Occlusion CTVT pgs 1220 1222 Orthodontics studies the

Occlusion CTVT pgs 1220 -1222 � Orthodontics studies the way in which the teeth meet each other. � Occlusion- the normal position of the teeth in the mouth Easier to assess when the mouth is closed In normal occlusion, teeth come together in a _____ bite. Should be assessed during the initial oral examination

Scissors Bite

Scissors Bite Evaluation �Three locations: 1. The mandibular canine tooth resides in the ________ space of the maxillary third incisor and the maxillary canine. 2. The maxillary fourth premolar occludes _____ to the mandibular first molar. � These two teeth together, constitute the ______ teeth. 3. Maxillary incisors are slightly ______ to the mandibular incisors. � Mandibular incisors should rest on the ______ of the maxillary incisors

Normal Scissors Occlusion: When all three locations are normal- the premolars interdigitate toward the opposing interdental space.

Malocclusion 1258 -60 “Orthodontic Probs” �Malocclusion is an abnormality in the way the teeth occlude Can occur in any of the three head shapes, but is more common in _________ breeds.

Malocclusions �There are four classes of malocclusions. Class I- one or more teeth is in an abnormal position � Easily fixed with orthodontic correction OR not needed � Examples: Rostral Cross-bite and Caudal Cross-bite Class II-IV are skeletal malocclusions due to differing jaw lengths �Why are we concerned with maloccluded teeth?

Class I: Rostral Cross-bite �Maxillary incisors are ____ to the mandibular incisors. Canines are in their normal location! �Possible causes: �Treatment: Orthodontic movement or extraction of the abnormal teeth. Treat vs. not treat?

Rostral Cross-bite

Rostral Cross-bite

Class I: Caudal Cross-bite �Maxillary premolars/molars are positioned _______ to the mandibular opposing premolars/molars �Occurs occasionally in ______ breeds �Treatment:

Class I: Lance Canine �Maxillary canine tooth is displaced _____. Eastcott referrals

Class II: Mandibular Distoclusion �Maxillary prognathism OR mandibular brachygnathism �Mandible is _____ than normal Referred to as “overshot” �Never an accepted standard! Concerns: Debris is not removed from teeth during normal chewing Hard palate trauma

Class III: Mandibular Mesioclusion � Mandibular prognathism OR maxillary brachygnathism � Mandible is _____ than normal Referred to as “undershot” �The mandibular canines sit _______ to the maxillary 3 rd incisors Concerns: Teeth lose some of their self-cleaning ability Maxillary teeth can traumatize soft tissue *Accepted as normal in _______ breeds!

Mandibular Mesioclusion

Mandibular Mesioclusion

Wry bite �Unilateral _____ of the jaw �A one-sided brachygnathic bite forms Jaw curves toward the shorter side In more severe cases, animal appears to have a crooked head

What Do You See Here?

Persistent Deciduous Teeth CTVT pg 1260 �A deciduous tooth that remains after the permanent tooth has already erupted �Most common in the ______ breeds Concerns: 1. Interfere with normal eruption pathway of permanent teeth ______ & ______ Early detection is key! When should this be discussed with client? 2. Are a reservoir for debris ________

What numbers are these persistent teeth? Describe the spatial positioning of the permanent canine:

Persistent Deciduous Teeth Treatment: Interceptive Orthodontics Tooth should be removed as a whole Possible complications: Iatrogenic damage to: � permanent tooth � surrounding soft tissue

Polydontia �Supernumerary teeth should not be confused with persistent deciduous teeth. These are extra ______ teeth Concerns: �Crowding �Attrition Treatment: extraction

Hypodontia �One or more teeth do not form in the dental arcade. �Un-errupted permanent tooth or hypodontia? How do you confirm? �If permanent tooth is absent, a deciduous tooth can remain in the arch for months to years. �No treatment necessary