Anterior Open Bite Research Articles

Early treatment for anterior open bite: Choosing adequate treatment approaches

Anterior open bite is considered one of the most challenging malocclusions to correct, especially regarding stability. There are numerous publications on the subject but with controversial information. Disagreements occur in most aspects of this malocclusion, such as the definition of an open bite, its etiological factors, treatment timing, and ideal treatment alternatives. The lack of consensus on the etiology of anterior open bite has led to different treatment approaches, which may explain the high rate of post-treatment instability. Furthermore, the etiological factors of this malocclusion typically result in myofunctional imbalance, which alters the harmony of muscular forces responsible for maintaining an adequate occlusion. Nevertheless, the literature indicates a scarcity of scientific evidence that myofunctional therapy helps to correct open bites. In addition, there is evidence that eliminating deleterious habits allows spontaneous overbite correction and brings physiological and psychological benefits to the child. Considering the possibility of a spontaneous reduction of this malocclusion with age, it is understood that not every child needs early treatment. To avoid overtreatment, the choice for intervention should assess possible causes and severity, the patient's age, and parental concerns. Therefore, this paper discusses possible early treatment approaches for anterior open bite.

Maxillary sinus and alveolar bone levels in subjects with skeletal anterior open bite: Is there room for mini-implant supported molar intrusion?

Objective: To compare the maxillary sinus (MS) and alveolar bone (AB) heights in adult subjects with normal occlusion and those with skeletal anterior open bite (AOB). Study Design: Cross-sectional. Setting: Aga Khan University Hospital, Karachi. Period: December 2020 to June 2021. Material & Methods: The study was conducted on the pretreatment orthodontic records of sixty adult subjects (30 males, 30 females). Skeletal high angle cases with AOB >1 mm were included in skeletal AOB while a matched sample with normal dental and skeletal relationships was included in normal occlusion group. The MS and AB heights were measured on lateral cephalograms and orthopantomograms at interdental regions from maxillary 1st premolar to 2nd molar. The MS and AB heights were compared between males and females and between skeletal AOB group and normal occlusion groups using independent sample t-test. Results: The mean age of the subjects with skeletal AOB (22.68±4.04 years) and those with normal occlusion (23.19±4.68 years) were comparable (p=0.653). In general, MS height and AB heights were greater in males than females. There was no significant difference in the MS height between the skeletal AOB and normal occlusion groups for both genders (p>0.05). However, both males and females with skeletal AOB had greater AB heights between 2nd premolar and 1st molar and between 1st molar and 2nd molar than those with normal occlusion (p<0.05). Conclusion: The MS height in skeletal AOB and normal occlusion groups were comparable. Subjects with skeletal AOB had maximum AB height mesially and distally to maxillary 1st molar that was significantly greater than those with the normal occlusion.

Root resorption during maxillary molar intrusion with clear aligners: a randomized controlled trial.

To compare changes in maxillary molar root resorption, intrusion amount, dentoskeletal measures, and maximum bite force (MBF) between clear aligners (CA) and fixed appliances with miniscrew (FM) during molar intrusion. Forty adults with anterior open bite were randomized into either CA or FM groups. Lateral cephalograms, cone-beam computed tomography (CBCT), and MBF were collected at pretreatment (T0) and 6 months of treatment (T1). Maxillary molar intrusion in FM were intruded by nickel-titanium (NiTi) closed-coil spring delivered force (150 grams/side) while clear aligners combined with squeezing exercise were performed in CA. Parametric tests were used for statistical analysis. After 6 months of treatment, significant root resorption of 0.21-0.24 mm in CA and 0.38-0.47 mm in FM were found while maxillary molars were intruded 0.68 and 1.49 mm in CA and FM, respectively. CA showed significant less root resorption and intrusion than FM. Overbite, bite closing, and MBF increased significantly. CA showed significantly less overbite and SN-MP changes but more MBF increase than FM. MBF in CA was correlated with the amount of maxillary molar intrusion (r = 0.736, P < .05). Maxillary molar intrusion and root resorption in CA were half the amount in FM in 6 months. The amount of maxillary molar root resorption was one-third of the intrusion distance. CA displayed less overbite increase and bite closing but more MBF increase than FM. MBF in CA was positively correlated with the molar intrusion amount.

Prevalence and Influencing Factors of Mixed Dentition Malocclusion in Children Aged 6-12 Years in Jinzhou, China.

To investigate the prevalence, clinical manifestations and related risk factors of malocclusion in schoolchildren of Jinzhou City, China. A total of 2162 children aged 6-12 years were randomly selected from various districts of Jinzhou. Conventional clinical examination was performed by stomatologists, and the results were described based on different clinical manifestations of malocclusion and individual normal occlusion. Further, a questionnaire survey completed by children's parents or guardians provided the demographic data, lifestyle, and oral habits. The distribution of individual normal occlusion and malocclusion was documented in percentage, and Pearson's Χ2 was used for two-factor analysis. The data were statistically analysed using SPSS software (version 25.0) with a significance level of α = 0.05. A total of 1129 boys and 1033 girls were included in this study, i.e. 52.2% and 47.8% of the total number of children, respectively. The prevalence of malocclusion in children aged 6-12 years old in Jinzhou was 67.9%, of which crowded dentition was the most common form, with a prevalence of 71.8%, followed by deep overbite, anterior crossbite, dental spacing, deep overjet, anterior edge-to-edge occlusion, and anterior open bite. In the logistic regression model, the results showed that BMI index had little effect on the occurrence of malocclusion (p > 0.05), while dental caries, bad oral habits, retained primary teeth, and a low labial frenum were all related to the occurrence of malocclusion (p < 0.05). Moreover, the higher frequency and duration of bad oral habits were associated with a higher likelihood of malocclusion. The prevalence of malocclusion in children aged 6-12 years in Jinzhou is high. In addition, bad oral habits (such as lip biting, tongue thrusting, biting/gnawing objects, unilateral chin supporting, and unilateral mastication) and other related risk factors (such as dental caries, mouth breathing, retention of primary teeth, and low labial frenum, etc) were associated with malocclusion.

Dentoskeletal features and growth pattern in Beckwith-Wiedemann spectrum: is surgical tongue reduction always necessary?

ObjectivesThe role of tongue reduction surgery (TRS) in preventing excessive mandibular growth and anterior open bite in children with Beckwith–Wiedemann Spectrum (BWSp) is still controversial. This cross-sectional study aimed at comparing craniofacial growth pattern in children affected by BWSp either treated or not treated with early TRS for severe macroglossia. Considering the invasive nature of such surgery, the present study could help in clarifying the need for TRS to reduce or prevent growth disturbances.Materials and methodsOrthopantomography and lateral skull x-ray images were taken either from surgically treated or non-surgically treated patients, aged 5 to 8 years, to compare dentoskeletal features and craniofacial growth by cephalometric analysis. Molecular testing results were collected from their medical records.ResultsEighteen BWSp patients were consecutively recruited: 8 underwent TRS at 14.9 ± 2.2 months of age, while 10 did not. Anterior open bite and dental class III were more frequently observed in the surgically treated group, but none showed skeletal class III. No statistically significant differences were observed in growth pattern, but children treated with TRS showed a tendency towards both maxillary and mandibular prognathism with protruding lower lip. Growth pattern seemed to be not related to molecular subtypes.ConclusionsThese preliminary data suggest that early TSR does not improve craniofacial growth pattern and dentoskeletal features in BWSp children.Clinical relevanceReductive glossectomy may not be justified for preventing or avoiding oro-facial deformities in BWSp; therefore, early monitoring of maxillofacial development of each affected child has a great clinical significance.

Amelogenesis imperfecta: More than just an enamel problem.

This article will provide an overview of the clinical presentation, treatment considerations, and sequencing of treatment for a patient with amelogenesis imperfecta (AI). The different types and subgroups of AI will be described, focusing on Type I hypoplastic form of the condition. Patients with AI all have abnormal enamel formation but some may also present with vertical dysgnathia, anterior open bite, and posterior crossbite. A case report demonstrates the sequencing and implementation of necessary orthodontic and prosthodontic treatments, beginning in the mixed dentition and ending with esthetic and functional permanent restorations in the permanent dentition. AI is a disorder of tooth enamel formation but may also affect the face, jaw relationship, occlusion, compromised esthetics, and can potentially cause psychological damage due to the appearance of the teeth. Treatment of AI should be initiated at a young age.

Camouflage Correction of Skeletal Class III Severe Open Bite with Tooth Ankylosis Treated by Temporary Anchorage Devices: A Case Report

Tooth ankylosis is a disorder characterized by the fusion of tooth and alveolar bone. This case report describes the treatment of a severe open bite due to tooth ankylosis. A 14-year-old female patient with a chief complaint of masticatory dysfunction was diagnosed with skeletal Class III severe anterior open bite and tooth ankylosis. She visited our university hospital with a chief complaint of an anterior open bite. After the surgical luxation of the ankylosed maxillary right central incisor, the tooth was orthodontically retracted using a nickel-titanium wire. The right mandibular lateral incisor and canine were luxated and retracted using intermaxillary elastics from a temporary anchorage device (TAD), which was inserted in the opposite jaw. During the treatment, skeletal Class III malocclusion deteriorated due to anterior growth of the mandible. Therefore, TADs were inserted into the retromolar pad on both sides of the mandible and retracted into the mandibular dental arch. Although the mandibular right canine was luxated several times, it could not be brought to the occlusal line, and was thus extracted; the extraction space was replaced with a prosthesis. Consequently, a normal overjet and overbite with a straight profile were achieved. Extrusion of ankylosed teeth by intermaxillary elastics from a TAD is a valid treatment option for patients with severe open bites.

Anterior open bite self-correction after cessation of non-nutritive sucking habits: a systematic review.

Non-nutritive sucking habits likely may cause occlusal changes such as anterior open bite (AOB) if they persist over extended time. To assess if there is self-correction of AOB after cessation of non-nutritive sucking habits in children older than 4 years old, through a systematic review. Data sources included PubMed, Scopus, Web of Science and Latin American and Caribbean Health Sciences (LILACS) databases, gray literature as Google Scholar, the database System for Information on Gray Literature in Europe (OpenGrey) and ProQuest Dissertations and Theses Database, also hand searches of the included studies references. Studies assessing occlusal changes in children aged 4-12 years with AOB traits and non-nutritive sucking habits after the discontinuation of the habit were included. Two authors independently assessed eligibility and extracted data. The risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale and the Joanna Briggs Critical Appraisal Checklist for quasi-experimental studies. The confidence in cumulative evidence was assessed using the GRADE criteria. Over 3100 studies, only 5 met the inclusion criteria. There is often self-correction of AOB after discontinuing the non-nutritive sucking habit, even in cases older than 4 years old. The improvement ranged between 50 and 100%. The overall quality of evidence was very low. AOB self-correction after discontinuing a non-nutritive sucking habit is possible, even after 4 years old, although with very low certainty in the body of evidence. It is not clear after what age the removal from the habit is unlikely to facilitate AOB self-correction. International Prospective Register of Systematic Reviews code: CRD42016052171. There was no conflicting interest from the review authors.

Surgical-Orthodontic Treatment of Class III Malocclusion with Anterior Open Bite

A 21-year-old female came with chief complaints of inability to incise food and poor esthetics. The patient presented with a concave facial profile, long face with a steep mandibular angle, incompetent lip closure, and acute nasolabial angle. Intraorally, she had negative 6 mm overjet, 3 mm open bite and dental crowding. She was diagnosed as severe skeletal Class III malocclusion and anterior open bite. The treatment plan included orthodontic treatment with orthognathic surgery and extraction of maxillary second molars, which were supra-erupted and tipped buccally. The pre-operative orthodontic alignment took 11 months. The surgical correction included maxillary Le Fort I osteotomy with 4 mm advancement, mandibular intraoral vertical ramus osteotomy with 6.5 mm setback and genioplasty. The total surgical-orthodontic treatment time was 16 months. The final result presented a straight profile with stable occlusion. The patient’s facial and dental esthetics, masticatory function, and quality of life were all significantly improved after surgical-orthodontic treatment.

Prevalence and Associated Factors of Malocclusion among Preschool Children in Huizhou, China: A Cross-Sectional Study.

This survey examined the prevalence of malocclusion and its associated factors in 3- to 5-year-old children in Huizhou, China. Children were recruited from 21 kindergartens using a multistage sampling method. Two examiners performed oral examinations on the children, assessing occlusal traits, including primary molar and canine relationship, overjet, crossbite, overbite, anterior open bite, scissor bite, midline deviation, crowding, and spacing. Caries experience was recorded. Self-administered questionnaires were distributed to collect background information and oral health-related habits. Chi-square test, Mann-Whitney U test, and binary logistic regression were conducted. The study invited 1485 children and eventually recruited 1454 (52.9% boys; response rate: 97.9%). The prevalence of malocclusion was 68.3%, and deep overbite was found in 48.6% of the children. Children who had lip-biting habits had a higher prevalence of deep overbite than those who did not (OR = 2.36, p < 0.05). Children who had digit-sucking habits and dental caries in anterior maxillary teeth had a lower prevalence of deep overbite than those who did not (OR = 0.73 and 0.70, respectively, p < 0.05). In conclusion, over half of the children in Huizhou who participated in the study had malocclusion. Dental caries in anterior maxillary teeth, digit-sucking, and lip-biting were the associated factors of deep overbite.

Non-Surgical Camouflage Treatment of a Skeletal Class III Patient with Anterior Open Bite and Asymmetry Using Orthodontic Miniscrews and Intermaxillary Elastics

This case report presents the non-surgical orthodontic camouflage treatment of an 18-year-old male patient with skeletal Class III asymmetry and severe anterior open bite. The anterior open bite was corrected by extrusion of the maxillary and mandibular anterior teeth and clockwise and counterclockwise rotation of the maxillary and mandibular occlusal plane, respectively, using intermaxillary Class III elastics between the maxillary posterior buccal miniscrews and mandibular canines and anterior vertical elastics between the maxillary and mandibular canines. Class III dental relationships and dental asymmetry were corrected via unilateral distalization of the mandibular dentition on the left side using a closed coil spring between the buccal shelf screw and hook. The patient’s smile esthetics and dental relationship were improved with a more favorable facial profile, and facial asymmetry was slightly alleviated after orthodontic camouflage treatment. The total treatment time was 15 months. A modified wraparound retainer with a scalloped labial bow, tongue crib, and tooth positioner was used simultaneously to prevent the potential relapse.

Replantation of autotransplanted mature third molar in anterior open bite patient: case report

Replantation of autotransplanted mature third molar in anterior open bite patient: case report

Orthognathic Surgery as Class III Skeletal Treatment in a 31-Year-Old Female with Mandible Prognathism: A Case Report.

Mandible prognathism or malocclusion skeletal class III is facial deformities. These deformities can affect orofacial function, such as mastication, speech, and function of the temporomandibular joint. Besides the physical effects of these deformities, the psychosocial impact on the individual is often essential, and such deformities can affect the quality of life and self-confidence. Orthognathic surgery is designed to correct these deformities because these deformities could not have been corrected by only orthodontic treatment. Therefore, at Hasan Sadikin General Hospital, orthognathic surgery is the treatment choice for mandibular prognathism or malocclusion skeletal class III. In this case report, we present a 31-year-old female with mandibular prognathism, difficulty in closing her mouth and anterior open bite. Surgery was performed by Le Fort 1 osteotomy for advancing maxilla and bilateral sagittal split osteotomy for setback mandible. Two weeks after surgery, patient came back to the orthodontic department for occlusion treatment.

Management of moderate crowding by two-arch distalization using passive self-ligating lingual brackets, in-house digital indirect bonding, and mini-screw anchorage: A case report

This case report presents the management of an adult patient with moderate crowding in both arches and anterior crossbite with passive self-ligating lingual brackets. The orthodontic setup and bracket positioning was done digitally with an in-house approach. Virtual setup and bracket placement was performed on Autolign software (Diorco, Gyeonggi-do, Korea). The indirect bonding trays were vacuum-formed on printed malocclusion models with resin brackets. Two palatal and two buccal shelf miniscrews were used for two-arch distalization to correct proclined incisors and anterior open bite after leveling and alignment stage. After 12-month treatment, normal overbite,overjet and well-aligned dentition were achieved without premolar extraction. The incisors were uprighted slightly and the protrusive lower lip was retracted with improvement of facial harmony. One-year retention records confirmed that the outcome was stable. In-house digital setup and bracket placement could be a cost-effective approach for indirect lingual bracket bonding. Two-arch distalization with miniscrew anchorage may have the possibility of managing moderate crowding cases without premolar extraction or interproximal stripping.

Association of breastfeeding duration with the development of non-nutritive habits, and transversal and vertical occlusal alterations in preschool children: A cross-sectional study.

Breastfeeding has multiple nutritional, immunological and psychological benefits, as well as a positive influence on the development of the stomatognathic system. The present study attempted to determine the relationship between the duration of breastfeeding and the development of non-nutritive habits, and transversal and vertical occlusal alterations in preschool children. This cross-sectional study involved 155 preschoolers aged 2-5 years from 3 public schools in Lima, Peru. The sample was divided into 2 groups with regard to the duration of breastfeeding: group A (n = 50) included infants that had been breastfed for up to 6 months; and group B (n = 105) included infants that had been breastfed for 6-12 months. Two trained and calibrated dentists evaluated each group, and clinically determined the presence or absence of transversal or vertical occlusal alterations. Likewise, the children's parents or caregivers were consulted to determine the development of non-nutritive habits. A significant association was found between breastfeeding duration and the development of the oral breathing habit; groups A and B showed a prevalence of 30.0% and 16.2%, respectively (p = 0.048). Likewise, breastfeeding duration affected the appearance of oral breathing (OR (odds ratio) = 0.84; 95% CI (confidence interval): 0.74-0.96; p = 0.011). Furthermore, the use of a bottle for more than 24 months significantly influenced the appearance of oral habits (OR = 3.55; 95% CI: 1.20-10.55; p = 0.022) and open bite (OR = 12.12; 95% CI: 1.16-126.31; p = 0.037). Breastfeeding duration of 6-12 months was shown to be a protective factor in preventing the appearance of oral breathing. Posterior crossbite (PCB), open bite and deep bite seemed not to be influenced by breastfeeding duration. However, the use of a bottle for more than 24 months significantly influenced the appearance of anterior open bite.

Can Condylectomy Alone Achieve Facial Symmetry in Patients With Hemimandibular Hyperplasia (Condylar Hyperplasia Type 2)?

The purpose of the present study was to evaluate the 3-dimensional orofacial changes occurring after proportional condylectomy in patients with unilateral condylar hyperplasia type 2 (hemimandibular hyperplasia). Eight patients underwent proportional condylectomy that was not followed by orthognathic surgery or orthodontic treatment for at least 1 year. The precondylectomy and postcondylectomy photographs and radiographs were analyzed cephalometrically and compared. The average length of the condylar segment removed was 13mm and this resulted in almost equal heights of the ramus-condyle units of both sides. Evaluations in the vertical plane improved after surgery; however, when the preoperative asymmetry was significant, the residual asymmetry continued to be notable after condylectomy. Transverse plane evaluations improved after condylectomy, and chin position was satisfactorily centralized in all patients. In the horizontal plane, mandibular setback occurred, and this was considered favorable when the preoperative skeletal profile was class III, whereas the opposite was when the patient was class I before surgery. The occlusion improved gradually over the postoperative months by the intrusion on the affected side and extrusion on the unaffected side into a bilaterally balanced posterior contacts with residual anterior open bite. In conclusion, condylar hyperplasia type 2 patients with mild asymmetry and low esthetic demands can benefit from proportional condylectomy as the sole treatment to both stop the hyperplastic condylar growth and improve the asymmetry to some extent. Surgeons should be able to predict the change that is expected to occur after proportional condylectomy and discuss this with the patient before surgery.

Treatment of Severe Anterior Open-bite Accompany with Impacted Canine: A Case Report

Introduction: The anterior open bite is a multifactorial malocclusion and a challenge between orthodontists. Based on the origin, divided in two types as dental and skeletal, and appear in the anterior or posterior segments, (unilateral or bilateral). Dental open-bite in the most of patients have environmental etiologic factor such as oral habits, tongue trust, mouth breathing, large tongue. In skeletal type, excessive vertical growth of the maxilla is etiologic factor and accompany with downward-backward rotation of the mandible.Case Report: The case was a 27 years woman with an anterior open bite and unilateral impacted upper canine and congenital missing of lower 2nd premolar in the left side and retained 2nd lower deciduous molar and upper canine in the left side. She consulted for orthodontic treatment in Tehran Dental School of Shahid Beheshti University of Medical Sciences in October of 2017.The Orthodontic treatment was down with MBT slot 22 system (USA. Orthoorganizer, inc) for apply extrusive force on impacted upper canine in left side with auxiliary 014 ss, segmented arch wire. loop arch wire technique with 16 × 22 ss rectangular continuous arch wire was used for space closing in extraction site and correction overbite. The extracted teeth were right lower 2nd premolar and left 2nd deciduous molar and 1st premolars in upper arch. As recommended advancement genioplasty for correction chin deficiency the patient refused it. Conclusion: In this technique we used Orthodontic treatment alone instead of Orthognathic surgery for open bite correction.

Analysis of orocraniofacial changes in children with congenital zika syndrome: a case series

This article aims to describe orocraniofacial alterations in children with Congenital Zika Syndrome. A descriptive case series study was carried out with 20 children with the syndrome, attended at a rehabilitation center in the city of Recife, Pernambuco, Brazil. The presence of oral, craniofacial and neurological alterations, oral health condition and gestational period were evaluated. Data were obtained from medical records and interviews with the children's mothers, followed by a physical examination. Among the main alterations found are microcephaly, craniofacial disproportion, epicanthal folds, bruxism, anterior open bite, ankyloglossia, tongue interposition and delay in teeth eruption. The child may have difficulty reporting any discomfort due to neurological impairment, therefore, these findings reinforce the importance of preventive dental consultations and the performance of the dental surgeon in the elaboration of protocols and guidelines aimed at providing a better quality of life for these patients.

Orthodontic treatment of children with anterior open bite and posterior crossbite: An analysis of the stomatognathic system.

Dental malocclusions are deviations from normalities due to the inadequate growth and development of the dental arch which provides functional changes to the stomatognathic system. The aim of this longitudinal study was to evaluate the electromyographic activity (EMG) the masseter and temporalis muscles, strength of the orofacial tissues and occlusal force of children with anterior open bite (n=15) and posterior crossbite (n=20), 7 days after the removal of the orthodontic apparatus. A fixed horizontal palatal crib was used in the treatment of anterior open bite and the fixed appliances Hyrax or MacNamara was used in the treatment of posterior crossbite. EMG of the masticatory muscles was recorded using an electromyograph with wireless sensors during mandibular tasks. Habitual chewing was assessed using the integral of the linear envelope of the electromyographic signal in the masticatory cycles. The strength of the tongue and facial muscles was measured using the Iowa Oral Pressure Instrument. T-Scan was used to analyze the force of occlusal contact. Molar bite force was measured by digital dynamometer. Significant differences (p<0.05) were found in the EMG data of the masseter and temporalis muscles in the static and dynamic mandibular tasks. There were no significant difference in strength of orofacial tissues, occlusal contact force and molar bite force 7 days after the removal of the orthodontic apparatus. The results of this study suggest that the orthodontic treatment of anterior open bite and posterior crossbite in children promoted functional alteration in the electromyographic activity of masseter and temporalis muscles.

Critical appraisal of confounding factors of observational studies on the association between dentofacial features and dental trauma in a Brazilian population

Dental trauma is a highly prevalent dental emergency. Children and adolescents without inadequate lip coverage, increased overjet, and anterior open bite are associated with the occurrence of traumatic dental injuries. Observational studies do not allow the inference of causality, one of the reasons being: the potential confounding factors. Therefore, this review aimed to critically appraise the confounding factors considered in epidemiological studies that associate dentofacial features with the occurrence of dental trauma in Brazilian children and adolescents. Studies included in the qualitative synthesis of a recently published comprehensive systematic review and meta-analysis on the topic were screened. Studies that only mentioned the performance of bivariate analyzes or that did not mention the performance of multivariate analyzes were excluded. Evaluation of control statements for possible confounders and bias consideration was performed for each selected study. Confounding factors in these studies were also identified and categorized according to their domains. Fifty-five observational studies were screened, of which 11 were excluded due to the mention of only bivariate analyzes or the lack of multivariate analyses. The remaining 44 studies were critically appraised. Of these, 9 studies specifically mentioned the term confounding, and 12 studies mentioned the term bias. However, only 14 studies mentioned limitations on confounding factors in their findings. Among the 99 different variables identified, the most used were type of trauma, followed by sex and age. Most studies did not acknowledge the control for possible confounding factors and rarely stressed the need for caution in interpreting their results. Cross-sectional studies do not allow inferring a cause-and-effect relationship between dentofacial features and dental trauma.