For many years I wanted to do a thorough discussion of the Lhasa Apso head, but never had the right graphic material to support it.  There have been many differing opinions about the Lhasa head.  The reason for the conflict seems to be that people have never actually seen the complex structure under the hair and skin.  In writing about the head, imagination, not fact, seems to be the source material.  When I recently obtained the skull of a very beautiful, ideally proportioned Lhasa, I finally had the material I needed to properly illustrate the "real thing".

The Lhasa Apso head is a shortened version of the normal canine head, but one which must still be able to survive the rigors of altitude and climate found in Tibet.  A comparison of the normal domestic dog and Canis Latrans, the coyote, with the Apso, shows us just how far the Lhasa Apso skull deviates from the norm.  Any deviation beyond this would not be survivable at 16,000 ft. Thus the very short nose, with it's folded up turbinate bones, the large prominent eye, are features incompatible with a Tibetan breed.

Notice how although the braincase and orbit are roughly the same size as the coyote's, the facial skeleton has been markedly reduced in size and robustness of bone.

First, so that we can communicate meaningfully, we have to take a look at the anatomy and define some terms . Figure 1.  is the lateral view of the Lhasa skull. The skull is composed 10 paired bones. Beginning at the front of the skull, is the Maxilla, which holds the upper teeth, and forms the middle portion of the lower rim of the orbit, and the floor of the nasal cavity. The nose is roofed over by the Nasal bones. The Frontal bone forms the upper part of the orbital rim, and extends backward to form about 1/3 of the cranial vault. There it meets the Parietal bone, which extends back to the nuchal ridge at the back of the skull.  This ridge is where the neck muscles attach to the posterior skull.  Beneath the nuchal ridge, is the Occipital bone, which in the dog is quite small, and articulates with the first spinal vertebra.  The Temporal bone forms the lateral base of the skull, and holds the ear structures. It is continuous with the Parietal bone superiorly, while anteriorly it narrows into the zygomatic process. The zygomatic arch is formed from 2 bones,  the Zygoma, which is very small in the dog, extending laterally and posteriorly from the sides of the maxilla just above the molar teeth,  and the zygomatic process of the temporal bone. There are two more bones, which we do not see on the surface examination of the skull: the Palate, the roof of the mouth, and the Sphenoid,  which forms the base of the skull, through which the blood vessels, and the 12 cranial nerves pass on their way to the brain. The Mandible of course, is attached to the skull via the temporo-mandibular joints.

What does the American Standard say about the head of the Lhasa?
Head: heavy head furnishings with good fall over eyes, good whiskers and beard; skull narrow, falling away behind the eyes in a marked degree, not quite flat, but not domed or apple shaped; straight foreface of fair length. Nose black, the length from tip of nose to eye to be roughly about one third of the total length from nose to back of skull.
Eyes: dark brown, neither very large and full, nor very small and sunk.
Ears: pendant, heavily feathered.
Mouth and muzzle: the preferred bite is either level or slightly undershot. Muzzle of medium length; a square muzzle is objectionable.

Fantasy #1: "Falling away behind the eyes"
That there are fantasies about the Lhasa head is not surprising, considering the language of our standard. The first bit of imagination used to describe the head dates back to 1901, in Lionel Jacobs' description of the Lhasa.  Though I am sure Sir Lionel knew what he meant by "falling away behind the eyes",  it seems that he was alone.  Since then, this phrase has been copied into every subsequent standard.  Because no-one has ever known what it meant, no-one has ever been willing to discard it, lest it be important.  In my opinion, this phrase adds no insight into structure, and only serves to confuse.  It has, however, given rise to a lot of fanciful speculation.   As is immediately apparent, the skull does not "fall away", but rises gradually behind the eyes to form the cranial vault.  As can be seen in Fig. 2, The eye is situated in the lower part of the orbital fossa. ("fossa" = "bowl or cavity"). The globe protrudes from the bony fossa, and is, unlike the human eye, unprotected by any bone laterally.  One thing that might strike you as impossible when you look at these pictures, is the placement of the eye.  "The eyeball dosn't protrude like that"!  Yes it does. Please take your Lhasa and gently palpate the eye and its surrounding bony structures.

Another important feature seen in Fig.2 is the temporal muscle.  This is one of the two muscles which close the jaws. These muscles are very well developed in all carnivores, for obvious reasons. The large Temporalis arises on the entire side of the skull, and inserts on the flat surfaces of the coronoid process of the mandible.   To get to the mandible it must pass through the bony zygomatic arch, nearly filling that space.   This has important implications for the structure of the head, as we shall see later.

Fantasy #2.  The Lhasa head is widest through the eyes. We used the bony tear duct, (which corresponds to the medial corner of the eye), the nuchal ridge, and the anterior teeth (plus a quarter inch allowance for the soft tissue of the lip) as our landmarks in measuring the muzzle to cranium ratio. From the measured dimensions, we see that the Lhasa whose skull appears in the photograph had very correct proportions.  The actual dimensions are as follows:
Total Length of head:  12 cm.  (4.73 in.)
Length of muzzle:          4 cm.  (1.58 in.)
Length of cranium:        8 cm.  (3.15 in.)
Width each orbit:           2.8 cm.(1.10 in.)
Maximum width of head (bi-zygomatic):    8 cm.  (3.15 in.)
Maximum width of cranium (bi-parietal):  5.4 cm.(2.13 in.)
Width across orbits (bi-orbital):                6.5 cm.(2.56 in.)
Width between orbits(inter-orbital):         2.2 cm.(0.87 in.)

As can be seen immediately, the widest part of the head is at the rear part of the temporal - zygomatic arch.  In our specimen, this diameter is 8 cm, - equal to the length of the cranium.  At the level of the eyes, the diameter measures only 6.5 cm.  (Keep in mind that the length of the entire head is 12 cm.)

There is another feature of the head, not mentioned in the standard, which is important to the Tibetan Lhasa. The Lhasa has a prominent malar (or cheek) bone which brings the eye into a more frontal position than on most dogs, and protects the eyes from dust, injury, cold and desiccation. This malar complex is formed by parts of the Maxilla and Zygoma, and can be seen well in Fig.3 and Fig.5.  It supports the outer half of the eye, and imparts an almond shape to the eye. Without a rather prominent malar bone placed just beneath the eye, the eyelids lack support and tend to fall away from the eyeball, making the eye rounded and more protuberant, thus exposing it to injury and drying. This frontal eye placement is a feature of the heads of all four Tibetan breeds, and has a lot to do with the uniquely "Tibetan" expression they share. (Frontal eye placement also contributes to good binocular vision, necessary in a mountain watchdog.) This malar complex is a facial bone, which adds slightly to the width of the head at the level of the eye, and should not be confusedwith the skull, (the cranium) which is narrow, nor with the zygomatic arch.

Does this mean that our specimen does not have the "skull narrow" according to the standard? Here we have a confusion of words. Does "skull" refer to the cranium alone, or to the entire head?   In future versions of the standards it might be helpful to distinguish between the cranium, - the braincase, and the facial skeleton, which together make up the head, or skull.   In either case it is "narrow" so long as you compare apples to apples.  The cranium is 8 cm long and 5.4 cm wide.  Narrow by any definition.  The entire head is 12 cm long and 8 cm wide at its widest point - also "narrow".

One point that must be remembered is that at the time the first standard was written, there was some confusion of the Lhasa Apso with the Shih-Tzu. Certainly the forshortened head of the Lhasa is not "narrow" compared to that of a Borzoi, but the word "narrow", in the case of the Lhasa, was in reference to the much shorter headed Shih-Tzu.

In a carnivore the widest part of the head is at the level of the posterior zygomatic arch.  Why must this be so?   Why isn't our Lhasa's head widest at the eyes, as so many writers have described it?

Canines have to catch their prey with their jaws.  They do not even have the powerful claws of their feline counterparts. Consequently, the power of those jaw muscles is awesome.  There are two muscles which close the jaws: the Temporalis, and the Masseter. The Temporalis originates in a broad area occupying most of the lateral cranial wall.  This massive muscle then passes under the zygomatic arch to attach to the Coronoid Process of the mandible, a broad, flattened tongue of bone projecting upward into the zygomatic arch. (see fig.5) The arch must be able to accomodate this massive muscle, or the dog would not be able to close its jaws.  Hence, unless the Lhasa had eyes on stalks, like a hammerhead shark, the widest part of the head must be the bi-zygomatic diameter.  This arch has to be strong and massive because the second muscle of chewing, the Masseter, originates along the surface of the arch itself, and attaches to the flat surface of the of the mandible inferior to the insertion of the Temporalis.   To the carnivore, this bony arch is as important as his heart or lungs, because without a massive arch,  he can't eat.

One fanciful explanation I have encountered for "falling away behind the eyes" involves the invention of an imaginary anatomic anomaly which is clearly impossible.  (This appeared in a national dog publication.) The authors of this "explanation" say that the Zygomatic arches become narrower posteriorly as in the diagram in Fig 4B.  When the black and white diagram is superimposed on the photograph of real skull, it becomes obvious that such a zygomatic arch would not permit the attachment of a normal jaw.

All mammalian skulls are built on more or less the same pattern. The Coronoid process of the mandible is positioned within the Zygomatic arch so that the muscles that close the jaws can attach to the mandible. An animal such as the one proposed in the diagram in Fig. 4B would be unable to move its jaw, because the coronoid processes cannot fit within the arch. And even if one could imagine some sort of jaw to fit into the abnormal space, there is no room for the temporal muscle.

This attempt to explain an obscurely worded item in the standard by imagination rather than by study of the anatomy is not only dishonest, but potentially damaging to the breed.  When this kind of absurd "information" is presented as fact in national publications, and presented in judging seminars by national clubs, we are telling judges to look for a monstrosity which, if it were ever born, could not possibly be viable.

Fantasy #3: The top of the nose of the Lhasa Apso is level with the lower eye rim.  Please look again at the photos of the lateral skull.  The inferior rims of the orbits are considerably lower than the bridge of the nose.   This is not only true of every dog, but every carnivore, including yourself!   Yet, this statement, because it was written by a lady prominent in the breed,  continues to be quoted as fact.  Just look. Believe your own senses rather than the words of "experts".   In photos, if we tip the head down we can set the rim level with the nose, as in fig 5., but look again at the lateral photos.

It might be argued that the end of the nose is lower than the bridge of the nose, but then we have to abandon "straight foreface",  and accept a drooping, downfaced Lhasa as correct.  I think that everyone agrees that the essence of Lhasa expression is the straight foreface, without which the expression is alien.  Again - just look.

Fantasy #4: The Lhasa Apso is an Oriental breed, and therefore should be undershot.
Seemingly without regard to the fact that the Lhasa is not an "oriental", but a central Asian breed, this notion has brought with it a number of maladaptive alterations to the breed.  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". 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). However in the Lhasa standard we have always understood that "mouth level" means that the upper and lower jaws are equal in length.  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.

The grossly undershot mouth, in which there is no occlusion between upper and lower incisors, is a unhealthy mouth, leading to early loss of teeth. Without contact and pressure from the teeth in the opposite jaw, the teeth are extruded, and bone is lost from around the unopposed teeth, causing them to be loosened and lost early in life. 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 jaw is markedly prognathic, 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.

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 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. 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 incisor teeth as being in as broad and straight a line as possible, 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.).  In the Apso, as in every other breed which is not extremely foreshortened,  the incisors form a slight curve, and the mandibular canines are placed posterior to the lateral incisors.  This is necessary for normal occlusion of the canines and premolars.  If the incisors are in a straight line with the canines, then there can be no normal canine occlusion.   Just look.  Look at the teeth and how they occlude.  Unfortunately our specimen was a 13 year old, whose teeth were partly missing, but the structure is still there.

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 Bhutan have had scissor bites. You, then, have to decide whether the original Tibetan Lhasa, or the New Revised English version represents the true breed.

In conclusion, I hope this photoessay has been helpful to you in understanding the relationships of the head structures,  Again I urge you to examine the statements of the "experts" against what you see for yourself.   Of course, before you see, you must look - which is what I hope I have helped you to do!