Relationship of the functional oropharynx to craniofacial morphology.

The association between the functional oropharyngeal airway (defined as the minimal sagittal dimension at right angles to the airstream) and craniofacial morphology was investigated using 16 craniofacial variables taken from lateral cephalometric radiographs. The sample consisted of 70 subjects (31 males and 39 females) 10 to 13 years of age. There was no difference in ages between males and females, and no correlation with age except upper face height. Oropharyngeal airway was positively correlated with length of the mandible (Gon-Men), the distance between the third cervical vertebra and the hyoid bone (C3-Hy), and cranial base angle (NSBa). Although short mandibular length is a characteristic finding in patients with obstructive sleep apnea, none of the subjects in this study had this diagnosis.

The dawn of rapid maxillary expansion.

The first report of lateral maxillary expansion by separation of the maxilla, written by Angell and published in 1860, was discredited. Applying our present-day knowledge of the technique to the original documents indicates that the case history agrees in general with current observations. The arguments mounted against Angell, especially by McQuillen, may be dismissed as irrelevant and Angell's thesis is upheld. In addition, good reason exists to accept three further "firsts" in this unprecedented work: (1) The significance of the first permanent molars in occlusal development, (2) the use of a double-action jackscrew, and (3) the use of a retention plate.

[Effect of rapid maxillary expansion on respiratory problems: 10-year retrospective study]. / El efecto de la expansión maxilar rápida en problemas respiratorios: diez años de estudio retrospectivo.

Rhinomanometric studies have demonstrated that the maxillary fast expantion (ERM) reduces the nasal resistance of the air conduct and thus achieving the normal limits, in must cases. The hypotesis is that breathing will change from buccal to nasal, concluding that the nasal defense mechanisms (filtration, humidification and warming of inhaled air) will reduce some respiratory pathologies.

Rapid maxillary expansion in the treatment of nocturnal enuresis.

There is growing consensus that upper airway obstruction is a causative factor in nocturnal enuresis. This phenomenon has an unhappy history, although some surgeons in the past have touched on its treatment through the relief of upper airway obstruction. Only recently have sleep laboratory investigations presented a clearer, though still incomplete, picture of the etiology of nocturnal enuresis through disturbed sleep patterns. The obstruction is usually an adenoidal hypertrophy or, less commonly, an anterior nasal stenosis. While the otolaryngologist can readily cope with the former, surgical difficulties make treating the latter problematic. In many cases, the constriction can be reduced by rapid maxillary expansion. In the ten cases examined in this study, nocturnal enuresis ceased within a few months of maxillary expansion.

A quantified comparison of craniofacial form with nasal respiratory function.

Rhinomanometry provides a means to quantify the nasal airway in terms of its conductive efficiency by use of the inverse or resistance to airflow. In samples of 21 male and 26 female subjects, nasal airway resistance was compared with a number of form measurements and the coefficients of correlation were calculated. Statistical significance was found in some of the relationships with nasal airway resistance, particularly the maxillary-mandibular plane angle, the palate-tongue distance, the palatal width, and the facial index.

The effect of rapid maxillary expansion on nasal airway resistance.

There has been a long-standing controversy over the efficacy of rapid maxillary expansion to relieve nasal obstruction and improve respiration. Recently rhinomanometry has provided a discipline for the investigation into nasal airway physiology with quantifiable parameters for evaluation and comparable studies. In this trial, a sample of 26 patients (13 male and 13 female, age range 10.10 to 19.6 years), receiving rapid maxillary expansion as part of their orthodontic mechano-therapy, were appraised for nasal airway resistance before and after expansion. The posterior rhinomanometric technique was used, measuring the respiratory flow between pharynx and the nostrils at a preset pressure difference between these two points. The formula for calculating the resistance is derived from the electrical Ohm's Law and requires that the pressure difference be divided by the flow. Reductions were recorded in all cases with an average of 36.2 per cent (range 11.6-58.6). The correlation between the resistance reductions and the delivered expansions (increases in trans-palatal widths) was weak (r = 0.32). In view of the probable significance of the liminal valve in nasal resistance, expansions in this area were assessed by changes in the trans-alar widths. The correlation between trans-alar increases and the trans-palatal expansions was weak (r = 0.115), as it was between the trans-alar increases and the reductions in nasal airway resistance (r = 0.30).

The relationship of rapid maxillary expansion to surgery with special reference to midpalatal synostosis.

This study is a multi-disciplinary approach to the regulation of the maxillary width in adults, based on published histological evidence of midpalatal synostosis and the analysis of nine cases. The treatment involves the maximal use of rapid expansion for movement with the minimal surgical intervention to free maxillae. The results provide a modus operandi for oral surgeon/orthodontist association with a three-stage series of age-related incremental surgical procedures to meet the resistance to maxillary separation and a tie-up with orthognathic surgery. It seems unnecessary to intervene surgically to free the maxillae under 25 years of age. Stage 1 applies between 25 and 30 years, Stage 2 between 30 and 40 years, and Stage 3 between 40 and 50 years. Attention is drawn to the respiratory improvement following these technics.

A study of basal movement with rapid maxillary expansion.

This investigation was undertaken to examine the effect of rapid maxillary expansion horizontally and posterior to the dental arch, there being some doubt that the expansion would be carried in this dimension and whether dilation of the non-tooth-bearing bones (palatines and sphenoidal pterygoid processes) was possible. The increases in the intermolar arch widths and the interpterygoid hamular widths were recorded in a group of thirty-two orthodontic patients. (twelve male and twenty female, aged 8 to 24 years), before and after rapid maxillary expansion. The mean percentage increase in interhamular widths to intermolar widths was 58 percent (range, 35 percent to 89 percent). The correlation between the relative increases was weak (r = +0.55). A slight reduction in the percentage increases in interhamular widths to intermolar widths as age advanced suggested an age factor, but the correlation was very weak (r = -0.33). From this evidence, it would seem that rapid maxillary expansion will separate the palatine bones and splay outward the pterygoid processes of the sphenoid bone.