The coronoids – An area less explored among temporomandibular jointdisorders

Background: A large number of disorders affecting the masticatory system can cause restriction of mouth opening. The most common conditions related to this problem are those involving the temporomandibular joint (TMJ) and the masticatory muscles, is an usual finding. Coronoid process hyperplasia is a rare cause of mandibular hypo mobility. Literature review states that the morphological variation in the shape of coronoid process and sigmoid notch may be due to hereditary or functional changes and have a correlation with the mode of degree of attachment of temporalis muscle. Materials and Methods: A Study was conductedin 100 (200joints) South Indian individuals who presented with various temporomandibular joint disorders. The shape of coronoid process and sigmoid notch and length of coronoid process were analysed bilaterally using Cone Beam Computed tomography (CBCT). Morphological alteration of coronoid process and its length and sigmoid notch were analysed and compared for differences on either sides. Results: The length of coronoid process was found to be approximately 1.9 mm longer on the right side than on the left side; the mean value of right side being 14.96mm and left side being 13.06mm Triangular coronoid process was found to be the commonest with 31% right side and 60% in left side followed by beak shaped with 48% right side and 20% in left side and then round shaped with 21% right side and 20% in left side. The shape of sigmoid notch wide shape was found to be the commonest with 60 % right side and 41 % in left side followed by sloping shape with 32% right side and 23% in left side and then round shape with 8% right side and 36% in left side.