Association between occlusal features and masticatory function in Hong Kong preschool children: a survey with one-year longitudinal follow-up.

BACKGROUND: Mastication is important for breaking down food, aiding swallowing and nutrients absorption, and is therefore fundamental to a child's development. Studies have shown poor masticatory function to be associated with younger age and presence of caries. However, studies of the association between masticatory function and malocclusion yielded contradictory results. The aim of this study is therefore to investigate the association between three-dimensional occlusal features with masticatory function, among preschool children in Hong Kong. METHODS: Self-administered questionnaires on masticatory function in three domains, namely general chewing difficulty, requiring help when eating different food types and increased preference for soft food were completed by parents. Information on non-nutritive sucking habits and basic demographics were also collected in the questionnaire. Clinical examinations were conducted to record three-dimensional occlusal features and presence of caries. Baseline investigations and one-year follow-ups were undertaken for 1,566 and 996 preschool children. Association of poor masticatory function with occlusal features, sucking habits and caries was investigated using chi-squared tests. Binomial logistic regressions were then carried out incorporating any significant factors identified. Longitudinal analysis of the one-year follow-up data was carried out to investigate whether improved occlusal features, sucking habits and caries resulted in better masticatory function. RESULTS: In the cross-sectional study, the first domain of general chewing difficulty was associated with caries and thumb/digit sucking. The second domain of requiring help when eating different food types was associated with the male sex, younger age, caries and pacifier use. The last domain of increased preference for soft foods was associated with caries and thumb/digit sucking. Occlusal features, including abnormal overjet and unilateral permanent molars not in contact, were significantly associated with poor masticatory function in the bivariate analyses, but were not significant in the logistic regressions. In the longitudinal analysis, general chewing difficulty was found to improve in those of older age and those with resolved anterior crossbite. Less help was required to eat meat in those with fewer caries. Similarly, less help was required to eat food containing bones in those with reduced pacifier use. Preferences for eating soft foods was reduced in those who developed a normal overjet. CONCLUSIONS: The study identified significant relationships between masticatory difficulties and factors associated with age, gender, active caries, and non-nutritive oral habits such as thumb/digit sucking and pacifier use. Younger children and males required more assistance with certain food types. Active caries and thumb/digit sucking habits contributed to general masticatory difficulties and preference for soft foods. The one-year follow-up indicated that improvement in masticatory function varies across age cohorts and were associated with improved occlusal features, such as resolution of anterior crossbite and normalized overjet, reduced pacifier use, and a decrease in the number of decayed teeth.

Low-level laser-aided orthodontic treatment of periodontally compromised patients: a randomised controlled trial.

Low-level laser irradiation (LLLI) shows effects in orthodontic pain relief and periodontal inflammation control. The aim of this article is to investigate the analgesic and inflammation-modulatory effects of low-level laser irradiation among orthodontic patients with compromised periodontium. A randomised controlled trial with split-mouth design was conducted in 27 adults with treated and controlled chronic periodontitis over 6 months. One side of the dental arch underwent repeated treatment under a 940-nm diode laser (EZlase; Biolase Technology Inc.) with a beam size of 2.8 cm2 for 60 seconds at 8.6 J/cm2, whilst the other side received pseudo-laser treatment. Laser irradiation was applied repeatedly for 8 times during the first 6 weeks after bracket bonding and monthly thereafter until the end of orthodontic treatment. Subjective pain (assessed by visual analogue scale in pain diary and by chairside archwire activation), periodontal status (assessed by periodontal clinical parameters), cytokines in gingival crevicular fluid (interleukin 1ß, prostaglandin E2, substance P) and periodontopathic bacteria (Porphyromonas gingivalis and Treponema denticola) in supragingival plaque were assessed. The intensity of pain was lower on the laser-irradiated side at multiple follow-up visits (P < 0.05). The pain subsided 1 day earlier on the laser side, with a lower peak value during the first week after initial archwire placement (P < 0.05). The laser side exhibited a smaller reduction in bite force during the first month (mean difference = 3.17, 95% CI: 2.36-3.98, P < 0.05 at 1-week interval; mean difference = 3.09, 95% CI: 1.87-4.32, P < 0.05 at 1-month interval). A smaller increase was observed in the plaque index scores on the laser side at 1-month (mean difference = 0.19, 95% CI: 0.13-0.24, P < 0.05) and in the gingival index scores at the 3-month follow-up visit (mean difference = 0.18, 95% CI: 0.14-0.21, P < 0.05). Laser irradiation inhibited the elevation of interleukin-1ß, prostaglandin E2 and substance P levels during the first month (P < 0.05). However, no intergroup difference was detected in the bacteria levels. Low-level laser irradiation exhibits benefits in pain relief and inflammation control during the early stage of adjunctive orthodontic treatment in periodontally compromised individuals.

The association between nutritive, non-nutritive sucking habits and primary dental occlusion.

BACKGROUND: The development of primary dentition can be affected by oral sucking habits. Therefore, this study aims to investigate the association of nutritive and non-nutritive sucking habits with primary dentition development. METHODS: One thousand one hundred and fourteen children aged 2 to 5 years old in Hong Kong were recruited in a cross-sectional study. Information on their nutritive (e.g. breastfeeding and bottle feeding) and non-nutritive sucking habits (e.g. pacifier use and thumb/digit sucking) was collected via questionnaires. The children's primary occlusions were examined in three dimensions. RESULTS: Children who were breastfed for more than 6 months had a lower proportion of daily pacifier use (p < 0.05). Children who used pacifiers daily had a higher proportion of thumb/digit sucking (p < 0.05). Children who used pacifiers daily for more than one year had higher chances of developing an anterior open bite (p < 0.05) and a reduced overbite (p < 0.05). Those exhibiting daily thumb/digit sucking for more than one year had higher chances of developing Class II incisor and Class II canine relationships, an increased overjet and anterior open bite (p < 0.05). CONCLUSION: Pure breastfeeding for more than 6 months is inversely associated with daily pacifier use and daily pacifier use is positively associated with daily thumb/digit sucking. Children with more than one year of daily pacifier use and thumb/digit sucking have higher chances of developing abnormal dental relationships in the sagittal (i.e. Class II incisor and Class II canine relationships and increased overjet) and vertical (i.e. anterior open bite) dimensions, respectively.

Association of breastfeeding and three-dimensional dental arch relationships in primary dentition.

BACKGROUND: The benefits of breastfeeding on oral health are still inconclusive, especially the association on occlusion. This study aimed to investigate the association of breastfeeding and the development of primary dentition. METHODS: A cross-sectional study was conducted with 851 Asian children aged 2-5 years old in Hong Kong. Questionnaires were completed by the parents to collect information on breastfeeding and the non-nutritive sucking habits. The children's dental arch relationships were examined in the sagittal, vertical, and transverse dimensions by an experienced examiner. RESULTS: Children who experienced pure breastfeeding for more than 6 months had a lower chance of developing a class II incisal relationship (P < 0.05) or an increased overjet (P < 0.05), and had wider intercanine (P < 0.05) and intermolar widths (P < 0.05). Vertically, no association on the extent of overbite or openbite was found (P > 0.05). CONCLUSIONS: Pure breastfeeding for more than 6 months is positively associated with primary dental arch development in the anterior sagittal dental segment and on the horizontal arch width in primary dentition. Therefore, pure breastfeeding for more than 6 months is recommended, as it is associated with lower chance of the development of abnormal dental relationships. The results will be valuable for education and promotion of maternal breastfeeding.

Biomechanical Considerations in the Orthodontic Treatment of a Patient with Stabilised Stage IV Grade C Generalised Periodontitis: A Case Report.

Orthodontic treatment of periodontally compromised patients presents unique challenges, including controlling periodontal inflammation, applying appropriate force, designing an effective dental anchorage, and maintaining treatment results. Deteriorated periodontal support leads to alterations in the biological responses of teeth to mechanical forces, and thus orthodontists must take greater care when treating patients with periodontal conditions than when treating those with a good periodontal status. In this article, we report the case of a 59-year-old woman with stabilised Stage IV grade C generalised periodontitis characterised by pathological tooth migration (PTM). The assessment, planning, and treatment of this patient with orthodontic fixed appliances is described. Moreover, the anchorage planning and biomechanical considerations are detailed. Specific orthodontic appliances were employed in this case to produce force systems for achieving precise tooth movement, which included a cantilever, mini-screws, and a box loop. Careful application of those appliances resulted in satisfactory aesthetic and functional orthodontic outcomes in the patient. This case highlights the importance of multidisciplinary collaboration in the treatment of patients with severe periodontitis and the potential for tailored biomechanical approaches in orthodontic treatment to furnish good outcomes.

Effects of Low-Level Laser Therapy on Dentin Hypersensitivity in Periodontally Compromised Patients Undergoing Orthodontic Treatment: A Randomised Controlled Trial.

OBJECTIVES: This study aimed to assess the effects of low-level laser therapy (LLLT) on dentin hypersensitivity (DH) in periodontally compromised patients undergoing orthodontic treatment. METHODS: This triple-blinded randomised controlled trial included 143 teeth with DH from 23 periodontally compromised patients. Teeth on one side of the dental arch were randomly assigned to the LLLT group (LG), while those on the contralateral side were allocated to the non-LLLT group (NG). After orthodontic treatment commenced, patients' orthodontic pain (OP) perceptions were documented in pain diaries. DH was assessed chairside by a visual analogue scale (VASDH) at fifteen timepoints across the orthodontic treatment and retention. VASDH scores were compared among timepoints by the Friedman test, among patients with varying OP perceptions using the Kruskal-Wallis tests, and between the LG and NG with the Mann-Whitney U test. RESULTS: DH generally decreased over the observation (p < 0.001). The VASDH scores differed among patients with varying OP perceptions at multiple timepoints (p < 0.05). The generalized estimating equation model showed teeth in the LG had a significantly lower VASDH score than the NG at the 3rd month of treatment (p = 0.011). CONCLUSION: LLLT could be potentially beneficial in managing DH in periodontally compromised patients undergoing orthodontic treatment.

Oral Hygiene is Associated with Orthodontic Pain in Patients with Treated and Stabilised Periodontitis.

PURPOSE: This prospective cohort study aimed to 1) determine whether oral hygiene (OH) is a factor affecting orthodontic pain and 2) reveal whether orthodontic pain affects OH practice during orthodontic treatment. MATERIALS AND METHODS: 35 adults aged 22-59 years with treated and stabilised periodontitis were recruited. The pre-bonding (baseline) and 1-month post-bonding OH as well as periodontal status were recorded. The experience, duration and maximum intensity of orthodontic pain within the first week after bonding were documented. In addition, the concentrations of cytokines in the gingival crevicular fluid (GCF) were recorded at baseline, 1 day and 1 week after bonding. RESULTS: Patients who experienced orthodontic pain in the first week of orthodontic treatment had a higher baseline gingival index (GI) than patients who never experienced orthodontic pain (p < 0.05), and patients who experienced a longer duration and higher intensity of orthodontic pain in the first week of orthodontic treatment also had a higher baseline GI (p < 0.05). Patients who experienced orthodontic pain in the first week of orthodontic treatment had statistically significantly higher concentrations of interleukin 1ß (IL-1ß) in GCF at 1 day post bonding than those who never experienced pain, while baseline GI was positively associated with cytokine concentrations in GCF at 1 week post bonding (p < 0.05). In addition, neither the experience of orthodontic pain nor its duration and intensity were associated with the level of post-bonding OH (p > 0.05). CONCLUSIONS: The finding that increased gingival inflammation accounted for the longer duration and higher intensity of orthodontic pain in treated and stabilised periodontal patient shows that oral hygiene instructions and supportive periodontal care are of great importance prior to and during adjunctive orthodontic treatment in periodontally compromised individuals.