The　quality　of　oral　and　maxillofacial　surgery　(OMS)　significantly　depends　on　the　accuracy　of　surgical　navigation.　In　this　article,　a　vision-based　markerless　surgical　navigation　system　is　developed　to　overcome　the　shortcomings　in　the　currently　available　technologies.　Registration　methods　both　for　patient　and　surgical　instrument　tracking　are　improved　to　increase　the　navigation　performance.　For　patient-image　registration,　we　propose　an　efficient　texture-less　pose　estimation　method　using　only　shape　information.　An　innovative　strategy　is　developed　to　effectively　reject　the　outliers　and　improve　the　pose　accuracy,　which　is　the　first　attempt　at　introducing　geometric　matching　information　to　guide　PnP　calculation.　For　surgical　instrument　tracking,　a　position-sensing　marker　is　used　to　achieve　robust　and　convenient　instrument　localization　with　high　accuracy.　Experiments　were　conducted　on　the　3-D-printed　maxilla　and　mandible　models　to　evaluate　the　navigation　performance.　Evaluation　results　validate　the　effectiveness　of　the　proposed　pose　estimation　method　in　improving　the　pose　accuracy　for　texture-less　teeth.　Besides,　it　is　revealed　that　the　position-sensing　marker　can　be　localized　with　high　accuracy　even　under　nonideal　visibility　conditions,　which　expands　the　motion　range　of　the　instrument　and　decreases　the　size　of　the　tool.　The　entire　system　has　a　sufficiently　small　target　registration　error　(TRE).　These　experimental　results　have　verified　that　the　proposed　surgical　navigation　system　can　provide　practical　guidance　for　OMS　with　satisfactory　accuracy.　©　1963-2012　IEEE.