Microstomia is a medical term that refers to an abnormally small or narrow opening of the mouth. This condition can result from various causes, including congenital disorders, surgical procedures, or neuromuscular diseases. Microstomia can lead to difficulties with speaking, eating, oral hygiene, and dental care. Treatment options may include physical therapy, surgery, or the use of specialized medical devices to help widen the mouth opening.

A dental impression technique is a method used in dentistry to create a detailed and accurate replica of a patient's teeth and oral structures. This is typically accomplished by using an impression material, which is inserted into a tray and then placed in the patient's mouth. The material sets or hardens, capturing every detail of the teeth, gums, and other oral tissues.

There are several types of dental impression techniques, including:

1. Irreversible Hydrocolloid Impression Material: This is a common type of impression material that is made of alginate powder mixed with water. It is poured into a tray and inserted into the patient's mouth. Once set, it is removed and used to create a cast or model of the teeth.

2. Reversible Hydrocolloid Impression Material: This type of impression material is similar to irreversible hydrocolloid, but it can be reused. It is made of agar and water and is poured into a tray and inserted into the patient's mouth. Once set, it is removed and reheated to be used again.

3. Polyvinyl Siloxane (PVS) Impression Material: This is a two-part impression material that is made of a base and a catalyst. It is poured into a tray and inserted into the patient's mouth. Once set, it is removed and used to create a cast or model of the teeth. PVS is known for its high accuracy and detail.

4. Addition Silicone Impression Material: This is another two-part impression material that is made of a base and a catalyst. It is similar to PVS, but it has a longer working time and sets slower. It is often used for full-arch impressions or when there is a need for a very detailed impression.

5. Elastomeric Impression Material: This is a type of impression material that is made of a rubber-like substance. It is poured into a tray and inserted into the patient's mouth. Once set, it is removed and used to create a cast or model of the teeth. Elastomeric impression materials are known for their high accuracy and detail.

The dental impression technique is an essential part of many dental procedures, including creating crowns, bridges, dentures, and orthodontic appliances. The accuracy and detail of the impression can significantly impact the fit and function of the final restoration or appliance.

"Edentulous jaw" is a medical term used to describe a jaw that is missing all of its natural teeth. The term "edentulous" is derived from the Latin word "edentulus," which means "without teeth." This condition can affect either the upper jaw (maxilla) or the lower jaw (mandible), or both, resulting in a significant impact on an individual's ability to eat, speak, and maintain proper facial structure.

Edentulism is often associated with aging, as tooth loss becomes more common in older adults due to factors like gum disease, tooth decay, and injury. However, it can also affect younger individuals who have lost their teeth due to various reasons. Dental professionals typically recommend the use of dentures or dental implants to restore oral function and aesthetics for patients with edentulous jaws.

A complete denture is a removable dental appliance that replaces all of the teeth in an upper or lower arch. It is also commonly referred to as a "full denture." A complete denture is created specifically to fit a patient's mouth and can be made of either acrylic resin (plastic) or metal and acrylic resin.

The upper complete denture covers the palate (roof of the mouth), while the lower complete denture is shaped like a horseshoe to leave room for the tongue. Dentures are held in place by forming a seal with the gums and remaining jawbone structure, and can be secured further with the use of dental adhesives.

Complete dentures not only restore the ability to eat and speak properly but also help support the facial structures, improving the patient's appearance and overall confidence. It is important to maintain regular dental check-ups even if all teeth are missing, as the dentist will monitor the fit and health of the oral tissues and make any necessary adjustments to the denture.