Chow says OMF is the only speciality that treats disorders of the temporomandibular joint, the small joint located in front of the ear where the skull and lower jaw meet.

'When patients feel pain in the joint, they will go to ear, nose and throat doctor as they feel pain in front of the ear,' he says. 'The ear, nose and throat doctor will transfer him to an orthopaedic doctor who will refer the patient to us. [Most of our patients come to us] through referrals.'

The poor public understanding of the speciality was revealed recently in a survey conducted by OMF specialist Alfred Lau Sze-lok. In June last year, 104 people aged 18 years or above were interviewed on how much they know about the field. Three out of four of the respondents said they had never heard of the speciality. For those who had heard of the discipline, they wrongly subsumed general dentistry, dental cleaning and orthodontics into OMF surgery.

Lau says OMF surgery involves oral and jaw surgeries. 'We do all surgeries inside the month such as the removal of wisdom teeth and tongue tumours. Cosmetic surgeries include shortening protruding chins and mandible (lower jaw) reductions, to make the face slimmer. We also treat patients born with congenital deformities like cleft lips and asymmetrical faces.'

Lau says the poor public understanding of the discipline has to do with the overlapping of OMF surgery with some medical disciplines in Hong Kong.

'There's a clearer distinction between our field and other dental disciplines overseas. But in Hong Kong, general dentists can also do surgeries involving wisdom tooth and dental implants. There's no regulation proscribing general dentists from doing the surgeries. But if the surgeries are to be conducted near nerves and there are high risks involved, the patients will be referred to us.

'Our work also overlaps with that of ear, nose and throat specialists and head and neck doctors who do surgeries involving tongue cancer, salivary glands and the jaw.'

There are 51 registered OMF specialists in Hong Kong. The University of Hong Kong is the only tertiary institute that provides training of OMF specialists. In Hong Kong, a graduate of a five-year dental degree has to get specialist training for a further six years for qualification. Because the dental specialists have to get involved in surgeries, they have to be well-versed in medicine in addition to their dental training, Lau says. 'We need to know pre- and post-operative care and common diseases like diabetes and heart disease.'

While Hong Kong categorises OMF surgery as a dental discipline, countries like Britain subsume it under the school of medicine, requiring practitioners to receive specialist training in both dentistry and medicine, lasting 12 years. But Chow questions the need for such lengthy training.

'The 12 years is on top of the five-year dental degree,' he says. 'If we follow what Britain does, we [would] need to invest a lot of resources into training.'

Lau agrees: 'Many things learnt as part of a full medicine course can be wasted. Disciplines such as gynaecology have nothing to do with us.'

Chow says some patients have run into problems with insurers because OMF is sometimes classified as a dental speciality. 'Due to their lack of understanding of the speciality, insurers see some of our patients as purely dental cases, which are not covered under insurance policies. They even teach our patients to shun our speciality so that they can make insurance claims. Other patients who want to be eligible for claims check themselves into hospital even though their condition does not require a hospital stay. In fact, temporomandibular joint disorders are no different from other orthopaedic ailments.'

Lau says rising public awareness can lead to better collaboration between OMF specialists and other medicine professionals. 'For example, in a surgery on jaw bone reconstruction, we and orthopaedic doctors can work together. After we remove a chunk of tumour-infested jaw, we need the help of orthopaedic doctors to extract bone from the leg for reconstruction.

'Ear, nose and throat or cosmetic doctors involved in jaw surgeries do not know much about teeth alignment. A collaboration with us can provide better treatment for patients.'