Facial flaps can be divided into two types: Axial and Random. An axial flap has a named artery supplying it. The surviving length of an axial flap will remain constant regardless of the width of the flap. A random flap has smaller unnamed vessels and is not as stable. It’s surviving length is in direct proportion to the width. A random flap’s surviving length can be lengthened by “delaying” the flap. To delay a flap, it is elevated but left in position as a bipedicle flap. Two weeks later it is raised as a unipedicle flap and placed into position to close the defect. Interpolation flaps traverse skin in order to reach the defect. If placed over the skin, they will have a pedicle. The pedicle can be divided in 3 to 6 weeks depending upon the type of flap and the condition of the patient. Flaps may be “trained” by occluding the blood supply in the pedicle for progressive lengths of time. This allows for an earlier transection of the pedicle. Continue reading
Cleft lip repair can be initiated at any age, but optimal results occur when the first operation is performed between two and six months of age. Surgery is usually scheduled during the third month of life.
While the patient is under general anesthesia, the anatomical landmarks and incisions are carefully demarcated with methylene blue ink. An endotracheal tube prevents aspiration of blood. The surgical field is injected with a local anesthestic to provide further numbing and blood vessel constriction (to limit bleeding). Myringotomy (incisions in one or both eardrums) is performed, and myringotomy tubes are inserted to permit fluid drainage. Continue reading
Cleft lip repair (cheiloplasty) is surgical procedure to correct a groove-like defect in the lip.
A cleft lip does not join together (fuse) properly during embryonic development. Surgical repair corrects the defect, preventing future problems with breathing, speaking, and eating, and improving the person’s physical appearance. Continue reading
Secure archwire engagement and low friction as a combination
Other bracket types—most notably Begg brackets—have achieved low friction by virtue of an extremely loose fit between a round archwire and a very narrow bracket, but this is at the cost of making full control of tooth position correspondingly more difficult. Some brackets with an edgewise slot have incorporated shoulders to distance the elastomeric from the archwire and, thus, reduce friction, but this type of design also produces reduced friction at the expense of reduced control. A deformable elastomeric ring cannot provide and sustain sufficient force to maintain the archwire fully in the slot without actively pressing on the archwire to an extent that increases friction. Continue reading
Advantages of self-ligating brackets
These advantages apply in principle to all self-ligating brackets, although the different makes vary in their ability to deliver these advantages consistently in practice:
more certain full archwire engagement;
low friction between bracket and archwire;
less chairside assistance;
faster archwire removal and ligation. Continue reading
Self-ligating brackets have an inbuilt metal labial face, which can be opened and closed. Brackets of this type have existed for a surprisingly long time in orthodontics— the Russell Lock edgewise attachment being described by Stolzenberg in 1935. Many designs have been patented, although only a minority have become commercially available. Self-ligating braces are defined as “a [dental] brace, which utilizes a permanently installed, moveable component to entrap the archwire”. Self-ligating braces may be classified into two categories: Passive and Active. Continue reading
Spaced dentition is characterized by interdental spaces and lack of contact points between the teeth. Spacing can be localized or generalized due to the number of teeth included. It is a common esthetic problem for many patients. A study in European adults showed that patients with broad midline spacing were perceived as being less socially successful and having lower intelligence. Continue reading
Crossbite is an occlusal irregularity where a tooth (or teeth) has a more buccal or lingual position (that is, the tooth is either closer to the cheek or to the tongue) than its corresponding antagonist tooth in the upper or lower arcade. Continue reading
Lasers used in dentistry are engineered and designed to perform special functions without changing or damaging the surrounding tissues or materials.
The functioning of a laser goes back to Albert Einstein’s quantum theory of radiation and includes other theories that help explain the local tissue damage. The first laser was demonstrated in 1960. It was ruby laser, 694nm wavelength. Interest in the medical implications of laser light was high and already in 1967 , some of the first reports appeared on the effects of very low doses of ruby light on biological tissues. In animal studies, it was observed that experimental wounds healed better if irradiated and that even the shaved fur of the experimental animals reappeared faster in the irradiated areas. There appeared to be a biological window for the dose. If too low, there was no effect, if too high there was a suprresive effect. Not much later, the Helium-Neon laser was introduced in research and the results were similar. Later on, diode lasers were introduced and they provide the same results, although some wavelengths appeared to be better for certain indications. In particular, the introduction of infrared lasers improved the optical penetration of the ligh, reaching deeper lying tissues. The first commercially available lasers in the early 80’s were extremely low powered, below 1mW was used, in spite of the fact that the first scientific reports used 25 mW. This partly explains the initial contoversy about therapeutic dosage to be used. With the rapid developement of laser diodes, the powers of therapeutic lasers have changed dramastically and diode lasers today are typically in the range of 50-500 mW. Increased power has not only shortened the treatment time but also improved the therapeutic results.
Whitening of a tooth through the application of chemical agents to oxidize / reduce the organic pigmentation in the tooth.
BLEACHING OF DISCOLORED TEETH: