Fontanelle and uncinate process in the lateral wall of the human nasal cavity

Objectives: Although a complete anatomic knowledge of the fontanelle is a p rerequisite to perform a surgical antrostomy opening, Little is known about the boundary, shape, and size of the fontanelle, The purpose of this paper is to determine the best site for maintaining the patency of a surgical an trostomy opening by defining the anatomic boundaries, shape, and size of th e fontanelle as web as its histological structure. Materials and Methods: O ne hundred sagittally divided heads were utilized. Mucosa overlying the lat eral nasal wall was carefully removed with an operating microscope under ex magnification. In some cases, a double mucous membrane, including the post eroinferior portion of the uncinate process, was cut as a whole and embedde d in paraffin, The sections were stained with H&E. Results: The boundary of the fontanelle and the location of the natural ostium were described in de tail. Eight patterns of the posteroinferior portion of the uncinate process were observed. There were three major fontanelle shapes when observed from the medial aspect to the lateral: triangular, pencil-like, and oval. The t riangular type was the most common. The anterior portion of the fontanelle was shorter than the posterior when observed medially and was wider than th e posterior portion when observed inferiorly. Conclusions: The anterior por tion of the fontanelle is more prone to stenosis than the posterior portion . An antrostomy in the posterior fontanelle may be more ideal for a mid dle meatal antrostomy of the maxillary sinus.