Odontogenic keratocysts located in the buccal mucosa: A description of two cases and review of the literature.

Odontogenic keratocysts make up 4%-12% of all odontogenic cysts. Most cysts are sporadic but sometimes they arise in the context of basal cell nevus syndrome (Gorlin syndrome). Most odontogenic keratocysts arise in the posterior region of the mandible, but they can occur anywhere in the jaw. In rare instances, they are located peripherally in the gingiva. Even more rare, they are found in the soft tissues of the mouth. There have been a few case reports and small case series of such peripheral odontogenic keratocysts. Some controversy exists as to whether these truly represent a peripheral counterpart of the intraosseous odontogenic keratocysts and if their origin is at all odontogenic. We hereby present two cases of peripheral odontogenic keratocysts, both being located in the soft tissue of the buccal mucosa, and review the literature on peripheral odontogenic keratocysts.

Early thyroxine treatment in Down syndrome and thyroid function later in life.

OBJECTIVE: The hypothalamus-pituitary-thyroid (HPT) axis set point develops during the fetal period and first two years of life. We hypothesized that thyroxine treatment during these first two years, in the context of a randomized controlled trial (RCT) in children with Down syndrome, may have influenced the HPT axis set point and may also have influenced the development of Down syndrome-associated autoimmune thyroiditis. METHODS: We included 123 children with Down syndrome 8.7 years after the end of an RCT comparing thyroxine treatment vs placebo and performed thyroid function tests and thyroid ultrasound. We analyzed TSH and FT4 concentrations in the subgroup of 71 children who were currently not on thyroid medication and had no evidence of autoimmune thyroiditis. RESULTS: TSH concentrations did not differ, but FT4 was significantly higher in the thyroxine-treated group than that in the placebo group (14.1 vs 13.0 pmol/L; P = 0.02). There was an increase in anti-TPO positivity, from 1% at age 12 months to 6% at age 24 months and 25% at age 10.7 years with a greater percentage of children with anti-TPO positivity in the placebo group (32%) compared with the thyroxine-treated group (18.5%) (P = 0.12). Thyroid volume at age 10.7 years (mean: 3.4 mL; range: 0.5-7.5 mL) was significantly lower (P < 0.01) compared with reference values (5.5 mL; range: 3-9 mL) and was similar in the thyroxine and placebo group. CONCLUSION: Thyroxine treatment during the first two years of life led to a mild increase in FT4 almost 9 years later on and may point to an interesting new mechanism influencing the maturing HPT axis set point. Furthermore, there was a trend toward less development of thyroid autoimmunity in the thyroxine treatment group, suggesting a protective effect of the early thyroxine treatment. Lastly, thyroid volume was low possibly reflecting Down-specific thyroid hypoplasia.

Effects of early thyroxine treatment on development and growth at age 10.7 years: follow-up of a randomized placebo-controlled trial in children with Down's syndrome.

CONTEXT: In 2-year-old children with Down's syndrome (DS), early T4 treatment was found to result in slightly better motor development and growth. OBJECTIVES: This study sought to determine long-term effects of early T4 treatment on development and growth in children with DS with either an elevated or normal neonatal TSH concentration. DESIGN: Patients received a single follow-up visit 8.7 years after a randomized placebo-controlled trial (RCT) comparing T4 and placebo treatment during the first 2 years of life. SETTING: Dutch Academic Hospital. PARTICIPANTS: All children who completed the RCT (N = 181, of 196 randomly assigned children) were invited for the follow-up study. A total of 123 participants enrolled, at a mean age of 10.7 years. INTERVENTIONS: T4 or placebo treatment from the neonatal period until 2 years. MAIN OUTCOME MEASURES: Primary: mental and motor development. Secondary: communication skills, fine-motor coordination, height, weight, and head circumference (HC). Outcomes were compared between T4- and placebo-treated children, and between treatment groups with either a normal (<5 mIU/L), or elevated (≥ 5 mIU/L) TSH concentration at original trial entry. RESULTS: Mental or motor development, communication skills, or fine-motor coordination did not differ between T4- (N = 64) and placebo-treated children (N = 59). T4-treated children had a larger HC (50.4 vs 49.8 cm, P = .04) and tended to be taller (133.2 vs 131.1 cm, P = .06). These differences were somewhat greater in children with TSH ≥ 5 mIU/L (HC: T4, 50.5 vs placebo, 49.7 cm; P = .01; height: T4, 133.8 vs placebo, 130.8 cm; P = .02), but were not found in children with TSH <5 mIU/L (HC: T4, 50.1 vs placebo, 50.0 cm; P = .75; height: T4, 132.1 vs placebo, 131.6 cm; P = .22). CONCLUSIONS: Early T4 treatment of children with DS does not seem to benefit mental or motor development later in life. However, the positive effect on growth is still measurable, especially in children with an elevated plasma TSH concentration in the neonatal period.