FACE · Airway · Bite
The face is a complex system of moving parts.
In order to provide an esthetic result with any cosmetic, dental or orthognathic treatment, the hard and soft tissues of the face need to have correct shape and be in their proper position and provide proper function.
In fact, proper form, position and function of the face is the very definition of physical beauty. This is our goal for each and every patient.
The bones of the face support the airway through which we breathe. When the skeleton is not aligned properly the airway can collapse while sleeping and cause snoring, disrupted sleep and obstructive sleep apnea. Orthognathic surgery restores proper position of the bones and dramatically expands the airway. In fact, orthognathic surgery is the most successful intervention available for treating obstructive sleep apnea.
A cone beam CT by iCAT
The airway volume is measured from the top of C2 to the bottom of C4. The volume as measured is 4.85cm3 – well below the anecdotal OSA threshold of 10cm3.
The valve is the smallest cross-sectional area of the airway. As well, the valve (yellow line) is .5cm2, well below the anecdotal cross-section minimum of 1cm2.
Obstructive sleep apnea diagnosis and treatment and facial examination. Take a look at the spinal posture change after the airway was expanded with orthognathic surgery.
The proper fit of the teeth (occlusion) relies on an intricate interaction between the form of the teeth and their position in the bone, the relationship of the jaws, the facial and jaw muscles and the temporomandibular joints.
A functional occlusion (bite) is a relationship between the temporomandibular joints and the dentition which maintains joints, muscles, teeth, and the periodontal ligament structures in a state of equilibrium or health. Dentistry defines a stable occlusion as class I with maxillary and mandibular arches coordinated (no crossbites) and an overbite-overjet of approximately 3mm. The functional occlusion as defined by dentistry does not include facial and/or airway criteria. It is important that treatment not only correct occlusal function but simultaneously meet facial and airway correction.
Managing the bite
To accomplish this, we work closely with the dentist, prosthodontist and orthodontist to achieve a functional occlusion. The bite is planned from the very beginning, at the consultation, and great care is taken to achieve the planned bite. The orthodontic setup needs to be accurate, the tooth sizes and shapes need to be correct and the surgery, in orthognathic surgery cases, needs to be performed with exactness. After initial treatment, the bite is checked constantly to monitor any possible changes using articulating tape which measures bite contact to within 21 microns. The bite is adjusted to the final micron level either by gently reshaping the teeth through a process called occlusal equilibration. With our understanding of how a correct bite fits and functions and close attention to detail, the success of orthognathic surgery, prosthetic rehabilitation or orthodontics is improved greatly.
—Dr. Michael Gunson