The dentition of snakes serves a key function in their nutrition, as their feeding strategy is directly related to the shape and size of teeth in various dental bones. The morphology of snake's jaws is highly variable and can be considered an important source of taxonomic information. As such, dentition has been used for over a century to describe and identify taxa, continuing to be an important tool in both taxonomy and phylogeny. The goal of this study was to analyze the maxillary dentition of 15 species of neotropical opisthoglyphous snakes (Clelia plumbea, Helicops carinicaudus, Oxyrhopus clathratus, Oxyrhopus guibei, Oxyrhopus rhombifer, Philodryas aestiva, Philodryas nattereri, Philodryas olfersii, Philodryas patagoniensis, Pseudoboa haasi, Siphlophis compressus, Thamnodynastes nattereri, Thamnodynastes strigatus, Tomodon dorsatus, and Tropidodryas striaticeps), with an emphasis on species found in the state of Paraná, Brazil, as a system to assess intra- and interspecific differences among them. This study aimed to examine the maxillary morphology of snakes with different diets but all belonging to the same colubrid lineage. Additionally, it sought to evaluate the applicability of alternative techniques for osteological material preparation and to interpret the observed variation from functional (diet) and evolutionary perspectives, based on available phylogenies. Two preparation techniques were used: dry preparation and diaphanization methods. The analysis of the specimens was conducted using a Leica stereoscopic microscope, and data obtained were analyzed using PAST software. The results suggested that measuring the jaws alone was insufficient to determine the phylogeny or specialized diet of the assessed opisthoglyphous species.