Changes

[[File:Dog incisor occlusion.jpg|right|200px|thumb|Occlusal assessment of the incisors of a dog.<small>''© Lisa Milella 2013''</small>]]

[[File:Dog incisor occlusion.jpg|right|200px|thumb|Occlusal assessment of the incisors of a dog.<small>''© Lisa Milella 2013''</small>]]

By definition, malocclusion is an abnormality in the position of the [[:Category:Teeth - Anatomy & Physiology|teeth]]. The clinical significance of malocclusion is that it may cause discomfort and sometimes pain in the affected animal. In some cases, it may be the direct cause of severe oral pathology.  

By definition, malocclusion is an abnormality in the position of the [[:Category:Teeth - Anatomy & Physiology|teeth]]. The clinical significance of malocclusion is that it may cause discomfort and sometimes pain in the affected animal. In some cases, it may be the direct cause of severe oral pathology.  

 

===Normal Occlusion===

===Normal Occlusion===

The ideal occlusion can be described as the perfect interdigitation of the upper and lower teeth. In the normal dog, the ideal tooth positions in the arches are defined by the '''occlusal, inter-arch and interdental relationships''' of the teeth.  

The ideal occlusion can be described as the perfect interdigitation of the upper and lower teeth. In the normal dog, the ideal tooth positions in the arches are defined by the '''occlusal, inter-arch and interdental relationships''' of the teeth.  

'''Mandibular Prognathic Bite''': In the mandibular prognathic bite, often called ‘undershot’, the [[Skull and Facial Muscles - Anatomy & Physiology|mandible]] is longer than the [[maxilla]] and some or all of the mandibular teeth are rostral to their normal position. If the dental interlock prevents the mandible from growing rostrally to its full genetic potential, lateral or ventral bowing of the mandible may occur to accommodate the shortening in length. This results in an open bite and is characterized by increased space between the premolar cusp tips. In addition, the caudal angle of the mandible is caudal to the temporomandibular joint to accommodate the extra length of the mandible.

'''Mandibular Prognathic Bite''': In the mandibular prognathic bite, often called ‘undershot’, the [[Skull and Facial Muscles - Anatomy & Physiology|mandible]] is longer than the [[maxilla]] and some or all of the mandibular teeth are rostral to their normal position. If the dental interlock prevents the mandible from growing rostrally to its full genetic potential, lateral or ventral bowing of the mandible may occur to accommodate the shortening in length. This results in an open bite and is characterized by increased space between the premolar cusp tips. In addition, the caudal angle of the mandible is caudal to the temporomandibular joint to accommodate the extra length of the mandible.

 

'''Mandibular Brachygnathic Bite''': A mandibular brachygnathic bite, often called ‘overshot’, and occurs when the mandible is shorter than normal. This often results in the mandibular canine [[Category:Teeth - Anatomy & Physiology|teeth]] contacting the [[Hard Palate|palate]], causing trauma.  

'''Mandibular Brachygnathic Bite''': A mandibular brachygnathic bite, often called ‘overshot’, and occurs when the mandible is shorter than normal. This often results in the mandibular canine [[Category:Teeth - Anatomy & Physiology|teeth]] contacting the [[Hard Palate|palate]], causing trauma.  

 

'''Wry Bite''': A wry bite occurs if one side of the head grows more than the other side. In its mildest form a one-sided prognathic or brachygnathic bite develops. In more severe cases, a crooked head and bite develop with a deviated midline. An open bite may also develop in the incisor region so that the affected teeth are displaced vertically and do not occlude.  

'''Wry Bite''': A wry bite occurs if one side of the head grows more than the other side. In its mildest form a one-sided prognathic or brachygnathic bite develops. In more severe cases, a crooked head and bite develop with a deviated midline. An open bite may also develop in the incisor region so that the affected teeth are displaced vertically and do not occlude.  

 

'''Narrow Mandible''': In some animals, the mandible is too narrow with respect to the upper jaw. The result is that the lower canines impinge on the maxillary [[Gingiva|gingivae]] or the [[Hard Palate|hard palate]] instead of fitting into the diastema between the upper third incisor and upper canine on either side. The animal may not be able to close its mouth and injury to the gingivae or palatal mucosa commonly occurs. In severe, untreated cases an oronasal communication may develop over time. This condition is seen in both the primary (deciduous) and permanent dentition. Persistent mandibular primary canines will further exacerbate the condition, as the permanent mandibular canines erupt medially to their primary counterparts. The incorrect dental interlock will interfere with the normal growth in width and length of the developing mandible. The condition can also be caused by persistent primary mandibular canines in a mandible of normal width. <font color="red">(pic 7 malocclusion)</font color>

'''Narrow Mandible''': In some animals, the mandible is too narrow with respect to the upper jaw. The result is that the lower canines impinge on the maxillary [[Gingiva|gingivae]] or the [[Hard Palate|hard palate]] instead of fitting into the diastema between the upper third incisor and upper canine on either side. The animal may not be able to close its mouth and injury to the gingivae or palatal mucosa commonly occurs. In severe, untreated cases an oronasal communication may develop over time. This condition is seen in both the primary (deciduous) and permanent dentition. Persistent mandibular primary canines will further exacerbate the condition, as the permanent mandibular canines erupt medially to their primary counterparts. The incorrect dental interlock will interfere with the normal growth in width and length of the developing mandible. The condition can also be caused by persistent primary mandibular canines in a mandible of normal width. <font color="red">(pic 7 malocclusion)</font color>