Megavitamin-B6 syndrome has been reported in doses as low as 24 mg/day.Symptoms may also be dependent on the form of vitamin B6 taken in supplements. It has been proposed that vitamin B6 in supplements should be in pyridoxal or pyridoxal phosphate form rather than pyridoxine as these are thought to reduce the likelihood of toxicity. A tissue culture study, however, showed that all B6 vitamers that could be converted into active coenzymes (pyridoxal, pyridoxine and pyridoxamine) were neurotoxic at similar concentrations. It has been shown, in vivo, that supplementing with pyridoxal or pyridoxal phosphate increases pyridoxine concentrations in humans, meaning there are metabolic pathways from each vitamer of B6 to the all other forms. Consuming high amounts of vitamin B6 from food has not been reported to cause adverse effects.Early diagnosis and cessation of vitamin B6 supplementation can reduce the morbidity of the syndrome. Cause
While vitamin B6 is water-soluble, it has a half-life of 25–33 days and accumulates in the body where it is stored in muscle, plasma, the liver, red blood cells and bound to proteins in tissues. Potential mechanisms
The common supplemental form of vitamin B6, pyridoxine, is similar to pyridine which can be neurotoxic. Pyridoxine has limited transport across the blood–brain barrier explaining why the central nervous system is spared. Cell bodies of motor fibers are located within the spinal cord that is also restricted by the blood-brain barrier explaining why motor impairment is rare.
However, with two jaw surgery a relapse leading to bite opening may happen due to condylar remodeling and resorption. Stability and relapse
Surgery vs. non-surgery
Geoffrey Greenlee and others published a meta-analysis in 2011 which concluded that patients with orthognathic surgical correction of open bite had 82% stability in comparison to non-surgical correction of open bite which had 75% of stability after 1or more year of treatment. Both the groups started with 2–3 mm of open bite initially. Molar intrusion
Man-Suk Baek and others evaluated long-term stability of anterior open bite by intrusion of maxillary posterior teeth. Their results showed that the molars were intruded by 2.39 mm during treatment and relapsed back by 0.45 mm or 22.8%. The incisal overbite increased by 5.56 mm during treatment and relapsed back by 1.20 mm or 17%. They concluded that majority of the relapse occurred during first year of treatment. See also
Cephalometric analysis
Intrusion (orthodontics)
Long face syndrome
MEAW Technique
Malocclusion


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