[Radiological assessment of long-term outcomes of restorative treatment in patients with shortened dental arches]

BACKGROUND

Restoring the integrity of the dentition with orthopedic structures should be carried out strictly according to indications, taking into account the condition of the supporting teeth and/or teeth limiting the defect.

OBJECTIVE

To conduct a retrospective analysis of the results of orthopedic treatment of patients with shortened dentition according to clinical and radiological methods.

MATERIALS AND METHODS

The material for the study was data from cone beam computed tomography (CBCT) of 126 patients with shortened dentition (most patients with the absence of a second molar, as well as the absence of the first and second molars), who sought a consultation about missing teeth in the orthopedic and surgical department of the Federal State Budgetary Institution National Medical Research Center TsNIISiCHLKh Ministry of Health of Russia.

RESULTS

At the stages of treatment for patients in the study group, insufficient attention is paid to the restoration of terminal defects of the dentition in the upper and lower jaws, especially the restoration of second molars. This may be due to improper planning of dental treatment and insufficient motivation of the patient to carry out comprehensive dental rehabilitation. According to CT studies, the number of complications of orthopedic treatment in the area of supporting teeth and/or teeth limiting the included defect or terminal defect of the dentition in the masticatory region increases depending on the period of use of the orthopedic structure.

CONCLUSIONS

The use of cantilever structures leads to functional overload of the supporting teeth. Neglecting the restoration of a full dentition and prosthetics of end defects of the dentition leads to dentoalveolar advancement of antagonists of missing teeth and the appearance of complications such as functional overload of supporting teeth and resorption of alveolar bone.

Effect of Shortened Dental Arch on Temporomandibular Joint Intra-articular Disorders

AIMS

To investigate whether a shortened dental arch (SDA), as identified by reduced posterior occlusal contacts, is a risk factor for the progression of temporomandibular joint (TMJ) intra-articular disorders (ID), as identified using imaging techniques.

METHODS

This multisite, prospective observational study with a mean follow-up period of 7.9 years had a sample of 345 participants with at least 1 temporomandibular disorder (TMD) diagnosis at baseline. SDA was defined as reduced occlusal posterior support due to lack of occlusal intercuspal contacts in the molar region on the left and/or right side. SDA was assessed at baseline and at follow-up with metalized Mylar Tape. The presence or absence of a TMJ ID and the specific TMJ ID diagnoses for baseline and follow-up images were established by a calibrated, blinded radiologist at each of three sites by using bilateral magnetic resonance imaging for soft tissue imaging for disc displacement and by bilateral multidetector computed tomography or cone beam computed tomography for hard tissue imaging for degenerative joint diseases. Wilcoxon rank sum test and linear regression analyses were used to test for an impact of SDA on TMJ ID status.

RESULTS

At baseline, TMJ ID status of either side was not significantly affected by the presence of SDA on the ipsilateral or contralateral side of the jaw (all P > .05). Furthermore, the presence or absence of SDA at baseline was also not a significant predictor for progression of the TMJ ID status between baseline and follow-up (all P > .05).

CONCLUSION

The findings of this study suggest that there is no significant effect of SDA on progression of TMJ ID.

Incisor and molar overjet, arch contraction, and molar relationship in the mixed dentition in repaired complete unilateral cleft lip and palate: A qualitative and quantitative appraisal

OBJECTIVE

To compare the mixed dentition incisor and molar overjet, severity of contraction of the dental arch, and the sagittal molar relationship on the cleft side vs the noncleft side in children with repaired complete unilateral cleft of the lip and palate (UCLP).

MATERIALS AND METHODS

Orthodontic records taken prior to orthodontic preparation for alveolar bone grafting were screened to select study casts from patients with nonsyndromic repaired complete UCLP who did not have mandibular skeletal or dental asymmetry. The study sample comprised dental casts from 74 children aged 8.9 ± 1 years. Standardized digital photographs were acquired at 1:1 magnification. A coordinate system was developed using digital image-processing software (Photoshop CS4 and Adobe Illustrator). Incisor and molar overjet, Angle's classification, and arch contraction were recorded. Descriptive statistics, paired t-tests, and kappa statistics were used to compare the cleft and noncleft sides.

RESULTS

A negative overjet of -1 to -5 mm was often present at the incisors, with greater frequency and magnitude on the cleft side. Class II molar relation was more frequent on the cleft side (61.1%) than on the noncleft side (47.2%). Significantly greater contraction of the cleft side deciduous canine and deciduous first molar was noted, while the difference was very minor at the first permanent molar.

CONCLUSIONS

Cleft side maxillary arch contraction was most severe in the deciduous canine and first deciduous molar region and progressively less severe in the posterior region of the arch. A greater frequency and severity of negative overjet and Class II molar relationship was seen on the cleft side.

Relationship between Orthodontic Treatment Plan and Goslon Yardstick Assessment in Japanese Patients with Unilateral Cleft Lip and Palate: One-stage vs. Two-stage Palatoplasty

The present study targeted patients with unilateral cleft lip and palate (UCLP) undergoing either one - (Wardill technique) or two-stage palatoplasty (Perko technique). Correlations between Goslon Yardstick scores and orthodontic appliances used and whether an osteotomy was performed were investigated. No differences were observed between the two types of palatoplasty in terms of Goslon Yardstick scores. A palatal expander and protraction facemask were used in Phase I of orthodontic treatment. The palatal expander was selected for most patients with UCLP in Phase I, regardless of the surgical technique used. A protraction facemask was used in patients undergoing the Wardill procedure who had a Goslon Yardstick score placing them in Group 3 or 4. In contrast, a protraction facemask was used in patients undergoing the Perko procedure who had a Goslon Yardstick score placing them in Group 4. No significant differences were observed in the Goslon Yardstick scores yielded by either type of procedure. The Goslon Yardstick score in relation to whether an osteotomy was performed in Phase II as part of orthodontic treatment was determined, focusing on the relationship between that score and the palatoplasty method used. A protraction facemask was used in patients undergoing the Perko procedure, which eliminated the need for an osteotomy at a future date. However, a protraction facemask was also used in patients undergoing the Wardill option, and those patients were likely to require an osteotomy. In other words, the results suggest that the type of palatoplasty selected will determine the effectiveness of any orthodontic appliances used.

Differences in functional outcomes for adult patients with prosthodontically-treated and -untreated shortened dental arches: a systematic review

This review examined differences in functional outcomes and patient satisfaction when shortened dental arches are left untreated compared to their restoration to complete arch lengths with different prosthodontic interventions.

METHODS

A protocol was developed according to the criteria for a systematic review. All relevant databases were searched to identify appropriate clinical trials regardless of language or publication status. Predetermined eligibility criteria were applied, trial quality assessed and data extracted for each study. Relevant outcomes assessed were: functioning ability, patient satisfaction and harmful effects on oral structures.

RESULTS

Searches yielded 101 articles: 81 from electronic databases and 20 from reference lists of retrieved articles (PEARLing searches). Sixty-nine citations were assessed for eligibility after removing 32 duplicate records. After reading titles and abstracts, a total of 41 records were excluded and the full-texts of the remaining 28 records were read. Only 21 records were included for the SR because 7 records were excluded after reading the full-text reports. These 21 records report the outcomes of four randomized controlled trials (RCTs) and one non-randomized clinical trial (CT) which were pre-specified and used for this review. No on-going studies were found and no eligible studies were excluded for failure to report the reviewer's pre-specified outcomes. Outcomes were reported in the retrieved 21 articles. A narrative explanation of the pre-specified outcomes is reported for the 3 comparison groups (which were based on the different interventions used for the individual clinical trials). The shortened dental arch as a treatment option is encouraging in terms of functioning, patient satisfaction and cost-effectiveness. By using only high quality studies it was expected that the results would be more reliable when making conclusions and recommendations, but some of the included studies had to be downgraded due to methodological errors.

A case report of developmentally missing mental foramen

The inferior alveolar nerve is the mandibular division of the trigeminal nerve. Studies have documented variations in the course and branching pattern of the nerve. Here the author reports a case of developmentally missing mental foramen in an individual with normal sensory function. Identification of variations in the nerve pathway is essential for treatment planning in the area.

An interdisciplinary study of orthodontic, orthopedic, and otorhinolaryngological findings in 12-14-year-old preorthodontic children

BACKGROUND AND OBJECTIVE

Malocclusion, the body posture, and the breathing pattern may correlate, but this issue is still controversial. The aim of the study was to examine the relationship between the type of malocclusion, the body posture, and the nasopharyngeal obstruction in 12-14-year-old children.

MATERIAL AND METHODS

The study group consisted of 76 orthodontic patients (35 boys, 41 girls) aged 12-14 years (mean age, 12.79 years [SD, 0.98]). All the patients were examined by the same orthodontist (study model and cephalometric radiograph analysis), the same orthopedic surgeon (body posture examined from the front, the side, and the back), and the same otorhinolaryngologist (anterior and posterior rhinoscopy and pharyngoscopy) in a blind manner.

RESULTS

The prevalence of a poor body posture and a nasopharyngeal pathology was high in the present study. In total, 48.7% of the orthodontic patients had a kyphotic posture and 55.3% a rib hump in the thoracic region. The nasopharyngeal pathology was diagnosed in 78.9% of the patients. The patients with the kyphotic posture had a higher mandibular plane angle (MP-SN) and a lower sagittal position of the mandible SNB angle. A deeper overbite correlated with shoulder and scapular asymmetry. The kyphotic posture was diagnosed in 55.0% of the patients with the nasopharyngeal pathology.

CONCLUSIONS

The sagittal body posture was related to the vertical craniofacial parameters and hypertrophy of the tonsils and/or the adenoids. The study showed no relationship between the degree of crowding, the presence of a posterior cross bite, orthopedic parameters, and a breathing pattern.

[Alveolar bone and dental arch defects fulfillment in cleft lip and palate patients]

Nine cleft lip and palate patients aged 17-32 years were included in the study, all having significant maxilla alveolar bone defects. Oral rehabilitation was possible by means of bone augmentation with iliac crest graft, soft tissue plasty and subsequent dental implantation (3 to 6 months after first-step procedures).

Dentofacial morphology in Turner syndrome karyotypes

The overall aim of this thesis was to study dentofacial morphology in Turner syndrome (TS) versus controls and the influence hereupon from karyotype. One hundred thirty two TS females (5-66 years of age), from Göteborg, Uppsala and Umeå were participating. Cephalometric analysis, cast model analysis concerning palatal height, dental arch morphology and dental crown width were performed. Eighteen primary teeth were analysed in polarized light microscopy, scanning electron microscopy, microradiography and X-ray microanalysis were performed. The TS females were divided according to karyotype into: 1 45,X; 2 45,X/46,XX; 3 isochromosome; 4 other. Compared to healthy females, TS were found to have a flattened cranial base as well as small and retrognathic jaws with a posterior inclination. The maxillary dentoalveolar arch was narrower and longer, while the mandibular dental arch was wider and longer in TS compared to controls. The palatal height did not differ comparing TS and healthy females. The dental crown width was smaller in TS for both permanent and primary teeth. Aberrant elemental composition, prism pattern and lower mineral density were found in TS primary enamel compared to enamel in primary teeth from healthy girls. Turner syndrome karyotype was found having an impact on craniofacial morphology, with the mosaic 45,X/46,XX exhibiting a milder mandibular retrognathism as well as fewer cephalometric variables differing from controls compared to other karyotypes. Also for the dentoalveolar arch morphology the 45,X/46,XX group had fewer variables differing from healthy females. The isochromosome TS group exhibited the smallest dental crown width for several teeth, while 45,X/46,XX hade the largest dental crown with for some teeth and fewer teeth than both 45,X and isochromosomes that differed from controls. Thus, the mosaic 45,X/46,XX seemed to exhibit a milder phenotype, possibly due to presence of healthy 46,XX cell lines.

Modified Hyrax expander for the correction of upper midline deviation: a case report

This article describes a case report of a patient treated by the modified version of the Hyrax rapid palatal expander described by Farronato et al. in 2009. This device can be utilized for the treatment of patients in mixed dentition who, due to the maxillary hypoplasia and to the premature exfoliation of some deciduous teeth, manifest a migration of the permanent incisors with a reduction or closure of the space for the permanent teeth substituting those previously exfoliated. This expander presents a vestibular arm for correcting maxillary asymmetric transverse discrepancies. The activation method, the therapeutic benefits as well as the clinical advantages are described. The use of this appliance allows to restore the correct transverse maxillary diameters, to regain space and at the same time to restore the symmetry of the midlines up to 5-6 mm. Moreover, a recovery of the arch length can be obtained, as demonstrated by the case report presented. The expander with vestibular arm represents an interceptive treatment which can reduce the duration of the orthodontic therapy with fixed appliances.

Effectiveness of the passive lingual arch for E space maintenance in subjects with anterior or posterior rotation of the mandible: a retrospective study

OBJECTIVE

The aim of this study was to determine whether or not lingual arches in subjects with anterior or posterior mandible rotation can produce different effects in the prevention of first permanent molar mesial migration.

SUBJECTS AND METHODS

Forty-two patients with a mean age of 9 ± 0.8 years were selected from the Department of Orthodontics, University of Catania, Italy. These subjects were treated with a passive mandibular fixed lingual arch. The sample was divided into 3 groups according to the gonial angle in order to establish the pattern of mandible growth: mandibular posterior rotation (MPR), mandibular growth in straight-downward direction (MSD) and mandibular anterior rotation (MAR). Lateral cephalograms and study models of the patients before and after treatment were examined to determine any positional changes of the mandibular first molars and incisors.

RESULTS

Statistically significant differences between the MPR group and the other 2 (MSD and MAR) were found as regards mandibular first molar and incisor positional changes. No significant differences were found between the MSD and MAR groups.

CONCLUSION

The results indicate that the effect of lingual arch is influenced by mandibular growth patterns. In patients with MPR, the lingual arch preserves arch length but the mesial migration of first permanent molars is not completely blocked.

[Microcirculation in supporting tissues in patients with unilateral terminal defect of dental arch]

By the method laser Doppler fluometry microcirculation in a mucosa of an alveolar process at orthopedic treatment of patients with unilateral trailer defect of a dentition with application of the prosthetic design leaning on dental implants with the help unklammer of bracing. Taped dynamics of change of indicators testified to compensatory changes in regulation of a fabric blood flow in reply to a rendered load. Studying of microhemodynamic processes in tissues of a prosthetic bed, according to LDF, has shown stimulating influence of rational orthopedic treatment on a microcirculation condition.

Dental and skeletal changes following surgically assisted rapid maxillary anterior-posterior expansion

BACKGROUND

Lengthening the maxillary dental arch as a treatment approach for patients with maxillary deficiency and dental crowding is seldom reported. The purpose of this study was to assess dental and skeletal changes in the maxilla in the correction of maxillary deficiency associated with a retruded maxillary arch using a surgically assisted rapid maxillary anterior-posterior expansion appliance.

METHODS

Predistraction and postraction lateral cephalometric and periapical radiographs and maxillary dental casts of six young adolescents (four boys, two girls, mean age 11 years, 2 months) were examined. These patients received a maxillary anterior segmental osteotomy and distraction osteogenesis with an anteroposteriorly oriented Hyrax expansion appliance based on the biological principles of bone distraction.

RESULTS

The retruded dental arch and dental crowding were successfully corrected. Significant forward movement of the point anterior nasal spine, point A, central incisors and first premolars was noted. The maxillary dental arch depth increased an average of 4.2 mm while the arch width remained unchanged. In total, 11.5 mm of dental space was created in the maxillary arch which was sufficient to resolve dental crowding. New bone formation along the distraction site was observed three months after distraction.

CONCLUSIONS

The use of maxillary anterior segmental osteotomy combined with a Hyrax expansion distraction appliance was effective in arch lengthening and creation of dental space. An overcorrection in this interdental distraction osteogenesis could be a good treatment option for children with maxillary deficiency combined with crowded maxillary dentition.

Les séquelles maxillaires dans les fentes labioalvéolopalatovélaires. Prise en charge orthodontique

Routine othodontic management is unavoidable in all patients with cleft lip and palate after primary surgery. This management combines dental arch alignment with maxillary expansion of the lesser fragment before alveolar bone grafting. To treat dental arch asymmetry, the space of the missing lateral incisor is preserved until the age of dental implant. Otherwise, dento-orthopedic treatment attempts to normalize transversal dental dimension once alveolar bone grafting is done in order to prepare the surgical advancement of the maxilla.

Les séquelles maxillaires dans les fentes labioalvéolopalatovélaires. Place de la chirurgie orthognathique

Maxillary hypoplasia is a common sequel in cleft lip and palate deformities. After primary surgery to close lip and palate, patients routinely need extensive treatment particularly orthodontic management. With this type of approach, maxillary hypoplasia is less frequent and severe and subsequent orthognathic surgery is efficient in most cases. Without the proper management maxillary hypoplasia may be severe and patients will need a modified management and specific revision. At the end of maxillar growth, the first aim of treatment is to achieve continuity of the maxillary arch with gingivoperiosteoplasty. The transversal insufficiency can then be treated by distraction osteogenesis. Orthodontic treatment should leave place for missing teeth.

Distraction Osteogenesis in Adolescents with Maxillary Arch Deficiency and Dental Crowding: A 3-Year Follow-Up

BACKGROUND

In this study, the authors evaluated the long-term results after using anterior segmental osteotomy and distraction osteogenesis for the correction of sagittal maxillary deficiency associated with dental crowding.

METHODS

Six young adolescents (four boys and two girls) underwent surgery and distraction at a mean age of 11.2 years (range, 10 to 12 years) and were followed up for 3 years. A tooth-borne distraction device was used for interdental distraction. The evaluation consisted of hard- and soft-tissue profile analysis and dental arch measurements before, immediately after, and 3 years after distraction.

RESULTS

The results showed that the facial profile, the occlusion, and the dental crowding could be successfully corrected and that the results were stable after 3 years' follow-up. The mean facial convexity angle was changed from 1 to 8 degrees. The average advancement at point A was 4 mm and the SNA increased by an average of 4 degrees. Lengthening of the dental arch by an average of 4 mm created approximately 8 mm of new space, sufficient to resolve the dental crowding in all patients, thus avoiding an extraction of healthy teeth.

CONCLUSION

The results of this study demonstrated that anterior segmental maxillary osteotomy combined with distraction osteogenesis offers an alternative for the treatment of adolescents suffering from sagittal maxillary deficiency with dental crowding.

Evaluation of tongue pressure on the inferior dental arch in patients with mandibular prognathism

The aim of the present study was to find out whether there is a difference between the force exerted by the tongue (pressure) in patients with mandibular prognathism and healthy controls and to determine the difference in tongue pressure on the inferior dental arch in patients with mandibular prognathism before and after mandibular setback.

MATERIAL AND METHODS

Patients with mandibular prognathism were compared with healthy controls and data on tongue pressure were collected.

RESULTS

Tongue pressure on the inferior dental arch in patients with mandibular prognathism ranged from 1.98 N to 12.26 N (mean 5.356 N). Tongue pressure in the control group ranged from 2.36 N to 16.9 N (mean 6.56 N), with most of the values ranging from 4.02 N to 7.84 N.

CONCLUSIONS

Tongue pressure on the inferior dental arch is reduced in patients with mandibular prognathism. 1. Surgical treatment for mandibular prognathism using vertical ramus osteotomy does not affect tongue pressure, contradicting the view that the tongue is the main cause of skeletal relapse after mandibular setback. 2. There is no need for routine tongue size reduction prior to orthognathic surgery for mandibular prognathism.

[Comparison of shortened dental arches with complete dental arches by clinical examinations]

PURPOSE

Recently, there have been reports in favor of avoiding prosthodontic intervention as Shortened Dental Arch (SDA) in Northern Europe. However, many of these reports were conducted through interviews and questionnaires, and so the evaluation of the results lacked objectivity. Thus, this research analyzed the clinical status of SDA.

METHODS

For the selection of subjects, seven patients (average age: 59.3+/-13.2 years old) who had had the free-end missing on both sides of the lower dental arches for over five years were chosen as the SDA group. As the complete dental arch (CDA) group, seven patients (average age: 61.3+/-9.6 years old) who had no clinical defects in their masticatory function, and who had no missing teeth other than the third molar, were selected. Measurement items in this study were occlusal contact areas for the mandible premolar, center of force, occlusion time, and interdentium. The Mann-Whitney U test was used for statistical analysis and the significance level was assumed to be 5%.

RESULTS

The results were as follows: 1) The occlusal contact area of the mandible premolar of SDA was significantly large. 2) The center of force of SDA was significantly forward. 3) The occlusion time of SDA had a tendency of prolongation. 4) Interdentium of 3 2 | 2 3, 4 3 | 3 4 and 5 4 | 4 5 of SDA were significantly wide.

CONCLUSIONS

There were differences of clinical parameters between SDA and CDA in this study.

Estimating arch length discrepancy through Little's Irregularity Index for epidemiological use

The objective of this study was to evaluate the diagnostic capability of Little's Irregularity Index (LII) in order to estimate the arch length discrepancy (ALD) in a dental arch. Dental casts with a full permanent dentition, excluding third molars, from 200 12- to-16-year-old schoolchildren from a representative high school located in Lima, Peru, were used. Incisal irregularity was measured using the LII, whereas ALD was calculated as the difference between available and required space in each dental arch anterior to the first permanent molars. The receiver-operator characteristic (ROC) curve was used to contrast the LII with three different dichotomized ALDs and locate optimized cut-off points. Correlation between ALD and LII was -0.68 (P < 0.001). According to ROC curves, LIIs of 2.45, 4.00, and 4.55 mm were the optimized cut-off points to estimate negative ALDs higher than 0, 3, and 6 mm, respectively. LII's highest diagnostic capability was found for estimating negative ALD greater than 3 mm with a sensibility of 0.78 and a specificity of 0.76. Based on the present findings, LII could potentially be used in epidemiological surveys as a valid and less time-consuming measurement of crowding compared with ALD; however, further studies are needed to test the reliability of this approach in field settings.

Efficacy of a posterior implant support for extra shortened dental arches: a biomechanical model analysis

The purpose of this study was to test the efficacy of utilizing implants underneath distal free-end denture bases to establish a stable occlusal support for extreme shortened dental arches (ESDA). The authors constructed a two-dimensional finite element model of the ESDA where only lower anterior teeth remain. Posterior occlusal support was provided by a fixed partial denture with an osseointegrated implant (IFPD), fixed cantilever partial denture (CFPD), or a removable partial denture with or without an implant underneath (IRPD and RPD). A dentate mandible model was the control. When muscle vectors simulating clenching force were applied, stress levels on the temporal bone surface area under each configuration were compared, to evaluate the efficacy in establishing the occlusal support. The largest stress increase in temporal bone was found in the ESDA situation followed by the RPD. The least amount of stress increase was found with the IFPD followed by IRPD when the implant was placed in the molar region. The stress increase with IRPD was about 20-45% of the amount with RPD. Our results suggest that IFPD provides most favourable and stable occlusal support, however, IRPD with a single posterior implant also provide stable occlusal support with reducing the stress levels in the temporomandibular joint.

Finite element analysis of fixed partial denture replacement

The purpose of this study was to investigate, by means of the finite element method the mechanical behaviour of three designs of fixed partial denture (FPD) for the replacement of the maxillary first premolar in shortened dental arch therapy. Two-dimensional, linear, static finite element analyses were carried out to investigate the biomechanics of the FPDs and their supporting structures under different scenarios of occlusal loading. Displacement and stress distribution for each design of FPD were examined, with particular attention being paid to the stress variations along the retainer-abutment--and the periodontal ligament-bone interfaces. The results indicated that displacement and maximum principal stresses in the fixed-fixed, three-unit FPD were substantially less than those in the two-unit cantilever FPDs. Of the two cantilever FPDs investigated, the distal cantilever design was found to suffer less displacement and stresses than the mesial cantilever design under similar conditions of loading. The highest values for maximum principal stress in the cantilever FPDs were found within the connector between the pontic and the retainer, and within the periodontal ligament and adjacent bone on the aspect of the retainer away from the pontic.

Lobster-claw syndrome

Lobster-Claw syndrome is a rare autosomal dominant, hand-foot malformation with Oro-dental features. This is a rare condition and from the available reports so far, cases being reported are less than 1%. Most reports have focused on the hand-foot deformity of this syndrome. This paper highlights the typical Oro-dental features associated with this syndrome such as retained deciduous teeth, hypodontia and variation in crown size, arch length and arch width.

Palatal and dental arch morphology in Down syndrome

The analysis of palatal vault morphology and maxillary dental arch shape was carried out in the sample of 42 Down syndrome (DS) patients with trisomy 21. The data were compared to those of healthy controls from the same population matched for age and sex. Palatal morphology and upper dental arch shape were studied on hard plaster casts of the patients and controls. No sexual dimorphism in palatal and dental arch shape was observed in DS and controls. Normal palatal shape was more frequent in controls than in DS subjects (52.38% vs. 28.57%; p < 0.05). DS patients displayed significantly higher frequency of shelf-like or "stair palate" (38.1%) than controls (11.9%) (p < 0.02). The younger age group (3-14 year) showed much higher frequency of "stair palate" than controls (26.19% vs. 2.38%; c2 = 9.72; p = 0.003). The older group of DS patients did not show increased frequency of such shape of the palatal vault. There was no significant difference in dental arch shape between DS patients and controls. High frequency of shelf-like palate in DS subjects is decreasing by age. The obtained results indicate that palatal vault morphology is subjected to the age related changes. These changes can be attributed to the growth of caraniofacial structures and increased tonus of tongue and other orofacial muscles.

Use of distraction osteogenesis in cleft palate patients

Distraction osteogenesis (DO) has been used recently to correct maxillary hypoplasia with predictable and stable results. In patients with clefts of the secondary palate, DO can also be used to aid in vertical alveolus augmentation and rapid orthodontic tooth movement. If an osteotomized dental arch can be transported to a new position without complications, it would reduce or eliminate the need for a secondary bone graft to the cleft alveolus in cleft patients and help prevent dentoalveolar defects by approximating the native alveolar bone and gingiva. Mobilizing a segment in the dentoalveolar region also results in the creation of new bone and attached gingiva. This report shows that the application of DO for skeletal expansion and rapid movement of tooth-bone segments should receive more careful consideration in the treatment of patients with clefts of the palate.

Rapid palatal expansion in the young adult: time for a paradigm shift?

A 19-year-old man presented for correction of a malocclusion that included a transverse maxillary deficiency. The patient was informed that he required orthognathic surgery to expand his upper jaw and correct his malocclusion, but he refused surgical expansion. Recent evidence indicates that rapid palatal expansion can be used without surgery in young adults; the decision was therefore made to treat the patient nonsurgically. Rapid palatal expansion of the maxillary arch was accomplished by means of a Hyrax appliance, with post-treatment radiographs revealing an opening of the midpalatal suture. The belief still persists among some clinicians that young adult patients require orthognathic surgery for palatal expansion, despite recent evidence supporting a nonsurgical approach after closure of the midpalatal suture.

Combined therapy with pendulum and lingual arch appliances in the early mixed dentition

PATIENTS AND METHOD

In 20 patients with arch length deficiency and anterior crowding, pendulum and lingual arch appliances were inserted simultaneously in the upper and in the lower arch respectively to gain space. The patients were divided into two groups according to their dental eruption stage: ten children (six boys, four girls; mean age: 9 years, 6 months) were in the early mixed dentition, while an adolescent comparison group of the same size (three boys, seven girls; mean age: 12 years, 3 months) were in the permanent dentition at the beginning of treatment.

AIM

The main purpose of the study was to investigate whether simultaneous therapy with pendulum and lingual arch appliances is to be recommended, i.e. whether this therapy should take place as interceptive treatment in the early mixed dentition or only in the permanent dentition in adolescence. Parameters were the extent and quality of dentoalveolar effects and the side effects (mesial movement of the incisors, protrusion of the incisors, tipping of molars).

RESULTS

The treatment course was documented by means of study casts and lateral cephalograms. Assessment of the diagnostic records yielded the following findings: In the early treatment group the maxillary molars were distalized by the pendulum appliance by a mean distance of 4.0 +/- 1.46 mm, resulting in distal tipping by 6.1 +/- 2.18 degrees. The incisors were moved reciprocally by 1.08 +/- 1.06 mm to anterior and protruded by 7.65 +/- 4.84 degrees. In the comparison group molar distalization and molar tipping were less pronounced (2.86 +/- 1.54 mm/4.25 +/- 3.78 degrees ), while mesial movement of the incisors was comparably high at 1.62 +/- 0.99 mm. At only 3.8 +/- 2.9 degrees, incisor protrusion was significantly less pronounced than in the early treatment group (p = 0.045). The proportion of molar distalization in the total movement was higher in patients in the early mixed dentition: 79.83 +/- 15.38% vs 60.71 +/- 26.64%. During the early therapy with the lingual arch appliance in the lower arch, the molars were uprighted to the distal by 2.4 +/- 0.97 degrees and the incisors were tipped to labial by 5.0 +/- 1.83 degrees. In the adolescent control group, molar uprighting was less pronounced and the degree of incisor protrusion was significantly lower (2.75 +/- 1.11 degrees, p = 0.004).

CONCLUSION

With the appropriate indication, the combined therapy with the two compliance-independent appliances described can be recommended for gaining sagittal arch length in the early mixed dentition.

Early bone grafting in Tessier number 4 cleft: a case report

Rare craniofacial clefts have an incidence of at least 1 per 100,000 live births. A Tessier number 4 cleft is one of the most rare craniofacial clefts, with less than 50 cases being reported in the literature. Both soft and bony tissue abnormalities take place in the cleft morphology, so not only clinical examination of the maxillofacial region but a detailed radiological workup is needed to assess clearly the nature of the clefts. A patient with a Tessier number 4 cleft is presented, whose bony defect was obliterated with autogenous iliac bone graft chips and soft tissue reconstruction was performed with multiple Z-plasty flaps. Postoperative clinical and radiological results demonstrate fine healing and good cosmesis. Although controversy still exists about the treatment of facial clefts with early bone grafts, advantages of performing both bony and soft tissue reconstructions in a single session make this treatment a good alternative with satisfactory clinical and radiological results.

An adult case of skeletal open bite with a severely narrowed maxillary dental arch

Surgically assisted rapid maxillary expansion is proposed as an efficient approach for adult patients with transverse maxillary deficiency. This article reports the treatment of an 18-year, seven-month old male patient with an anterior open bite and a severely narrowed upper dental arch. A posterior crossbite was present on both sides. For the correction of the posterior crossbite, a lateral maxillary expansion of more than 8 mm was required. A surgically assisted rapid maxillary expansion with Le Fort I corticotomy and mandibular setback with a sagittal splitting ramus osteotomy were determined as the treatment plan. The total treatment time was 24 months including five months of post-surgical observation. After the treatment, an acceptable occlusion was achieved with a Class I molar relationship. The amount of actual maxillary expansion was 6.3 mm at the canines and 9.7 mm at the first molars. The relapse of the expansion was 0.9 mm and 0.1 mm at the corresponding regions two years after the surgically assisted maxillary expansion. It is emphasized that surgically assisted rapid maxillary expansion is a secure and efficient approach for achieving a desirable lateral maxillary expansion with stability in adult patients demonstrating transverse maxillary deficiency. Furthermore, it is suggested that longterm observation of the maxillary arch width after retention is of a great importance for the maintenance of the acceptable treatment outcome.

Problems, obstacles and complications with transpalatal distraction in non-congenital deformities

INTRODUCTION

The transpalatal distractor is a bone-borne device that eliminates negative orthodontic effects during and after maxillary expansion. It produces virtually parallel expansion in the coronal plane. Orthodontic appliances can be installed at an earlier date than when tooth-borne expanders are used. Our aim was to improve the technique by reviewing the difficulties encountered during applications in the past.

PATIENTS AND METHODS

The files of 57 patients were analyzed for problems (difficulties requiring surgical intervention), obstacles (difficulties requiring surgical intervention but not interfering with the result), and complications (difficulties not resolved at the end of the treatment).

RESULTS

Twenty-nine difficulties occurred. In 25 cases they were considered to be a 'problem'. Nine problems were surgery related and 16 problems were related to the distraction device itself (14 episodes of loosening of the module, two instances of loss of one osteosynthesis screw). 'Obstacles' occurred in three cases, i.e. loosening of an abutment plate. There was only one 'complication': unilateral infraorbital hyposensibility in a case of a high level corticotomy.

CONCLUSION

The expansion goal was achieved in all patients. Loosening of the module proved to be the major cause of discomfort. The incidence of difficulties has lead to a change in the design of the hardware and in the surgical protocol.

The compensation of dental arch and teeth in patients with skeletal protrusion and deviation of mandible

OBJECTIVE

To investigate the compensation of dental arch and teeth in patients with skeletal protrusion and deviation of mandible.

METHODS

Measurement of 11 dental models was performed, midline of palate was defined as central line, the distance of every contact point to the midline was measured in each side. The dental arch symmetry was observed. Occlusion plane was defined as conference plane, the buccal or lingual inclination of posterior teeth in upper and lower arch was measured.

RESULTS

Upper arch was asymmetry in these patients, the arch width of deviated side (the side that the chin was deviated to) was broader than the other side. The posterior teeth of upper and lower arch were more buccally and lingually inclined respectively.

CONCLUSIONS

Skeletal protrusion and deviation of mandible may result in compensation of dental arch and teeth, the de-compensation is important in pre-operative orthodontic treatment.

[Prosthodontic correction of severe deep vertical overbite combined with dimensional discrepancy of the upper and lower dental arch. 31 years follow-up]

Sz. S. a 39-years-old patient was referred to our department in 1968. Patient's masticatory dysfunction, orofacial pain syndrome and substantial weight loss was due to a combined genuine and acquired deep vertical overbite aggravated by a marked difference between the size of the lower and upper jaw bones. The premolars and molars had already been extracted. The lower incisors bit onto the palatal gingiva in centric occlusion causing direct mechanical irritation on the palate. Consequently the centric occlusion position of the mandible was only defined by the contact between the lower central incisors and the palatal soft tissue. According to the literature this kind of defect can only be corrected by a combined surgical prosthodontic therapy (increasing the mandibular arch by vertical osteotomy combined with bone grafting followed by complex prosthodontic reconstruction). Because patient refused any kind of surgical treatment a special upper full arch bridge was constructed with an extended occlusal surface on the palatal surfaces of the front crowns to provide full occlusal contact for the mandibular anterior teeth. The OVD was raised by 11 mm. The present paper reports the history of a 31 years long prosthodontic treatment and patient's follow up. It is shown how the correct centric occlusion, the masticatory functions, the phonetics and also the esthetics could have been maintained by a series of gradually changing fixed restorations meeting the demands imposed by the continuing tooth loss.

[Distraction osteogenesis for correction of maxillary constriction]

OBJECTIVE

To study the methods and effects of distraction osteogenesis for correction of maxillary constriction.

METHODS

10 cases (5 males, and 5 females, aged 16-33 years, average 19.6) were treated by distraction osteogenesis for correction of maxillary constriction. Le Fort I osteotomy and palatal suture osteotomy for the upper jaw were made before opening of the Hyrax screw expander. Totally four times of opening the screw a day were performed. 2 cases were expanded unilaterally. The AP head films were analyzed using Image and Database Analysis System (IDAS) before and after expansion.

RESULTS

1. Expansion of upper arch was achieved done within a few days, and the maxilla, maxillary dental base and the posterior teeth were expanded as much as 3.84 mm, 3.25 mm, and 5.61 mm respectively. 2. The new bone was formed between the opened suture in two weeks, and filled the suture in 2 to 3 months. 3. Maxillary teeth tipped bucally a little bit.

CONCLUSIONS

Distraction osteogenesis rapid maxillary expansion could get a good result following Le Fort I and palatal suture osteotomy for correction of maxillary constriction.

X trisomy in an infertile bitch: cytogenetic, anatomic, and histologic studies

Three copies of the X chromosome were identified in a 5-year-old mixed breed infertile bitch. One year after the cytogenetic examination, the bitch died due to gastritis hemorrhagica, an inflammation of the mucus coat of the stomach. Dental studies showed congenital lack of some premolar and molar teeth. Ovaries were of normal shape and size. Also, histologic sections of the ovaries revealed their normal structure, with two corpora lutea and primary follicles. Phenotypic effects of X trisomy are discussed.

Distraction osteogenesis in Silver Russell syndrome to expand the mandible

Distraction osteogenesis is a method commonly used to activate bone regeneration in nonunions and osseous defects and for lengthening procedures of tubular bones. This technique involves the sectioning of a bone and the subsequent deliberate, controlled movement of the opposing sectioned edges to lengthen, widen, or reposition a bone, or all three. In this report, a patient with Silver Russell syndrome and severe mandibular hypoplasia was treated by means of distraction osteogenesis of the midsymphysis to widen the mandible in concert with sagittal-ramus osteotomies to lengthen the mandible. This treatment created significantly increased arch length in the mandible, which was necessary to facilitate the patient's orthodontic treatment. We believe this is the first reported case of distraction osteogenesis to widen the mandible with the use of a tooth-borne appliance.

Upper dental arch morphology of adult unoperated complete bilateral cleft lip and palate

Literature has shown that, even with the conservative nontraumatic surgical techniques, early repairing surgeries induce changes in the upper dental arch morphologic characteristics in patients with cleft lip and palate. The evaluation of unoperated adult cleft patients enables us to exclude the influence of treatment, emphasizing the morphologic characteristics inherent to the presence of the cleft and its functional counterbalances, that is, the morphologic pattern imposed by cleft. In this study, the maxillary dental casts of 31 unoperated adult complete bilateral cleft lip and palate patients (20 men and 11 women) were compared to a noncleft sample matched for gender. Intercanine, inter-first premolar, inter-second premolar and inter-first molar arch widths measurements as well as arch length were measured from xerox copies taken of the models. The findings indicate the presence of premaxillary prognathism and a progressive increase in the constriction of the dental arches. This constriction of the maxillary segments, even in the absence of surgical intervention, is a result of the absence of an intact palate between the two maxillary processes. Although gender significantly influenced the size of the maxillary arches in the noncleft patients, similar differences were not observed in the cleft group. It seems that the presence of the cleft in itself has the greater influence on the morphologic characteristics of the maxillary arch than gender.

Stability of transverse maxillary dental arch dimensions following orthodontic-surgical correction of anterior open bites

A sample of 130 patients with vertical maxillary hyperplasia; mandibular hypoplasia with a high mandibular plane angle; narrow, tapered maxillary dental arch form; and anterior vertical open bite were collected from three different institutions to evaluate the stability of transverse maxillary arch dimensions after correction of the open bite. Surgical treatment consisted of Le Fort I or bimaxillary osteotomies. Intermolar, interpremolar, and anterior arch widths were measured three-dimensionally on dental casts using a Reflex microscope, and transverse stability after orthodontic or surgical maxillary expansion was analyzed. Orthodontic expansion followed by a one-piece Le Fort I intrusion osteotomy was performed in 77 patients, and surgical maxillary expansion by a multisegment Le Fort I intrusion osteotomy was performed in 53 patients. The increase of transverse arch width and the relapse after orthodontic or surgical expansion were not significantly different. The transverse arch width in these two groups did not relapse in 20% of the patients after a mean follow-up of 69 months. An additional bilateral sagittal split osteotomy had no detectable effect on stability. Patients who underwent a multisegment Le Fort I osteotomy stabilized with rigid internal fixation showed better transverse stability than those with intraosseous wire fixation and maxillomandibular fixation. Maxillary intermolar and interpremolar arch width relapses were not correlated with tongue interposition or loss of interdigitation. The relapse of these arch widths showed significant correlations with clockwise rotation of the mandible but not with changes of overbite or overjet.

Characteristic dental arches and occlusion in patients with aspartylglucosaminuria

Aspartylglucosaminuria (AGU) is a lysosomal storage disorder with progressive mental retardation as a presenting manifestation. The disorder is caused by a single nucleotide change in the gene encoding aspartylglucosaminidase (AGA). This rare disease is relatively common in Finland: we were able to examine 81 Finnish AGU-patients for dental and oral changes. Tooth crown size and crown shape were normal, but dental malocclusions were common, and prevalences of spacing, large overjet, anterior open bite, and lateral crossbite exceeded Finnish population prevalences (P < 0.0001). Dental arches were already large in childhood, and in adult patients, when compared to Finnish population standards, the lower dental arch was larger in all dimensions (P < 0.001). Almost all patients had abnormally large tongues, which we assumed to be the reason for the structural abnormalities observed.

An American Board of Orthodontics case report: the nonsurgical orthodontic correction of a Class III malocclusion

This is a case report of a patient with a skeletal Class III malocclusion and maxillary arch length deficiency. The patient was treated without extraction or surgery by increasing the maxillary arch length. Protraction of the maxillary complex and A point was the result. Favorable growth of both the maxilla and the mandible resulted in a functional Class I occlusion and an improved skeletal relationship. [This case report was presented to the American Board of Orthodontics in partial fulfillment of the requirements for the certification process conducted by the Board.]

Influence of maxillary constriction on nasal resistance and sleep apnea severity in patients with Marfan's syndrome

BACKGROUND

Marfan's syndrome is associated with a high prevalence of obstructive sleep apnea (OSA). As this syndrome is associated with a characteristic constricted maxilla and high-arched palate, we reasoned that nasal airway constriction and resultant high nasal airway resistance (NAR) may contribute to the development of OSA. Therefore, the aim of this study was to measure NAR in patients with Marfan's syndrome. In addition, we aimed to examine the influence of maxillary morphology on both NAR and the severity of OSA.

METHOD

We measured NAR in 13 consecutive patients with Marfan's syndrome and 13 control subjects. NAR was measured by posterior rhinomanometry, and expressed as the inspiratory resistance at a flow of 0.5 L/s. Dental impressions were taken to evaluate maxillary arch morphology, allowing measurement of the following distances: intercuspid (ICD), interpremolar (IPD), intermolar (IMD), and maximum hard palate height (MPH). Ten of the patients and four of the control subjects had previously undergone nocturnal polysomnography.

RESULTS

Mean NAR for the Marfan group was more than twice that in the control group (7.7 +/- 1.2 vs 2.9 +/- 0.4 cm H2O/L/s; p < 0.005). The patients also had marked constriction of the maxillary arch compared with control subjects. Two of the lateral maxillary measurements were significantly inversely correlated with NAR. There were significant correlations between various maxillary arch measurements (MPH/ICD, MPH/IPD, MPH/IMD) and the apnea/hypopnea index.

CONCLUSION

These data suggest that high NAR is a common feature of Marfan's syndrome. Maxillary constriction with a relatively high hard palate appears to be a major reason for the high NAR. The significant correlations between indexes of maxillary constriction and sleep apnea severity suggest that maxillary morphology may play an important role in the pathophysiology of OSA in Marfan's syndrome.

[Analysis of the interaction of genotypic and paratypic factors in the development of maxillo-dental anomalies in ontogeny]

Component analysis of total phenotypic variance was used to analyze data on 80 pairs of twins aged 3 to 18 years, examined in the Stupino outpatient dental clinic, Moscow oblast. Genotypic and environmental factors are shown to play different roles in the development of abnormalities of teeth, dental arches, and occlusion at different ontogenetic periods of deciduous, mixed, and permanent dentition. Periods when paratypic factors prevailed were revealed. This made it possible to identity periods when prophylaxis and orthodontic treatment are the most advisable.

Maxillary canine impaction in patients with transverse maxillary deficiency

Extensive literature exists concerning impacted maxillary canines. Tooth-size/arch-size discrepancy (lack of space) is a common etiologic factor of impacted canines. No studies exist documenting transverse maxillary deficiency as a causative factor for impacted canines. The purpose of this study was to determine whether patients with impacted maxillary canines have transverse deficiency and if other factors, such as arch length, arch perimeter, and arch form contribute to canine impaction. Fifty-seven (57) subjects with eighty-one (81) impacted maxillary canines were compared to one hundred-three (103) nonimpacted subjects. Intermolar (IM) and intercanine (IC) width, arch length (AL), arch perimeter (AP), and arch form were recorded for each subject. The experimental and control groups were compared using a Z test and Chi-square analysis. Results indicate subjects with canine impactions demonstrate profound transverse maxillary deficiency located in the anterior portion of the dental arch: No significant difference in arch form is noted between the experimental and control groups (p > 0.05).

Three-dimensional comparison between the palatal forms in infants with complete unilateral cleft lip, alveolus, and palate (UCLP) with and without Hotz's plate

A three-dimensional measuring system was developed to analyze changes in palatal forms of UCLP infants. This system quantified the change of the curved surface on a palate by automatically superimposing two wireframe models obtained from casts at different stages of growth. It also analyzed the curvature of the palatal surface. This system was used to study the palates of 20 infants with unilateral cleft lip and palate (UCLP), from the first to fourth months after birth (12 with Hotz's plate and 8 without, selected at random). Both major and lesser maxillary segments without Hotz's plate remained anterior and lateral although those with Hotz's plate moved mesially during the fourth month after birth. In addition, the degrees of curvature on the palatal surfaces with Hotz's plate were less than those without Hotz's plate.

Osteogenesis of the mandibular arch in Ts16 mice

Males and females homozygous for the Robertsonian translocation specific for chromosomes 16 and 17 Rb(16.17)Bnr and male and females homozygous for the Robertsonian translocation for chromosomes 6 and 16 Rb(6.16)24Lub were bred to produce double heterozygotes [Rb(16.17)Bnr/Rb(6.16)24Lub]. Experimental data were based on 156 features: 70 euploid (control), 86 trisomic. Affected fetuses were identified by decreased size, shortened faces (flattened snouts), oedema, petechiae, open eyelids, and dysplastic ears. Identification of trisomics was substantiated by karyotyping the metaphasic spreads. Five gestational days were studied (14-18). Fetal age was assumed to be accurate as fertilization occurred within half an hour of copulation. Euploid specimens followed normal developmental paths of chondrogenesis, osteogenesis and related tissues. In trisomics, developmental faults increased unequally between gestational days 15 and 17: some tissues were mildly and others acutely affected. Among the trisomic disorders were diminished growth, lagging mitotic activity, and retarded and poorly ordered tissue development, especially of bone. All of these contributed to hypoplasia, hypocellularity, reduced vascular supply and enlarged intercellular spaces. Intensities of the mandibular abnormalities varied among litters and littermates. The severity of the developmental disorders of an individual Ts16 specimen differed among the tissue components studied. Of the trisomic mandibular tissues, bone was most frequently involved and Meckel's cartilage least.