Doctors Corner – Sleep Apnea
Surgical treatments of obstructive sleep apnea (OSA), such as uvulopalatopharyngoplasty (UPPP), expansion sphincter pharyngoplasty (ESP) and the Pillar implant procedure, while relatively successful in moderating OSA are not able to entirely eliminate it. And it is well known in the medical literature that CPAP (continuous positive airway pressure), which is the standard medical treatment for OSA, has a relatively low compliance rate amongst men and women of all ages. Many patients fall into the camp of refusing to have surgery as too radical of an approach and yet unwilling to wear a CPAP mask because of discomfort or personal reasons.
This presents a conundrum for doctors and patients alike in terms of treatment. An alternative approach is the use of MAS (mandibular advancement splint) appliance that treats OSA by pushing the lower jaw forward and thus opening up the airway mechanically. However, these appliances do not alter the airway permanently and in some cases can lead to malocclusion, as the lower jaw can actually shift forward into a class III occlusion, and/or lead to TMD (temporomandibular dysfunction). Again some patients find these appliances objectionable, as there are uncomfortable, unsightly and may lead to further dental problems in the future.
There are quite a few patients that are falling between the cracks of treatment because of the above reasons. Furthermore, it is well know that patients with maxillary constriction have increased nasal resistance and are quite often mouth-breathers. Combine this with retrognathia in one or both jaws with concomitant tongue posture and there will be an associated retroglossal airway narrowing. Additionally, even a mild degree of retrognathia is associated with an intrinsically smaller pharynx due to the underdevelopment of the jaws and the associated structures.
These patients often suffer from a transverse deficiency in one or both jaws. The best treatment option for these patients is structural development of the jaws and consequently the oral cavity. This is normally done surgically in adults, as it is believed that the jaws have finished developing and will no longer expand using a dental appliance. Medical literature is replete with surgically assisted rapid maxillary expansion, axillary and mandibular distraction osteogenesis, and maxillomandibular advancement, as it is believed that the jaws of adults will only expand and advance with surgery, as growth is completed by adulthood. It is well known that the environment plays a key role in the development of the human body. Cranio-facial growth is a complex interaction between genetics and environmental influences and not solely a predetermined genetic outcome.
As a result growth can be initiated in the adult by altering and/or stimulating the oral environment by intermittent gentle force, thereby activating growth factors involved in the process. Bone is a highly vascular matrix that has great plasticity and is metabolically active for a lifetime. This matrix is in a constant state of remodeling with coordinated actions of bone resorption and bone formation. Unlike the rest of the body, growth of the jaws and mid-facial region are highly dependant on the interaction of the environment on growth genes. Hard and soft foods highly influence the formation of the teeth and jaws, as well as, thumb sucking, tongue thrusting, allergies, deviated septum, infections of the tonsils and adenoids, bottle feeding, poor quality of food, pollution, clenching, grinding, etc. It is now believed that these negative environmental influences are responsible for dampening or hampering the gene derived mechanisms of growth. The blueprint is still intact. However, it is the growth outcome that has been inhibited by the environmental factors. Growth is inherently built into the tissue and this is what allows for structural change and stability within the cranio-facial system. Exostoses or bony growth is frequently seen in patients that clench or grind as these postural activities stress the bone and activate new bone. This new bone is activated by compensation and may be a way for the body to stabilize malocclusive activity. Bone is constantly in the process of formation and resorption, and will deposit in areas of stress and in areas of growth. The stress process is inherently very different as it is an immune reaction and the new tissue that is laid is fibrous as it is a repair process involving large amounts of collagen tissue and cross-linking that eventually leads to tissue contraction. This is the kind of bone formed with exostoses due to a traumatic bite and/or with rapid maxillary expansion using an appliance that traumatizes and splits the mid-palatal and inter-maxillary suture. The bone growth that results is a filling-in process due to injuring of the suture. Instead growth does not involve tissue injury; rather it is directional and initiated by the underlying genetic blueprint.
The DNA appliance? works with the body by allowing for physiological change by developing the facial bones via genetic potential. The directionality of the force and not the strength of the force create the potential for growth by activating chemical factors involved in growth. The appliance is worn only at night; allowing for rest and regeneration of the tissue involved. This is important, as development is not dependant on muscular function or posture. Furthermore, the appliance does not initiate wound healing, which is an immune response to trauma and not a growth response. Rather growth of the jaws and mid-facial regions can be initiated by gentle force that is more directional in nature. This directional force instructs the body, allowing it to respond deeply by activating the growth process via messaging. This technology is unique as the patient’s mid-facial region expands laterally and also anteriorly, enlarging the mid-face and creating spatial definition to the functional spaces that lay superiorly and posteriorly to the maxillae. In some cases a small mandible will initiate growth once the maxillae has been expanded, as a larger maxillae allows for development if the lower jaw was physically trapped by it. If growth is not initiated then a lower appliance will be used to expand the mandible to counterpart the mid-facial development of the maxillae.
Mid-facial hypoplasia and obstructive sleep apnea often go hand in hand, as the facial architecture has not spatially developed to allow for sufficient airway space. This is easily seen in those suffering from Down syndrome, as mid-facial hypoplasia typically seen in these individuals contributes to pharyngeal obstruction. Obstructive sleep apnea is a common finding in those suffering from Down syndrome. The flatten facial architecture in a hypoplastic individual does not need to be severe to interfere with airway function, as jaws that are too small for a large tongue will also be a contributing factor in some individuals. Furthermore, a high arched palate is associated with a small pharyngeal airway; a MAS device will not drop the palate or advance the mid-face, instead it will only thrust the lower jaw forward in order to mechanically provide more airway space.
The DNA appliance™ is designed with a wire loop extension that is approximately 7mm long (actual length will be determined by patient’s anatomy) and curved at a 45-degree angle from the end of the palate towards the throat that controls the tongue during sleep and preventing blockage of the airway space. This will help control soft tissue interference during sleep, while the appliance slowly expands the maxillary arch laterally and anteriorly, as a consequence of this activity a high vaulted palate will widen and drop, providing additional space for the tongue. By changing the oral cavity we are able to affect many of the environmental reasons that lead to cranio-facial deficiencies, helping to eliminate, reduce or curtail them, however, not all environmental influences will be eliminated, reduced or curtailed. Some or many of these factors will remain in place and will affect the results. Since there is no way to predict how much the jaws will grow and develop compared to the outcome for surgery where length can be predetermined, each individual will have varying results. Some results will be superior, with full facial development and large airspaces, while others will be modest, however, this is a non-invasive approach very suitable for those patients that refuse surgery and/or CPAP therapy.