William Bacon

Cephalometric evaluation of pharyngeal obstructive factors in patients with sleep apneas syndrome.

To determine accurately the morphological characteristics specific to patients with sleep apneas syndrome (SAS), a group of 43 adult males with SAS was compared in a cephalometric evaluation with a homologous control group. In SAS patients, the soft palate was elongated; the sagittal dimensions of upper face and anterior cranial base were reduced and correlated with reduced bony pharynx opening; and the increased lower face height was associated with a retruded position of the chin and tongue, thus contributing to lower pharynx crowding. With the four variables entering the discriminant function analysis, 93 percent of the whole population was correctly classified. If anatomical rehabilitation of the pharynx is to be envisaged, the leading factors to consider should be: soft palate length, maxillary position, chin and tongue position, in that order.

Treatment of Class III malocclusion: the key role of the occlusal plane

Patients with a Class III malocclusion generally present with a counterclockwise inclination of the occlusal plane, converging with Campers line towards the front. This slope has an effect on mandibular movement (forward posture) and on chewing mechanisms in general. As dysfunctional mastication is likely to influence facial growth and inter-arch stability negatively, early orthopedic therapy of the occlusal unbalance concurrent with Class III malocclusion is justified. The aim of this article is to present a method of Class III treatment based on a correct re-orientation of the occlusal plane in order to achieve an optimal masticatory mechanism, essential for stability of early treatment outcomes.

Le sourire dans la représentation et l’image de soi

Does the smile play a part in the patients self-esteem and social well-being? The assessment of the smile is part of the clinical examination and it contributes to the diagnosis. Other criteria besides quantitative or metric ones are considered in this work and make it original. Philosophical, psychological and sociological aspects have been considered to understand the role of the smile in human relationships and self-representation. The quest for beauty is universal but its assessment remains subjective even if attempts at objectivity have been made. Self-esteem is fundamental for the individuals mental and social well-being. A human being has to submit to the rules and customs of his fellow-men if he wants to be part of the society in which he lives. Even if some aesthetic standards cannot be skirted and seem to be universal, the reality of beauty is perverted by social diktats, so is the representation of the smile. It is therefore essential to listen to ones patient before considering his teeth.

Cyclophosphamide-induced temporomandibular synostosis

The study of malformations helps toward a better understanding of normal development, which is of significance to the orthodontist. Experiments in teratology have induced an extensive variety of facial abnormalities, but temporomandibular joint (TMJ) synostosis has never been previously reported. Ten pregnant female rabbits were treated with a daily injection of 50 mg. cyclophosphamide (DNA synthesis inhibitor), from day 11 to day 14, which is the period that precedes formation of the face. The control sample comprised five female rabbits. The fetuses were obtained by cesarean section on day 28 and stained with alizarin. Six of the ten treated female animals produced offspring that had TMJ synostosis. The skull with TMJ synostosis showed a retrognathic mandibular pattern in relation to the maxilla, and the bony trabeculae in the mandibular angle showed a downward orientation instead of the horizontal orientation seen in animals without synostosis. The length of the heads was significantly smaller in the treatment group than in the control group; within the treatment group, the heads with synostosis were significantly smaller than those without synostosis. It could be hypothesized that the cyclophosphamide might have affected intrinsic factors in the temporomandibular mesenchyma; an impairment in the development and function of the mandibular musculature, which is a vital factor in joint development and maintenance, might also have contributed to the genesis of the malformation. The association of immobilization and mandibular hypodevelopment seems to be in agreement with todays theories on maxillofacial growth.