Invisalign System as a Treatment of a Skeletal Open Bite: A Case Report With a 5-Year Follow-up

Background: Orthodontic treatments of skeletal open bite are among the most challenging and at high relapse. Available therapies vary from behaviour-modifying appliances in growing patients to surgical approach in adults. Recently, clear aligners, such as Invisalign®, have also been proposed as a treatment modality, to be used alone or in combination with temporary anchorage devices. Case report: A 19-year-old female presented with 3-mm anterior open bite, peg-shaped upper lateral incisors, incorrect tongue posture at rest and during function. Due to aesthetic request, an orthodontic camouflage with Invisalign® was carried out for 17½ months, along with myofunctional therapy and composite veneers on upper lateral incisors. During the first months of retention, intermaxillary vertical elastics were maintained at night-time as positive feedback to the tongue. A 5-year follow-up confirmed stability of the results. Conclusions: A system of clear aligners in combination with myofunctional therapy was effective in the treatment of a skeletal open bite malocclusion, with stability at 5 years. The closure of the anterior open bite was obtained through a combination of lower molar intrusion, incisor extrusion and counterclockwise rotation of the mandible. In selected cases of optimal compliance, Invisalign® may constitute a feasible treatment option in management of open bite in non-growing patients.

MORPHOLOGY OF THE FIRST MANDIBULAR TOOTH MICROTUS GREGALIS (RODENTIA, ARVICOLINAE) FROM THE MIDDLE PLEISTOCENE OF THE PRE-ALTAI PLAIN

In this paper morphological structure of the first lower molar m1 tooth of the narrow-skulled vole from alluvial deposits of the Pre-Altai Plain Middle Neo-Pleistocene is described. Morphological study of the vole remains showed that they belong to the modern species Microtus gregalis. At the same time, the study sample showed significant differences, both in morphological structure and in the size of the first lower molar, in comparison with the recent representatives of the same territory. The set of morphological and morphometric data shows that the studied voles occupy an intermediate position between M. gregaloides of the Early and M. gregalis of the Late Neo-Pleistocene. The ratio of m1 morphotypes also showed the relative primitiveness of the M. gregalis sampling. Morphological study of remains of the narrow-skulled vole from the Solonovka, Petropavlovskoe and Malinovka-4 locations confirmed the previously determined age for sediments containing the remains of microtheriofauna.

Effects of long-term use of the lower lingual arch from 8.5 years to 13.2 years

ABSTRACT Objectives To investigate the effects of long-term use of the lower lingual arch (LLA) on the sagittal and vertical positions of the permanent lower incisors and first molars. Materials and Methods The sample consisted of 98 patients who were treated with an LLA (LLA group) and 39 patients who were treated without an LLA (no-LLA group). The positional changes of the lower incisors and first molars were analyzed after performing mandibular structural superimpositions on lateral cephalometric radiographs taken before treatment (T1) and at the end of LLA therapy (T2). The mean ages at T1 and T2 were 8.5 years and 13.2 years, respectively. Study casts were analyzed to quantify arch dimensional changes. Results Mesial movement of the lower molar cusp was similar between the LLA and no-LLA groups, but the vertical position was slightly greater at T2 in the LLA group. In the LLA group, there was a molar tip-back effect, and the lower incisors were proclined 4.2° more than in the no-LLA group. Arch perimeter decreased 3.6 ± 2.6 mm without an LLA and 0.97 ± 3.7 mm with an LLA. Intercanine and intermolar widths both increased about 1 mm more with an LLA (P < .0001). Conclusions The LLA does not seem to restrict mesial movement and vertical eruption of the lower incisors and molars in the long term. The LLA effectively preserves the arch perimeter at the expense of a slight lower incisor proclination.

REHABILITATION OF MASTICATION AND LACK OF SPACE TREATMENT IN NARROW EDENTULOUS WITH FIXED-FIXED BRIDGE

Background: Loss of posterior teeth can lead to disharmony in the curvature of the jaw. Antagonistic teeth and surrounding teeth will migrate to the edentulous causing reduced mastication function and TMJ disturbance. Several cases of narrow edentulous occurred due to tooth shifting caused by edentulous that was left empty for a long period. Creating a fixed-fixed bridge is aimed to restore the aesthetics, function, and comfort for patients which caused by the missing teeth. Fixed-fixed bridge consist of a retainer that function as a support to the abutment; a pontic that function to replace the missing tooth; and a connector that function to connect the pontic and the retainer. A narrow space for pontics can disrupt the aesthetic and functional aspects. Case Report: A 24 year-old male patient was referred to Prosthodontic Clinic, Gusti Hasan Aman Dental Hospital with a complain of pain on the jaw joint and missing of left lower molar for about 5 years. Patient always masticate on one side after the left lower molar was missing. Extraoral examination found the patient to be in good condition, no enlargement of major salivary glands, the vital signs were good, but upon TMJ examination there was clicking sounds on the left side. Intraoral examination showed space narrowing resulted from mesial and distal drifting of 37 and 35 but not significant, therefore it was still possible to perform rehabilitation using fixed-fixed bridge with abutments on 37 and 35 with modification of pontic shape for 36 to resemble a premolar tooth with occlusal surface resembling a molar tooth. Treatment planning for fixed prosthetic using fixed-fixed bridge with porcelain fused to metal material on 35, 36, and 37 with ridge lap pontic type modification Conclusions: Treatment was successful to provide enough space for the pontic by modification of the shape and the size of the pontic. Keywords: Fixed-fixed bridge. lack of space, mastication.

New Middle Eocene proboscidean from Togo illuminates the early evolution of the elephantiform-like dental pattern

Africa has played a pivotal role in the evolution of early proboscideans (elephants and their extinct relatives), yet vast temporal and geographical zones remain uncharted on the continent. A long hiatus encompassing most of the Eocene (Ypresian to the Early Priabonian, around 13 Myr timespan) considerably hampers our understanding of the early evolutionary history of the group. It is notably the case with the origin of its most successful members, the Elephantiformes, i.e. all elephant-like proboscideans most closely related to modern elephants. Here, we describe a proboscidean lower molar discovered in Lutetian phosphate deposits from Togo, and name a new genus and species, Dagbatitherium tassyi . We show that Dagbatitherium displays several elephantiform dental characteristics such as a three-layered Schmelzmuster, the presence of a mesoconid, transversely enlarged buccal cusps and the individualization of a third lophid closely appressed to a minute distal cingulid. Dagbatitherium represents a stem Elephantiformes, pushing back the origin of the group by about 10 Myr, i.e. a third of its currently known evolutionary history. More importantly, Dagbatitherium potentially unlocks the puzzle of the origin of the unique elephantiform tooth crown organization by bridging a critical temporal and morphological gap between early bunodont incipiently bilophodont proboscidean taxa and more derived elephantiforms.

Возрастная структура популяции азиатского бурундука (Tamias sibiricus) в Северном Приохотье

The age-related variability of the abrasion degree of the masticatory surface of the first lower molar in the Northern Priokhotye population of the Siberian chipmunk has been studied. It has been revealed that, in young of the current year, from the time they abandoning breeding burrows to the hibernation period, the index of abrasion of the masticatory surface m1 is 0.6-3.5 %. The area of exposed dentin on the molar masticatory surface increases annually by 5-6 % averagely in overwintered adult animals. According to the abrasion index, 4-5 age classes are distinguished in the population. The group of animals aged 1+ yrs dominates in number (40.8 %). The specific survival rate of individuals in the range from 1 to 3 years is approximately 0.5. After three years, it drops sharply (0.23). Less than 3 % of individuals survive up to 4 years or more in the population.

Jaw region endometriosis: case report

Introduction: Endometriosis is a chronic gynecological disease, which refers to the presence of endometrial glands and stroma outside the uterine endometrium. This entity has a frequency of 10 to 15% in women of reproductive age, and its most common site of presentation is the ovary. At the extrapelvic level, the most common location is the gastrointestinal and genitourinary location. However, it can occur in any location. Presentation: The case of a 40-year-old female patient with a face tumor in the mandibular region is described, presenting with a disease time of 2 years. Among the important antecedents, two months before the appearance of the tumor region, the patient underwent endodontic surgery of a lower molar tooth, contiguous to the mandibular. Likewise, one month before the appearance of the tumor, the patient underwent an exploratory laparoscopy for electrofulguration of endometriotic foci in the uterine myometrium. The patient underwent a surgical resection of the tumor in the mandibular region described; and after reviewing the histological and immunohistochemical slides at the institution, the diagnosis of endometriosis was established. Conclusion: Extrapelvic endometriosis is rare in our country, and its diagnosis requires experience and visual training in the recognition of normal endometrial tissue. The presentation of this case was considered important because it would be the first case reported in Peru and in the world, of an endometriosis located in the mandibular region.

Hexavalent chromium exposure alters bone remodeling in the developing tooth alveolus and delays tooth eruption

Although it has been demonstrated that exposure of lactating rats to CrVI delays tooth eruption, the effects of CrVI exposure on bone remodeling in the developing alveolus during tooth eruption remain unknown. Our purpose was to analyze the effect of CrVI in the alveolus of the first lower molar of rats. Thirty-two suckling Wistar rats were divided into two groups. The experimental group received 12.5 mg/kg body weight/day of potassium dichromate dissolved in saline solution by oral gavage as of day 4 of the experiment; the control group received an equal dose of saline solution. Each group was divided into two sub-sets and euthanized at the ages of 9 and 15 days, respectively. Histochemical and histomorphometric studies of the bone surfaces of the developing tooth alveolus were performed. The percentage of bone formation surfaces was lower in experimental animals than in age-matched controls. The percentage of bone resorption surfaces was significantly lower in 9-day-old experimental rats than in controls and significantly higher in 15-day-old experimental rats than in controls. Exposure to CrVI during lactation alters the sequence of bone resorption and formation in the walls of the developing alveolus, both of which are necessary for tooth eruption, thus causing a delay.