Malocclusion

Malocclusion by George Jones

Malocclusion in it's most simplistic terms is "bad bite." Within the standard for each breed is specifications as to what is the acceptable parameters for bite. For most breeds the scissors bite is ideal.
Scissors bite is one in which the upper incisors just overlap and touch the lower incisors.
There are 6 primary types of malocclusion:
A) Overbite
(overshot, parrot mouth, class two, overjet, mandibular branchygnathism)
In this condition the upper jaw is longer than the lower jaw. There is a gap between the upper and lower incisors when the mouth is closed. Some puppies that are born with an overbite might self-correct if the bite is no larger than the head of a wooden match. In most breeds of dog the bites are "set" by the time a puppy is ten months old. An overshot bite will rarely improve after the puppy reaches ten months.
Some puppies with overshot bites will experience difficulties when their permanent teeth come in. Due to the increased size of the permanent teeth, as they come in they can damage the soft parts of the mouth. Overbites should be carefully watched, as sometimes extractions become necessary.
B) Underbite
(undershot, reverse scissors bite, class 3, prognathism)
In this condition the lower jaw is longer than the upper jaw. If the upper and lower jaw meet each other edge to edge, the bite is referred to as an even or level bite. In some breeds of dog an underbite is the correct bite. Check your breed standard.
C) Anterior crossbite
In this case both sides of the bite close normally, however one or more of the lower incisors are positioned in front of the upper incisors. This is the most common of all malocclusions. Anterior crossbite is not considered to be hereditary in nature and is usually correctable.
D) Posterior crossbite
Posterior crossbite is the condition in which one or more of the lower premolars overlaps the upper premolars. This conditions is a rare occurrence, appearing predominantly in larger nosed dog breeds.
E) Wry mouth
Of the malocclusions this is the worst form. A dog with wry mouth has one side of the jaw that is longer than the other side. This problem can lead to difficulty in grasping and chewing food. Wry mouth appears to be hereditary and correction is difficult (if possible).
F) Base narrow canines
The lower canine teeth project inward in relation to the jaw. These misaligned canine can damage the upper palate. This condition is often due to retained baby teeth and usually can be corrected.

Return to Medical Index
Return to Bark Bytes Home

All rights reserved. No part of this publication shall be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording or otherwise, without written permission from Bark Bytes, Inc.