32977

Down syndrome is NOT associated with maxillary retrognathia. Instead, it is characterized by maxillary HYPOPLASIA (underdevelopment), giving the appearance of relative mandibular prognathism. Down syndrome patients commonly have periodontal disease due to immune system dysfunction, premature loss of deciduous teeth, and delayed eruption of both deciduous and permanent teeth due to developmental delays.

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The enlargement of gingiva caused by cyclosporine is a non-inflammatory fibrous overgrowth, which is a common side effect of the immunosuppressant medication.

58938

Anthracoid bacilli, such as those in the genus Bacillus, are capable of fermenting various sugars, including glucose, maltose, lactose, and sucrose. This fermentation process results in the production of acid and gas, which can be detected by observing changes in the pH of the medium and the formation of gas bubbles. This statement is true as it accurately describes the typical sugar fermentation profile of these bacteria.

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Chlorides are not typically used for disinfection of silicone impression materials. Silicone is more resistant to chemicals, but chlorides can potentially degrade the material’s integrity.

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Nerve membrane stabilization action of local anaesthetic agents is due to preventing conductance of Na ions from the exterior of the nerve to the interior.

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Endotoxins are components of the outer membrane of Gram-negative bacteria and are released when the bacteria die or divide. This structural characteristic differentiates them from exotoxins, which are secreted by living bacteria.

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Omission, in the context of behavioral management in pediatric dentistry, involves removing a desirable stimulus (in this case, the mother's presence) to decrease the likelihood of the inappropriate behavior recurring. This is a form of negative punishment.

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ankylosed teeth are also known as submerged teeth.
submerged teeth are decidous teeth most commonly mandibular second molars
Most common permanant tooth found to be ankylosed is premolars.

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Linear incision is the factor of least importance in alveolar flap design. While other factors like closure over bone, tension-free closure, and proper base-to-length relationship are critical for healing, the exact linearity of incision is less crucial than these functional aspects.

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The nerve to masseter passes through the mandibular notch to enter the muscle on its medial surface

The nerve to the masseter muscle is the masseteric nerve, which is a branch of the mandibular nerve (CN V3), the largest division of the trigeminal nerve (cranial nerve V). The masseter muscle is one of the muscles of mastication that lifts the lower jaw, contributing to the action of biting and chewing.

The masseteric nerve originates from the anterior division of the mandibular nerve and typically passes:

1. Deep to the medial pterygoid muscle: The medial pterygoid muscle is located in the infratemporal fossa, which is the space deep to the zygomatic arch and medial to the temporomandibular joint (TMJ). The masseteric nerve runs in a deep position relative to the medial pterygoid muscle as it travels towards the masseter muscle. This muscle is involved in the side-to-side movement of the jaw, known as lateral excursion.

2. Posterior to the temporomandibular joint: The TMJ is the articulation between the mandible and the temporal bone of the skull. It is a synovial joint that allows for the hinge movement of the jaw, such as opening and closing the mouth. The masseteric nerve passes behind the TMJ to reach the masseter muscle. This nerve does not actually cross the joint itself but runs in a position posterior to it.

3. Superior to the zygomatic arch: The zygomatic arch is the bony structure that extends from the zygomatic process of the temporal bone to the zygomatic bone of the skull. It forms the prominence of the cheek. The masseteric nerve runs superior to the zygomatic arch to reach the masseter muscle. The arch serves as a landmark for the nerve's course, and the nerve typically does not pass through the arch itself.

4. Through the mandibular notch: This statement is not entirely correct. The masseteric nerve does not pass through the mandibular notch, which is a depression on the medial surface of the ramus of the mandible, but rather it passes above (superior to) the notch. The mandibular notch is the location where the masseteric nerve and the other branches of the mandibular nerve leave the infratemporal fossa and enter the submandibular space to innervate the muscles of mastication, including the masseter. The nerve then runs along the lateral surface of the lateral pterygoid plate and enters the deep surface of the masseter muscle.

In summary, the masseteric nerve passes deep to the medial pterygoid muscle, posterior to the TMJ, and superior to the zygomatic arch. It does not pass through the mandibular notch; instead, it runs superior to it before reaching the masseter muscle. The anatomical pathway of this nerve allows it to effectively innervate the masseter muscle, which is crucial for the function of the muscle in mastication.