Oral Health Status and Oral Health-Related Behaviours of Hong Kong Students with Vision Impairment

This cross-sectional epidemiological study aimed to describe dental caries and oral hygiene conditions among visually impaired students in Hong Kong. Students aged 6-21 years from two specialised schools for those with vision impairment were invited. Information on sociodemographic background and oral health-related behaviours was collected through an online parent-reported questionnaire. Dental caries and oral hygiene were assessed using the Decayed, Missing and Filled Teeth (DMFT) index and the Visible Plaque Index (VPI), respectively. Chi-square, Mann-Whitney U and Kruskal-Wallis H tests were conducted to analyse the association between students' background and oral health status. A total of 73 participants were recruited, of whom 57.5% were male. Their mean (SD) age was 12.9 (4.7) years. Their mean DMFT score (SD) was 1.0 (1.8), and 43.8% had caries experience. The mean VPI (SD) was 0.76 (0.30). Their caries experience was significantly associated with their snacking habits (p = 0.013). Male participants had poorer oral hygiene than females (p = 0.048). In summary, dental caries is prevalent among visually impaired students in Hong Kong and their oral hygiene condition is unsatisfactory. Caries experience is significantly associated with snacking frequency, whereas oral hygiene is associated with gender. More specially designed preventive oral health measures should be provided for visually impaired students and their caretakers.

Accuracy and safety of in-house surgeon-designed three-dimensional-printed patient-specific implants for wafer-less Le Fort I osteotomy

OBJECTIVES

The design and fabrication of three-dimensional (3D)-printed patient-specific implants (PSIs) for orthognathic surgery are customarily outsourced to commercial companies. We propose a protocol of designing PSIs and surgical guides by orthognathic surgeons-in-charge instead for wafer-less Le Fort I osteotomy. The aim of this prospective study was to evaluate the accuracy and post-operative complications of PSIs that are designed in-house for Le Fort I osteotomy.

MATERIALS AND METHODS

The post-operative cone beam computer tomography (CBCT) model of the maxilla was superimposed to the virtual surgical planning to compare the discrepancies of pre-determined landmarks, lines, and principal axes between the two models. Twenty-five patients (12 males, 13 females) were included.

RESULTS

The median linear deviations of the post-operative maxilla of the x, y, and z axes were 0.74 mm, 0.75 mm, and 0.72 mm, respectively. The deviations in the principal axes for pitch, yaw, and roll were 1.40°, 0.90°, and 0.60°, respectively. There were no post-operative complications related to the PSIs in the follow-up period.

CONCLUSIONS

The 3D-printed PSIs designed in-house for wafer-less Le Fort I osteotomy are accurate and safe.

CLINICAL RELEVANCE

Its clinical outcomes and accuracy are comparable to commercial PSIs for orthognathic surgery.

TRIAL REGISTRATION

Clinical trial registration number: HKUCTR-2113. Date of registration: 29 July 2016.

Factors affecting periodontal healing of the adjacent second molar after lower third molar surgery: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis aim to evaluate the effect modifiers which may influence the periodontal healing of the adjacent second molar after lower third molar surgery.

MATERIALS AND METHODS

Prospective studies including patients with third molars requiring removal, with at least 6 months follow-up were considered. Outcomes were periodontal probing depth (PPD) reduction, final PPD, clinical attachment level (CAL) change, final CAL, alveolar bone defect (ABD) reduction, and final ABD depth. Meta-regression was performed to identify factors.

RESULTS

Fourteen studies were included in the quantitative synthesis. At 6 months, the PPD reduction was 1.06 mm (95% CI, 0.72 to 1.39 mm) and the remaining PPD was 3.81 mm (95% CI, 3.00 to 4.62 mm). Baseline PPD was strongly correlated with the remaining PPD at 6 months (p < 0.001, adjusted R² = 70.05%).

CONCLUSIONS

Lower third molar surgery results in a modest reduction in PPD, CAL, and ABD; however, periodontal defects still remain at 6 months and beyond. Baseline PPD is strongly correlated with final PPD. While age is not shown to have effect on most of the periodontal parameters, a larger baseline PPD is more likely to manifest with increasing age and third molar surgery should be done before severe periodontitis occurs to avoid persistent periodontal defects.

CLINICAL RELEVANCE

This study shows that lower third molar surgery results in modest improvement in periodontal parameters on adjacent second molars and identified factors such as baseline PPD which may affect the healing, which may guide the pre-, peri-, and post-operative management of lower third molar surgery.