Anthropometry of the head and face

This new edition includes more than 107,000 terms and definitions, more than 5,000 new to this edition. More than 45 consultants from all the major medical and health science specialties have reviewed each word for accuracy and clarity, including new consultants for the specialties of endocrinology, gastroenterology, geriatrics, and rheumatology. The art program has also been extensively enhanced and now includes approximately 1,500 images and illustrations.

Stedman's Medical Dictionary

The aim of this study is to evaluate the validity of the use of digital models to assess tooth size, arch length, irregularity index, arch width and crowding versus measurements generated on hand-held plaster models with digital callipers in patients with and without malocclusion. Studies comparing linear and angular measurements obtained on digital and standard plaster models were identified by searching multiple databases including MEDLINE, LILACS, BBO, ClinicalTrials.gov, the National Research Register and Pro-Quest Dissertation Abstracts and Thesis database, without restrictions relating to publication status or language of publication. Two authors were involved in study selection, quality assessment and the extraction of data. Items from the Quality Assessment of Studies of Diagnostic Accuracy included in Systematic Reviews checklist were used to assess the methodological quality of included studies. No meta-analysis was conducted. Comparisons between measurements of digital and plaster models made directly within studies were reported, and the difference between the (repeated) measurement means for digital and plaster models were considered as estimates. Seventeen relevant studies were included. Where reported, overall, the absolute mean differences between direct and indirect measurements on plaster and digital models were minor and clinically insignificant. Orthodontic measurements with digital models were comparable to those derived from plaster models. The use of digital models as an alternative to conventional measurement on plaster models may be recommended, although the evidence identified in this review is of variable quality.

Orthodontic measurements on digital study models compared with plaster models: a systematic review

Autism and asperger syndrome.

Background The paradigm shift from occlusion to esthetics places more emphasis on the subtle relationships among the teeth and the interplay with the soft tissues. The authors of this study quantified the ideal and maximum acceptable deviations for smile characteristics. Methods The authors created a survey by using a digital image editing software package, which enabled raters to manipulate intraoral photographs featured in the survey. They altered smile characteristics in photos of a sex-neutral face showing nasal tip to mentolabial fold. The authors administered an electronic survey in Boston (n = 78); Columbus, Ohio (n = 81); and Seattle (n = 84). An interactive interface allowed raters to select the ideal for each smile characteristic presented and identify the range of acceptability for the variables. Results Raters were reliable (κ = 0.34–0.88). Survey location was not significant except that raters from the West accepted a broader smile than did those from the Midwest and the East. Raters identified ideals and thresholds for the following smile characteristics: smile arc; buccal corridor; gingival display; canine and posterior crown torque, ideal and large corridor; maxillary midline to face; maxillary to mandibular midline; overbite; maxillary central incisor gingival height discrepancy; maxillary lateral incisor gingival height discrepancy; maxillary central to lateral incisal step; maxillary central incisor crown width-to-height ratio; maxillary central-to-lateral incisal ratio; and occlusal cant. Generally, the values for ideal paralleled existing data, and new guidelines for some variables emerged. The ranges of acceptability were large. Conclusions The ideal and an acceptable range for each smile characteristic can be identified reliably. Practice implications Laypeople can reliably identify ideal smile characteristics. The ranges of acceptable deviations for smile characteristics are large, and practitioners should avoid unnecessarily sensitizing patients to minor discrepancies.

Esthetics and smile characteristics from the layperson's perspective: a computer-based survey study.

BACKGROUND Digital copies of study models may avoid the storage and retrieval issues of plaster study models, but measurements made on digital models may not be as accurate as measurements made on traditional study models. AIM To determine the reliability and validity of tooth size-arch length discrepancies (TALD), irregularity indices and arch lengths (four- and six-segment analyses) measured directly on study models with digital calipers with the same measurements measured on digital copies of the study models with proprietary software. METHODS The irregularity indices and TALDs (four- and six-segments) were measured on 50 sets of pretreatment plaster models. The plaster models were measured using manual calipers with a digital readout. The models were then couriered to OrthoCAD and digital copies emailed to the authors. The digital models were measured with the proprietary software provided with the digital models. Repeat measurements of the TALDs and the irregularity indices were subjected to intraclass correlations (ICC) to assess the reliability. The least squares means of variation was used to assess validity and the impact of measuring arch length (four- and six-segments) on the digital models, and the implications on the TALDs. RESULTS There were high correlations (ICC) ranging from 98.6-99.9 per cent for both the irregularity indices and the TALDs. The choice of manual over computer and four-segment over six-segment analysis had a significant effect when measuring lower arch lengths (p < 0.05), but they had no effect on the upper arch findings. CONCLUSIONS Reliable measurements of the irregularity index and the TALD can be made on digital models. Computer measurements of TALDs on digital models were more consistent than manual measurements of TALDs on plaster models. Six-segment analyses of lower arch lengths on digital and plaster models gave more consistent findings than the four-segment analyses.

Accuracy and validity of space analysis and irregularity index measurements using digital models.

https://link.springer.com/content/pdf/10.1186%2Fs40510-015-0106-9.pdf

Facial asymmetry assessment in adults using three-dimensional surface imaging

Influence of lips on the perception of malocclusion

Background: Active self-ligating brackets may be more efficient than conventional pre-adjusted brackets. Aims: To determine if self-ligating brackets are more efficient than conventional pre-adjusted brackets when used in a specialist practice setting. Methods: Seven hundred and sixty two patients, consecutively treated with fixed appliances, were evaluated retrospectively. All patients were treated by one orthodontist in a private orthodontic practice. Three hundred and eighty three patients were treated using a conventional pre-adjusted bracket system and 379 patients were treated with active self-ligating brackets. The total treatment time, number of appointments, appointment intervals, number of bracket breakages and number of unscheduled emergency appointments were recorded. Pretreatment characteristics identified by the ICON were related to these variables. Results: The average treatment duration was 15.7 months (Range: 4.1‐40.5 months; SD: 5.6 months). Comparable amounts of time were spent in rectangular and round archwires by both appliances. Overall, there was no statistically significant difference between the durations of treatment with active self-ligating brackets and conventional pre-adjusted brackets. The number of debonded brackets and other emergency visits was significantly higher in patients treated with active self-ligating brackets. The treatment characteristics associated with prolonged treatment were: extraction of teeth, a Class II molar relationship and the degree of maxillary crowding or spacing. Conclusions: Active self-ligating brackets appear to offer no measurable advantages in orthodontic treatment time, number of treatment visits and time spent in initial alignment over conventional pre-adjusted orthodontic brackets. (Aust Orthod J 2008; 24: 102‐109)

Mithran S. Goonewardene

Papers

Accuracy and validity of space analysis and irregularity index measurements using digital models.

Facial asymmetry assessment in adults using three-dimensional surface imaging

Influence of lips on the perception of malocclusion

Comparison of active self-ligating brackets and conventional pre-adjusted brackets.

Morphologic changes of the palate after rapid maxillary expansion: A 3-dimensional computed tomography evaluation