Correlation between the frequency of eruption disorders for first permanent molars and the occurrence of malocclusions in early mixed dentition.

OBJECTIVE: We analyzed the incidence of eruption disorders in 6-year molars during the first phase of mixed dentition, and then determined the risks for later dental arch development according to specific combinations of orthodontic malocclusions. We, thus, aimed to derive potential conclusions for preventative orthodontics. SUBJECTS AND METHODS: In this cross-sectional study, 8,041 kindergarten and school children with early mixed dentition were randomly selected and clinically examined. Examinations were performed in two consecutive years during the standard dental screening that school children undergo. The average age was 6.9 years. We defined an eruption of the 6-year molars as being disturbed when (1) the distal cusps had erupted further than the mesial cusps, (2) the mesial inclination of the occlusal surface revealed disturbed eruption, and (3) the 6-year molar had erupted below the second primary molar. RESULTS: Disturbed eruption of the first permanent molars was observed in 102 of these children. The upper 6-year molars were affected more often (88.5%) than the lower molars. Bilateral disturbed eruption of the upper molars was the most frequent combination of symptoms found. Although disturbed eruption was diagnosed most often in 6- and 7-year-old children, the 8-year-old children presented 20% of the eruption disorders. Moreover, 72.6% of the children with disturbed eruption presented at least one additional orthodontic malocclusion. Crowding (p ≤ 0.001), lateral malocclusions (p ≤ 0.001), and mandibular prognathism (p = 0.009) were present significantly more often in children with disturbed eruption of 6-year molars. CONCLUSION: Delayed eruption and false direction of eruption of the upper 6-year molars may-already at an early stage-raise the likelihood of problems during later dental arch development, such as crowding in the sagittal and transverse directions or Class III developments.

Interrelation between occlusal findings and orofacial myofunctional status in primary and mixed dentition: Part III: Interrelation between malocclusions and orofacial dysfunctions.

AIM: It was the purpose of this study to analyze the relationship between selected types of malocclusion and specific types of static and dynamic orofacial dysfunction and to compare the results with subjects presenting regular occlusion. We aimed to identify which orthodontic and functional symptoms in early dentition would lead to malocclusion later on. SUBJECTS AND METHODS: Occlusal relations and myofunctional status were evaluated in 3,041 children. We diagnosed dynamic and static myofunctional disorders as well as oral habits by means of functional examinations. RESULTS: No orofacial dysfunctions were found in 11.2% of the children with primary dentition and in 10.2% of the children with early mixed dentition. We observed no correlation between the existence of distoclusion and functional disorders. Lateral crossbite in mixed dentition, as well as increased overjet and frontal open bite in primary and early mixed dentitions appeared significantly more frequently in children with orofacial dysfunctions. Individuals with frontal open bite, lateral crossbite, reduced and increased overjet presented static dysfunctions significantly more frequently than those in dentitions with normal occlusion. Dynamic dysfunctions were significantly more prevalent in subjects with frontal open bite and lateral crossbite than in those with normal occlusion. CONCLUSIONS: Our results enable us to prognosticate which children risk future orthodontic problems. Any child presenting one of the four occlusal disorders plus one static or two dynamic dysfunctions is a child more likely to develop orthodontic problems later on. Orthodontic prevention and early treatment must include functional rehabilitation so as to eliminate or at least diminish those factors causing undesirable developments.

Relationship between occlusal findings and orofacial myofunctional status in primary and mixed dentition. Part II: Prevalence of orofacial dysfunctions.

AIM: The aim of this study was to provide basic data on the prevalence of orofacial dysfunctions in primary and early mixed dentition and to examine occlusal relationships in their functional context, and to analyze the need for and potential of orthodontic prevention and early treatment. SUBJECTS AND METHODS: We assessed the occlusal relationships and myofunctional status of 3,041 children. The presence of dynamic and static myofunctional disorders and any oral habits were documented during functional analysis. RESULTS: The frequency of myofunctional disorders was statistically significantly higher in children with increased maxillary overjet, frontal open bite, lateral crossbite and mandibular prognathism, and there was a statistically significant increase in the prevalence of orofacial dysfunctions and oral habits from primary to mixed dentitions. CONCLUSIONS: Habitual open mouth posture (expressing hypotonia in the perioral muscles) and a visceral swallowing pattern become established during the primary dentition and are increasingly carried over into the mixed dentition period. Both criteria, along with assessment of occlusal relationships, are appropriate parameters with which to identify "children at risk for orthodontic treatment".

[Relationship between occlusal findings and orofacial myofunctional status in primary and mixed dentition. Part I: Prevalence of malocclusions].

AIM: The aim of this study is to provide basic data on the prevalence of malocclusions and orofacial dysfunctions in the primary and early mixed dentition, to examine occlusal relationships in their functional context, and to analyze the need for and potential of orthodontic prevention. SUBJECTS AND METHODS: Occlusal relationships and myofunctional status were evaluated in 766 children in the primary dentition and in 2,275 children in the early mixed dentition. Orthodontic findings in single jaws and intermaxillary occlusal relationships were clinically analyzed in all three dimensions. RESULTS: Normal occlusal relationships were found in 25.3% of children in the primary dentition. Frequency of children with normal dentitions fell significantly in the mixed dentition (7.3%). Prevalence of bilateral distoclusion increased significantly from the primary to the mixed dentition. Increased maxillary overjet was diagnosed in 49.3% and 59.0% of the children in the primary and mixed dentition, respectively. Prevalence of lateral crossbites increased significantly from primary to mixed dentition (7.2% vs. 12.0%). Deep bites and edge-to-edge bites were found significantly more often in the early mixed dentition. CONCLUSIONS: The significant increase in the prevalence of malocclusions between the primary and mixed dentition--distoclusion and lateral crossbite, and the impairment of vertical occlusal relationships in the mixed dentition in particular--reveal the need for orthodontic prevention. They highlight the absence of applied interceptive and early treatment measures in orthodontics. The indication system in current use for early orthodontic treatment here in Germany fails to fulfill the requirements for prevention-oriented dental care.

Presurgical orthopaedic treatment of newborns with clefts--functional treatment with long-term effects.

AIM: Presentation of an orthopaedic/orthodontic treatment protocol within the framework of complex rehabilitation of patients with clefts of lip, alveolus and palate. Presurgical orthopaedic treatment aims at reduction of cleft size by guiding growth and functional rehabilitation. Long-term results of maxillary development and occlusion at young adult age are reported. PATIENTS AND METHODS: 43 newborns with unilateral (19) or bilateral (24) clefts of lip, alveolus and palate were examined until their deciduous dentition was complete. In 29 patients a late follow-up was performed at age 17.3 years (mean). Maxillary dental casts were evaluated prior to and following presurgical orthopaedic treatment at the time the deciduous dentition was complete and at young adult age (2 to 5 years after termination of orthodontic treatment). Parameters were width of the alveolar and palatal cleft as well as width and length of the dental arch. In the adults occlusion was studied and the occlusal outcome was related to the therapeutical input. RESULTS: Presurgical orthopaedic treatment reduced the cleft width by taking advantage of normal growth. At the age of 3 to 4 years the development of the upper dental arch was in line with that of non-cleft children. CONCLUSION: Maxillary growth may be guided in almost physiological terms even in patients with a cleft of lip, alveolus and palate. Prerequisite is functional rehabilitation by means of orthopaedic treatment at age 1 to 12 months in terms of functional orthodontic therapy and a surgical protocol saving tissues with growth potential.

Epidemiology of Hoffmeister's "genetically determined predisposition to disturbed development of the dentition" in patients with cleft lip and palate.

OBJECTIVE: Type and prevalence rates of the symptoms of Hoffmeister's "genetically determined predisposition to disturbed development of the dentition" were studied in patients with clefts. PATIENTS: Data of 263 patients with nonsyndromic clefts of lip (alveolus and palate) or isolated cleft palates were examined in a retrospective study. SETTING: The clefts were classified as cleft lip or cleft lip and alveolus, cleft palate, unilateral cleft lip and palate, and bilateral cleft lip and palate. All patients were scrutinized for 28 individual symptoms. Prevalences of the individual symptoms were statistically evaluated regarding cleft type and gender by using the chi-square test and were also compared with findings in patients without clefts. RESULTS: In 97.7% of the patients with clefts, at least one symptom was found. Microdontia of individual teeth, hypodontia, and hyperodontia were the symptoms most frequently recorded. Comparison of the different cleft types revealed differences regarding the prevalences of supernumerary lateral incisors (p = .051), infraposition of deciduous molars (p < .001), and atypical tooth bud position (p = .030). Comparison of the prevalences of 10 symptoms recorded in the patients with clefts with the prevalences recorded in patients without clefts showed nine symptoms were found much more frequently in the population with clefts. CONCLUSION: These findings support the hypothesis that clefting is part of a complex malformation associated with other dental anomalies resulting from disturbed development of the dentition. Patients with clefts are also likely to present other deficiencies of dental development and tooth eruption in both dentitions, even in regions not affected by the cleft.

Epidemiology of Hoffmeister's genetically determined predisposition to disturbed development of the dentition in patients with true skeletal class III malocclusion.

AIM: The prevalence of symptoms of Hoffmeister's "genetically determined predisposition to disturbed development of the dentition" as studied in patients with true skeletal Class III malocclusion; results of the study were compared with those found in the scientific literature regarding samples from the normal population and from orthodontic patients. PATIENTS AND METHODS: The prevalence of 20 defined symptoms was evaluated in 120 patients with true skeletal Class III malocclusion. The patients were selected on the basis of a positive family history and on the presentation of typical characteristics of a skeletal Class III morphology in a lateral cephalogram. The mean age of the patients evaluated was 12.4 years. The patients' files, 1161 radiographs and plaster casts were analyzed. The prevalence of the individual symptoms was compared by means of the chi(2)-test (p < or = 0.05). RESULTS: 118 patients (98.3%) were found to have 292 symptoms of "genetically determined predisposition to disturbed development of the dentition". Increased distance between molar buds, atypical tooth bud position and atypical root shape were the symptoms recorded most frequently. With regard to the simultaneous existence of several symptoms, the combination of four such symptoms was most frequent (20.8%), followed by the combination of three symptoms (15.8%), and five symptoms (15.0%). Congenital hypodontia was found in 19.2% of the patients. CONCLUSION: It should be kept in mind for patients with true skeletal Class III malocclusion that this type of dysgnathia is most likely combined with other symptoms of disturbed development of the dentition. The higher prevalence of those symptoms found in patients with skeletal Class III malocclusion when compared with the normal population and other orthodontic patients renders orthodontic treatment of those patients more difficult and calls for comprehensive clinical and radiological examination prior to any treatment.

Orthodontic findings in the deciduous and early mixed dentition--inferences for a preventive strategy.

AIM AND METHOD: The aim of the present epidemiologic study was to obtain representative basic data on the frequency, extent and age-dependence of malocclusions in the deciduous and early mixed dentition. The developmental tendencies of specific malocclusions were investigated from the aspect of orthodontic prevention. The collective comprised 8,864 preschool and school-aged children, of whom 1,225 were in the deciduous dentition (mean age 4.5 years) and 7,639 in the mixed dentition (mean age 8.9 years). The orthodontic data were clinically assessed as sagittal, transversal, or vertical single-arch and occlusal findings. In addition, the malocclusions were classified according to their primary symptoms. Early infantile habits, tongue dysfunctions, speech defects and incompetent lip closure were registered separately. RESULTS: 57% of the children were found to have malocclusions, with the frequency rising statistically significantly in dependence on age from the deciduous to the mixed dentition (p < or = 0.001). The mean extent of excessive overjet increased significantly from the deciduous to the mixed dentition. Crossbite with mandibular midline discrepancies were observed significantly more frequently in the deciduous dentition. Although the frequency of anterior open bite underwent a significant decline from the deciduous to the mixed dentition, open bite was the malocclusion most frequently associated with dysfunction in both groups. The significant increase in traumatic deep bite in the mixed dentition indicates an unfavorable developmental tendency in this anomaly until after the eruption of the permanent incisors. CONCLUSION: The need for preventive orthodontic therapy and for the intensified application of interceptive and early treatment measures is stressed in view of the high number of malalignments and malocclusions in the deciduous and mixed dentition and the tendency for some forms of malocclusion to deteriorate as the dentition develops.

Epidemiological significance of Hoffmeister's "Genetically determined predisposition to disturbed development of the dentition".

BACKGROUND AND AIM: Hoffmeister was the first to recognize the common genetic origin of structurally very varied disturbances in the development of the dentition. He coined the term "microsymptoms of a genetically determined predisposition to disturbed development". The purpose of the present study was to examine the incidence of those microsymptoms in a group of patients undergoing orthodontic treatment. PATIENTS AND METHODS: The orthodontic findings in 4208 patients were evaluated, and nine characteristic symptoms were registered with reference to the panoramic and other radiographs and to the patients' records. RESULTS: 1297 patients (30.8%) were found to have one or more symptoms of genetically determined predisposition to disturbed development. The most frequent symptoms were atypical position of tooth buds (12.2%), absence of tooth buds of permanent teeth (9.2%), and displaced teeth (7.0%). 73.5% of the patients had only one symptom, and 26.5% two or more. Microdontia and displaced teeth were associated particularly frequently with other symptoms of predisposition to disturbed development. Genetically determined predisposition to disturbed development of the dentition is accordingly not rare but is of great epidemiological significance and may provide early indications of potential developmental disorders such as missing tooth buds or displacement of teeth.

Maxillary canine displacement and genetically determined predisposition to disturbed development of the dentition.

BACKGROUND: The relationship between maxillary canine displacement and the simultaneous occurrence of "genetically determined predisposition to disturbed development of the dentition" as defined by Hoffmeister was investigated in 675 patients. PATIENTS AND METHODS: Panoramic radiographs taken of each patient during the first and the second mixed dentition periods were evaluated. Canine inclination and the distance between the tip of the canine and a line connecting the cusps of the molars were computed in five different age groups according to Dausch-Neumann. RESULTS: Statistical analysis revealed 34 patients with "potential canine displacement", who exhibited further symptoms of "genetically determined predisposition to disturbed development of the dentition" significantly more frequently than the total group. The symptoms concerned were agenesia, displaced tooth buds, rotated or tilted incisors, aplasia and microdontia of lateral incisors. CONCLUSION: Careful follow-ups in patients with a predisposition to disturbed dental development enables risks to be anticipated and canine displacement to be detected at an early stage.

Position of the hyoid bone in cleft lip, alveolus, and palate: variation of normal anatomy or sign accompanying the malformation?

OBJECTIVE: To compare the hyoid bone position in patients with clefts of lip, alveolus, and palate with orthodontic patients with no cleft. DESIGN: Retrospective cephalometric long-term study. PATIENTS: Lateral cephalograms of 23 patients with a complete unilateral cleft were compared with those of 24 orthodontic patients with no cleft with an Angle class 1 occlusion. Twenty-five of the patients were girls, and 22 were boys. The age of the patients with cleft at the beginning of the study was 8.1 +/- 0.7 years and at the end 14.8 +/- 0.6 years. The patients without cleft were 8.4 +/- 0.8 years old at the beginning and 14.4 +/- 0.6 years at the end of the study. MAIN OUTCOME MEASURES: Cephalometric analysis was used to determine the skull growth pattern as well as the positions of the head and hyoid bone twice in all 47 persons. RESULTS: With increasing age of the patients, the skull growth pattern changed from vertical to horizontal growth, but no significant differences were found between patients with and without cleft. Head position did not differ significantly between patients with and without cleft. However, hyoid bone position differed significantly. The hyoid in patients with cleft was located more caudally and more anteriorly than in patients without cleft. CONCLUSION: The hyoid bone in a subset of north German adolescents with complete unilateral cleft lip and palate was found to be caudal and anterior, compared with a control group.