Periodontal considerations during orthodontic intrusion and extrusion in healthy and reduced periodontium.

In patients with advanced periodontal disease, pathological tooth migration may occur, which may require subsequent orthodontic treatment for both aesthetic and functional purposes. When planning orthodontic treatment mechanics, intrusive or extrusive forces are frequently indicated. Understanding tissue reactions during these movements is essential for clinicians when devising a comprehensive orthodontic-periodontal treatment plan. This knowledge enables clinicians to be fully aware of and account for the potential effects on the surrounding tissues. The majority of our understanding regarding the behavior of periodontal tissues in both healthy and compromised periodontal conditions is derived from animal studies. These studies offer the advantage of conducting histological and other assessments that would not be feasible in human research. Human studies are nevertheless invaluable in being able to understand the clinically relevant response elicited by the periodontal tissues following orthodontic tooth movement. Animal and human data show that in dentitions with reduced periodontal support, orthodontic intrusion of the teeth does not induce periodontal damage, provided the periodontal tissues do not have inflammation and plaque control with excellent oral hygiene is maintained. On the contrary, when inflammation is not fully controlled, orthodontic intrusion may accelerate the progression of periodontal destruction, with bacterial plaque remnants being displaced subgingivally, leading to further loss of attachment. Orthodontic extrusion, on the other hand, does not seem to cause further periodontal breakdown in dentitions with reduced periodontal support, even in cases with deficient plaque control. This is attributed to the nature of the tooth movement, which directs any plaque remnants coronally (supragingivally), reducing the risk of adverse effects on the periodontal tissues. This specific type of tooth movement can be leveraged to benefit periodontal conditions by facilitating the regeneration of lost hard and soft periodontal tissues in a coronal direction. As a result, orthodontic extrusion can be employed in implant site development, offering an advantageous alternative to more invasive surgical procedures like bone grafting. Regardless of the tooth movement prescribed, when periodontal involvement is present, it is essential to prioritize periodontal therapy before commencing orthodontic treatment. Adequate plaque control is also imperative for successful outcomes. Additionally, utilizing light orthodontic forces is advisable to achieve efficient tooth movement while minimizing the risk of adverse effects, notably root resorption. By adhering to these principles, a more favorable and effective combined orthodontic-periodontal approach can be ensured. The present article describes indications, mechanisms, side effects, and histological and clinical evidence supporting orthodontic extrusion and intrusion in intact and reduced periodontal conditions.

Headgear therapy in children with Class II malocclusion and the role of compliance on treatment outcome: A nine-month randomized controlled trial.

OBJECTIVES: To evaluate three-dimensional movements of maxillary teeth during headgear treatment in Class II growing children, using digital analytical tools, and to determine the effects of compliance on these movements. MATERIALS AND METHODS: A 9-month parallel-group randomized controlled trial was carried out on 40 children with Class II malocclusion, aged 8-12 years, half assigned to receive a cervical headgear and half to a no-treatment group, using block randomization. Subjects in the treatment group were instructed to wear the headgear for 12 hours daily and monitored using an electronic module. After 9 months, the following dental outcomes were measured: first maxillary molar distalisation, rotation, tip and torque, arch depth, and interpremolar and intermolar distances. Caregivers and participants were not blinded to group assignments, but those assessing outcomes were. Linear regression models were used to detect differences between groups and correlation coefficients to find correlations between compliance and dental outcomes. RESULTS: All 40 included patients were analysed. A significant difference in molar distalisation was observed between the treatment (1.2 mm) and control groups (-0.2 mm). Arch depth change was also increased to a larger extent in the treatment groups (1.3 mm vs 0.1 mm), as was the interpremolar distance (1.9 mm vs 0.4 mm). In contrast, no significant differences in molar rotation or torque change were observed. With regard to compliance, average compliance was 55%. A significant correlation was found between molar distalisation and compliance in the treatment group. CONCLUSIONS: Headgear therapy has significant effects on molar distalisation, arch depth, and arch width. Compliance has a significant positive effect on molar distalisation.

Long-term stability of posterior crossbite correction, treated in the mixed or permanent dentition of growing children: A systematic review and meta-analysis.

When treating posterior crossbite, the primary goal is to achieve long-term crossbite correction. The majority of studies however focus on relapse of the increase in the transverse dimension, but not relapse of the crossbite itself, which is an essential outcome. The aim of the present study was to determine long-term stability (2 years minimum post-treatment) of posterior crossbite correction, treated in mixed or early permanent dentitions of growing children. Following registration in PROSPERO (CRD42022348858), an electronic literature search including PubMed, Embase, Web of Science, the Cochrane Library, and a manual search were conducted up to January 2023, to identify longitudinal studies looking into the long-term stability of crossbite correction in growing children. Data extraction and risk of bias assessment were carried out, and subsequently, a random-effects meta-analyses models were used to calculate estimates for relapse of the crossbite and relapse at the transverse level. Twenty-two studies were included, of varying designs and quality, representing 1076 treated patients, with different expansion appliances and protocols. Meta-analysis results showed that 19.5% (95% CI: 15%; 25%) of patients present with relapse of posterior crossbite at long-term follow-up. At the transverse level, 19.3% of the total expansion (including overexpansion) relapsed (95% CI: 13%; 27%) regardless of whether there a was relapse of the crossbite itself. Data from existing studies, with a moderate level of evidence, indicate that the long-term stability of posterior crossbite correction in growing children is unfavourable in roughly 1 in 5 growing children, with crossbite relapse long-term. On average, 19% of the maxillary expansion performed (including overexpansion) relapses long-term, which may occur in cases with or without relapse of the crossbite.

Effects of age and diet consistency on the expression of myosin heavy-chain isoforms on jaw-closing and jaw-opening muscles in a rat model.

BACKGROUND: Skeletal craniofacial morphology can be influenced by changes in masticatory muscle function, which may also change the functional profile of the muscles. OBJECTIVES: To investigate the effects of age and functional demands on the expression of Myosin Heavy-Chain (MyHC) isoforms in representative jaw-closing and jaw-opening muscles, namely the masseter and digastric muscles respectively. METHODS: Eighty-four male Wistar rats were divided into four age groups, namely an immature (n = 12; 4-week-old), early adult (n = 24; 16-week-old), adult (n = 24; 26-week-old) and mature adult (n = 24; 38-week-old) group. The three adult groups were divided into two subgroups each based on diet consistency; a control group fed a standard (hard) diet, and an experimental group fed a soft diet. Rats were sacrificed, and masseter and digastric muscles dissected. Real-time quantitative polymerase chain reaction was used to compare the mRNA transcripts of the MyHC isoforms-Myh7 (MyHC-I), Myh2 (MyHC-IIa), Myh4 (MyHC-IIb) and Myh1 (MyHC-IIx)-of deep masseter and digastric muscles. RESULTS: In the masseter muscle, hypofunction increases Myh1 (26, 38 weeks; p < .0001) but decreases Myh4 (26 weeks; p = .046) and Myh2 (26 weeks; p < .0001) expression in adult rats. In the digastric muscle, hypofunction increases Myh1 expression in the mature adult rats (38 weeks; p < .0001), while Myh2 expression decreases in adult rats (26 weeks; p = .021) as does Myh4 (26 weeks; p = .001). Myh7 expression is increased in the digastric muscle of mature adult rats subjected to hypofunction (38 weeks; p = <.0001), while it is very weakly expressed in the masseter. CONCLUSION: In jaw-opening and jaw-closing muscles, differences in myosin expression between hard- and soft-diet-fed rats become evident in adulthood, suggesting that long-term alteration of jaw function is associated with changes in the expression of MyHC isoforms and potential fibre remodelling. This may give insight into the role of function on masticatory muscles and the resultant craniofacial morphology.

Do patients with different craniofacial patterns have differences in upper airway volume? A systematic review with network meta-analysis.

BACKGROUND: Craniofacial skeletal discrepancies have been associated with upper airway dimensions. OBJECTIVE: To identify differences in upper airway volume across different sagittal and vertical skeletal patterns. SEARCH METHODS: Unrestricted literature searches in eight databases/registers for human studies until May 2023. SELECTION CRITERIA: Cross-sectional studies measuring upper airway volumes using three-dimensional imaging in healthy patients of different sagittal (Class I, Class II, and Class III) or vertical (normodivergent, hypodivergent, and hyperdivergent) craniofacial morphology. DATA COLLECTION AND ANALYSIS: Duplicate independent study selection, data extraction, and risk of bias assessment. Random-effects frequentist network meta-analysis was performed followed by subgroup-analyses and assessment of the quality of clinical recommendations (confidence in effect estimates) with the CINeMA (Confidence in Network Meta-Analysis) approach. RESULTS: Seventy publications pertaining to 66 unique studies were included with 56 studies (5734 patients) contributing to meta-analyses. Statistically significant differences were found for total  pharyngeal airway volume, with Class II having decreased airway volume (-2256.06 mm3; 95% Confidence Interval [CI] -3201.61 to -1310.51 mm3) and Class III increased airway volume (1098.93 mm3; 95% CI 25.41 to 2172.45 mm3) compared to Class I. Significant airway volume reductions for Class II were localized mostly at the oropharynx, followed by the palatopharynx, and the glossopharynx. Significant airway volume increases for Class III were localized mostly at the oropharynx, followed by the intraoral cavity, and hypopharynx. Statistically significant differences according to vertical skeletal configuration were seen only for the oropharynx, where hyperdivergent patients had reduced volumes compared to normodivergent patients (-1716.77 mm3; 95% CI -3296.42 to -137.12 mm3). Airway differences for Class II and Class III configurations (compared to Class I) were more pronounced in adults than in children and the confidence for all estimates was very low according to CINeMA. CONCLUSIONS: Considerable differences in upper airway volume were found between sagittal and vertical skeletal configurations. However, results should be interpreted with caution due to the high risk of bias, owing to the retrospective study design, inconsistencies in anatomic compartment boundaries used, samples of mixed children-adult patients, and incomplete reporting. CLINICAL TRIAL REGISTRATION: PROSPERO (CRD42022366928).

Global Trends in Knowledge, Attitude, and Awareness of Orthodontists Regarding the Management of Patients with Cleft lip and/or Palate: A Systematic Review.

The aim of the present systematic review was to assess the trends in knowledge, attitude, awareness, and practice among orthodontists regarding the management of patients with cleft lip and/or palate.An a priori protocol was developed as per the best practices of evidence-based medicine and registered in Prospero (CRD42022306107). The literature search was conducted electronically, using MeSH-terms, keywords, and Boolean-operators "AND" and "OR" in different combinations in multiple databases and screening of titles and abstracts followed by full-text evaluation was performed. The risk of bias (ROB) was assessed using Joanna Briggs Institute critical appraisal checklist.Five studies were included in the qualitative synthesis and three of them showed a high ROB. When participants were questioned about which other specialists worked in the cleft team in addition to the orthodontists, 84% of them in one study reported it to be general dentists. Furthermore, the absence of an interdisciplinary team was reported in two studies from Africa. When asked about the percentage of their practice devoted to the care of patients with cleft lip and palate (CLP) one study reported that 52% of orthodontists had treated <10 such patients in their entire career.The present systematic review highlights the lack of knowledge and experience among orthodontists and orthodontic residents regarding the management of patients with CLP. Efforts must be made to design validated questionnaires and conduct methodologically sound studies in different geographical locations to develop adequate modules for improving the knowledge of orthodontists in this domain.

Longitudinal changes of the insertion of the maxillary labial frenum in children and adolescents undergoing orthodontic treatment.

INTRODUCTION: This study aimed to evaluate potential vertical changes in the position of the maxillary labial frenum (MLF) insertion in growing children and to compare these changes to the vertical growth of the dentoalveolar process and lower facial third. METHODS: This retrospective longitudinal study investigated records of 33 healthy children. Dental casts, lateral cephalograms, and photographs were evaluated at pretreatment (T0), posttreatment (T1), and 3-5 years into retention (T2). To evaluate the vertical changes of MLF insertion in relation to the vertical growth of the dentoalveolar process, the palatal plane (PP) was used as a reference. These changes were also compared between different MLF typologies (ascribed as thin or fibrous). RESULTS: The distance from MLF to PP only slightly increased from T0 to T2 by 0.6 ± 0.5 mm (P <0.001), whereas the distance between the incisal edge and PP increased significantly from T0 to T2 by 2.6 ± 0.8 mm (P <0.001). A positive correlation was found (r = 0.94; P <0.001) between the changes from the incisal edge to the PP and the MLF to the incisal edge between T0 and T2. No correlation was found between the change from the incisal edge to the PP and MLF to PP between T0 and T2. Thin MLF types showed a larger increase in distance from their insertion to the incisal edge (2.6 ± 0.8 mm) than thick MLF types (1.8 ± 0.7; P <0.03). CONCLUSIONS: The MLF remains stable compared with the PP, whereas the maxillary incisal edge moves away from the PP, indicating increased vertical growth of the alveolar process. Dentists should be aware of those changes before performing interventions such as unnecessary frenectomies.

Spontaneous correction and new development of posterior crossbite from the deciduous to the mixed dentition.

AIM: To determine (a) the prevalence of spontaneous correction of posterior crossbites from the deciduous to the mixed dentition and (b) the development of new posterior crossbite cases during the eruption of the first permanent molars, in orthodontically untreated children. MATERIALS AND METHODS: A cohort of pupils aged 4-12 years participated in annual dental screenings, from 2001 to 2019. Data were collected prospectively but examined retrospectively. Children were selected who had been initially screened in their deciduous dentition and on at least one consecutive year, presenting with a posterior crossbite in the deciduous or mixed dentition. Those with a posterior crossbite in the deciduous dentition were evaluated to see whether the crossbite persisted in the mixed dentition, and vice versa. RESULTS: Of the 2571 children participating in the annual dental screenings, 1076 children were in the deciduous dentition at their first screening appointment, with 693 having attended at least two screening appointments. Of these 693 children, 70 had a posterior crossbite in the deciduous dentition (10.1%). The crossbite persisted in the mixed dentition in only 16 out of these 70 children. Twenty-six out of the 623 children who did not have a posterior crossbite in the deciduous dentition developed one in the mixed dentition. LIMITATIONS: The retrospective data collection, multiple examiners carrying out the dental screenings, and the absence of data on para-functions and oral habits were some of the limitations of the present study. CONCLUSIONS: In the present sample, 1 in 10 children have a posterior crossbite in the deciduous dentition, which is however autocorrected in about three-quarters of cases. On the other hand, 4% of children developed a new crossbite in the mixed dentition. It may thus be reasonable in cases with posterior crossbite in the deciduous dentition to wait for the first permanent molars to erupt before initiating treatment.

Evaluation of natural head position over five minutes: A comparison between an instantaneous and a five-minute analysis with an inertial measurement unit.

BACKGROUND: Head posture is a balance of several positions and therefore shows inherent variation. Most methods available to quantify this are however instantaneous, not providing information about its variation over time. A dynamic recording of head posture would thus be beneficial. OBJECTIVES: The purpose of this study was to evaluate the variation in natural head position (NHP) over 5 min using an inertial measurement unit (IMU). METHODS: Fifteen healthy young volunteers were asked to sit on a chair and keep their head in the self-balanced position for 5 min. A mirror was then revealed in front of them, and they were asked to look at their eyes for 20 s. This procedure was undertaken on two separate occasions with a one-week interval. This was compared to an instantaneous measurement of head position at a specific time point corresponding to the 15th second of the recording. RESULTS: During the 5 min of recording, the participants tended to elevate their head progressively by a mean of 1.5°, which is then corrected by looking at oneself in the mirror. Most participants tended to rotate their head to the left and continued that progressive rotation despite looking in the mirror. The roll axis had no systematic changes observed between the self-balanced position and the mirror-guided position and was the most reproducible axis. Moderate to good correlations were found comparing both sessions for each axis. CONCLUSION: The comparison between the five-minute analysis and the instantaneous measurement showed a systematic difference on the pitch axis but no differences for the yaw and roll. These results suggest that the variation in the NHP during a period of 5 min is generally specific to each participant with a head elevation and rotation to the left in most cases.

A Retrospective Longitudinal Treatment Review of Multidisciplinary Interventions in Nonsyndromic Robin Sequence With Cleft Palate.

OBJECTIVE: To document and analyze the overall longitudinal institutional treatment experience of children with nonsyndromic Robin sequence (RS) from infancy to early adulthood. DESIGN: Retrospective longitudinal treatment review. SETTING: A tertiary-care, referral, teaching hospital. PATIENTS: Children with nonsyndromic RS and cleft palate (N = 117) born between December, 1985, and January, 2012. INTERVENTIONS: Data regarding airway management, nutritional management, audiological interventions, orthodontic treatment, and surgical interventions were documented and analyzed in different growth/developmental stages. Comparative data from other international centers were collected from the literature. RESULTS: Airway management during infancy involved prone positioning (92%), nasopharyngeal airway (6%), tracheostomy (2%), and mandibular distraction osteogenesis (1%). Feeding with nasogastric, gastrostomy, and/or gastrojejunostomy tubes was used in 44%, Haberman feeders in 53%, and Mead Johnson feeders in 3%. Gastroesophageal reflux disease was documented in 6% of the sample. During childhood and early adolescent years, pharyngeal flap surgery was carried out in 22% of the children, while 11% had secondary palatal surgery. Audiological management included the use of tympanostomy tubes in 62%, with several children needing multiple tube replacements. At least 18% were diagnosed with obstructive sleep apnea. Adenoidectomy or adenotonsillectomy was undertaken in 4%. Analysis of data pertaining to middle childhood and adolescent years showed that orthodontic treatment was conducted for most children for crowding, tooth agenesis, and skeletal and/or dental dysplasia. Orthognathic surgery frequency (<18%) was low. CONCLUSIONS: Institutional treatment experience of children with nonsyndromic RS involves multidisciplinary care at different ages and stages of their development.

How Informative Is YouTube Regarding Feeding in Infants with Cleft Lip and Palate?

OBJECTIVE: To assess the characteristics of popular videos on YouTube about the feeding of infants with cleft lip and palate (CLP) and analyze the adequacy of information provided by them. DESIGN: A cross-sectional design was used. METHODS: YouTube was systematically searched for consecutive relevant videos about the feeding of infants with CLP, using predefined keyword combinations, without any limitations on language or duration. Scrutiny of the top 50 videos for each keyword combination was performed and a self-designed data-extraction sheet was used. A content adequacy index was developed by an expert group, and used to assess content adequacy, classifying it into categories from excellent to poor. RESULTS: From an initial retrieval of 200 videos, 42 were included in the final assessment. The videos originated from nine different countries, with more than half coming from the USA and in English. Five of the videos came from the channel of the American Cleft Palate-Craniofacial Association. Content adequacy analysis showed that no video could be classified as excellent, while 33.3% were classified as optimal, 21.4% as suboptimal and 45.2% as poor. CONCLUSIONS: The content adequacy of the majority of videos on YouTube, relating to the feeding of infants with CLP was inadequate, with only one third of them achieving optimal content adequacy. Efforts must be made to develop informative and standardized videos for social media and video-sharing platforms, perhaps through professional associations to ensure that families with an infant with CLP receive appropriate information.

Final Posttreatment Occlusion in Patients With Unilateral Cleft Lip and Palate.

OBJECTIVE: To evaluate final posttreatment occlusion in patients with complete unilateral cleft lip and palate (cUCLP) by comparing (1) 3 treatment centers, (2) males and females, (3) cleft and noncleft sides, (4) right- and left-sided clefts, and (5) orthodontic treatment with/without orthognathic surgery (OS). DESIGN: Retrospective cohort study. PATIENTS: Blinded posttreatment dental casts of 56 patients (19.4 ± 1.4 years) with cUCLP from 3 centers in Switzerland. MAIN OUTCOME MEASURE: Occlusal assessment using the modified Huddart/Bodenham (MHB) index. RESULTS: Our sample comprised 35 males and 21 females, 46 with left- and 10 with right-sided clefts, of which 32 had undergone OS. The final posttreatment occlusion showed a median MHB score of 0 (interquartile range: -1.0 to 2.0) in the total sample and did not seem to depend on treatment center, sex, or OS. The MHB scores for the anterior buccal and the buccal segments were more negative on the cleft than on the noncleft side (P = .002 and P = .006, respectively). When the cleft was on the left side, the MHB score tended to be more positive in the labial (P = .046) and anterior buccal segments (P = .034). CONCLUSIONS: This study shows a very satisfactory final posttreatment occlusion in patients with cUCLP. The more constricted buccal occlusion on the cleft side emphasizes the attention that should be given in correcting the more medially positioned lesser maxillary segment. The influence of cleft-sidedness should be analyzed further on a sample including more patients with right-sided clefts.

Measuring the difference in natural head position between the standing and sitting positions using an inertial measurement unit.

AIMS: The purpose of this study was to compare the natural head position (NHP) in the sitting position to the NHP in a standing position using inertial measurement unit (IMU) and lateral photographs. MATIERIALS & METHODS: Twenty healthy young adult volunteers were asked to look at a mirror located at 1 metre in front of their eyes while being recorded with the IMU system. Lateral photographs were also taken. This procedure was undertaken for the standing and sitting positions, on two separate occasions within a one-week interval. RESULTS: A strong correlation was found between the IMU system and the lateral photographs (r > .99) with regard to the pitch axis, the absolute mean difference was 0.4 ± 0.5 (p = .99) for both standing and sitting positions. We found that in the sitting position the head was elevated by 2.5 ± 2.4 (p < .05) more than in the standing position, but no significant differences were observed for the other two axes (roll and yaw). CONCLUSION: The IMU system is comparable to lateral photographs for pitch assessment. Except for a slight elevation of the head in the sitting position, no clinical differences were observed for the NHP when comparing the standing and sitting positions.

Sella Turcica Bridging and Tooth Agenesis in Children With Unilateral Cleft Lip and Palate.

AIM: To investigate differences in sella turcica size and bridging in children with unilateral cleft lip and palate (UCLP) with or without concomitant dental anomalies. PATIENTS AND METHODS: A cross-sectional study was carried out looking at 56 children with nonsyndromic UCLP. Lateral cephalograms, taken before alveolar bone grafting, were used to assess sella turcica height, width, area, and bridging. Panoramic radiographs were used to evaluate the presence of dental anomalies in the cleft area including agenesis, supernumerary, and peg-shaped lateral incisors. Differences between sella turcica measurements in the presence or absence of dental anomalies were assessed using t tests. Differences between the prevalence of dental anomalies and sella turcica bridging were assessed using χ2 and Fisher exact tests. Multinomial logistic regression was used to investigate potential associations between sella measurements and dental anomalies. RESULTS: Twenty-six of the 56 children presented with agenesis of the cleft-side lateral incisor, while 7 had a supernumerary, and 19 had a peg-shaped lateral incisor. With regard to sella turcica bridging, 27 children had no calcification, 25 partial and 4 complete calcification. Children with agenesis of the cleft-side lateral incisor showed a shorter sella maximum height (P = .010) and a smaller area (P = .019). When looking at sella turcica bridging, 100% of children with complete calcification showed agenesis of the cleft-side lateral incisor, compared with 52% and 33% of children with partial calcification and no calcification, respectively (P = .034). CONCLUSIONS: Children with UCLP and sella turcica bridging are more likely to present with agenesis of the cleft-side maxillary lateral incisor.

Does age influence self-perception of the soft-tissue profile in children?

INTRODUCTION: Appreciation of the soft-tissue profile is important in orthodontic diagnosis and treatment. However, are the patients themselves aware of their profile appearance? We aimed to evaluate if age influences self-perception of the soft-tissue profile in children. METHODS: The study population for this prospective cross-sectional investigation consisted of 3 groups of 60 patients, classified according to age (<12 years; 12-15 years; >15 years). Each subject's right-sided facial profile was photographed to obtain a silhouette. Facial profile silhouette templates were created to represent the local population. Each subject's photograph was inserted into the corresponding template, and the subjects were asked to identify themselves. Facial profile self-recognition was recorded as a binary variable (yes or no). Other recorded variables included age, sex, and sexual maturity rating (using Tanner staging). Chi-square tests were used to analyze facial profile self-recognition between different subgroups, and stepwise multiple regression was used to predict the probabilities of facial profile self-recognition, with age, sexual maturity rating, and other recorded variables as independent variables. RESULTS: Eighty percent of subjects aged >15 years recognized their own profile, compared with only 55% and 50% of subjects aged 12-15 years and <12 years, respectively. Subjects aged >15 years were significantly more likely to recognize their profile than younger subjects (P = 0.001). Similarly, subjects with the most advanced sexual maturity rating (stage V) were significantly more likely to recognize their profile (85% self-recognition) than those in groups I-IV (P <0.001). Girls were more likely to recognize their profiles than boys (P = 0.028). When using multiple regression analysis, sexual maturity rating appears to be the only significant predictor for facial profile self-recognition (R2 = 0.25; P <0.001). CONCLUSIONS: Facial profile self-recognition seems to improve with age and sexual maturity (sexual maturity rating stage V). Because orthodontic treatment planning takes possible soft-tissue changes into account, it is important to evaluate the degree of self-perception of the patients to adapt our goals and treatment discussions.

Prevalence, distribution, and age at clinical detection of missing permanent incisors.

OBJECTIVES: To determine the prevalence and distribution of clinically missing permanent incisors, and the age at which they are detected, in school-aged children. METHODS: A total of 2573 children aged 4-13 underwent oral health screening on at least one occasion between 2001 and 2017. In order to define a threshold age, after which permanent incisor agenesis could be suspected clinically with reasonable certainty, children who had been seen for at least three consecutive years, with any clinically missing permanent incisor were selected (n = 19). The maximum age of detection among these children was chosen as the threshold age. Based on this, a total of 766 children at or above the threshold age were screened for a cross-sectional epidemiological survey. Chi-squared tests were used to compare the prevalence of clinically missing permanent incisors among boys and girls, comparing unilateral versus bilateral, and right- versus left-sided missing teeth. RESULTS: Roughly 2% of the sample presented with at least one clinically missing maxillary lateral incisor. This was bilateral in half of cases. Clinically missing mandibular incisors were found in 0.5% of children. Finally, the threshold age for clinical suspicion of maxillary lateral incisor agenesis was set at 11.5 years. Agenesis was confirmed in all of the children attending a follow-up radiographic visit. CONCLUSIONS: Approximately 1 in 50 children present with a clinically missing maxillary lateral incisor. The age at suspicion of maxillary lateral incisor agenesis can sometimes be several years after its expected eruption, perhaps due to significant variation in eruption times.

Perception of pain in Class II malocclusion children treated with cervical headgear: a randomized controlled trial.

OBJECTIVES: The aims of this study were: 1. to evaluate the experience of pain perceived by children during separator placement and headgear wear; 2. to find possible associations between the perceived intensity of pain and the levels of Substance P (SP) and interleukin-1 beta (IL-1ß) in the gingival crevicular fluid (GCF) during these procedures; 3. to identify other factors, such as previous pain experience, which could be associated to the patients' perceived discomfort or pain during treatment. TRIAL DESIGN: Nine-month parallel-group randomized controlled trial. METHODS: Forty Class II malocclusion children (8-12 years) were included, half of which received a cervical headgear while the other half did not receive any treatment during the study period. Baseline pain data were recorded including previous experience to general and dental pain, Corah's Dental Anxiety Scale, and baseline pain using a visual analogue scale (VAS). Elastic separators were placed in children for 1 week, followed by molar band and cervical headgear placement. Children were seen at various time points throughout the 9-month period where at each appointment, a VAS assessment of pain as well as GCF sampling was carried out to quantify the levels of SP and IL-1ß. Multiple regression analysis was performed to ascertain the influence of factors including sex, age, time, headgear wear, and baseline pain data on pain severity. RESULTS: Pain severity and SP and IL-1ß levels in the GCF follow a similar pattern, with peaks being observed 1 day after orthodontic elastic separator placement. Pain was more severe after the placement of orthodontic separators than following cervical headgear wear. With regard to pain predictors, pain is more severe in older children, those with a worse previous general pain experience, and those with higher levels of IL-1ß, particularly after elastic separator placement. CONCLUSIONS: Orthodontic pain and discomfort following orthodontic separator placement and cervical headgear wear depends on factors including age, previous pain experience, and the level of IL-1ß in the GCF.

Sella turcica morphometrics in children with unilateral cleft lip and palate.

OBJECTIVE: To use morphometric methods to investigate the size and shape of the sella turcica in children with unilateral cleft lip and palate (UCLP). SETTING AND SAMPLE POPULATION: Fifty-six healthy children with non-syndromic UCLP, from a major paediatric teaching hospital, with lateral cephalograms taken prior to alveolar bone grafting, were compared with an age- and sex-matched control group of healthy children without orofacial clefts, with lateral cephalograms taken prior to orthodontic treatment. MATERIALS AND METHODS: In this cross-sectional study, conventional measurements were performed on the sella turcica to measure width, height and area on lateral cephalograms. Sella shape was also analysed using 11 points defining the sella turcica contours, using geometric morphometrics. Procrustes superimposition was used to register all sella contour tracings to calculate average sella shape. Principal component analysis was applied to the residuals of the point coordinates, and principal components (PCs) of shape were extracted. RESULTS: Statistically significant differences between the UCLP and control groups were found for sella posterior height, midpoint height, maximum height and area, where all of these were smaller in children with UCLP. Principal component analysis revealed that the first two PCs accounted for 84.7% of total shape variance. There was a statistically significant difference in sella shape between children with UCLP and control children. CONCLUSIONS: In children with UCLP, the sella turcica is shorter and with a smaller surface area when compared to matched non-cleft children. Moreover, sella turcica shape, when disregarding size, seems to differ to that of non-cleft children.

Spontaneous eruption of impacted maxillary incisors after surgical extraction of supernumerary teeth: a systematic review and meta-analysis.

OBJECTIVES: To evaluate the spontaneous eruption potential of impacted human permanent teeth localized in the anterior part of the maxilla, after the surgical extraction of obstacles in their eruption pathway, by means of a systematic review and meta-analysis. MATERIALS AND METHODS: A systematic literature search was carried out to locate studies reporting on the percentage of anterior permanent teeth erupting after surgical removal of the obstacle, without other interventions. Eruption potential of impacted teeth was calculated using a random-effects meta-analysis. Information about the sex proportion, follow-up duration, age and years during which the study was carried out was used for subgroup analyses. RESULTS: A total of twelve studies were included, with a total sample size of 960 cases and a follow-up period of up to 36 months. The results show that more than 65.5% of impacted teeth erupt spontaneously following surgical extraction of the obstacle, with an odds ratio of 4 (95% CI 1.9, 8.2) (p < 0.001) favouring spontaneous eruption. CONCLUSIONS: When faced with an impacted maxillary anterior tooth, surgical extraction of the obstacle can lead to spontaneous eruption of the impacted tooth in the majority of cases, with better success with a longer follow-up for up to 3 years. CLINICAL RELEVANCE: Based on the present meta-analysis, clinical recommendation would be to surgically remove the obstacle impeding the eruption of a maxillary anterior permanent tooth and wait for the eruption of the tooth for a period of 12-36 months, depending on the age of the patient.

Class II functional appliance treatment and dynamic three-dimensional mimic muscle evaluation.

BACKGROUND: Functional appliances have skeletal and dentoalveolar treatment effects, but knowledge on their effect on facial expressions is limited. OBJECTIVE: To analyse changes in facial expressions, using three-dimensional (3D) mimic muscle evaluation, in growing children with Class II malocclusion and large overjet, undergoing functional appliance treatment. METHODS: Fifteen growing children with Class II division 1 malocclusion, selected prospectively, had dynamic 3D recordings of facial expressions prior to and 12 months after commencing functional appliance treatment. Facial expressions recorded were smile and lip pucker, and the movements of the oral commissures were analysed, as well as mouth width and its symmetry. A control group of fifteen age- and sex-matched growing children without immediate need for orthodontic treatment had similar recordings prior to and after a 12-month observation period. RESULTS: In the treatment group, the Class II malocclusion in all children improved after 12 months of functional appliance wear. With regard to movements of the oral commissures, the initial recordings of the treatment group did not show any significant differences to the control group for neither smile nor lip pucker. Differences were noted however when looking at mouth width asymmetry, where this tended to become more symmetrical in the functional appliance treatment group, during rest and during smiling, while it became more asymmetrical in the untreated control group. CONCLUSION: The use of removable functional appliances in children with Class II division 1 malocclusion may have a positive effect on mouth width symmetry when smiling, making it more symmetrical.