85% of ectopic maxillary canines are palatally located•Risk of resorption of lateral incisor rootRisk of resorption of lateral incisor root is greater if ectopic canine is palatal (approx 12% affected)•Extraction of 1ocanine may improve path of eruption of 2ocanineCarter NE. in: Paediatric Dentistry (3rded). Welbury RR, et al. Oxford University Press (2005).
Vertical parallax to locate impacted caninesX-ray tube at 0-5oX-ray tube at +60oMnemonics:Mnemonics:•““Your Your palpal moves with you”moves with you”(Object located palatally will appear to “move” in the same direction as the X ray tube)•““SLOB rule: Same = Lingual, Opposite = Buccal”SLOB rule: Same = Lingual, Opposite = Buccal”(Object located lingually / palatally will appear to “move” in the same direction as the X- ray tube; object located buccally will appear to “move” in the direction opposite to that of the X-ray tube)
SPACE LOSSSPACE LOSSresulting from caries resulting from caries and and early loss of primary teethearly loss of primary teeth
Early loss of primary teethEarly loss of primary teeth•Early loss generally worsens crowding•Usually the distal tooth drifts forwardIncisors: Space loss unlikely once Cs eruptedCanines: Balance extractionsFirst molars: Space maintain/balance if 6’s not fully erupted and in Class I occlusionSecond Molars: Space maintain
Ortho considerations prior to extractionsOrtho considerations prior to extractions•Age (dental development) of patientAge (dental development) of patient•Degree of crowding Degree of crowding –Conserve lower arch in Cl. II div 2Conserve lower arch in Cl. II div 2–Conserve upper arch in Cl. IIIConserve upper arch in Cl. III•Caries statusCaries status•Presence/absence of other teeth (e.g. 8s)Presence/absence of other teeth (e.g. 8s)•Type of malocclusionType of malocclusion
Space loss•Space loss:–Maxilla > mandible–Worse prior to eruption of 6s–Loss of E > loss of D–Crowded arches–No opposing tooth•? Use of space maintainersLaing E, Laing E, et al. et al. Space maintenanceSpace maintenanceInt J Paediatr Dent2009; 19: 155-1622009; 19: 155-162
Early loss of primary molars may lead to problems:•Crowding•Midline shift•Ectopic eruption•Dental impaction•Crossbite formationLaing E, et al.et al.Int J Paediatr DentInt J Paediatr Dent2009; 19: 155-1622009; 19: 155-162 Crowding and impaction of 35 Resulting from early loss of 75
Space maintainersSpace maintainersAdvantagesAdvantages•Retain space, so overcoming problems of loss of arch length•May lessen need for later complex ortho treatmentDisadvantagesDisadvantages•Plaque retentive•May contribute to gingivitis•May predispose to caries•May impinge on soft tissues•May interfere with eruption of adjacent teeth•May fracture/become dislodged•Compliance problems/loss of appliance (removable SM)•Regular review required The best space maintainer is a well-maintained primary toothLaing E, Laing E, et al.Int J Paediatr Dent2009; 19: 155-1622009; 19: 155-162