Dental Arch Relationships and Reverse Headgear Effects in Southern Chinese Patients with Unilateral Cleft Lip and Palate: A Retrospective Study.

OBJECTIVE: To evaluate the severity of the dental arch relationships and the treatment outcomes of reverse headgear (RHG) in southern Chinese patients with unilateral cleft lip and palate (UCLP). DESIGN: A retrospective study. SETTING: Faculty of Dentistry, The University of Hong Kong. PATIENTS: Thirty-eight UCLP patients with complete records. Among them, 14 were later treated with RHG (RHG group) and 24 were under review (non-RHG group) before definitive orthodontic or in conjunction with orthognathic surgery. INTERVENTIONS: Study models at T1 (aged 9.4 ± 0.4 years old), prebone grafting and before any orthodontic treatment started; T2 (aged 11.3 ± 0.6 years old), after bone grafting, and RHG treatment (RHG group) or under review (non-RHG group); and T3 (aged 15.3 ± 3.2 years old), pretreatment of definitive orthodontic or in conjunction with orthognathic surgery. MAIN OUTCOME MEASURES: With satisfactory intra- and interexaminer agreement proven by the kappa value, the dental arch relationships of the study models at T1, T2, and T3 were assessed by a solo calibrated examiner using the GOSLON Yardstick. RESULTS: The median GOSLON score for southern Chinese patients with UCLP at T1 was 4.0. Sixty percent of the patients were categorized as "poor" at T1. RHG significantly improved dental arch relationships from T1 to T2, and the improvement was maintained until T3 assessed by the GOSLON Yardstick. CONCLUSIONS: The dental arch relationships in southern Chinese UCLP patients at 8 to 10 years old are unfavorable. RHG treatment shows positive effects in improving the dental arch relationships in UCLP patients, as assessed by the GOSLON Yardstick.

Prevalence of adenoid hypertrophy among 12-year-old children and its association with craniofacial characteristics: a cross-sectional study.

BACKGROUND: Identifying the prevalence of adenoid hypertrophy (AH) and craniofacial factors associated with this condition requires studies with random sampling from the general population, and multiple criteria can be used for assessing AH on lateral cephalometric radiograph (LCR). The present analysis represents the first report performed according to these requirements in a large cross-sectional sample of children. METHODS: LCRs of 517 12-year-old children (286 males, 231 females) randomly selected from the general population were retrospectively retrieved. AH was defined using three criteria (At/Nd, Ad-Ba/PNS-Ba, 1-Npaa/Npa), and twelve craniofacial variables were measured (SNA, SNB, ANB, Wits, Cd-Gn, MnP^SN, MxP^MnP, TPFH/TAFH, OPT^SN, C2ps-C4pi^SN, H-CV, H-FH). Skeletal characteristics were compared between children with and without AH using Mann-Whitney U test. Binary logistic regression (adjusted for sex and skeletal growth) was used to independently quantify the association between craniofacial factors and AH. RESULTS: The prevalence of children with AH was 17.6% (according to At/Nd), 19.0% (according to Ad-Ba/PNS-Ba), and 13.9% (according to 1-Npaa/Npa). Children with AH presented greater antero-posterior jaw discrepancy (larger ANB, smaller SNB), greater mandibular divergence (larger MnP^SN), forward head posture (larger OPT^SN and C2ps-C4pi^SN), and anteriorly positioned hyoid bone (larger H-CV). Larger SNA (OR = 1.39-1.48), while smaller SNB (OR = 0.77-0.88) and Wits (OR = 0.85-0.87), were associated with greater likelihood of having AH, independently from the assessment method used. CONCLUSIONS: The prevalence of children with AH ranged from 13.9 to 19.0% based on LCR. Greater antero-posterior maxillo-mandibular discrepancy and mandibular retrusion were independently associated with higher likelihood of having AH.

Evaluation of the relationship between malar projection and lower facial convexity in terms of perceived attractiveness in 3-dimensional reconstructed images.

BACKGROUND: This study aimed to investigate dental student's perception of facial attractiveness with regard to different combinations of anteroposterior malar-jaw positions using 3-dimensional (3-D) reconstructed images of subjects. METHODS: Two Chinese young adults (1 male and 1 female) with straight profiles and average malar projections were selected for the study. 3-D facial images and cone-beam computed tomography images of these two subjects were superimposed using 3-D imaging software. Lateral and oblique views of nine different images were created by moving the maxillomandibular complex and/or zygomatic bone by 4 mm either forward or backward along the sagittal plane. One hundred three undergraduate dental students (n = 24, 33, and 46 students from the Year 3, 4, and 5, respectively) then scored lateral and 45° oblique view images of the newly reconstructed faces. RESULTS: In the present study, images with a neutral malar and retruded jaws were found to be the most attractive in both male and female subjects. In addition, the Protruded malar (PM) group (p < 0.001), and the Retruded Jaws (RJ) group were rated more attractive (p < 0.001). Furthermore, the Relatively Prominent malar (RP) group was rated more attractive (p < 0.001) when malar-jaw relative positions were compared. CONCLUSION: This study shows that a neutral or a protruded malar favours facial attractiveness in both Chinese male and female subjects. Therefore, an appropriate relationship between malar projection and lower facial convexity should be taken into consideration while designing the orthodontic/orthognathic treatment plans for enhanced aesthetic outcomes.