but it is less common than CMV.

In summary, CMV is the most frequent and clinically significant infection in transplant patients.

Which of the following hormones increase the sensitivity of heart to epinephrine?

 # Which of the following hormones increase the sensitivity of heart to epinephrine?

A. Parathyroid

B. Insulin

C. Thyroid

D. Glucagon

The correct answer is:

C. Thyroid

Explanation:

Thyroid hormones (primarily T3 and T4) increase the sensitivity of the heart to catecholamines, including epinephrine. This effect is due to:

• Increased β-adrenergic receptor density: Thyroid hormones upregulate the expression of β-adrenergic receptors in the heart, enhancing responsiveness to epinephrine and norepinephrine.
• Increased myocardial contractility and heart rate: By amplifying the effects of catecholamines, thyroid hormones contribute to increased cardiac output and sympathetic tone.

Other options:

• A. Parathyroid hormone (PTH): This hormone regulates calcium and phosphate metabolism, with no direct role in cardiac sensitivity to epinephrine.
• B. Insulin: While insulin affects glucose metabolism and has some cardiovascular effects, it does not directly increase heart sensitivity to epinephrine.
• D. Glucagon: Glucagon has some inotropic and chronotropic effects on the heart, but it does not enhance the heart's sensitivity to epinephrine.

Thyroid hormones play a key role in modulating the cardiovascular system, particularly through their interaction with catecholamines.

Most common cause of multiple fetal anomalies is:

 # Most common cause of multiple fetal anomalies is:

A. Syphilis

B. Tetracycline

C. Rubella

D. Rubeola

The correct answer is C. Rubella.

The correct answer is:

C. Rubella

Explanation:

Rubella, especially when contracted during the first trimester of pregnancy, is a significant cause of multiple fetal anomalies. This is due to its teratogenic effects, which can result in congenital rubella syndrome (CRS). The anomalies caused by CRS can include:

• Cardiac defects (e.g., patent ductus arteriosus, pulmonary artery stenosis)
• Ocular defects (e.g., cataracts, retinopathy, glaucoma)
• Auditory defects (e.g., sensorineural hearing loss)
• Neurological defects (e.g., microcephaly, developmental delays)

Other options:

• A. Syphilis: Can cause congenital syphilis with specific anomalies (e.g., skeletal deformities, Hutchinson teeth), but it is not the most common cause of multiple fetal anomalies.
• B. Tetracycline: Causes specific anomalies, mainly involving dental staining and hypoplasia, not a wide range of fetal anomalies.
• D. Rubeola (measles): While it can cause complications in pregnancy, it is less associated with multiple fetal anomalies compared to rubella.

Rubella is particularly significant due to its potential to cause a broad spectrum of anomalies when maternal infection occurs early in pregnancy.

Mean diameter of inferior alveolar nerve is:

 # Mean diameter of inferior alveolar nerve is:

A. 10 mm

B. 4.7 mm

C. 8 mm

D. 1.7 mm

The correct answer is B. 4.7 mm.

The inferior alveolar nerve is a branch of the mandibular nerve (the third division of the trigeminal nerve), responsible for providing sensory innervation to the lower teeth, chin, and lower lip. Its diameter is significant in clinical practices like dental anesthesia, nerve preservation during surgeries, and implant placement.

• The mean diameter of 4.7 mm reflects the nerve's size as it travels through the mandibular canal.

Inferior Alveolar – exits the mental foramen as the mental nerve and continues as the incisive nerve.

● The nerve to mylohyoid is a motor and sensory branch of the inferior alveolar nerve

● The nerve to anterior belly of the digastric muscle is a motor branch of the inferior alveolar nerve