The Maxillary Sinus in Three Genera of New World Monkeys: Factors That Constrain Secondary Pneumatization

Abstract

The air filled cavities of paranasal sinuses are thought by some to appear opportunistically in spatial ''gaps'' within the craniofacial complex. Anthropoid primates provide excellent natural experiments for testing this model, since not all species possess a full complement of paranasal sinuses. In this study, two genera of monkeys (Saguinus and Cebuella) which form maxillary sinuses (MS) as adults were compared to squirrel monkeys (Saimiri spp.), in which a MS does not form. Using microCT and histomorphometric methods, the spatial position of paranasal spaces was assessed and size of the adjacent dental sacs was measured. In Saguinus, secondary pneumatization is underway perinatally, and the sinus extends alongside deciduous premolars (dp). The MS overlaps all permanent molars in the adult. In Saimiri, the homologous space (maxillary recess) extends no farther posterior than the first deciduous premolar at birth and extends no farther than the last premolar in the adult. Differences in dental size and position may account for this finding. For example, Saimiri has significantly larger relative dp volumes, and enlarged orbits, which encroach on the internasal space to a greater degree when compared to Saguinus. These factors limit space for posterior expansion of the maxillary recess. These findings support the hypothesis that secondary pneumatization is a novel, opportunistic growth mechanism that removes ''unneeded'' bone. Moreover, paranasal spaces occur in association with semiautonomous skeletal elements that border more than one functional matrix, and the spatial dynamics of these units can act as a constraint on pneumatic expansion of paranasal spaces. Anat Rec,

Minor contributions of the maxillary sinus to the air-conditioning performance in macaque monkeys

“…The paranasal sinus is often thought to reduce the weight of the cranium and save bony materials by eliminating unnecessary bony resources (Rae and Koppe, 2004;Smith et al, 2005;Zollikofer and Weissmann, 2008). Although its biological advantages are still argued, the paranasal sinus is believed to develop opportunistically from the nasal meatus if there are few structural disturbances, in that the pneumatization begins and progresses (Zollikofer and Weissmann, 2008;Smith et al, 2010). The paranasal sinus might develop and form as a spandrel, i.e.…”

Distribution of Olfactory and Nonolfactory Surface Area in the Nasal Fossa of Microcebus murinus: Implications for Microcomputed Tomography and Airflow Studies

“…Therefore, our knowledge of the specific distribution of mucosae over these elements informs comparative analyses in a crucial manner. A broader base of histological data on these structures has become more important as high resolution study of the internal nose is now possible using CT technology (Rowe et al, 2005;Craven et al, 2007;Smith et al, 2010). The present study offers a framework for future quantitative work.…”

“…This enables a more detailed assessment of the total SA produced by turbinals, and the proportion to which they augment the nasal airway or its recesses. This information provides crucial background for understanding the intricate internal nasal skeletal anatomy that has recently become far more accessible for study with improved technology such as high resolution computed tomography (CT) (e.g., Rowe et al, 2005;Rossie, 2006;Smith et al, 2010;Van Valkenburgh et al, 2011).…”

Nasal architecture in <i>Procynocephalus wimani</i> (Early Pleistocene, China) and implications for its phyletic relationship with <i>Paradolichopithecus</i>

“…These findings suggest that the genetic basis for the formation of the maxillary sinus has been secured since the ancestral loss of this feature in phenotype in cercopithecoids; it is usually silent in these two and other genera of Papionina. Although its biological advantages are still argued (Rae and Koppe, 2004;Rossie, 2008;Smith et al, 2010), the maxillary sinus is believed to develop opportunistically from the middle meatus if there are few structural disturbances as the pneumatization begins and progresses (Zollikofer and Weissmann, 2008;Smith et al, 2010). Whereas such disturbances occurring during the perinatal period are yet to be reported, the heterogeneity discovered here could reflect an anatomical variation that has been retained to release such disturbances in the two genera.…”