Analysis of the periodontal status of patients with mandibular-bonded retainers

PURPOSE: This clinical study evaluated the periodontal status of patients with bonded retainers as compared to a non-treated control group. METHODS: Forty dental students were included in the sample and divided into the following two groups: 1) a test group of 20 subjects that, after orthodontic treatment, have been bonded retainer users for at least 2 years and 2) a control group of 20 patients that never experienced orthodontic treatment nor used any bonded retainer. The region associated with the retainer in the test group and the lower canine-to-canine region in the control group were examined according to the following clinical parameters: plaque index (PI), bleeding on probing (BOP), gingival recession (GR), clinical attachment level (CAL) and probing depth (PD). RESULTS: No differences were observed for GR or BOP (P>0.05). In contrast, the test group showed higher values of CAL and PD at proximal sites when compared to controls (P<0.05). In addition, IP was significantly increased at buccal and lingual sites (P<0.05). CONCLUSION: The placement of orthodontic bonded retainers negatively affected periodontal health, resulting in increased PI, PD and CAL.

Influência da proporção entre as alturas do ramo mandibular e dentoalveolar posterior na inclinação do plano mandibular

OBJETIVO: avaliar a existência de correlação entre a proporção da altura do ramo mandibular (AR) com a altura dentoalveolar posterior total (ADAPT) e a inclinação do plano mandibular (PM). MÉTODOS: dois examinadores avaliaram 81 telerradiografias laterais de pacientes, com idades a partir de 18 anos, do arquivo do curso de especialização em Ortodontia e Ortopedia Facial da Faculdade de Odontologia da UFBA. As radiografias foram digitalizadas, os pontos marcados e as medidas obtidas através do programa Radiocef 1.0. Mediu-se a inclinação do plano mandibular para caracterizar o padrão vertical da face e dividir as radiografias em três grupos: grupo de face normal (GN), de 22º a 28º, de face curta (GC), menor que 22º, e de face longa (GL), maior que 28º. A inclinação do plano palatino serviu como critério de exclusão, sendo que valores abaixo de -2,5° ou acima de 3,5º foram excluídos. Desta forma, 46 telerradiografias laterais totalizaram a amostra. RESULTADOS: a AR diferiu entre GC e GL, porém não houve diferença estatisticamente significante para as alturas dentoalveolares posteriores. Houve baixa correlação entre a AR e a ADAPT nos grupos, no entanto, a correlação da proporção entre essas alturas com a inclinação do PM mostrou-se estatisticamente significante e negativa. CONCLUSÃO: este é um fator a ser levado em consideração na avaliação do PM, quando do diagnóstico e tratamento das displasias verticais dentofaciais.

Dimensões dos arcos dentários na má oclusão Classe II, divisão 1, com deficiência mandibular

OBJETIVO: identificar alterações dimensionais nos arcos dentários superior e inferior na má oclusão Classe II, divisão 1, com deficiência mandibular (Padrão esquelético II). MÉTODOS: 48 pacientes com má oclusão Classe II, igualmente divididos quanto ao gênero, foram comparados com 51 indivíduos com oclusão normal, sendo 22 do gênero masculino e 29 do gênero feminino. Todos os 99 indivíduos estavam no estágio de dentadura permanente, com os segundos molares permanentes irrompidos ou em irrupção, com idade média de 12 anos e 5 meses (desvio-padrão de 1 ano e 3 meses), numa faixa etária oscilando entre 11 anos e 4 meses e 20 anos. CONCLUSÃO: os resultados permitem concluir que, na má oclusão Classe II, divisão 1 com deficiência mandibular, o arco dentário superior encontra-se alterado, mostrando-se atrésico e mais longo, enquanto o arco dentário inferior é pouco influenciado pela discrepância sagital de Classe II.

Relationship between maxillary and mandibular base lengths and dental crowding in patients with complete Class II malocclusions

Objective: To verify the relationship between maxillary and mandibular effective lengths and dental crowding in patients with Class II malocclusions. Materials and Methods: The sample comprised 80 orthodontic patients with complete Class II malocclusions in the permanent dentition (47 male, 33 female) who were divided into two groups according to the amount of mandibular tooth-arch size discrepancy. The maxillary and mandibular effective lengths (Co-A and Co-Gn) and tooth-arch size discrepancies were measured on the initial cephalograms and dental casts, respectively. Intergroup comparisons of apical base lengths were performed with independent t-tests. Correlation between base length and dental crowding was examined by means of Pearson's correlation coefficient (P < .05). Results: Patients with Class II malocclusion and moderate to severe crowding had significantly smaller maxillary and mandibular effective lengths than subjects with the same malocclusion and slight mandibular crowding. A weak inverse correlation was also found between maxillary and mandibular effective lengths and the severity of dental crowding. Conclusion: Decreased maxillary and mandibular effective lengths constitute an important factor associated with dental crowding in patients with complete Class II malocclusion. (Angle Orthod. 2011;81:217-221.)

Changes in temporomandibular joint disc position and form following Herbst and fixed orthodontic treatment

Objective: To determine the changes in the position and form of the temporomandibular joint articular disc in adolescents with Class II division 1 malocclusion and mandibular retrognathism treated with the Herbst appliance (phase I) and fixed orthodontic appliance (phase II). Materials and Methods: Thirty-two consecutive adolescents went through phase I of treatment and 23 completed phase II. The temporomandibular joints were evaluated qualitatively by means of magnetic resonance images at the beginning of treatment (T1), during phase I (T2), at the end of phase I (T3), and at the end of phase II (T4). Results: Significant changes in disc position were not observed with the mouth closed between T1 X T3 (P = .317), T3 X T4 (P = .287), or T1 X T4 (P = .261). At T2, on average, the disc was positioned regressively. With the mouth open, no difference was observed between T1 X T3 (P = .223) or T1 X T4 (P = .082). We did observe a significant difference between T3 X T4 (P < .05). Significant changes in the disc form were found with the mouth closed between T1 X T2 (P < .001) and T2 X T3 (P < .001). Conclusions: At the end of the two-phase treatment, in general terms, the position and form of the initial articular discs were maintained; however, in some temporomandibular joints some seemingly adverse effects were observed at T4. (Angle Orthod. 2010;80:843-852.)

The relative effects of severe burn injury and pre- and post-natal protein deprivation on mandibular condyle morphology

The mandible has a mixed embryological origin, and its growth is associated with the secondary cartilage of the condyle process (CP). In this area, growth depends on an array of intrinsic and extrinsic factors that influence protein metabolism. In the present study, we used an adolescent rat model to evaluate the growth and development of the CP under conditions of pre- and postnatal protein deficiency, combined with or without the stress of severe burn injury (BI). We found that protein deficiency severely undermined the growth of the CP, by altering the thickness of its constituent layers. BI is also capable of affecting CP growth, although the effect is less severe than protein deficiency. Interestingly, the summed effect of protein deficiency and BI on the CP is less severe than protein deficiency alone. A possible explanation is that the increased carbohydrates in a hypoproteic diet stimulate the production of endogenous insulin and protein synthesis, which partially compensates for the loss of lean body mass caused by BI.

Mandibular gland secretions of meliponine worker bees: further evidence for their role in interspecific and intraspecific defence and aggression and against their role in food source signalling

Like ants and termites some species of stingless bees (Meliponini), which are very important pollinators in the tropics, use pheromone trails to communicate the location of a food source. We present data on the communicative role of mandibular gland secretions of Meliponini that resolve a recent controversy about their importance in the laying of such trails. Volatile constituents of the mandibular glands have been erroneously thought both to elicit aggressive/defensive behaviour and to signal food source location. We studied Trigona spinipes and Scaptotrigona aff. depilis (`postica`), two sympatric species to which this hypothesis was applied. Using extracts of carefully dissected glands instead of crude cephalic extracts we analysed the substances contained in the mandibular glands of worker bees. Major components of the extracts were 2-heptanol (both species), nonanal (T. spinipes), benzaldehyde and 2-tridecanone (S. aff. depilis). The effect of mandibular gland extracts and of individual components thereof on the behaviour of worker bees near their nest and at highly profitable food sources was consistent. Independent of the amount of mandibular gland extract applied, the bees overwhelmingly reacted with defensive behaviour and were never attracted to feeders scented with mandibular gland extract or any of the synthetic chemicals tested. Both bee species are capable of using mandibular gland secretions for intra-and interspecific communication of defence and aggression and share 2-heptanol as a major pheromone compound. While confirming the role of the mandibular glands in nest defence, our experiments provide strong evidence against their role in food source signalling.

Influence of ovariectomy and masticatory hypofunction on mandibular bone remodeling

Introduction: This study was designed to examine the effect of masticatory hypofunction and estrogen deficiency on mandible bone mass and compare this site with spine and femoral bone. Methods: Twenty-four rats were ovariectomized (OVX) or Sham-operated (Sham) and analyzed after feeding with hard diet (Hard) or soft diet (Soft). They were divided into four groups: (GI)Sham-Hard; (GII)OVX-Hard; (GIII)Sham-Soft and (GIV)OVX-Soft. Bone mineral density (BMD) was measured in the spine and femur in the baseline and at the end of the study, and Delta BMD (final BMD - baseline BMD) was calculated. In mandible bone, BMD and histomorphometry were analyzed at the end of the experiment. Results: Sham rats showed higher spine (GI: 13.5%vs GII: 0.74%, P < 0.01; GIII: 10.67%vs GIV: -4.36%, P < 0.001) and femur Delta BMD (GI: 14.43%vs GII: 4.42%, P < 0.01; GIII: 10.58%vs GIV: 0.49%, P < 0.001) than OVX, but no difference was observed in mandible BMD among these groups (P > 0.05). Soft-diet groups showed decreased mandible BMD compared with hard-diet groups (GIV vs GII, P < 0.01; GIII vs GI, P < 0.01). Similarly, mandibular condyle histomorphometry showed that soft-diet groups presented a significant decrease in trabecular thickness and volume (GIV vs GII, P < 0.05; GIII vs GI, P < 0.01) compared with hard diet. Conclusion: Our results suggest that mandibular bone loss resulted from decreased of mechanical loading during mastication, and was not affect by estrogen depletion.

Mandibular Function is Severely Impaired in Systemic Sclerosis Patients

Aims: To evaluate the presence of temporomandibular disorders (TMD) in systemic sclerosis (SSc) patients and its possible association with the severity of skin involvement. Methods: The presence of TMD was evaluated in 35 SSc women and 30 age- and sex-matched healthy controls by means of the anamnestic (A(i)) and clinical (D(i)) Helkimo indices; the jaw mobility was further analyzed (M(I)). Skin involvement was scored by the Modified Rodnan Skin Score (MRSS). Results: Signs and symptoms of TMD were more frequent in SSc patients than in controls, the frequency distribution of the different clinical dysfunction indices differing significantly (P < .001) between patients (D(i)0 8.6%, D(i)I 48.6%, D(i)II 22.8%, and D(i)III 20%) and controls (D(i)0 50%, D(i)I 33.3%, and D(i)II 16.7%). Cyclophosphamide for severe and rapidly progressive cutaneous fibrosis was prescribed in six out of seven patients with severe signs (D(i)III), in contrast this treatment was indicated for only two out of 25 patients with mild to moderate signs (D(i)I and D(i)II, P <. 001). Impaired jaw mobility was more frequent in SSc patients than controls (P < .001). It was severe in 77.1% (M(I)II) and mild in 22.9% (M(1)I) of the cases, in contrast to controls (M(I)0 33.4%, M(I)I 53.3%, and M(I)II 13.3%; P < .001). Approximately half of SSc patients with severe (M(I)II) but none of those with mild impairment were on cyclophosphamide treatment for severe cutaneous fibrosis (P = .02). Conclusion: Severe signs of TMD according to the anamnestic and clinical Helkimo indices were very frequent in SSc patients. J OROFAC PAIN 2010;24:197-202

Oral Mucosal Melanoma of the Mandibular Gingiva: A Case Report

Orla mucosal melanoma is rare and is reported to be more aggressive than cutaneous melanoma. The incidence of oral mucosal melanoma peaks at 41 to 60 years of age and the male to female ratio is 2 to 1. Preferred sites in the oral mucosa include the hard palate and maxillary alveolar crests. Risk factors have not been clearly identified, but melanotic pigmentation is present in one-third of patients prior to the diagnosis of melanoma. We report an unusual case of oral mucosal melanoma of the mandibular gingiva with the main characteristics of an in situ lesion and areas of superficial invasion in a 45-year-old woman. The patient was treated with surgical resection of the lesion and a 54-month follow-up shows no evidence of recurrence. Oral mucosal melanomas are aggressive neoplasms that may arise from prior pigmented lesions in the oral mucosa. Classification of these tumors is not well-established and the main prognostic factor appears to be lymph node compromise. The main treatment modality is surgical resection. Cutis. 2010;86:89-93.

Transillumination-guided Study of the Endoscopic Anatomy of the Lacrimal Fossa

Dacryocystorhinostomy is the treatment of choice for the obstruction of the lachrymal apparatus. At the end of last century, the development of the endoscopic instruments for nasosinusal surgery has made it possible to do it through the endoscopic pathway. Nonetheless, anatomical variations make it difficult to have reproducibility endonasaly. Aim: study the endoscopic anatomy of the lachrymal fossa through transillumination of the common canaliculus. Study design: experimental. Materials and Methods: we dissected 40 lachrymal pathways from 20 human cadavers, in three stages: 1. identification and dilation of the lachrymal canaliculus. 2 Optic fiber beam introduction; 3 - endoscopic dissection of the lachrymal sac, describing its position. Results: the most frequent position of the lachrymal sac was between the free border of the middle turbinate and its insertion immediately underneath it. The maxillary line was seen in 95% of the cases. Septoplasty was needed in 12.5%, unicifectomy in 35% and middle turbinectomy in 7.5%. Conclusion: Although the lachrymal sac has a more frequent location, its position varied considerably. The transillumination of the common canaliculus proved useful, solving the problem of the anatomical variability.

Tentorial Posterior Fossa Meningioma Which Is the Ideal Surgical Approach: Supra/Infratentorial Combined or Retrosigmoid?

Tentorial meningiomas account for 2% to 3% of all intracranial meningiomas. The authors present their experience with posterior fossa tentorial meningiomas, and discuss the main features, which influence approaches and complications of the different surgical techniques. Twenty-four patients had meningiomas localized predominantly in posterior fossa. Their historical records and radiologic examinations were reviewed in accordance with Simpson`s classification. The extension of tumor removal was Simpson grade I in 12 patients (50%), grade II in 12 patients (50%), and grades III and IV in none of the patients. In 22 patients (91.66%), the meningioma was classified as grade I and in 2 cases (8.33%) classified as grade 11 (atypical meningioma). The combined supra/infiratentorial was employed in 12 cases, and complete resections were most common with this approach compared with retrosigmoid technique. Postoperative complications occurred in 10 patients (41.6%) with major deficits in 3 patients (12.5%). The authors believe that careful preoperative choice of the surgical approach should be based Oil tumor location and extension. It is then possible to achieve the best radical microsurgical tumor resection, avoiding additional injury to neurovascular structures.

Mandibular appliance modulates condylar growth through integrins

Functional orthopedic therapy corrects growth discrepancies between the maxilla and mandible, possibly through postural changes in the musculature and modulation of the mandibular condylar cartilage growth. Using Wistar rats, we tested the hypothesis that chondrocytes respond to forces generated by a mandibular propulsor appliance by changes in gene expression, and that integrins are important mediators in this response. Immunohistochemical analyses demonstrated that the use of the appliance for different periods of time modulated the expression of fibronectin, alpha 5 and alpha v integrin subunits, as well as cell proliferation in the cartilage. In vitro, cyclic distension of condylar cartilage-derived cells increased fibronectin mRNA, as well as Insulinlike Growth Factor-I and II mRNA and cell proliferation. A peptide containing the Arginine-Glycine-Asparagine sequence (RGD), the main cell-binding sequence in fibronectin, blocked almost all these effects, confirming that force itself modulates the growth of the rat condylar cartilage, and that RGD-binding integrins participate in mechanotransduction.