puppy overshot jaw factory

This condition is most often spotted at either the first or second puppy checks or between 6 and 8 months of age as the permanent (adult) teeth erupt. Either the deciduous or permanent lower canines occlude into the soft tissues of the roof or the mouth causing severe discomfort and, possibly, oral nasal fistulae.

Secondly, the growth of the mandible is rostral from the junction of the vertical and horizontal ramus. If the lower canines are embedded in pits in the hard palate, the normal rostral growth of the mandible(s) cannot take place normally due to the dental interlock caused by the lower canines being embedded in hard palate pits. This can cause deviation of the skull laterally or ventral bowing of the mandibles (lower jaws).

Thirdly, the permanent lower canine is located lingual to the deciduous canine. This means that if the deciduous lower canines are in a poor position it is a certainty the permanent teeth will be worse. See the radiograph below. The deciduous canines are on the outside of the jaws and the developing permanent canines are seen in the jaw as small "hats". It is clear that the eruption path of the permanent canines will be directly dorsal and not buccally inclined as is normal.

The permanent successor tooth is located lingual to the deciduous tooth and wholly within the jaw at this stage. Any use of luxators or elevators on the lingual half of the deciduous tooth will cause permanent damage to the developing enamel of the permanent tooth. See the images below showing canines (and also the third incisor) with extensive damage to the enamel. The radiograph also shows how much damage can occur to the teeth - see the top canine and adjacent incisor. Some severely damaged teeth need to be extracted while other can be repaired with a bonded composite. This damage is avoidable with careful technique using an open surgical approach.

Do not try ball therapy with deciduous (puppy) teeth. There are two main reasons for this. Puppy teeth are fragile and can easily break. More importantly, the adult canine tooth bud is developing in the jaw medial to the deciduous canine tooth (see radiograph above in the puppy section). If the deciduous crown tips outwards the root will tip inwards. This will push the permanent tooth bud further medial than it already is.

The intention of the procedure is to keep the pulp alive and allow the shortened lower canines to develop normally and contribute to the strength of the lower jaws.

The advantage of this procedure is that the whole of the root and the majority of the crown remain. The strength and integrity of the lower jaw is not weakened by the procedure and long term results are very good due to the use of Mineral Trioxide Aggregate as a direct pulp dressing.

However, many owners are concerned (rightly) about the loss of the tooth and the weakness it may cause to the lower jaw(s). It is not our preferred option. This is not an easy surgical extraction and the resulting loss of the root causes a weakness in the lower jaws. This is compounded if both lower canines are removed.

Normally a composite resin bite plane is bonded onto the upper teeth (see below) with an incline cut into the sides. The lower canine makes contact with the incline when the mouth closes and, over time, the force tips the tooth buccally. This takes around four to eight weeks. The lower canine will often migrate back into a lingually displaced position when the bite plane is removed. This can occur if the tooth height of the lower canine is too short (stunted). If the lower canine is not self-retained by the upper jaw when the mouth is shut further surgery may be required.

Enzo is the Hawthorne Hills Veterinary Hospital Pet of the Month for May. Everyone knows that puppies need vaccines to keep them healthy and protected from diseases. However, it can be easy to underestimate the benefits of thorough and regular examinations when puppies are growing into adulthood. Every breed has special characteristics that make them unique and add to their appeal and sometimes there are physical changes that need to be addressed quickly. For this reason our veterinarians believe in examinations with every vaccine, especially during a puppy’s formative months.

Enzo is a short-haired Havanese and he was born with his lower jaw shorter than the upper jaw. This is called an Overbite, also referred to as an Overshot Jaw, a Parrot Mouth or Mandibular Brachygnathism. This malocclusion is a genetic change and can be seen in a number of breeds, oftentimes collie related breeds and dachshunds. Occasionally this change happens because of differences in the growth of the upper and lower jaws, and in many cases it doesn’t cause any significant problems other than cosmetically.

Dr. Robin Riedinger evaluated Enzo at his first visit when he was just 11 weeks of age and while the lower jaw was too short, there was no evidence of damage and no indication that this was causing a problem for Enzo. When there is abnormal occlusion of the teeth, it is important to monitor closely for trouble caused by the teeth being aligned improperly. Malocclusions can lead to gum injuries, puncturing of the hard palate, abnormal positioning of adjacent teeth, abnormal wear and bruising of the teeth, permanent damage and subsequent death of one or more teeth, and in the long run, premature loss of teeth. Some malocclusions can be severe enough to interfere with normal eating and drinking.

Within three weeks, when Enzo was only 3.5 months old, it was clear that our doctors would need to intervene. The left and right sides of Enzo’s upper jaw (maxilla) were growing at different rates because the lower canine teeth were being trapped by the upper canine teeth. This is called Dental Interlock. Because the teeth are ‘locked’ in place, the lower jaw cannot grow symmetrically and this creates a number of other problems. Early intervention is critical.

The solution for Dental Interlock is to extract the teeth from the shorter jaw; in this case, the lower ‘baby’ canines and thereby allow the lower jaw (mandible) to grow in the best way possible. This procedure is most effective when the Dental Interlock is discovered early and the extractions are performed quickly. In some cases, this can be as early as ten weeks of age. Dr. Riedinger consulted with a local veterinary dental specialist to confirm the treatment plan and to get advice on extracting the deciduous teeth without damaging the developing adult canines. Dental radiographs are essential to proper extraction technique and also to ensure that there are no other abnormalities below the gumline.

Once extracted, each deciduous canine tooth was about 2 centimeters long; the roots were about 1.5 centimeters. Many people are surprised to learn that the root of a dog’s tooth is so large – 2/3 to 3/4 of the tooth is below the gumline. This is one reason why it is so important to use radiographs to evaluate teeth on a regular basis, not just in a growing puppy. Adult teeth can, and frequently do, have problems that are only visible with a radiograph.

Enzo came through his procedure extremely well. He was given pain medications for comfort and had to eat canned foods and avoid chewing on his toys for the next two weeks to ensure that the gum tissue healed properly. As he continues to grow we will be monitoring how his jaw develops and Dr. Riedinger will also be watching the alignment of his adult canine teeth when they start to emerge around six months of age. Hopefully this early intervention will minimize problems for Enzo in the future.

Occlusion is defined as the relationship between the teeth of the maxilla (upper jaw) and mandibles (lower jaw). When this relationship is abnormal a malocclusion results and is also called an abnormal bite or an overbite in dogs and cats.

ninja edit: +1 pound puppy, have had a few. Now have Pug. Ultimate kids dog. Did lots of research and bought from very reputable breeder and not factory or backyard where problems end up enhanced.

An overbite is a genetic, hereditary condition where a dog"s lower jaw is significantly shorter than its upper jaw. This can also be called an overshot jaw, overjet, parrot mouth, class 2 malocclusion or mandibular brachynathism, but the result is the same – the dog"s teeth aren"t aligning properly. In time, the teeth can become improperly locked together as the dog bites, creating even more severe crookedness as the jaw cannot grow appropriately.

Dental examinations for puppies are the first step toward minimizing the discomfort and effects of an overbite. Puppies can begin to show signs of an overbite as early as 8-12 weeks old, and by the time a puppy is 10 months old, its jaw alignment will be permanently set and any overbite treatment will be much more challenging. This is a relatively narrow window to detect and correct overbites, but it is not impossible.

Small overbites often correct themselves as the puppy matures, and brushing the dog"s teeth regularly to prevent buildup can help keep the overbite from becoming more severe. If the dog is showing signs of an overbite, it is best to avoid any tug-of-war games that can put additional strain and stress on the jaw and could exacerbate the deformation.

If the dog is young enough, however, tooth extraction is generally preferred to correct an overbite. Puppies have baby teeth, and if those teeth are misaligned, removing them can loosen the jaw and provide space for it to grow properly and realign itself before the adult teeth come in. Proper extraction will not harm those adult teeth, but the puppy"s mouth will be tender after the procedure and because they will have fewer teeth for several weeks or months until their adult teeth have emerged, some dietary changes and softer foods may be necessary.

An under bite (under shot, reverse scissors bite, prognathism, class 3) occurs when the lower teeth protrude in front of the upper jaw teeth. Some short muzzled breeds (Boxers, English Bull Dogs, Shih-Tzu’s, and Lhasa Apsos) normally have an under bite, but when it occurs in medium muzzled breeds it is abnormal. When the upper and lower incisor teeth meet each other edge to edge, the occlusion is considered an even or level bite. Constant contact between upper and lower incisors can cause uneven wear, periodontal disease, and early tooth loss. Level bite is considered normal in some breeds, although it is actually an expression of under bite.

In order to fully understand bite faults, you must also understand what is correct and why. This goes beyond having the right number of the right teeth in the right places. A dog’s dental equipment is a direct inheritance from his wild carnivorous ancestor, the wolf. Dog dentition is also very similar to the wolf’s smaller cousin, the coyote. Figure 1 is a coyote skull, exhibiting a normal canine complement of teeth. Each jaw has six incisors at the front, followed by two canines, then eight premolars (four to a side). When we come to the molars, the top and bottom jaws differ. The lower jaw has six and the upper only four. A normal dog will have a total of 42 teeth.

A wolf grips with the front of his mouth. The four canine teeth puncture the prey. Their overlapping structure (see Fig. 2,combined with jaw strength, prevents the prey animal from pulling free. When catching bad guys, the idea isn’t to poke them full of holes and have them for dinner, but to hang on until the guy with the gun and the handcuffs arrives

Once the prey is down, the premolars are used for biting off chunks of meat that are swallowed hole. The 4th upper premolar and the first lower molar on each side are especially developed for this task. (Fig. 3) The carnasals are the most massive teeth in the canine jaw. They are very sharp and their location mid-way down the length of the jaw puts them at the point where jaw pressure is greatest.

All these specialized teeth are not independent entities. Their position in the jaw is determined by their function and they require a properly formed skull and lower jaw to function efficiently. The muzzle must be long enough and broad enough to accommodate the teeth in their proper locations. The animal must have sufficient bite strength to hold onto whatever it has grabbed, be it prey or perpetrator. Jaw strength comes not only from the muscles, but the shape of the skull.

Figure 4 shows the skulls of a coyote and an Australian Shepherd. Aussies have normally-shaped heads, so the shape of its skull is very similar to that of the coyote. The jaw muscles attach to the lower jaw and along the sagittal crest, the ridge of bone along the top and back of the skull. In between it passes over the zygomatic arch, or cheekbone. Wrapping around the cheekbone gives the bite much more strength than would a straight attachment from topskull to jaw. This attachment also serves to cushion the brain case from the flailing hooves of critters that don’t want to become dinner or get put in a pen.

You will note that the crest on the coyote is more pronounced than on the Aussie and its teeth are proportionally larger. This is a typical difference between domestic dogs and their wild kin. Wild canids need top efficiency from their dental equipment to survive. We have been providing food for our dogs for so long that the need for teeth as large and jaws as strong as their wolf ancestors has long passed. Fig 5 Coyote (left) and Aussie (right). Note the straighter angulation around the zygomatic arch (cheekbone) of the Aussie. Jaw strength is reduced in the dog by a less acute angle around the zygomatic arch. Note the more pronounced angle in the coyote as compared to the Aussie. (Fig. 5) This is another typical difference between wolf or coyote and dog skulls. The larger sagital crest allows for a larger, and therefore stronger, muscle. The only breed with an angulation around the zygomatic arch that approaches that of the wolf is the American Pit Bull Terrier/American Staffordshire Terrier. Pit/AmStaffs also have a relatively short jaw, giving their heads a more cat-like structure: Broad + Short + Strong Muscles = Lots of Bite Strength.

Breeds with long, narrow heads have even straighter angulation around the cheekbone, and therefore an even weaker jaw. The narrow jaw may also cause crowding of the incisors. Toy breeds with round heads often have little or no sagittal crest and very weak jaws. Short-muzzled breeds may not have room for all their teeth resulting in malocclusion, meaning they don’t come together properly. The jaws of short-muzzled breeds may also be of unequal lengths.

The more we have altered skull and jaw shape from the norm, the less efficient the mouth has become. In some cases, this isn’t particularly important. There is no reason for a Collie or a Chihuahua to bite with the strength of a wolf. However, jaws that are so short it is impossible for all the teeth to assume normal positions and undershot bites that prevent proper occlusion of the canines and incisors are neither efficient nor functional, despite volumes of breed lore justifying those abnormalities in breeds where they are considered desirable.

Now that we know what is “right,” for most breeds, anyway, and why it is right, let’s look at what can be wrong, why it is wrong and what, from a breeding standpoint, can be done about it. Most breeds with normal skull structure were originally developed to perform a function (herding, hunting, guarding, etc.) Since that structure is the most efficient it was maintained, with minor variations, in most functional breeds. Typical dental faults in these breeds are missing teeth and malocclusions. It is evident that these faults are inherited, but not a great deal is known about the specifics of that inheritance. In some breeds, some defects appear to have a simple mode of inheritance, but this is not the case across all breeds. That, plus the complex nature of dental, jaw and skull structure, indicates that in most cases the faults are likely to be polygenic, involving a group of genes.

Missing teeth obviously are not there to do the work they are intended for. They should be considered a fault. The degree of the fault can vary, depending on which teeth and how many are missing. The teeth most likely to be absent are premolars, though molars and sometimes incisors may occasionally fail to develop. Missing a first premolar, one of the smallest teeth, is much less a problem than missing an upper 4th premolar, a carnasal. The more teeth that are missing, the more faulty and less functional the bite becomes. If you have a dog with missing teeth, it should not be bred to other dogs with missing teeth or to the near relatives of such dogs. Though multiple missing teeth are not specifically faulted in either Australian Shepherd standard, you should think long and hard before using a dog that is missing more than a couple of premolars. Fig 6 Undershot bite. While the molars and some of the premolars occlude properly, the incisors and canines don"t even meet and are essentially useless. This is a farmed silver fox. Malocclusions this severe are extremely unusual in wild foxes. (photo courtesy Lisa McDonald) Malocclusions most frequently result from undershot and overshot bites, anterior crossbite and wry mouth. An undershot bite occurs when the lower jaw extends beyond the upper. This may happen because the lower jaw has grown too long or the upper jaw is too short. Selecting for shorter muzzles can lead to underbites. An overshot bite is the opposite, with the upper jaw longer than the lower. In either case, the teeth will not mesh properly. With slight over or undershot bites, the incisors may be the only teeth affected, but sometimes the difference in jaw length is extreme (Fig. 6) leaving most or all of the teeth improperly aligned against those in the opposite jaw. A bite that is this far off will result in teeth that cannot be used at all, teeth that interfere with each other, improper wear and, in some cases, damage to the soft tissues of the opposite jaw by the canines.

In wry mouth, one side of the lower jaw has grown longer than the other, skewing the end of the jaw to one side. The incisors and canines will not align properly and may interfere. It is sometimes confused with anterior crossbite, in which some, but not all, of the lower incisors will extend beyond the upper incisors but all other teeth mesh properly.

Minor malocclusions, including “dropped” incisors and crooked teeth, also occur in some dogs. Dropped incisors are center lower incisors that are shorter than normal. Sometimes they will tip slightly outward and, when viewed in profile, may give the appearance of a bite that is slightly undershot. Dropped incisors tend to run in families and are therefore hereditary. Crooked teeth may be due to crowding in a too-small or too-narrow jaw or the result of damage to the mouth, though the former is more likely.. Fig 7 Even (level) bite. This is a wolf. Some consider an even, or level, bite to be a type of malocclusion. Breed standards vary on whether they do or do not fault it. In the Australian Shepherd, the ASCA standard faults it while the AKC standard does not. There is clearly no consensus among dog people. Those who fault the even bite claim that it causes increased wear of the incisors, but there is little evidence to support this. A number of years ago the author, upon coming across a wolf with an even bite (Fig. 7), undertook a survey of wolf dentition. Teeth and jaws were inspected on 39 wolves, 9 of which were captive and the balance skulls of wild wolves trapped over a wide span of time and geography. Of the 39, 16 had even bites. This included five of the captive group, all of whom were related. Even discounting those, fully a third of the wild wolves had even bites. No structural fault is tolerated to this degree in a natural species, particularly in a feature so critical to the survival of that species.

Result = NO pups with underbites but some may be carries of "w" and/or "y" Using the same example above lets" say the sire is also carrying "w" like the dam. Results = you COULD have a puppy with a slight underbite IF mom passed her "w" AND the dad passed his "w" also. The pups with the slight underbite would be "ww"

There was no much attention paid until now to bite and teeth quality of Louisiana Catahoula. The reason is that Catahoula is the American breed and there is generally only a little attention focused on this matter. Both NALC standard, valid since 1977 (last revision in 1994) and UKC standard (2008) say that: „A scissors bite is preferred, but a level bite is acceptable. Full dentition is greatly desired, but dogs are not to be penalized for worn or broken teeth. Overshot or undershot bite are serious faults, but not disqualifying“. Catahoula is working breed and working qualities have been always more demanded than an ideal conformation and a superior bite. This is also the heritage we must deal with now.

Evaluation of European breeds and breeding was always more strict in this point of view and more focused on correct bite and full dentition, namely in breeds that preserve more or less normal skull parameters. Thus, scissor bite and full dentition is what most of breed standards demand and faults are more penalized. There is a good reason for it, because an efficient function needs a proper skull and jaw structure and teeth position. However, some anomalies were found also in wild living wolves and some faults are fairly common among various dog breeds even if not wanted.

Full dentition with all adult teeth fully erupted consist of incisors (Incisives – I), canines (Caninus – C), premolars (Praemolares – P), and molares (Molares – M). Upper and lower jaw differ in a number of molars. The teeth pattern is following:

In training and performing Schutzhund the preferred grip is a „full mouth bite“. The dog should grasp subject’s arm or leg well into its mouth, between its molars and premolars and behind the canines. This is not the way a wolf does it. A wolf grips with the front of his mouth. The four canine teeth puncture the prey and their overlapping structure combined with jaw strength prevents the prey from pulling free. Once the prey is down, the premolars are used for biting off chunk of meat. The upper P4 and the lower M1 on each side are especially developed for this task. The carnasals are the most massive teeth in the canine jaw. They are very sharp and their location mid-way down the length of the jaw puts them at the point where jaw pressure is greatest. The incisors located at the front of the mouth are specialized for delicate work. They nibble the last bits of meat off bones and are also handy for scratching an itch or pulling something bothersome out of the coat or from between the pads. Molars, other than mentioned, are flat for grinding plant matter. Wolves eat also some fruits, grasses and other plant matter and this type of food must be chewed a little to start digestive process.

All those specialized teeth have their proper position in the jaw, which is determined by their function, and they require a properly formed skull and lower jaw to function efficiently. The muzzle must be long enough and broad enough to accommodate the teeth in their proper locations. Jaw strength comes not only from the muscles, but the shape of the skull (1).

Research among wild wolves showed that the most frequent anomaly was the absence of the last molar in the lower jaw, M3. As it does not change the function, the absence of M3 should not be considered breeding deficiency also in dogs (2).

Faults of bite concern also Catahoula breed. Dog’s bite is the way his teeth fit when his upper and lower jaws are closed. The standard type is a scissor bite, in which the upper incisors just overlap and touch the lower incisors and all premolars and molars fully fit. Another possible variation is a tight scissor bite, when upper and lower incisors touch each other more then above or lower incisors are outwards of longitudinal line of bottom jaw. Catahoula has also a level (even) bite permitted by the breed standard. It is when the upper and lower incisors meet exactly, surface to surface. This means that teeth can be worn down much faster, but it does not affect actually the function and both jaws are of the same length as in previous cases. Level bite is considered normal in some breeds, including Catahoula, nevertheless,  some consider this type of bite as an expression of underbite. On the other hand, research among wild wolves showed that fully a third of animals had even bites. No structural fault is tolerated to this degree in a natural species, particularly in a feature so critical to the survival of that species.

Undershot bite is when the upper jaw is perceptibly shorter than the lower jaw and the lower incisors are located in front of the upper ones. This is typical for some breeds such as Boxer, Bulldog, Pug, Pekinese, etc. that have a shorter foreface and longer lower jaw.

Overshot bite is caused by physically longer upper jaw than the lower one and the uneveness between them is larger than 2 mm. This fault occurs more often among dog breeds nowadays. Contrary to undershot, this fault can be controlled by genetics, nutrition, environment and by mechanical forces generated by the interlock of the upper and lower teeth. Overshot  can affect the mouth’s function more than undershot and indicates usually weakness in the lower jaw.

The incidence of level bites is increasing among Catahoulas beside some missing teeth. Undershot bite is one of more serious faults that occur in this breed. There is no doubt that such faults and abnormalities are inherited. Upper and lower jaws grow independently, factors influencing a size of jaw are different from those affecting the size of teeth and various genes are involved in this process. These problems are polygenic resulting from the action of many genes, thus it is difficult to eliminate them because there is no single „bad bite“ gene.  The length of the skull and the muzzle play a role and a dominant way of a shorter skull inheritance is known. Thus, this must be taken into account in case of Catahoula, too. A combination of parents with rather different length of their muzzles is not recommended, because it could increase the incidence of faults in bites and occurrence of undershot or overshot bites among offsprings. And we have proved already that Catahoulas may vary in their muzzle size in more than one third of its length.

Inheritance and elimination of severe dental faults is difficult in breeds more numerous than Catahoula. There is impossible to exclude from breeding all individuals that show any fault due to complicated, polygenic and often recessive way of inheritance in such a rare breed. However, those showing more serious faults, such as the overshot and the undershot bite and numerous and the most important teeth missing, should be surely excluded from breeding.

There was no much attention paid until now to bite and teeth quality of Louisiana Catahoula. The reason is that Catahoula is the American breed and there is generally only a little attention focused on this matter. Both NALC standard, valid since 1977 (last revision in 1994) and UKC standard (2008) say that: „A scissors bite is preferred, but a level bite is acceptable. Full dentition is greatly desired, but dogs are not to be penalized for worn or broken teeth. Overshot or undershot bite are serious faults, but not disqualifying“. Catahoula is working breed and working qualities have been always more demanded than an ideal conformation and a superior bite. This is also the heritage we must deal with now.

Evaluation of European breeds and breeding was always more strict in this point of view and more focused on correct bite and full dentition, namely in breeds that preserve more or less normal skull parameters. Thus, scissor bite and full dentition is what most of breed standards demand and faults are more penalized. There is a good reason for it, because an efficient function needs a proper skull and jaw structure and teeth position. However, some anomalies were found also in wild living wolves and some faults are fairly common among various dog breeds even if not wanted.

Full dentition with all adult teeth fully erupted consist of incisors (Incisives – I), canines (Caninus – C), premolars (Praemolares – P), and molares (Molares – M). Upper and lower jaw differ in a number of molars. The teeth pattern is following:

In training and performing Schutzhund the preferred grip is a „full mouth bite“. The dog should grasp subject’s arm or leg well into its mouth, between its molars and premolars and behind the canines. This is not the way a wolf does it. A wolf grips with the front of his mouth. The four canine teeth puncture the prey and their overlapping structure combined with jaw strength prevents the prey from pulling free. Once the prey is down, the premolars are used for biting off chunk of meat. The upper P4 and the lower M1 on each side are especially developed for this task. The carnasals are the most massive teeth in the canine jaw. They are very sharp and their location mid-way down the length of the jaw puts them at the point where jaw pressure is greatest. The incisors located at the front of the mouth are specialized for delicate work. They nibble the last bits of meat off bones and are also handy for scratching an itch or pulling something bothersome out of the coat or from between the pads. Molars, other than mentioned, are flat for grinding plant matter. Wolves eat also some fruits, grasses and other plant matter and this type of food must be chewed a little to start digestive process.

All those specialized teeth have their proper position in the jaw, which is determined by their function, and they require a properly formed skull and lower jaw to function efficiently. The muzzle must be long enough and broad enough to accommodate the teeth in their proper locations. Jaw strength comes not only from the muscles, but the shape of the skull (1).

Research among wild wolves showed that the most frequent anomaly was the absence of the last molar in the lower jaw, M3. As it does not change the function, the absence of M3 should not be considered breeding deficiency also in dogs (2).

Faults of bite concern also Catahoula breed. Dog’s bite is the way his teeth fit when his upper and lower jaws are closed. The standard type is a scissor bite, in which the upper incisors just overlap and touch the lower incisors and all premolars and molars fully fit. Another possible variation is a tight scissor bite, when upper and lower incisors touch each other more then above or lower incisors are outwards of longitudinal line of bottom jaw. Catahoula has also a level (even) bite permitted by the breed standard. It is when the upper and lower incisors meet exactly, surface to surface. This means that teeth can be worn down much faster, but it does not affect actually the function and both jaws are of the same length as in previous cases. Level bite is considered normal in some breeds, including Catahoula, nevertheless,  some consider this type of bite as an expression of underbite. On the other hand, research among wild wolves showed that fully a third of animals had even bites. No structural fault is tolerated to this degree in a natural species, particularly in a feature so critical to the survival of that species.

Undershot bite is when the upper jaw is perceptibly shorter than the lower jaw and the lower incisors are located in front of the upper ones. This is typical for some breeds such as Boxer, Bulldog, Pug, Pekinese, etc. that have a shorter foreface and longer lower jaw.

Overshot bite is caused by physically longer upper jaw than the lower one and the uneveness between them is larger than 2 mm. This fault occurs more often among dog breeds nowadays. Contrary to undershot, this fault can be controlled by genetics, nutrition, environment and by mechanical forces generated by the interlock of the upper and lower teeth. Overshot  can affect the mouth’s function more than undershot and indicates usually weakness in the lower jaw.

The incidence of level bites is increasing among Catahoulas beside some missing teeth. Undershot bite is one of more serious faults that occur in this breed. There is no doubt that such faults and abnormalities are inherited. Upper and lower jaws grow independently, factors influencing a size of jaw are different from those affecting the size of teeth and various genes are involved in this process. These problems are polygenic resulting from the action of many genes, thus it is difficult to eliminate them because there is no single „bad bite“ gene.  The length of the skull and the muzzle play a role and a dominant way of a shorter skull inheritance is known. Thus, this must be taken into account in case of Catahoula, too. A combination of parents with rather different length of their muzzles is not recommended, because it could increase the incidence of faults in bites and occurrence of undershot or overshot bites among offsprings. And we have proved already that Catahoulas may vary in their muzzle size in more than one third of its length.

Inheritance and elimination of severe dental faults is difficult in breeds more numerous than Catahoula. There is impossible to exclude from breeding all individuals that show any fault due to complicated, polygenic and often recessive way of inheritance in such a rare breed. However, those showing more serious faults, such as the overshot and the undershot bite and numerous and the most important teeth missing, should be surely excluded from breeding.

There was no much attention paid until now to bite and teeth quality of Louisiana Catahoula. The reason is that Catahoula is the American breed and there is generally only a little attention focused on this matter. Both NALC standard, valid since 1977 (last revision in 1994) and UKC standard (2008) say that: „A scissors bite is preferred, but a level bite is acceptable. Full dentition is greatly desired, but dogs are not to be penalized for worn or broken teeth. Overshot or undershot bite are serious faults, but not disqualifying“. Catahoula is working breed and working qualities have been always more demanded than an ideal conformation and a superior bite. This is also the heritage we must deal with now.

Evaluation of European breeds and breeding was always more strict in this point of view and more focused on correct bite and full dentition, namely in breeds that preserve more or less normal skull parameters. Thus, scissor bite and full dentition is what most of breed standards demand and faults are more penalized. There is a good reason for it, because an efficient function needs a proper skull and jaw structure and teeth position. However, some anomalies were found also in wild living wolves and some faults are fairly common among various dog breeds even if not wanted.

Full dentition with all adult teeth fully erupted consist of incisors (Incisives – I), canines (Caninus – C), premolars (Praemolares – P), and molares (Molares – M). Upper and lower jaw differ in a number of molars. The teeth pattern is following:

In training and performing Schutzhund the preferred grip is a „full mouth bite“. The dog should grasp subject’s arm or leg well into its mouth, between its molars and premolars and behind the canines. This is not the way a wolf does it. A wolf grips with the front of his mouth. The four canine teeth puncture the prey and their overlapping structure combined with jaw strength prevents the prey from pulling free. Once the prey is down, the premolars are used for biting off chunk of meat. The upper P4 and the lower M1 on each side are especially developed for this task. The carnasals are the most massive teeth in the canine jaw. They are very sharp and their location mid-way down the length of the jaw puts them at the point where jaw pressure is greatest. The incisors located at the front of the mouth are specialized for delicate work. They nibble the last bits of meat off bones and are also handy for scratching an itch or pulling something bothersome out of the coat or from between the pads. Molars, other than mentioned, are flat for grinding plant matter. Wolves eat also some fruits, grasses and other plant matter and this type of food must be chewed a little to start digestive process.

All those specialized teeth have their proper position in the jaw, which is determined by their function, and they require a properly formed skull and lower jaw to function efficiently. The muzzle must be long enough and broad enough to accommodate the teeth in their proper locations. Jaw strength comes not only from the muscles, but the shape of the skull (1).

Research among wild wolves showed that the most frequent anomaly was the absence of the last molar in the lower jaw, M3. As it does not change the function, the absence of M3 should not be considered breeding deficiency also in dogs (2).

Faults of bite concern also Catahoula breed. Dog’s bite is the way his teeth fit when his upper and lower jaws are closed. The standard type is a scissor bite, in which the upper incisors just overlap and touch the lower incisors and all premolars and molars fully fit. Another possible variation is a tight scissor bite, when upper and lower incisors touch each other more then above or lower incisors are outwards of longitudinal line of bottom jaw. Catahoula has also a level (even) bite permitted by the breed standard. It is when the upper and lower incisors meet exactly, surface to surface. This means that teeth can be worn down much faster, but it does not affect actually the function and both jaws are of the same length as in previous cases. Level bite is considered normal in some breeds, including Catahoula, nevertheless,  some consider this type of bite as an expression of underbite. On the other hand, research among wild wolves showed that fully a third of animals had even bites. No structural fault is tolerated to this degree in a natural species, particularly in a feature so critical to the survival of that species.

Undershot bite is when the upper jaw is perceptibly shorter than the lower jaw and the lower incisors are located in front of the upper ones. This is typical for some breeds such as Boxer, Bulldog, Pug, Pekinese, etc. that have a shorter foreface and longer lower jaw.

Overshot bite is caused by physically longer upper jaw than the lower one and the uneveness between them is larger than 2 mm. This fault occurs more often among dog breeds nowadays. Contrary to undershot, this fault can be controlled by genetics, nutrition, environment and by mechanical forces generated by the interlock of the upper and lower teeth. Overshot  can affect the mouth’s function more than undershot and indicates usually weakness in the lower jaw.

The incidence of level bites is increasing among Catahoulas beside some missing teeth. Undershot bite is one of more serious faults that occur in this breed. There is no doubt that such faults and abnormalities are inherited. Upper and lower jaws grow independently, factors influencing a size of jaw are different from those affecting the size of teeth and various genes are involved in this process. These problems are polygenic resulting from the action of many genes, thus it is difficult to eliminate them because there is no single „bad bite“ gene.  The length of the skull and the muzzle play a role and a dominant way of a shorter skull inheritance is known. Thus, this must be taken into account in case of Catahoula, too. A combination of parents with rather different length of their muzzles is not recommended, because it could increase the incidence of faults in bites and occurrence of undershot or overshot bites among offsprings. And we have proved already that Catahoulas may vary in their muzzle size in more than one third of its length.

Inheritance and elimination of severe dental faults is difficult in breeds more numerous than Catahoula. There is impossible to exclude from breeding all individuals that show any fault due to complicated, polygenic and often recessive way of inheritance in such a rare breed. However, those showing more serious faults, such as the overshot and the undershot bite and numerous and the most important teeth missing, should be surely excluded from breeding.

There was no much attention paid until now to bite and teeth quality of Louisiana Catahoula. The reason is that Catahoula is the American breed and there is generally only a little attention focused on this matter. Both NALC standard, valid since 1977 (last revision in 1994) and UKC standard (2008) say that: „A scissors bite is preferred, but a level bite is acceptable. Full dentition is greatly desired, but dogs are not to be penalized for worn or broken teeth. Overshot or undershot bite are serious faults, but not disqualifying“. Catahoula is working breed and working qualities have been always more demanded than an ideal conformation and a superior bite. This is also the heritage we must deal with now.

Evaluation of European breeds and breeding was always more strict in this point of view and more focused on correct bite and full dentition, namely in breeds that preserve more or less normal skull parameters. Thus, scissor bite and full dentition is what most of breed standards demand and faults are more penalized. There is a good reason for it, because an efficient function needs a proper skull and jaw structure and teeth position. However, some anomalies were found also in wild living wolves and some faults are fairly common among various dog breeds even if not wanted.

Full dentition with all adult teeth fully erupted consist of incisors (Incisives – I), canines (Caninus – C), premolars (Praemolares – P), and molares (Molares – M). Upper and lower jaw differ in a number of molars. The teeth pattern is following:

In training and performing Schutzhund the preferred grip is a „full mouth bite“. The dog should grasp subject’s arm or leg well into its mouth, between its molars and premolars and behind the canines. This is not the way a wolf does it. A wolf grips with the front of his mouth. The four canine teeth puncture the prey and their overlapping structure combined with jaw strength prevents the prey from pulling free. Once the prey is down, the premolars are used for biting off chunk of meat. The upper P4 and the lower M1 on each side are especially developed for this task. The carnasals are the most massive teeth in the canine jaw. They are very sharp and their location mid-way down the length of the jaw puts them at the point where jaw pressure is greatest. The incisors located at the front of the mouth are specialized for delicate work. They nibble the last bits of meat off bones and are also handy for scratching an itch or pulling something bothersome out of the coat or from between the pads. Molars, other than mentioned, are flat for grinding plant matter. Wolves eat also some fruits, grasses and other plant matter and this type of food must be chewed a little to start digestive process.

All those specialized teeth have their proper position in the jaw, which is determined by their function, and they require a properly formed skull and lower jaw to function efficiently. The muzzle must be long enough and broad enough to accommodate the teeth in their proper locations. Jaw strength comes not only from the muscles, but the shape of the skull (1).

Research among wild wolves showed that the most frequent anomaly was the absence of the last molar in the lower jaw, M3. As it does not change the function, the absence of M3 should not be considered breeding deficiency also in dogs (2).

Faults of bite concern also Catahoula breed. Dog’s bite is the way his teeth fit when his upper and lower jaws are closed. The standard type is a scissor bite, in which the upper incisors just overlap and touch the lower incisors and all premolars and molars fully fit. Another possible variation is a tight scissor bite, when upper and lower incisors touch each other more then above or lower incisors are outwards of longitudinal line of bottom jaw. Catahoula has also a level (even) bite permitted by the breed standard. It is when the upper and lower incisors meet exactly, surface to surface. This means that teeth can be worn down much faster, but it does not affect actually the function and both jaws are of the same length as in previous cases. Level bite is considered normal in some breeds, including Catahoula, nevertheless,  some consider this type of bite as an expression of underbite. On the other hand, research among wild wolves showed that fully a third of animals had even bites. No structural fault is tolerated to this degree in a natural species, particularly in a feature so critical to the survival of that species.

Undershot bite is when the upper jaw is perceptibly shorter than the lower jaw and the lower incisors are located in front of the upper ones. This is typical for some breeds such as Boxer, Bulldog, Pug, Pekinese, etc. that have a shorter foreface and longer lower jaw.

Overshot bite is caused by physically longer upper jaw than the lower one and the uneveness between them is larger than 2 mm. This fault occurs more often among dog breeds nowadays. Contrary to undershot, this fault can be controlled by genetics, nutrition, environment and by mechanical forces generated by the interlock of the upper and lower teeth. Overshot  can affect the mouth’s function more than undershot and indicates usually weakness in the lower jaw.

The incidence of level bites is increasing among Catahoulas beside some missing teeth. Undershot bite is one of more serious faults that occur in this breed. There is no doubt that such faults and abnormalities are inherited. Upper and lower jaws grow independently, factors influencing a size of jaw are different from those affecting the size of teeth and various genes are involved in this process. These problems are polygenic resulting from the action of many genes, thus it is difficult to eliminate them because there is no single „bad bite“ gene.  The length of the skull and the muzzle play a role and a dominant way of a shorter skull inheritance is known. Thus, this must be taken into account in case of Catahoula, too. A combination of parents with rather different length of their muzzles is not recommended, because it could increase the incidence of faults in bites and occurrence of undershot or overshot bites among offsprings. And we have proved already that Catahoulas may vary in their muzzle size in more than one third of its length.

Inheritance and elimination of severe dental faults is difficult in breeds more numerous than Catahoula. There is impossible to exclude from breeding all individuals that show any fault due to complicated, polygenic and often recessive way of inheritance in such a rare breed. However, those showing more serious faults, such as the overshot and the undershot bite and numerous and the most important teeth missing, should be surely excluded from breeding.

Undershot is a class III malocclusion that is also referred to as mandibular prognathism, maxillary brachygnathism, mandibular mesioclusion, or an underbite. This malocclusion is characterized by a shorter upper jaw and a longer lower jaw, resulting in lower teeth that are in front of the upper teeth. While this condition is normal for some breeds, such as Bulldogs, in many breeds it is unusual. An undershot jaw occurs when the lower jaw grows faster than normal and becomes longer than the upper jaw, and is usually evident around 8 weeks of age in puppies. This misalignment can cause soft tissue trauma, such as to the lips. When the incisors meet instead of fitting next to each other, it is called a level bite. When the malocclusion causes the lower incisors to be placed in front of the upper incisors, it is called a reverse scissors bite.

The cause of overshot and undershot jaws in dogs relate to the increased or decreased rate of growth of the upper and lower jaws in relation to one another. This can occur due to a: Genetic disorder Trauma; Systemic infection ;Nutritional disorder; Endocrine disorder; Abnormal setting of puppy teeth; Early or late loss of puppy teeth.

After a quick physical exam, your vet may have to sedate your dog in order to perform a thorough oral exam. This will assess your dog’s skull type and teeth location in relation to the teeth on the opposite jaw. Often, the placement of the upper and lower incisors in relation to one another can determine what type of malocclusion your dog has. Your vet will note any areas of trauma due to teeth striking those areas, and any cysts, tumors, abscesses, or remaining puppy teeth that may be present. A dental X-ray can also help to assess the health of the jaws and teeth. These diagnostic methods will lead to a diagnosis of an overshot or undershot jaw in your dog.

Treatment of a jaw misalignment will depend on the severity of the condition. If your dog has a misalignment, but can still bite and chew food without problems, no treatment may be needed. If the misalignment is caught early in a puppy’s life, it may only be temporary and may correct itself over time. However, there are times when intervention may be needed. If your puppy’s teeth are stopping the normal growth of his jaws, then surgery to remove those puppy teeth may be performed. This may allow the jaws to continue to grow, but will not make them grow. For older dogs who are experiencing pain and trauma due to misaligned jaws and teeth, oral surgery is generally performed to extract teeth that are causing trauma, to move teeth so that they fit, or to create space for a misaligned tooth to occupy. Other therapies include crown reductions or braces.

If your dog is genetically programmed to have an overshot or undershot jaw, intervention can help, but will not slow or stop the abnormal growth of either jaw. Prevent jaw misalignments in puppies by not breeding dogs who have overshot or undershot jaws.

“Penny” is a 2 month old Shih Tzu cross that was having problems eating hard food. When she came in for her dog grooming and puppy shots, one of her bottom canine teeth was in the wrong position and was poking a hole in her palate! The baby tooth is not only very sharp and causing Penny a lot of discomfort, but it is essentially locking her bottom jaw into place. Jaws have growth plates just like any other bone. When the jaw is locked into position every time Penny closes her mouth, the growth plate is also locked into position, and the jaw is unable to grow to its proper length.

You can download this article on puppy teeth problems as an ebook free of charge (and no email required) through the link below. This comprehensive article covers such topics as malocclusions, overbites, underbites and base narrow canines in dogs. Special emphasis is placed on early intervention – a simple procedure such as removing retained puppy teeth can save many problems later on.

The ‘carnassial’ teeth are the large specialised pair of teeth towards the back of the mouth on each side, which work together like the blades of a pair of scissors. The upper carnassial is the fourth premolar, while the lower one is the first molar The upper jaw is the maxilla, and the lower jaw is the mandible.

Malocclusion is the termed used for an abnormal bite. This can arise when there are abnormalities in tooth position, jaw length, or both. The simplest form of malocclusion is when there are rotated or crowded teeth. These are most frequently seen in breeds with shortened muzzles, where 42 teeth need to be squeezed into their relatively smaller jaws. Affected teeth are prone to periodontal disease (inflammation of the tissues supporting the teeth, including the gums and jawbone), and early tooth loss.

Class II malocclusions (‘overshot’) arise when the lower jaw is relatively short compared with the upper jaw. This type of occlusion is NEVER considered normal and can result in significant and painful trauma to the upper gums, hard palate and teeth from the lower canines and incisors.

Class III malocclusions (‘undershot’, ‘prognathism’) occur when the lower jaw is relatively long compared with the upper jaw. The upper incisors may either meet the lower ones (level bite) or sit behind them (reverse scissor bite). While this is very common, and considered normal for some breeds, it can cause problems if the upper incisors are hitting the floor of the mouth or the lower teeth (similar problems to rostral crossbite). If the lower canines are striking the upper incisors, the accelerated dental wear often results in dead or broken teeth.

Class IV malocclusions (‘wry bite’) occur when there is a deviation of one or both jaws in any direction (up and down, side to side or front to back). These may be associated with mild to severe problems with chewing, damage to teeth and oral tissues, and chronic pain.

Normal development of the teeth and jaws is largely under genetic control, however environmental forces such as nutrition, trauma, dental interlock and other mechanical forces can also affect the final outcome.

Most malocclusions involving jaw length (skeletal) abnormalities are genetic in origin. We need to recognise this as it has enormous implications if you are planning to breed, as once a malocclusion is established in a line, it can be heartbreaking work to try and breed it back out.

The exact genes involved in jaw development are not yet well understood. We do know that the upper and lower jaws grow at different rates, at different times, and are under separate genetic control. In fact, the growth of one only affects the growth of the other if there is physical contact between them via the teeth. This contact is called ‘dental interlock’.

When the upper and lower teeth are locked against each other, the independent growth of either jaw is severely limited. This can occasionally work in the dog’s favour, for example if the lower jaw is slightly long compared with the upper jaw, the corner incisors may lock the lower canines in position behind them, limiting any further growth spurts of the lower jaw.

However, in many cases, dental interlock interferes with jaw development in a negative way. A classic example we see regularly in our practice is when a young puppy has a class II malocclusion (relatively short lower jaw) and the lower deciduous canines are locked behind the upper deciduous canines, or trapped in the tissues of the hard palate. In these cases, even if the lower jaw was genetically programmed to catch up to the upper jaw, it cannot physically do so.

Extraction of these teeth will not stimulate jaw growth, but will allow it to occur if nature (ie genetic potential) permits. It also relieves the painful trauma caused by the teeth to the hard palate whenever the pup closes its mouth (and we all know how sharp those baby teeth are!!). More information on interceptive orthodontics can be found later in this book.

It is crucial to remember that genetic malocclusions are not usually seen in all puppies in an affected litter as they are not dominant traits. Puppies can carry the genes contributing to genetic faults without showing any physical signs at all. If an affected puppy is noted, extreme caution should be exerted when planning future breeding from the parents and siblings, and neutering of the affected puppy is strongly recommended.

Although diet often gets the blame for development of malocclusions, the role of nutrition is actually much less significant than is often believed. Obviously gross dietary deficiencies will affect bone and tooth development, for example severe calcium deficiency can lead to ‘rubber jaw’. However, the vast majority of puppies are on balanced, complete diets and have adequate nutrient intake for normal bone and tooth development.

One myth I have heard repeated by several owners is that strict limitation of a puppy’s dietary intake can be used to correct an undershot jaw. This is simply NOT true. Limiting calories will NOT slow the growth of the lower jaw relative to the upper jaw (both jaws receive the same nutrient supply). Such a practice is not only ineffective, it can be detrimental for the puppy’s overall growth and development.

Trauma, infection and other mechanical forces may affect growth and development of the jaws and teeth. Developing tooth buds are highly sensitive to inflammation and infection, and malformed teeth may erupt into abnormal positions (or not erupt at all!). Damage to developing teeth can also occur if the jaw is fractured.

Retained or persistent deciduous (puppy) teeth can also cause malocclusions by forcing the erupting adult teeth into an abnormal position. As previously mentioned, this may be a genetic trait, but can also occur sporadically in any breed of dog.

A full bite assessment can help differentiate between malocclusions which are due to shifting of teeth alone, and those which have an underlying genetic basis. Contact me if you would like to arrange a bite assessment for your puppy

Extraction of lower canine teeth – the roots of these teeth make up about 70% of the front of the jaw, and so there is a potential risk of jaw fracture associated with their removal. Some dogs also use these teeth to keep the tongue in position, so the tongue may hang out after extraction. ‡

This is the term we use when we remove deciduous teeth to alter the development of a malocclusion. The most common form of this is when we relieve dental interlock that is restricting normal jaw development. Such intervention does not make the jaw grow faster, but will allow it to develop to its genetic potential by removing the mechanical obstruction.

Extraction of deciduous lower canines and incisors in a puppy with an overbite releases the dental interlock and gives the lower jaw the time to ‘catch up’ (if genetically possible).

As jaw growth is rapid in the first few months of life, it is critical to have any issues assessed and addressed as soon as they are noticed, to give the most time for any potential corrective growth to occur before the adult teeth erupt and dental interlock potentially redevelops. Ideally treatment is performed from eight weeks of age.

Extraction of deciduous teeth is not necessarily as easy as many people imagine. These teeth are very thin-walled and fragile, with long narrow roots extending deep into the jaw. The developing adult tooth bud is sitting right near the root, and can be easily damaged. High detail intraoral (dental) xrays can help us locate these tooth buds, so we can reduce the risk of permanent trauma to them. Under no circumstances should these teeth be snapped or clipped off as this is not only inhumane, but likely to cause serious infection and ongoing problems below the surface.

Sometimes a puppy may be missing one or more teeth. In the absence of trauma (which is usually apparent for other reasons!), there are a couple of things that may be going on.

Sometimes, the tooth will be in a favourable position but caught behind a small rim of jawbone – again early surgical intervention may be successful in relieving this obstruction. If the tooth is in an abnormal position or deformed, it may be unable to erupt even with timely surgery.

Impacted or embedded teeth should be removed if they are unable to erupt with assistance. If left in the jaw, a dentigerous cyst may form around the tooth. These can be very destructive as they expand and destroy the jawbone and surrounding teeth. Occasionally these cysts may also undergo malignant transformation (ie develop into cancer).

Firstly, if there are two teeth in one socket (deciduous and adult), the surrounding gum cannot form a proper seal between these teeth, leaving a leaky pathway for oral bacteria to spread straight down the roots of the teeth into the jawbone. Trapping of plaque, food and debris between the teeth also promotes accelerated periodontal disease. This not only causes discomfort and puts the adult tooth at risk of early loss, but allows infection to enter the bloodstream and affect the rest of the body.

Puppies play rough, chew whatever they can get hold of, and have tiny teeth with very thin walls. Therefore fractures will sometimes occur. A common misconception is that broken deciduous teeth can be left until they fall out. Unfortunately this is NOT true. From the puppy’s point of view, broken teeth HURT, just as they do in children. Anyone who has had a bad toothache would agree that even a few weeks is a long time to wait for relief!

Broken teeth also become infected, with bacteria from the mouth gaining free passage through the exposed pulp chamber inside the tooth, deep into the underlying jawbone. This is not only painful, but can lead to irreversible damage to the developing adult tooth bud, which may range from defects in the enamel (discoloured patches on the tooth) through to arrested development and inability to erupt. The infection can also spread through the bloodstream to the rest of the body. Waiting for the teeth to fall out is NOT a good option!