Effects of hypodontia on craniofacial structures and mandibular growth pattern

Digital planning and decision making for severe congenital oligodontia with Angle class-III malocclusion

As maxillofacial surgery becomes increasingly digitized and the transformative impact of pre-surgical scanning and computer simulation is recognized, this clinical paper presents an algorithm for the selection of interventions in severe congenital oligodontia with Angle class-III malocclusion (OCIII) utilizing such technologies. A complex, multifactorial condition with varying degrees of craniofacial involvement, OCIII is associated with edentulous facial appearance, mandibular prognathism and deep underbite, as well as malocclusion. Our methodology involves the integration of CBCT imaging, intra- and extra- oral scanning, and 3D planning with the assessment of bone volume, number of missing teeth, skeletal discrepancies, and patient compliance in the selection of suitable treatments. This approach accounts for unique patient characteristics by promoting personalized medicine and facilitating the development of predictable treatment modality results by offering a decision-tree for standardized treatment selection in cases of OCIII. This study unequivocally establishes the importance of digital treatment planning for OCIII, enabling the adaptation of surgical protocol for specific concerns and underlying limitations, thereby orchestrating successful treatments, improving patient satisfaction, and surpassing conventional methods.

Overcoming three-dimensional challenges through objective decomposition and virtual-digital design: A multidisciplinary case on hypodontia treatment

A 15-year-old female sought multidisciplinary treatment for hypodontia, three-dimensional problems, deep overbite, multiple occlusal interferences, and collapse of the occlusion. Through virtual-digital design with objective decomposition, this patient underwent five steps of orthodontic treatment under the guidelines of the principles: removal of occlusal restriction is a prerequisite; transverse problems are solved first; then sagittal problems; and vertical correction runs through the treatment. After orthodontic and prosthetic treatment, aesthetic appearance and functional occlusion were achieved. In complex multidisciplinary cases with three-dimensional problems, which makes it difficult to formulate the final goal, virtual-digital design under objective composition and standardized comprehensive principle are effective and necessary.

Comparison of Skeletal, Dental, and Soft Tissue Changes Before and After Orthodontic Treatment in Patients with Congenitally Missing Bilateral Maxillary Lateral Incisors

(1) Background and Objectives: Congenitally missing bilateral maxillary lateral incisors (CMBMLIs) present significant aesthetic, functional, and psychosocial challenges that require an orthodontic approach based on multidisciplinary consensus. The aim of this study was to evaluate the skeletal, dental, and soft tissue changes in patients with CMBMLIs treated with space opening and closure methods and to compare these changes with those in untreated individuals. (2) Materials and Methods: A total of 53 patients (mean age 16 ± 3.5 years) were included, and three groups were formed: the study groups, consisting of the space opening group (n = 18) and the space closure group (n = 17), and the control group (n = 18), which had ideal occlusion. A total of 14 angular and 13 linear measurements were performed on lateral cephalograms before (T0) and after (T1) treatment. Statistical significance was set at p < 0.05. (3) Results: Compared to the control group, significant post-treatment changes were more evident in dental measurements and less evident in skeletal and soft tissue measurements. A statistically significant increase in the U1/SN angle was observed in the space opening group compared to the space closure group. The U1/NA angle increased significantly in both study groups, with a greater increase in the space opening group. However, although the change in U1/NA angle was not significantly different between groups, the increase was greater in the space opening group. No significant differences were found between the control and study groups in the nasolabial angle, upper lip length and thickness, and the distance from the upper and lower lips to the E-line. (4) Conclusions: While space opening and closure methods had minimal effects on most skeletal and soft tissue parameters, the space opening method significantly altered the maxillary incisor position. Considering the waiting period for prosthetic restoration after space opening and potential alveolar bone limitations, space closure is recommended for CMBMLIs when feasible because it ensures a more predictable planned maxillary incisor position.

Facial growth in patients with unilateral cleft lip and palate at 19 years of age after three different one-stage palatal repairs: a longitudinal study with prediction from cephalograms at 5 years of age

OBJECTIVES

To compare cephalometric long-term outcomes in patients with unilateral cleft lip and palate (UCLP) and treated with three different surgical protocols for palatal repair. Furthermore, to investigate growth longitudinally and evaluate the possibility to predict the outcome at age 19 from cephalometric values at 5 years.

MATERIALS/METHODS

Lateral cephalograms of 68 patients, operated according to the Veau-Wardill-Kilner technique (n = 13), the minimal incision technique (n = 39), or MIT with muscle reconstruction (MITmr) (n = 16) were assessed. At a mean age of 19.0 (SD 0.7) years, 17 skeletal and 6 soft tissue variables were analysed using analysis of variance (ANOVA) with pairwise comparison. Lateral cephalograms at a mean age of 5.1 (SD 0.4) years, from 32 of the 68 patients were used to predict values at 19 years, using a multiple linear regression.

RESULTS

There were statistically significant differences between the three surgical techniques for eight of the skeletal variables and for two of the soft-tissue variables at 19 years. The angle between the sella/nasion plane and the nasion/A plane (SNA) was 74.5 (SD 3.8) after Veau-Wardill-Kilner (VWK), 77.6 (SD 5.3) after minimal incision technique (MIT), and 76.7 (SD 2.6) after MITmr. Adjusted for baseline values, at 5 years, only face height had a significant effect dependent on surgical technique.

LIMITATIONS

Due to the exclusion criteria or missing medical records, only 43% of 157 consecutive patients could be included in the study.

CONCLUSION

MIT and MITmr resulted in better cephalometric results regarding facial growth sagittally and vertically compared to VWK. Most of the cephalometric variables measured showed a strong positive relation between the value at 5 and the value at 19 years of age.

Association between dental agenesis and facial morphology. A cross-sectional study in France

PURPOSE

Knowing the features of dental evolution and facial morphology, marked by an increase in the prevalence of agenesis and a tendency towards verticalization of the face, the main objective of this cross-sectional observational study was to assess the correlation between the occurrence of agenesis (of 3rd molars or other teeth) and facial morphology in the French population.

METHODS

The study was conducted at the University Hospital of Rennes, France, from June 2022 to October 2022. Patients aged 12-18 years who underwent a global orthodontic assessment were included. Data collected from medical examinations, panoramic, anteroposterior, and lateral x-rays were analyzed for cephalometric and dental features. The association between morphological parameters and agenesis of wisdom teeth or other teeth was assessed by univariate and multivariate analysis.

RESULTS

The study included 259 patients, of whom 89 presented agenesis. Logistic regression analyses identified several morphological parameters associated with agenesis. In the multivariate model, a negative correlation was found between tooth agenesis and FMA (OR = 0.85; p < 0. 001), facial axis (OR = 0.92; p = 0.040), and a positive one with SNB (OR = 1.17; p = 0.023), ANS-Xi-Pm (OR = 1.12; p = 0.013).

CONCLUSION

This study highlights the correlation between agenesis occurrence and specific cephalometric parameters in the French population. The findings suggest that transverse constriction of the maxilla, facial divergence, and anterior projection of the chin symphysis are associated with agenesis. Trial registration number: Opinion n°22.103, dated 06.04.2022.

The influence of three different primary treatment protocols on 5-year-old maxillary growth in patients with complete unilateral cleft lip and palate

The study evaluated the effects of three different primary treatment protocols on maxillary growth in patients aged 5 years with complete unilateral cleft lip and palate (UCLP). The secondary objective was to assess the influence of initial cleft severity, family history of class III, and status of permanent lateral incisor on maxillary growth. In total, 54 patients with non-syndromic complete UCLP were included and grouped as follows: group An underwent lip adhesion, cheilorhinoplasty associated with tibial periosteal graft for hard palate repair, and finally veloplasty; group B underwent lip adhesion, then cheilorhinoplasty with intravelar veloplasty, and finally a hard-palate repair; group C underwent cheilorhinoplasty with intravelar veloplasty and then a hard-palate repair. Five-year maxillary growth was assessed on dental models, both clinically and digitally. No difference was found with GOSLON-Yardstick scoring. Five-year measurements showed that group C tended to have the best maxillary arch morphology (p = 0.012). Initial cleft severity did not impact maxillary growth, but status of permanent lateral incisor and family history of class III did (p = 0.019 and p = 0.004, respectively). In patients aged 5 years, the two-stage approach appeared to be the least detrimental to growth development. Predictive factors for growth retardation included the absence of lateral incisor and a family history of class III.

Comparison of craniofacial morphology in individuals with and without hypodontia with a special focus on the number of congenitally missing teeth

Background

Hypodontia might negatively affect dental function and esthetics, what might affect patients' self-esteem, communication behavior, professional performance and thus quality of life. The aim of this study was to estimate the influence of number of congenital missing teeth on dentofacial features.

Methods

Lateral cephalograms of 60 individuals with hypodontia (study group) and 40 individuals without hypodontia (control group) were analyzed. Patients in the study group were divided into two subgroups according to the number of missing teeth (group A with hypodontia 1 to 4 teeth and group B with hypodontia 5 or more teeth). Cephalometric data were compared among the study and control groups and statistically analyzed.

Results

The results in the present study revealed a significantly shorter and more retrognathic maxilla, more prognathic chin position, more retruded incisors in both jaws, large interincisal angle, straighter facial convexity as well as more retruded upper and lower lips in the group B compared with the control group. In the group A only chin position was significantly more prognathic compared with the control group.

Conclusions

According to the results of present study impact of hypodontia on the craniofacial morphology and consequently on facial esthetics was found statistically significantly greater in patients with 5 or more congenitally missing teeth.

Relationship between craniofacial morphology and congenitally missing mandibular incisors

Background/purpose

Treatment of incisors‘ agenesis is challenging that arouses orthodontists’ interests. The purpose of this study was to compare the craniofacial pattern of individuals with or without congenitally missing mandibular incisors.

Materials and methods

This retrospective study included patients receiving orthodontic consultation between 1999 and 2019 at the Orthodontic Division of the Dental Department of Taipei Medical University Hospital. Cephalometric measurements were obtained through manual tracing and by using computer software. A total of 31 measurements were obtained to evaluate skeletal, dental and soft tissues, and chin morphology. A multivariate analysis of covariance, analysis of covariance, and Scheffé’s post hoc tests were used to analyze the differences among a group of patients with one congenitally missing mandibular incisor (M1), a group of patients with two congenitally missing mandibular incisors (M2), and the control group. Student's t-test was used to analyze the differences between the M1 or M2 group and the control group. Significance was set at P < 0.05.

Results

Significant differences were observed between the M and control groups in terms of lower incisor angulation and facial balance. Regarding chin morphology, significant differences were noted between the M and control groups and also among the M1, M2, and control groups.

Conclusion

The lower incisors of the M group are more retroclined than those of the control group, resulting in retrusive lower lips. Facial balance varies between the M and control groups. Congenitally missing mandibular incisors affect chin morphology, making the chin button prominent.

Evaluation of the effects of hypodontia on the morphology of craniofacial structures

OBJECTIVE

The study aimed to investigate the effects of hypodontia on the sagittal and vertical dimensions of the jaws, dentition and the related soft tissue.

MATERIALS AND METHODS

The hypodontia group included 111 patients whose growth was completed with one or more congenitally missing teeth (CMT). Sixty additional patients with skeletal and dental class I relationship, without CMT, and who completed growth, were included as the control group. The hypodontia group was divided into three subgroups according to the intermaxillary (maxillary or mandibular) location, intramaxillary (anterior or posterior) location and the severity of hypodontia (mild: 1-2 CMT or moderate: 3-6 CMT). Twenty-three measurements were performed on lateral cephalograms of the patients. The one-way and Kruskal-Wallis Analysis of Variance tests were used for the statistical analysis. The false discovery-rate analysis was applied for the multiple comparison adjustment.

RESULTS

No significant difference was found in the skeletal measurements between all hypodontia subgroups and the control (P > .05). Upper incisors were found to be retroclined in the anterior hypodontia group. The upper lip was found to be protruded in the mandibulary hypodontia group compared to the control (P < .05).

CONCLUSION

The mild-to-moderate hypodontia did not produce a significant skeletal effect. However, hypodontia can affect the incisors, especially when CMT is in the anterior region. Besides, the effects of severe hypodontia could not be evaluated due to the insufficient number of oligodontia patients.

Effect of Tooth Agenesis on Mandibular Morphology and Position

Congenital missing teeth (OMIM #106600) is the most common dental abnormality. The aim of the study was to evaluate the effects of tooth agenesis on the total mandibular length, length of the mandibular body and alveolar process, and the mandibular anteroposterior position. The material was obtained from the Department of Orthodontics, Medical University of Warsaw. The study group included 116 patients aged 9–18 years with a congenital absence of at least two permanent tooth buds in the maxilla and/or mandible (mean: 6.2 teeth missing/patient). All patients were Caucasians: 68 (59%) females and 48 (41%) males. The control group included 115 patients without tooth agenesis matched with the age and gender of the study group. A cephalometric analysis was performed, and it was focused on assessing anteroposterior mandibular measurements. This assessment was based on 17 measurements (12 linear and 5 angular). Statistical analysis of the cephalometric measurements between the study group and the control group showed significant changes regarding selected mandibular measurements. Tooth agenesis does not affect the total length of the mandible and the length of the mandibular body, but it might reduce the length of the mandibular arch length and result in a more retrusive mandibular position.

Development of dentofacial characteristics related to Incontinentia Pigmenti syndrome: A repeated cross-sectional study

INTRODUCTION

This research aimed to investigate the dentofacial characteristics of patients with Incontinentia Pigmenti (IP) (or Bloch-Sulzberger) syndrome in childhood, juvenile, and adulthood developmental stages.

METHODS

Fifteen female patients with a clinical diagnosis of IP, genetically confirmed by molecular testing, were included in this study. The records of 25 nonsyndromic females with Class I occlusion and lateral cephalograms obtained at similar developmental stages were selected from the American Association of Orthodontists Foundation Legacy Collection as a control group. Dentofacial features of subjects with IP and those in the control group were compared statistically using t test and Mann-Whitney rank-sum test (significance was defined as P <0.05).

RESULTS

In general, patients with IP had shorter maxillary and mandibular length, straight skeletal profile, hypodivergent growth pattern with a tendency to mandibular protrusion, shorter anterior facial height, Class III compensatory positioning of incisors, more retruded lips, and smaller maxillary incisor exposure. The degree of hypodontia severity had a significant impact on skeletal, dental, and soft-tissue features in patients with IP.

CONCLUSIONS

The results of this study showed that, since childhood, the dentofacial characteristics of patients with IP were progressively distancing from those of nonsyndromic patients with Class I occlusion, presenting their own orthodontic needs.

Is dental agenesis associated with craniofacial morphology pattern? A systematic review and meta-analysis

BACKGROUND/OBJECTIVE

Craniofacial discrepancies have been associated with congenital dental anomalies. The aim of this study was to determine if there is any scientific evidence in the literature regarding the association between dental agenesis and craniofacial morphology.

MATERIALS AND METHODS

A systematic review and meta-analysis following the PRISMA Statement were conducted and registered in PROSPERO database. A broad search was conducted on databases (PubMed, Virtual Health Library, Web of Science, and Scopus) and grey literature. Articles that were selected based on predetermined eligibility criteria were assessed for quality and risk of bias according to the guidelines described by Folkes and Fulton. Those articles with similarities were submitted to meta-analysis using the RevMan 5.3 program. The certainty of the evidence was tested using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation).

RESULTS

An electronic search of 975 articles resulted in 12 articles. These and four articles identified through manual search were eligible to be assessed for methodological quality and the risk of bias. Eleven articles presented moderate to high methodological quality. The included articles observed a reduced mandibular plane, a smaller maxilla and more differences with the increase in the severity of dental agenesis. Seven articles were included in the meta-analyses. Dental agenesis presented smaller SNA angle (P < 0.0001/CI -1.74 [-2.55, -0.92]) with moderate certainty of the evidence; and smaller ANB angle (P = 0.01/CI -0.80 [-1.44, -0.17]), with low certainty of the evidence.

CONCLUSIONS

This systematic review and meta-analysis demonstrated that dental agenesis may be associated with specific craniofacial morphology. Further studies are necessary due to the variation of the certainty of the evidence.

CONFLICT OF INTEREST

none declared.

REGISTRATION

PROSPERO (CRD42017055882).

Growth differences in patients with dental agenesis, how its location impacts facial morphology

Background/purpose

Non-formation of a tooth impacts the morphology of the alveolar bone, which may, in turn, generate an imbalance in facial growth. This retrospective case-control study aimed to determine whether observable differences exist in the facial growth of patients with dental agenesis relative to complete dentition controls.

Materials and methods

The sample comprised 75 patients with dental agenesis, and each case was paired with two controls of the same age and gender (n = 150). All patients were measured cephalometrically (31 variables), and both groups were compared with student's t- or Z-test (P < 0.05). Subsequently, ANOVA or Kruskal–Wallis tests (P < 0.05) were used to compare facial growth depending on the missing tooth's sagittal location in the dental arch (anterior or posterior agenesis); as well as its location in the affected bone (maxillary, mandibular, or both).

Results

Four measurements with significant differences were found, whereas ten were found in the sagittal location in the dental arch analysis. Regarding the affected bone, there were no affected variables.

Conclusion

it was found that patients with dental agenesis show differences in the sagittal growth of the upper jaw and in the position of the lower incisor. In the studied population, these changes are strongly influenced by the sagittal location of the missing tooth, while its location in the jaws does not affect facial growth.

Prevalence and Pattern of Hypodontia among Croatian Orthodontic Patients

Objective

The objective of this retrospective study was to assess the prevalence of hypodontia in the permanent dentition among Croatian orthodontic patients. The occurrence was evaluated concerning gender, specific missing teeth, the location, pattern of distribution in the maxillary and mandibular arches and sagittal and vertical skeletal pattern.

Material and Methods

The sample consisted of 194 patients (75 males and 119 females) from the Department of Orthodontics, Dental Clinic, Clinical Hospital Center Zagreb. Based on the severity of hypodontia the sample was divided into mild (1-2 missing teeth), moderate (3-5 missing teeth) and severe groups (6 or more missing teeth). The location of missing teeth was used to further divide the sample into anterior (intercanine region), posterior (premolars and molars) and anteroposterior groups. In addition, jaw localization of hypodontia was also considered.

Results

Permanent dentition hypodontia among Croatian orthodontic patients was found to be generally mild (80%), and a distribution was similar in the maxilla (39%) and the mandible (41%), as well as in the anterior and posterior segments of dental arch (44%). The number of missing teeth per person ranged from 1 to 12, with no significant difference between genders. The severity and location of hypodontia did not differ significantly between the genders, as well as in between the categories of sagittal and vertical skeletal patterns.

Conclusion

Present results suggest that the treatment plan for patients with hypodontia in permanent dentition should be individualized and adjusted for each case.

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Aim

The primary aim of this study was to evaluate the gender-based differences in patients with hypodontia. As a secondary outcome, the study looked into the correlation between hypodontia and other dental clinical features among Kosovar adolescents.

Material and Methods

3,306 students, aged between 15-21 years were examined in schools in Kosovo. Examinations were performed using a dental mirror to assess the number of teeth present, and dental impressions were taken from hypodontia subjects. Panoramic and periapical radiographs, as well as intraoral photographs, were taken in subjects who were suspected to have hypodontia to verify the diagnosis.

Results

77 of the examined subjects had hypodontia, among which 46 were females (59.7%) and 31 were males (40.3%). The most frequently missing teeth were the maxillary lateral incisors, followed by the mandibular second premolars. 68 patients (88.3%) had at least one dental clinical feature concurrent with hypodontia.

Conclusion

No significant difference was noted in the prevalence of hypodontia according to gender. Teeth rotation was the most commonly observed clinical feature followed by inclination.

Dental anomalies in craniofacial microsomia: A systematic review

Objective: To provide an overview on the prevalence and types of dental anomalies in patients with craniofacial microsomia (CFM). Eligibility criteria: Inclusion criteria were CFM and dental anomalies. The following data were extracted: number of patients, methodology, mean age, sex, affected side, severity of mandibular hypoplasia, dentition stage and dental anomalies. Information sources: Cochrane, EMBASE, PubMed, MEDLINE Ovid, Web of Science, CINAHL EBSCOhost and Google Scholar, searched until the 30 August 2019. Risk of bias: The quality was examined with the OCEBM Levels of Evidence. Included studies: In total, 13 papers were included: four retrospective cohort studies, four prospective cohort studies, four case‐control studies and one case series. Synthesis of results: The studies reported information on dental agenesis, delayed dental development, tooth size anomalies, tooth morphology and other dental anomalies. Description of the effect: Dental anomalies are more often diagnosed in patients with CFM than in healthy controls and occur more often on the affected than on the non‐affected side. Strengths and limitations of evidence: This is the first systematic review study on dental anomalies in CFM. However, most articles were of low quality. Interpretation: Dental anomalies are common in CFM, which might be linked to the development of CFM. The pathophysiology of CFM is not entirely clear, and further research is needed.

Mind the gap: A novel technique for space closure - a case report

Patients presenting with severe hypodontia can be challenging to manage. They often present with significant spaces within the dental arches and the lack of permanent teeth can make anchorage control difficult. This case report demonstrates a novel technique for diastema closure in a 14-year-old with severe hypodontia. The technique allows maintenance of root parallelism during space closure in cases with reduced anchorage support. The treatment plan was agreed on a multidisciplinary hypodontia clinic and involved an upper sectional fixed orthodontic appliance to close a 7-mm midline diastema aiding subsequent partial denture provision. Treatment commenced by bonding upper primary canines and central incisors. However, attempting space closure on a 0.019 × 0.025-inch stainless-steel working archwire resulted in tipping of the incisor crowns. Two brackets were therefore placed on the labial surface of each central incisor (one incisal and one gingival). Subsequently two stainless steel working archwires and elastomeric chain were used for diastema closure. This four-bracket system provided superior control allowing space closure by bodily tooth movement. Excellent root parallelism was achieved with this innovative technique.

Multidisciplinary approach to bilaterally missing lateral incisors: A case report

Maxillary lateral incisors are most common teeth to be found missing. They also are the most common teeth that need esthetic replacement. A 23-year-old female patient with missing maxillary lateral incisors was treated orthodontically: laterals were replaced with implants. Challenges while doing this case are discussed in the following case report.

Craniofacial shape differs in patients with tooth agenesis: geometric morphometric analysis

Aim

To evaluate the shape of the craniofacial complex in patients with tooth agenesis and compare it to matched controls.

Subjects and methods

The sample comprised 456 patients that were allocated to three groups: the agenesis group of 100 patients with at least one missing tooth, excluding third molars, the third molar agenesis group (3dMAG; one to four missing third molars) of 52 patients and the control group (CG) of 304 patients with no missing teeth. The main craniofacial structures depicted on lateral cephalograms were digitized and traced with 15 curves and 127 landmarks. These landmarks were subjected to Procrustes superimposition and principal component analysis in order to describe shape variability of the cranial base, maxilla and mandible, as well as of the whole craniofacial complex. For statistical analysis, permutation tests were used (10 000 permutations without replacement).

Results

Approximately half of the sample's variability was described by the first three principal components. Comparisons within the whole sample revealed sexual dimorphism of the craniofacial complex and its structures (P < 0.01). Differences between the agenesis group and matched controls were found in the shape of all craniofacial structures except for the cranial base (P < 0.05). Specifically, patients with agenesis presented with Class III tendency and hypodivergent skeletal pattern. However, the comparison between the 3dMAG and matched CG revealed no differences.

Conclusion

The shape of the craniofacial complex differs in patients with tooth agenesis suggesting that common factors are implicated in tooth development and craniofacial morphology.

Mean GOSLON Yardstick Scores After 3 Different Treatment Protocols—A Long-term Study of Patients With Unilateral Cleft Lip and Palate

Objectives:

(1) To evaluate dental arch relationships, with the Great Ormond Street, London and Oslo (GOSLON) Yardstick, of participants with Unilateral cleft lip and palate (UCLP) and treated with 1-stage palatal closure with 3 different surgical protocols (2) to compare the mean GOSLON ratings with other CLP centers.

Design:

Retrospective study of medical charts and dental models.

Setting:

Karolinska University Hospital, Stockholm, Sweden.

Participants:

Eighty-seven patients with UCLP operated with 1-stage palatal repair. Thirty-five were operated with Veau-Wardill-Kilner (VWK) technique 1975 to 1986, 31 with minimal incision technique (MIT) from 1987 to 1997, and 21 according to MIT with muscle reconstruction (MITmr) 1998 to 2004.

Interventions:

Dental casts at ages 5 (n = 87), 7 to 8 (n = 27), 10 (n = 81), 16 (n = 61), and 19 (n = 35) years were rated by 10 assessors with the GOSLON Yardstick. Information of other interventions was retrieved from patients’ charts.

Main outcome measures:

Mean GOSLON ratings.

Results:

A total of 82% of the participants were rated as having excellent to satisfactory outcome. Weighted κ statistics for the 10 assessors was good for inter-rater agreement and good/very good for intra-rater agreement.

Conclusions:

The mean GOSLON score in the Stockholm overall material at age 10 was 2.67. The VWK technique resulted in a greater need of orthognathic surgery than the MIT ( P < .01). The MITmr did not produce better dental arch relationships than MIT at age 5 ( P < .05). The best dental arch relationships were found in the MIT group at 10 years, mean 2.58, which is not significantly different from other centers with excellent outcome except Gothenburg and Vienna.

Alveolar bone resorption after primary tooth loss has a negative impact on straightforward implant installation in patients with agenesis of the lower second premolar

OBJECTIVES

To compare the alveolar bone dimensions in patients with lower second premolar (P2) agenesis prior to and after primary molar loss on CT scans, and assess the possibility for straightforward implant placement.

METHODS

Alveolar bone dimensions were evaluated on 150 mandibular CT scans in three groups: (i) agenesis of P2, with the primary tooth in situ, and regularly erupted first premolar (P1) and molar (M1) (AW); (ii) agenesis of P2, without the primary tooth in situ for ≥3 m, but regularly erupted P1 and M1 (AWO); and (iii) P1, P2, and M1 regularly erupted (CTR). The possibility of straightforward placement of an implant 3.5 or 4.3 mm in Ø × 10 mm long was digitally simulated and compared to the actually performed treatment.

RESULTS

Buccolingual width (7.3 ± 2.0 mm) at the coronal aspect of the ridge in the AWO group was statistically significantly smaller comparing with both the AW (9.2 ± 1.4 mm) and the CTR (9.5 ± 1.1 mm) group; width reduction appeared to be mainly due to "collapse" of the buccal aspect of the ridge. Simulated straightforward placement of implants with a diameter of 3.5 or 4.3 mm was possible in 62% and 56% of the cases in the AWO vs. 86% and 84% in the AW group (p = .006 and .002, respectively). Straightforward implant placement was actually possible in all patients (22) in the AW group, while 28% (11 of 39) of the patients in the AWO group needed additional hard tissue augmentation.

CONCLUSIONS

Significant dimensional differences exist in the alveolar ridge, especially in the coronal part, at lower P2 agenesis sites missing the primary tooth for ≥3 m, when compared to P2 agenesis sites with the primary tooth in situ. It seems thus reasonable to advise that the primary second molar should be kept as long as possible, in order to facilitate straightforward implant installation and reduce the probability of additional bone augmentation procedures.

Craniofacial characteristics of children with mild hypodontia

INTRODUCTION

The aim of our study was to evaluate the craniofacial characteristics of children with mild hypodontia using conventional and principal component (PC) analysis.

METHODS

We used radiographic images of 124 children (8-12 years old) with up to 4 missing teeth (55 boys, 69 girls) and of 676 reference children (365 boys, 311 girls) from the Rotterdam Generation R Study and the Nijmegen Growth Study in The Netherlands. Fifteen cephalometric measurements of children with hypodontia were compared with those of the reference children. Moreover, cephalometric parameters were combined into standardized PC scores using PC analysis, and the components were compared between the 2 groups.

RESULTS

PC analysis showed common dental characteristics for all types of hypodontia: a significant increase of the interincisal angle, and decreases of the maxillary and mandibular incisor angles. Other findings were consistent when both methods were applied: (1) anterior hypodontia was significantly associated with the high-angle (hyperdivergent) craniofacial pattern, (2) the tendency toward a Class III malocclusion was identified in maxillary hypodontia, and (3) we observed a significant reduction of lower posterior facial height in children with posterior and mandibular hypodontia.

CONCLUSIONS

Our findings suggest that children with mild hypodontia have distinctive skeletal and dental features.

Association between Tooth Agenesis and Skeletal Malocclusions

Objectives

The aim of this study was to evaluate the association between tooth agenesis and skeletal malocclusions in Brazilian non-syndromic orthodontic patients.

Material and Methods

Pretreatment orthodontic records of 348 patients of both genders and with various skeletal malocclusions were examined. Tooth agenesis was evaluated in panoramic radiographs. Angular measurements were taken from lateral cephalometric radiographs to classify the patient’s malocclusion as skeletal Class I, Class II and Class III. Subjects were divided into 2 groups, “with tooth agenesis” and “without tooth agenesis”. Chi-square or Fisher exact test was used to compare categorical data. ANOVA with Tukey’s post-test was used for means comparisons. An alpha of 5% was established.

Results

From 348 analysed patients, 28 presented tooth agenesis. There was no difference between genders (P = 0.27) nor mean age (P = 0.16). The most prevalent skeletal malocclusion was Class I (63.11%), followed by Class II (25.94%), and Class III (10.95%). The mean of congenitally missing teeth was 1.3 (SD 0.13). Thirteen subjects had premolar agenesis, 13 upper lateral incisor agenesis, 4 lower incisor agenesis and 2 molars agenesis. The group with tooth agenesis presented A point-nasion-B point (ANB) angle smaller (1.66 [SD 2.52]) than the group without tooth agenesis (2.86 [SD 2.49]) (P = 0.01). ANB angle had a negative correlation with the number of congenitally missing teeth (P = 0.039; r = -0.39).

Conclusions

Tooth agenesis is associated with a smaller A point-nasion-B point angle and is negatively correlated with the number of congenitally missing teeth.

Oral and Craniofacial Anomalies of Bardet-Biedl Syndrome: Dental Management in the Context of a Rare Disease

Standardized guidelines for the oral health management of patients with rare diseases exhibiting morphologic anomalies are currently lacking. This review considers Bardet-Biedl syndrome (BBS), a monogenic autosomal recessive nonmotile ciliopathy, as an archetypal condition. Dental anomalies are present in a majority of individuals affected by BBS due to abnormal embryonic orofacial and tooth development. Genetically encoded intrinsic oral structural anomalies and heterogeneous BBS clinical phenotypes and consequent oral comorbidities confound oral health management. Since the comorbid spectrum of BBS phenotypes spans diabetes, renal disease, obesity, sleep apnea, cardiovascular disease, and cognitive disorders, a broad spectrum of collateral oral disease may be encountered. The genetic impact of BBS on the anatomic development of oral components and oral pathology encountered in the context of various BBS phenotypes and their associated comorbidities are reviewed herein. Challenges encountered in managing patients with BBS are highlighted, emphasizing the spectrum of oral pathology associated with heterogeneous clinical phenotypic expression. Guidelines for provision of care across the spectrum of BBS clinical phenotypes are considered. Establishment of integrated medical-dental delivery models of oral care in the context of rare diseases is emphasized, including involvement of caregivers in the context of managing these patients with special needs.

Second premolar agenesis is associated with mandibular form: a geometric morphometric analysis of mandibular cross-sections

The aim of this study was to compare mandibular form (i.e., size and shape) between patients with agenesis of the lower second premolar (P2) and a control group with no agenesis. Three hypotheses were tested: (H1) agenesis causes a change in mandibular morphology because of inadequate alveolar ridge development in the area of the missing tooth (mandibular plasticity); (H2) agenesis is caused by spatial limitations within the mandible (dental plasticity); and (H3) common genetic/epigenetic factors cause agenesis and affect mandibular form (pleiotropy). A geometric morphometric analysis was applied to cross-sectional images of computed tomography (CT) scans of three matched groups (n=50 each): (1) regularly erupted P2; (2) agenesis of P2 and the primary second molar in situ; and (3) agenesis of P2 and the primary second molar missing for >3 months. Cross-sections of the three areas of interest (first premolar, P2, first molar) were digitized with 23 landmarks and superimposed by a generalized Procrustes analysis. On average, the mandibular cross-sections were narrower and shorter in patients with P2 agenesis compared with that in the control group. Both agenesis groups featured a pronounced submandibular fossa. These differences extended at least one tooth beyond the agenesis-affected region. Taken together with the large interindividual variation that resulted in massively overlapping group distributions, these findings support genetic and/or epigenetic pleiotropy (H3) as the most likely origin of the observed covariation between mandibular form and odontogenesis. Clinically, reduced dimensions and greater variability of mandibular form, as well as a pronounced submandibular fossa, should be expected during the treatment planning of patients with P2 agenesis.

The relationship between occlusal support and maxillary development: An animal study

Objective:

To test the hypothesis that maxillary development may be affected by occlusal support.

Materials and Methods:

The sample was composed by Wistar rats (5 weeks old) divided into three groups: Control (n = 10), extraction of mandibular molar teeth – left side (n = 10), extraction mandibular molar teeth – left and right sides (n = 10). The rats were sacrificed 8 weeks postextraction. Cone beam computed tomography scan images were taken for posterior measurement of maxillary length and width. Data were analyzed by one-way analysis of variance (Tukey test as post-hoc test).

Results:

Maxillary length was significantly shorter (P < 0.005) in both groups after tooth extraction. No difference was observed regarding maxillary width and body weight.

Conclusion:

Reduced occlusal support may impair the development of the maxilla in rats.

Oral and dental late effects in survivors of childhood cancer: a Children's Oncology Group report

PURPOSE

Multi-modality therapy has resulted in improved survival for childhood malignancies. The Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers provide practitioners with exposure- and risk-based recommendations for the surveillance and management of asymptomatic survivors who are at least 2 years from completion of therapy. This review outlines the pathophysiology and risks for oral and dental late effects in pediatric cancer survivors and the rationale for oral and dental screening recommended by the Children's Oncology Group.

METHODS

An English literature search for oral and dental complications of childhood cancer treatment was undertaken via MEDLINE and encompassed January 1975 to January 2013. Proposed guideline content based on the literature review was approved by a multi-disciplinary panel of survivorship experts and scored according to a modified version of the National Comprehensive Cancer Network "Categories of Consensus" system.

RESULTS

The Children's Oncology Group oral-dental panel selected 85 relevant citations. Childhood cancer therapy may impact tooth development, salivary function, craniofacial development, and temporomandibular joint function placing some childhood cancer survivors at an increased risk for poor oral and dental health. Additionally, head and neck radiation and hematopoietic stem cell transplantation increase the risk of subsequent malignant neoplasms in the oral cavity. Survivors require routine dental care to evaluate for potential side effects and initiate early treatment.

CONCLUSIONS

Certain childhood cancer survivors are at an increased risk for poor oral and dental health. Early identification of oral and dental morbidity and early interventions can optimize health and quality of life.