The Lhasa muzzle is a compromise between shortening to conserve heat and the requirement for a nasal chamber of adequate length to warm and humidify the inspired air. At one third of the total head length, it falls midway between the normal 1:1 head of the wolf type, and the extremely foreshortened heads of some ornamental breeds. The bite is the one which most often goes with this slightly modified head. The original standard adopted in both Britain and the USA in 1934 stated that the "mouth is level, otherwise slightly undershot preferred". The statement "mouth level" means that the upper and lower jaws are equal in length. The tooth occlusion in this situation will be either level, level-scissor or reverse scissor. (The "level-scissor" is a bite where the jaws are level, but the upper teeth overlap the lower. It is not a true scissor bite as in the German Shepherd, which is a true scissor mouth.) A level mouthed dog will have a typical "blunt" muzzle regardless of the dental occlusion... (In fact a "level mouth" would be a level mouth even with no teeth at all.) A secondary choice would be slightly undershot.

For quite a number of years the AKC in its official "Complete Dog Book" defined level mouth as "the normal canine mouth" (ie scissor bite). In 1978, the American standard changed the word "mouth" to the word "bite", thereby drastically altering the meaning. A level "mouth" refers to the jaws being level, which means the teeth can be level, scissor, or reverse scissor, whereas level "bite" means only one thing: a "pincer" bite. This change of one word has brought about the present confusion regarding level and scissor bites. The misguided change in the words "mouth" to "bite" caused a level-scissor bite, which was perfectly acceptable as a "level mouth" in 1977, to be unacceptable in 1978.

The English Standard has been altered twice since 1934. The English have recently opted for a more "Oriental" type face with an undershot, turned up muzzle, seemingly without regard to the fact that the Lhasa is not an "oriental", but a central Asian breed. The latest English change in the standard, while accepted by FCI, was rejected by their cousins in Australia. The new English standard of bite, which described the teeth as being in a straight line between the canines, was one of the major objections by the Australians. (Teeth in a straight line is a characteristic of the Bulldog, the Pekinese and several similar breeds, but not of the Lhasa Apso.).

The adoption of these changes apparently ignored the fact that the majority of the original dogs which came from the Himalaya as gifts from the Dalai Lama or collected by the Baileys and Cuttings had level mouths. They did not have the turned up, undershot mouths desired under the present English and FCI Standards. Photos and descriptions of the breed from the thirties and forties show this quite clearly. The much earlier description of the breed, printed in 1901, stated " Mouth quite level, but of the two a slightly overshot mouth is preferable to an undershot one."  Most of the recent specimens brought from the Himalayas have had scissor bites.  While in Europe, breeders and judges have adopted, as correct, a turned up, undershot jaw, against which a mountain existence would certainly select, because of the airway compromises involved. These jaw and dental abnormalities, some of which are actively sought by misguided western breeders and judges, are real disadvantages for a Tibetan dog.

Aside from strong historical arguments for rejection of the significantly undershot mouth in favor of the level mouth, there are even stronger biologic arguments. The undershot mouth, in which there is no occlusion between upper and lower incisors, is a unhealthy mouth, leading to early loss of teeth. All too often we see little rice-like teeth which have short roots and are lost early. Teeth are kept healthy, as any dentist will tell you, by contact and pressure from the teeth in the opposite jaw. Without this pressure, the teeth are extruded, and bone is lost from around the unopposed teeth, causing them to be loosened and lost early in life. In the grossly undershot bite, the canines are misoccluded, whereas in a level or reverse scissor bite, the lower canines fit into the space between the lateral incisor and canine of the upper jaw. This relationship is important in "anchoring" the bite in a stable occlusion. If the lower incisors lie in a straight line between the canines, there is malocclusion of the canines, with loss of stability of the anterior bite.  Because the undershot bite, in which the upper and lower incisors do not touch, and the canines do not mesh properly, is unhealthy (just as unhealthy as a "parrot mouth"), and a biologic disadvantage, it is not a suitable bite for a Tibetan dog.

You, then, have to decide whether you think the present day revised English and FCI versions of a Lhasa or the original Tibetan Lhasa represents the true breed.


Figures 1 and 2  are photos of a normal canine skull.  Note the unequal length of the upper and lower jaws (red arrows).  Also note the way the upper lateral incisor "locks" around the lower canine.  Also note the absence of space between the anterior teeth - they all mesh very tightly. 

Figures 3 and 4 are photos of a 6 year old male Lhasa Apso with a "reverse scissor" bite.  Note how the upper lateral incisors are displaced anteriorly by the lower canines and have been pushed out of line with the other upper incisors.  The lower canines  - in fact, the entire anterior segment of the lower jaw has moved forward so that now the two jaws are equal in length.


This slightly undershot bite is clearly not a normal canine bite, but is still a relatively healthy bite because some semblance of normal occlusion is preserved.  A bite in which the lower canine is located anterior to the upper lateral incisor is an unhealthy bite because there is no anterior occlusion.

There is a preoccupation with the "undershot look" here and in Europe.  Proponents of this look claim that the Apso is an "Oriental"  breed and therefore should share a "puggy"  heavy underjaw or chin with other "Oriental" breeds.  Not only is the Apso a Central Asian, rather than "Oriental" breed, but examination of the earliest photos we have of imports from Tibet reveal them to be quite the opposite of "puggy" faced, but instead bear a very strong resemblance to Cairn Terriers!  Here is a photo of two of the Bailey dogs from the 30's (imports or first generation).  Note the distinct "terrier" quality of the heads and the absence of a puggy "chin".