Beni Solow

Airway dimensions and head posture in obstructive sleep apnoea

The present cephalometric study aimed to describe the antero-posterior diameters of the pharyngeal airway in a sample of 50 male obstructive sleep apnoea (OSA) patients and a reference sample of 103 male students, and to examine the relationship between these diameters and the posture of the head and the cervical column. Subjects were recorded in the cephalometer standing with the head in its natural position (mirror position). Pharyngeal airway diameters were measured at seven levels ranging from the maxillary tuberosity to the vallecula of the epiglottis. The largest difference was observed at the level behind the soft palate where the diameter was 50 per cent narrower in the OSA sample than in the reference sample. Extension of the cranio-cervical angle and forward inclination of the cervical column were correlated with an increase in the three most caudal airway diameters in the OSA sample: at the uvula, the root of the tongue, and the epiglottis, but only to increase in the lowest diameter in the reference sample. The findings were considered to reflect a compensatory physiological postural mechanism that serves to maintain airway adequacy in OSA patients in the awake erect posture, most efficiently so at the lowest levels of the oropharyngeal airway.

Continued eruption of maxillary incisors and first molars in girls from 9 to 25 years, studied by the implant method

The aim of this study was to describe the average and individual patterns of continued eruption of the maxillary incisors and first molars in a longitudinal sample of girls. The sample comprised 14 series of lateral cephalometric films of girls, obtained from the archives of the implant study of Björk (1968). All subjects had bilateral posterior maxillary implants and one or two anterior maxillary implants. Subjects with craniofacial anomalies were excluded. The sample represented various types of malocclusions, but records during periods of orthodontic treatment were excluded from the calculation of average data and average curves. The final sample comprised 147 radiographs in the age range 9-25 years. Data were debugged by comprehensive numerical and graphical procedures. The average cumulative continued eruption from 9-25 years of age was 6 mm downwards and 2.5 mm forwards for the upper incisors, and 8 mm downwards and 3 mm forwards for the upper first molars. This resulted in an average reduction of the occlusal plane inclination (OLs/IPLs) of 4.5 degrees from 9-16 years. Attention is drawn to the fact that due to the continued eruption of the natural teeth, the use of osseointegrated implants with artificial teeth should not be recommended in childhood, adolescence, and early adulthood, unless special provision is made for later revision or replacement of the artificial teeth to compensate for the lack of continued eruption of such implants.

Mandibular advancement appliance for obstructive sleep apnoea: results of a randomised placebo controlled trial using parallel group design.

The aim of this trial was to evaluate the efficacy of a mandibular advancement appliance (MAA) for obstructive sleep apnoea (OSA). Ninety‐three patients with OSA and a mean apnoea–hypopnoea index (AHI) of 34.7 were centrally randomised into three, parallel groups: (a) MAA; (b) mandibular non‐advancement appliance (MNA); and (c) no intervention. The appliances were custom made, in one piece. The MAAs had a mean protrusion of the mandible of 74% (range 64–85%). Outcome measures, assessed after continuous use for 4 weeks, were AHI (polysomnography), daytime sleepiness (Epworth) and quality of life (SF‐36). Eighty‐one patients (87%) completed the trial. The MAA group achieved mean AHI and Epworth scores significantly lower (P < 0.001 and P < 0.05) than the MNA group and the no‐intervention group. No significant differences were found between the MNA group and the no‐intervention group. The MAA group had a mean AHI reduction of 14.1 (95% CI 7.4–20.8), and a mean Epworth score reduction of 3.3 (95% CI 1.8–4.8). Eight MAA patients (30%) achieved a reduction in AHI ≥75% ending with an AHI <5, half of them having baseline AHI >30. Sensitivity analyses confirmed these results. MAA had a significant beneficial effect on the vitality domain of SF‐36. Four MAA patients (14.8%) and two MNA patients (8%) discontinued interventions because of adverse effects. Our conclusion is that MAA has significant beneficial effects on OSA, including cure in some cases of severe OSA. Protrusion of the mandible is essential for the effect. MNA has no placebo effect. MAA may be a good alternative to CPAP in subsets of OSA patients.

The adenoid as a key factor in upper airway infections.

The adenoids (and the nasopharynx) play a key role in the normal functioning and in various pathologies of the upper respiratory tract. In this paper the role of adenoidal pathology and the beneficial effect of adenoidectomy in some upper respiratory tract and facial anomalies and diseases are discussed; otitis media with effusion, recurrent acute otitis media, sinusitis, snoring and sleep apnea and abnormal patterns in the midface growth and development.

Mandibular rotations: concepts and terminology

The paper proposes a terminology for describing the growth rotation of the mandible. Distinction is made between rotation (of a rigid body) and angular change (of a reference line). The terms true rotation and apparent rotation of the mandible are defined, and the term angular remodelling is introduced to describe the angular measure of the remodelling of the mandibular border.

Average surface remodeling of the maxillary base and the orbital floor in female subjects from 8 to 25 years. An implant study.

The present study aimed to analyze the surface remodeling of the maxilla by the method of metallic implants. The sample comprised 14 series of lateral cephalometric films of girls, and was derived from the files of the implant study of Björk. Implants had been inserted below the anterior nasal spine and on the lower anterior surfaces of the zygomatic arches. Various types of malocclusion were represented in the sample, but records during periods of orthodontic treatment and retention were excluded from the analysis. No subjects with craniofacial anomalies were included. The final sample comprised 155 radiographs in the age range 8 to 25 years. In addition to the anatomically defined reference points, six fiducial points and two implant points in the maxilla were digitized from each film. Data were debugged by comprehensive numerical and graphical procedures. The average relocation of the reference point subspinale (ss, Downs A point) was about 4.5 mm down and 0.5 mm forward from 8 to 25 years, whereas the reference point spinal (sp, ANS) was relocated about 4.5 mm down and 1 mm forward. The reference point pterygomaxillare (pm, PNS) was relocated 6 mm backward and 1.5 mm down by surface remodeling. The relocation of the sp and pm points resulted in an angular remodeling of the palatal plane of 2.5 degrees (backward). At the same time the maxillary complex rotated -1.5 degrees (forward) in relation to the anterior cranial base, resulting in a 1 degrees increase in the inclination of the palatal plane to the anterior cranial base. The orbital floor showed an average relocation of about 2.5 mm up and 2 mm backward by surface apposition, partly masking both the downward and forward sutural translation and the average forward growth rotation of the maxilla. Because of the angular remodeling of the palatal plane and the surface apposition on the hard palate, it is recommended that great caution be exerted in the interpretation of clinical treatment analyses based on superimposition on lines or structures defined by the anatomy of the bony palate during the period of growth.

A cephalometric unit for research and hospital environments

The paper describes a multi-projection cephalometer developed for research and hospital environments. The unit, which is a further development of the research cephalometer described by Bjork (1968), features improved control of the positioning of the patient, digital exposure control, and a number of technical innovations to facilitate the operation of the system.