The facial morphology in Down syndrome: A 3D comparison of patients with and without obstructive sleep apnea.

Obstructive sleep apnea (OSA) occurs at a high prevalence in patients with Down syndrome (DS). A polysomnogram, which is often cumbersome and challenging, remains the gold standard method of diagnosing OSA. OSA in patients with DS is often attributed to skeletal and soft-tissue structural alterations that are characteristic of the DS phenotype; as such, we hypothesized that assessing anthropometric facial measurements may be predictive of OSA in patients with DS. We used the 3dMDface sterophotography system to capture and create 3D facial images, and we subsequently identified facial landmarks using a single, experienced investigator and utilizing proprietary software to calculate inter-landmark distances and angles. We compared our findings with similar data for neurotypically developing participants. We further compared the findings in participants with DS with and without OSA. Participants with DS had maxillomandibular hypoplasia with smaller ear, nose, and eye measurements compared to neurotypically developing peers. We found no statistically significant differences in 3D photogrammetric measurements between participants with DS with or without OSA.

A predictive model for obstructive sleep apnea and Down syndrome.

Obstructive sleep apnea (OSA) occurs frequently in people with Down syndrome (DS) with reported prevalences ranging between 55% and 97%, compared to 1-4% in the neurotypical pediatric population. Sleep studies are often uncomfortable, costly, and poorly tolerated by individuals with DS. The objective of this study was to construct a tool to identify individuals with DS unlikely to have moderate or severe sleep OSA and in whom sleep studies might offer little benefit. An observational, prospective cohort study was performed in an outpatient clinic and overnight sleep study center with 130 DS patients, ages 3-24 years. Exclusion criteria included previous adenoid and/or tonsil removal, a sleep study within the past 6 months, or being treated for apnea with continuous positive airway pressure. This study involved a physical examination/medical history, lateral cephalogram, 3D photograph, validated sleep questionnaires, an overnight polysomnogram, and urine samples. The main outcome measure was the apnea-hypopnea index. Using a Logic Learning Machine, the best model had a cross-validated negative predictive value of 73% for mild obstructive sleep apnea and 90% for moderate or severe obstructive sleep apnea; positive predictive values were 55% and 25%, respectively. The model included variables from survey questions, medication history, anthropometric measurements, vital signs, patient's age, and physical examination findings. With simple procedures that can be collected at minimal cost, the proposed model could predict which patients with DS were unlikely to have moderate to severe obstructive sleep apnea and thus may not need a diagnostic sleep study.

Efficiency of piezotome-corticision assisted orthodontics in alleviating mandibular anterior crowding-a randomized clinical trial.

OBJECTIVES: The aim of this clinical trial was to investigate the duration of mandibular-crowding alleviation with piezotome-corticision orthodontics compared with conventional orthodontics. DESIGN: Single-centre, two-arm parallel group randomized controlled trial. SETTING: Orthodontic clinic at the University of Connecticut. ETHICAL APPROVAL: The study was approved by the Institutional Review Board (IRB # 12-0147-2). SUBJECTS AND METHODS: Forty-one adult subjects from a single centre with more than 5mm of mandibular anterior crowding were randomly allocated using block randomization into experimental and control groups. The experimental group received a corticision procedure with a piezotome on the labial aspect of the mandibular incisors in conjunction to a self-ligation fixed orthodontic appliance. The control group received the self-ligation fixed orthodontic appliance and no corticision. Same archwire sequence (0.014 inch followed by 0.014 × 0.025 inch copper-nickel-titanium) was followed for both groups. Mandibular study casts taken every 4-5 weeks were used to assess changes in the irregularity index by blinded outcome assessors. OUTCOME MEASURES: The time to alignment was calculated in days. RESULTS: Twenty-nine subjects (16 experimental and 13 control) completed the study. Overall, no significant difference in the time required to correct mandibular crowding with piezotome-corticision assisted (102.1 ± 34.7 days; 95% CI, 83.6 to 120.6) and conventional orthodontics (112 ± 46.2 days; 95% CI, 84-139.9) was observed. No complications with treatment or unintended consequences were observed on any of the subjects. LIMITATIONS: A high attrition rate. CONCLUSIONS: This randomized clinical trial found no evidence that piezotome-corticision assisted orthodontics was more efficient in alleviating mandibular anterior crowding. REGISTRATION: ClinicalTrials.gov, Identifier: NCT02026258. FUNDING: Division of Orthodontics, University of Connecticut. CONFLICT OF INTEREST: None.

Methodological challenges when performing a systematic review.

Well-conducted systematic reviews can provide a foundation upon which to base educational curricula, practice guidelines and healthcare policy. We aim to provide an overview of important methodological issues that need to be addressed during the five phases of performing a systematic review. 1. The specific problems to be addressed by the systematic review need to be formulated as clear, unambiguous and structured question/s. 2. Literature from multiple resources should be searched to avoid publication biases, as positive outcomes are more likely to be published than null/negative results. 3. The quality of selected articles should be assessed using a checklist, while the reliability of graders, as well as the quality of the checklist, needs to be established a priori. 4. Statistical heterogeneity needs to be assessed to determine if a meta-analysis is appropriate to pool the data. If not, a narrative synthesis of the evidence/overall findings needs to be performed within a clinical context.

Readability of websites containing information on dental implants.

UNLABELLED: It is recommended that health-related materials for patients be written at sixth grade level or below. Many websites oriented toward patient education about dental implants are available, but the readability of these sites has not been evaluated. OBJECTIVE: To assess readability of patient-oriented online information on dental implants. MATERIALS AND METHODS: Websites containing patient-oriented information on dental implants were retrieved using the Google search engine. Individual and mean readability/grade levels were calculated using standardized formulas. Readability of each website was classified as easy (≤ 6th-grade level) or difficult (≥ 10th grade level). RESULTS: Thirty nine websites with patient-oriented information on dental implant were found. The average readability grade level of these websites was 11.65 ± 1.36. No website scored at/below the recommended 6th grade level. Thirty four of 39 websites (87.18%) were difficult to read. The number of characters, words, and sentences on these sites varied widely. CONCLUSION: All patient-oriented websites on dental implants scored above the recommended grade level, and majority of these sites were "difficult" in their readability. There is a dire need to create patient information websites on implants, which the majority can read.

Stereophotogrammetry-based facial depth measurements: a novel method for quantifying facial projection.

BACKGROUND: Orthognathic surgery leads to alteration of the spatial relationship of the mandible and maxilla resulting changes in the degree of facial projection. Traditional 2-dimensional cephalometry and photographic techniques do not provide data on facial depth. Though stereophotogrammetry can be used as a noninvasive method for evaluating facial depth, the unavailability of ethnicity-specific norms hinder its routine use in clinical practice. The objectives of this study were to (a) generate an analytic scheme suitable for evaluating facial depth using stereophotogrammetry and (b) create normative data for the facial depth measurements for young Hong Kong Chinese adults. METHODS: Stereophotographic images from 41 male and 45 female ethnic Chinese young adults without facial deformities were analyzed. Facial depth measurements were performed based on standard anthropometric landmarks, with the aid of 3dMDVultus software. RESULTS: All facial depth measurements were found in absolute terms to be significantly higher in males. In contrast, the upper face, maxillary, and sublabial depth indices were significantly higher in females, whereas no significant gender differences emerged for lower facial and maxillomandibular indices. CONCLUSIONS: A novel method of using stereophotographic images for quantifying facial depth was evaluated. Normative facial depth measurements for young Hong Kong Chinese adults were established. This gender-specific database can be used as a reference in the diagnosis, treatment planning, or evaluation of outcomes after surgical correction of facial deformities.

Innovative primary care training: the Cambridge Health Alliance Oral Physician Program.

We evaluated the Oral Physician Program, a dental residency sponsored by Harvard Medical School, Harvard School of Dental Medicine, and the Cambridge Health Alliance that offers an innovative model for training dentists to provide limited primary care. The didactic and clinical experiences increased residents' medical knowledge and interviewing skills, and faculty assessments supported their role as oral physicians. Oral physicians could increase patients'-especially patients from underserved groups-access to integrated oral and primary care services.

Nasolabial soft tissue changes after Le Fort I advancement.

PURPOSE: To identify the nasolabial soft tissue changes that occur after Le Fort I advancement. MATERIALS AND METHODS: A prospective study of patients who had Le Fort I advancement at the Children's Hospital Boston from 2005 to 2007. The pre- and postoperative anthropometeric nasolabial measurements were recorded by a single examiner. RESULTS: A total of 37 patients with a mean age of 18.6 years at the time of operation and a mean follow-up of 12.6 months were recruited. Nearly one half of the study sample (16 of 37) had cleft lip/palate. Direct anthropometry showed a reduction of the nasal length by 1.3 mm while the nasal tip protrusion increased by 1.1 mm. The nasofrontal angle decreased by 9.8° and the upper lip moved forward by 4.15 mm, reflecting the advancement in the maxilla. The height of the cutaneous upper lip increased by 0.4 mm. No significant differences were found in the soft tissue response observed between the cleft and noncleft subjects. CONCLUSIONS: Le Fort I advancement produces elevation of the nasal tip, as seen by a reduction in the nasal length, an increase in the nasal tip protrusion, and a concomitant reduction in the nasofrontal angle. Additionally, the cutaneous lip height increased, most likely due to an unfurling of the upper lip.

Three-dimensional color maps: a novel tool for assessing craniofacial changes.

INTRODUCTION: Three-dimensional (3D) color maps are useful for analyzing data acquired by laser scanning, stereophotography, or computed tomography (CT). The authors aim to illustrate the different applications of color maps in the craniomaxillofacial region. METHODS: The images obtained from the above techniques at 2 different time points are superimposed based on a common area unaffected by the surgical intervention or growth. Using specialized software, the distance differences between the 2 superimposed images are depicted in a graphical format as a 3D color map. A color-coded scale indicating the distances accompanies these maps. RESULTS: 3D color maps can be manipulated and viewed in a variety of angles to extract the maximum diagnostic information. They facilitate the critical evaluation of facial asymmetry, accuracy of fusing CT and 3D photo data sets, and postsurgical changes. CONCLUSION: 3D color maps aid the objective assessment of craniofacial structures while enhancing visual comprehension and communication with patients.

Computer-aided maxillofacial surgery: an update.

INTRODUCTION: Recent developments in technology have revolutionized medicine and surgery. This article aims at providing an update on the current trends in computer-aided maxillofacial surgery and illustrates these advances with clinical cases. METHODS: The PubMed database was searched for articles published during the past 5 years using the keywords "maxillofacial" and "surgery, computer-assisted." Full texts of relevant articles were retrieved, and their study details were extracted. RESULTS: Among the 133 articles, most focused on cone-beam computed tomography (CBCT), stereophotography, surgical panning software, and intraoperative navigation. Stereophotography produces 3D facial photographs with natural color and texture, whereas CBCT generates excellent hard-tissue images with a substantially lower radiation than conventional CT scans. Information gathered from CBCT and stereophotography can be used for accurate diagnosis, virtual planning, and simulation of surgery with the aid of specialized software. The preplanned treatment can be executed accurately via intraoperative surgical navigation. CONCLUSION: Tremendous potential exists for computer-aided maxillofacial surgery as it moves from research to clinical care.

Application of digital anthropometry for craniofacial assessment.

Craniofacial anthropometry is an objective technique based on a series of measurements and proportions, which facilitate the characterization of phenotypic variation and quantification of dysmorphology. With the introduction of stereophotography, it is possible to acquire a lifelike three-dimensional (3D) image of the face with natural color and texture. Most of the traditional anthropometric landmarks can be identified on these 3D photographs using specialized software. Therefore, it has become possible to compute new digital measurements, which were not feasible with traditional instruments. The term "digital anthropometry" has been used by researchers based on such systems to separate their methods from conventional manual measurements. Anthropometry has been traditionally used as a research tool. With the advent of digital anthropometry, this technique can be employed in several disciplines as a noninvasive tool for quantifying facial morphology. The aim of this review is to provide a broad overview of digital anthropometry and discuss its clinical applications.

Nasal Morphology of the Chinese: Three-Dimensional Reference Values for Rhinoplasty.

OBJECTIVE: To determine normative nasal measurements for Chinese young adults, conditioned on demographics. STUDY DESIGN: A cross-sectional descriptive study. SETTING: A university hospital. SUBJECTS AND METHODS: Three-dimensional (3D) photographs were captured from 103 Chinese subjects between 18 and 35 years of age using a commercial stereophotographic system. Anthropometric landmarks were identified on these 3D surface images, and measurements suitable for nasal analysis were performed and contrasted against established Caucasian norms. Gender differences in anthropometric dimensions were also analyzed. RESULTS: Normative data for these measurements are made available. Linear nasal measurements, except those for mid-columella length, were significantly larger in men than in women; further, the nasal tip angle and nasofrontal angle were significantly larger in Chinese women. Contrasts of these new data against published Caucasian norms revealed dimensions that differ for these 2 groups. The Chinese normative mean values for morphological nose width, nasal tip angle, nasofrontal angle, and alar slope angle exceeded those reported for North American Caucasians. CONCLUSIONS: Gender-specific normative data for the Chinese nose were established in this study to provide a useful tool for surgeons in dealing with rhinoplasty. Moreover, the Chinese nasal anthropometric measurements in this study are broader and flatter than those reported for North American Caucasians.

A 3D anthropometric analysis of the orolabial region in Chinese young adults.

The orolabial region undergoes considerable changes after orthognathic surgery or orthodontic treatment. Ethnicity, age, and sex-specific norms are needed during the planning of interventions in this region. In 2008 the Br J Oral Maxillofac Surg published anthropometric measurements of the lips of Chinese children, but to our knowledge such reference data for young Chinese adults are not currently available. We therefore used digital anthropometry on 3-dimensional craniofacial images acquired from 103 healthy young Chinese adults with Class I skeletal pattern. Anthropometric landmarks were identified, which provided linear and angular measurements. All orolabial measurements were significantly larger in men than women, with the exception of the labiomental angle. In contrast, there were no sex differences in the anthropometric proportions. We therefore provide what we think are the first cross-sectional norms available for young Chinese adults. These norms can be used to evaluate the morphology of the lips objectively for preoperative diagnosis, planning of treatment, and assessment of postoperative outcomes.

Normative findings for periocular anthropometric measurements among Chinese young adults in Hong Kong.

Measurement of periocular structures is of value in several clinical specialties including ophthalmology, optometry, medical and clinical genetics, oculoplastic surgery, and traumatology. Therefore we aimed to determine the periocular anthropometric norms for Chinese young adults using a noninvasive 3D stereophotography system. Craniofacial images using the 3dMDface system were acquired for 103 Chinese subjects (51 males and 52 females) between the ages of 18 and 35 years. Anthropometric landmarks were identified on these digital images according to standard definitions, and linear distances between these landmarks were calculated. It was found that ocular measurements were significantly larger in Chinese males than females for intercanthal width, biocular width, and eye fissure lengths. No gender differences were found in the eye fissure height and the canthal index which ranged between 43 and 44. Both right and left eye fissure height-length ratios were significantly larger in females. This is the first study to employ 3D stereophotogrammetry to create a database of anthropometric normative data for periocular measurements. These data would be useful for clinical interpretation of periocular pathology and serve as reference values when planning aesthetic and posttraumatic surgical interventions.

How accurate are the fusion of cone-beam CT and 3-D stereophotographic images?

BACKGROUND: Cone-beam Computed Tomography (CBCT) and stereophotography are two of the latest imaging modalities available for three-dimensional (3-D) visualization of craniofacial structures. However, CBCT provides only limited information on surface texture. This can be overcome by combining the bone images derived from CBCT with 3-D photographs. The objectives of this study were 1) to evaluate the feasibility of integrating 3-D Photos and CBCT images 2) to assess degree of error that may occur during the above processes and 3) to identify facial regions that would be most appropriate for 3-D image registration. METHODOLOGY: CBCT scans and stereophotographic images from 29 patients were used for this study. Two 3-D images corresponding to the skin and bone were extracted from the CBCT data. The 3-D photo was superimposed on the CBCT skin image using relatively immobile areas of the face as a reference. 3-D colour maps were used to assess the accuracy of superimposition were distance differences between the CBCT and 3-D photo were recorded as the signed average and the Root Mean Square (RMS) error. PRINCIPAL FINDINGS: The signed average and RMS of the distance differences between the registered surfaces were -0.018 (±0.129) mm and 0.739 (±0.239) mm respectively. The most errors were found in areas surrounding the lips and the eyes, while minimal errors were noted in the forehead, root of the nose and zygoma. CONCLUSIONS: CBCT and 3-D photographic data can be successfully fused with minimal errors. When compared to RMS, the signed average was found to under-represent the registration error. The virtual 3-D composite craniofacial models permit concurrent assessment of bone and soft tissues during diagnosis and treatment planning.

Are neoclassical canons valid for southern Chinese faces?

BACKGROUND: Proportions derived from neoclassical canons, initially described by Renaissance sculptors and painters, are still being employed as aesthetic guidelines during the clinical assessment of the facial morphology. OBJECTIVE: 1. to determine the applicability of neoclassical canons for Southern Chinese faces and 2. to explore gender differences in relation to the applicability of the neoclassical canons and their variants. METHODOLOGY: 3-D photographs acquired from 103 young adults (51 males and 52 females) without facial dysmorphology were used to test applicability of four neoclassical canons. Standard anthropometric measurements that determine the facial canons were made on these 3-D images. The validity of the canons as well as their different variants were quantified. PRINCIPAL FINDINGS: The neoclassical cannons seldom applied to these individuals, and facial three-section and orbital canons did not apply at all. The orbitonasal canon was most frequently applicable, with a frequency of 19%. Significant sexual dimorphism was found relative to the prevalence of the variants of facial three-section and orbitonasal canons. CONCLUSION: The neoclassical canons did not appear to apply to our sample when rigorous quantitative measurements were employed. Thus, they should not be used as esthetic goals for craniofacial surgical interventions.

Three-dimensional cephalometric norms of Chinese adults in Hong Kong with balanced facial profile.

OBJECTIVE: The objectives of this study were (1) to develop a 3D cephalometric analysis scheme applicable to assessing dentofacial deformities; and (2) to create a normative database of 3D cephalometric measurements for adult Chinese in Hong Kong. STUDY DESIGN: A cross-sectional study was conducted on 50 male and 50 female adults with normal balanced facial profile and occlusion. Cone-beam computed tomography and stereo photogrammetry imaging were performed on all subjects. Three-dimensional virtual models were generated from imaging data, and cephalometric analysis was performed using specialized software. A new 3D cephalometric analysis scheme appropriate for orthognathic surgery as well as a new reference plane (supraorbital margin plane) for midfacial assessment was used in this study. RESULTS: The cephalometric norms generated in this study were comparable with those reported in the literature for conventional 2D cephalometric analysis and the unique features of Chinese faces. The results also showed significant differences between males and females in most of the facial height measurements (P < .01). CONCLUSIONS: This is the first database of 3D cephalometric norms based on CBCT and 3D photogrammetry of the Chinese population in Hong Kong. This can be a useful reference for characterizing facial deformities in 3 dimensions. Moreover, 3D cephalometric analysis has the potential of incorporating new measurement methods that are difficult if not impossible in 2D cephalometric analysis.

Three-dimensional photogrammetry for surgical planning of tissue expansion in hemifacial microsomia.

BACKGROUND: We aim to illustrate the applications of 3-dimensional (3-D) photogrammetry for surgical planning and longitudinal assessment of the volumetric changes in hemifacial microsomia. METHODS: A 3-D photogrammetric system was employed for planning soft tissue expansion and transplantation of a vascularized scapular flap for a patient with hemifacial microsomia. The facial deficiency was calculated by superimposing a mirror of the normal side on the preoperative image. Postsurgical volumetric changes were monitored by serial superimposition of 3-D images. RESULTS: A total of 31 cm(3) of tissue expansion was achieved within a period of 4 weeks. A scapular free flap measuring 8 cm × 5 cm was transplanted to augment the facial deficiency. Postsurgical shrinkage of the flap was observed mainly in the first 3 months and it was minimal thereafter. CONCLUSION: 3-D photogrammetry can be used as a noninvasive objective tool for assessing facial deformity, planning, and postoperative follow-up of surgical correction of facial asymmetry.