The vertebrate tongue is a complex muscular organ situated in the oral cavity and involved in multiple functions including mastication, taste sensation, articulation and the maintenance of oral health. Although the gross embryological contributions to tongue formation have been known for many years, it is only relatively recently that the molecular pathways regulating these processes have begun to be discovered. In particular, there is now evidence that the Hedgehog, TGF-Beta, Wnt and Notch signaling pathways all play an important role in mediating appropriate signaling interactions between the epithelial, cranial neural crest and mesodermal cell populations that are required to form the tongue. In humans, a number of congenital abnormalities that affect gross morphology of the tongue have also been described, occurring in isolation or as part of a developmental syndrome, which can greatly impact on the health and well-being of affected individuals. These anomalies can range from an absence of tongue formation (aglossia) through to diminutive (microglossia), enlarged (macroglossia) or bifid tongue. Here, we present an overview of the gross anatomy and embryology of mammalian tongue development, focusing on the molecular processes underlying formation of the musculature and connective tissues within this organ. We also survey the clinical presentation of tongue anomalies seen in human populations, whilst considering their developmental and genetic etiology.

Cyclopia is a rare form of lethal holoprosencephaly (HPE) due to incomplete cleavage of prosencephalon during embryogenesis, leading to failure of the orbits of the eye to divide into two cavities. We report two cases, one with cyclopia and another case of cyclopia with agnathia-otocephaly complex (AOC). AOC (also known as agnathia-microstomia-synotia syndrome) is a rare lethal congenital malformation of the first branchial arch characterised by the association of agnathia (agenesis of mandible) or mandibular hypoplasia, melotia (anteromedial malposition of ears), microstomia (small mouth), aglossia or microglossia (absent or rudimentary tongue). These two reported cases had in common a single eye and alobar HPE. The first case was live born and the second stillborn. Both mothers did not have antenatal care.

Aglossia is a rare congenital malformation that often occurs as an isolated disorder or is observed in association with other congenital deformities, particularly limb defects. We present a unique case of a 7-year-old girl with aglossia, hypodactyli, rudimentary ears, retrognathic and V-shaped mandible. Her parental history revealed intrauterine exposure of medicines. The patient had problems in difficulty in eating, speech, taste sensation and hearing. The present case does not fit into Hall's classification of oromandibular limb hypogenesis syndrome (OLHS) which best describes hypoglossia and limb deformities. Therefore, the purpose of this article is to document the rare variant of OLHS which can be included in Hall's classification. How to cite this article: Kalaskar RR, Godhane A, Kalaskar A, Demble S. A Rare Clinical Variant of Oromandibular Limb Hypogenesis Syndrome Type I B. Int J Clin Pediatr Dent 2016;9(1):78-81.

Isolated Congenital Aglossia (ICA) is a rare syndrome where an individual is born without a tongue. A few anecdotal reports have identified taste as a sensation experienced by the person with congenital aglossia (PWCA). To date no systematic investigations have been reported. This study aimed to systematically determine gustatory function in a PWCA. The current study utilized a randomized, double-blinded, controlled trial that tested the five basic tastes: sweet (sucrose), sour (acetic acid), salty (sodium chloride), bitter (caffeine), and umami (monosodium glutamate, MSG) in a 44 year old female PWCA. Five concentration levels (three for salty) were tested in triplicate for each stimulus. A nose clip was used to exclude contribution by olfactory detection. Contingency tables were constructed to determine relationships between identification accuracy and stimulus or concentration level. The sweet (17.1 g/L), salty (0.58 g/L), and bitter (0.02 g/L) stimuli were detected at comparable concentrations to those reported in non-randomized trials, while sour (0.02 g/L) was detected at a lower concentration. The most common substitution was salty for umami (n = 7). Identification accuracy was significantly associated with taste stimuli χ (2) = 12.634, p = 0.013. Concentration level was significantly associated with identification accuracy only for salty, χ (2) = 9.000, p = 0.011. This study has demonstrated the perception of different tastes in a PWCA. This is the first known report of umami being identified as a unique taste in a PWCA. Variations in threshold taste concentrations compared to normal individuals indicate certain gustatory dysfunction.