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.