Long-term follow-up of mandibular dental arch changes in patients with complete non-syndromic unilateral cleft lip, alveolus, and palate

Background Treatment of cleft lip and palate (CLP) requires a comprehensive interdisciplinary approach and long-term follow-up. Only a few studies are available that reported on changes after treatment, which showed that in particular the transverse dimension, in patients with CLP is prone to changes after treatment. However, those studies did not pay attention to concomitant changes in the mandibular arch that occur after treatment. Objectives To evaluate mandibular transverse dental arch dimensions and interarch transverse changes in patients with complete non-syndromic unilateral cleft lip, alveolus, and palate (CUCLAP) up to five years after treatment. Material and Methods Retrospective longitudinal study in 75 consecutive patients with CUCLAP directly after comprehensive treatment (T0), two (T2), and 5 years after treatment (T5). Great Ormond Street, London and Oslo (GOSLON) scores were available for all patients. Three-dimensional scans of all dental casts were made. Inter premolar and intermolar distances between the mandibular contralateral teeth were measured. The modified Huddart Bodenham (MHB index) was applied to assess the transverse interarch relationship. Paired t-tests and ANOVA were used to analyze transverse and interarch transverse changes. Linear regression analysis was done to define contributing factors. Results Paired t-tests showed a significant decrease of the mandibular inter first and second premolar distances (p < 0.05) and an increase of the inter second molar distance, whilst the MHB Index deteriorated at all time points for all segments and for the total arch score (p < 0.05). Linear regression showed no significant contributing factors on the decrease of the transverse distances. However, inter arch transverse relationship was significantly affected by age at the end of treatment, missing maxillary lateral incisor space closure, and the GOSLON Yardstick score at the end of treatment (p < 0.05), especially during the first two years after treatment. Conclusions Changes occurred in the mandibular arch expressed as changes in the transverse dimensions and interarch relationship measured by the MHB Index. A younger age at the end of treatment, space closure for a missing maxillary lateral incisor and a higher GOSLON score at the end of treatment negatively influence the interarch transverse deterioration especially in the first two years after treatment. For the transverse dimensional changes in the mandibular arch such influencing factors could not be determined.

Confluence of digital and conventional protocols in removable Prosthodontics- A clinical report

Digitization in removable Prosthodontics offers multiple advantages such as digital surveying, designing the framework with components and obtaining a 3D printed resin framework which can be tried intraorally and cast using conventional techniques, teeth arrangement. This technology is time-saving, highly accurate, also allows digital archiving of casts. This case report presents utilization of digital techniques and conventional protocols in rehabilitation of a bilateral posterior edentulous mandibular arch with an attachment retained cast partial denture.

Mammalian face as an evolutionary novelty

The anterior end of the mammalian face is characteristically composed of a semimotile nose, not the upper jaw as in other tetrapods. Thus, the therian nose is covered ventrolaterally by the “premaxilla,” and the osteocranium possesses only a single nasal aperture because of the absence of medial bony elements. This stands in contrast to those in other tetrapods in whom the premaxilla covers the rostral terminus of the snout, providing a key to understanding the evolution of the mammalian face. Here, we show that the premaxilla in therian mammals (placentals and marsupials) is not entirely homologous to those in other amniotes; the therian premaxilla is a composite of the septomaxilla and the palatine remnant of the premaxilla of nontherian amniotes (including monotremes). By comparing topographical relationships of craniofacial primordia and nerve supplies in various tetrapod embryos, we found that the therian premaxilla is predominantly of the maxillary prominence origin and associated with mandibular arch. The rostral-most part of the upper jaw in nonmammalian tetrapods corresponds to the motile nose in therian mammals. During development, experimental inhibition of primordial growth demonstrated that the entire mammalian upper jaw mostly originates from the maxillary prominence, unlike other amniotes. Consistently, cell lineage tracing in transgenic mice revealed a mammalian-specific rostral growth of the maxillary prominence. We conclude that the mammalian-specific face, the muzzle, is an evolutionary novelty obtained by overriding ancestral developmental constraints to establish a novel topographical framework in craniofacial mesenchyme.

Revisiting King Appliance Space Regainer in Children: A Case Report with 1-Year Follow-Up

In recent times, for successful resolution of space discrepancies, a plethora of interceptive measures involving nonextraction approaches have been employed judiciously. Immaculate diagnosis and treatment planning help to prevent failure in diagnosing a case of space discrepancy and space regaining. This article describes a case in which space loss in the posterior quadrant of mandibular arch was successfully regained by employing King Appliance space regainer in an adolescent male, following which successful eruption of unerupted tooth took place. Additionally, after 1 year of follow-up, no marked reduction in arch dimension was seen.

The pseudobranch of jawed vertebrates is a mandibular arch-derived gill

The pseudobranch is a gill-like epithelial elaboration that sits behind the jaw of most fishes. This structure was classically regarded as a vestige of the ancestral gill-arch like condition of the gnathostome jaw. However, more recently, hypotheses of jaw evolution by transformation of a gill arch have been challenged, and the pseudobranch has alternatively been considered a specialised derivative of the second (hyoid) pharyngeal arch. Here, we demonstrate by cell lineage tracing in a cartilaginous fish, the skate (Leucoraja erinacea), that the pseudobranch does, in fact, derive from the mandibular arch, and that it shares gene expression features and cell types with gills. We also show that the mandibular arch pseudobranch is supported by a spiracular cartilage that is patterned by a shh-expressing epithelial signalling centre. This closely parallels the condition seen in the gill arches, where cartilaginous appendages called branchial rays supporting the respiratory lamellae of the gills are patterned by a shh-expressing gill arch epithelial ridge (GAER). Taken together, these findings support serial homology of the pseudobranch and gills, and an ancestral origin of gill arch-like anatomical features from the gnathostome mandibular arch.

C-Shaped configuration of the canal in mandibular molars: A case report

The primary concern of this case report is to discuss and review the different etiological features of c shaped canals, with its incidence, along with anatomical features, diagnosis and management of the c shaped configuration of the canal in the molars of the mandibular arch. Literature revealed that c shaped canal configuration is slightly a different variation that has a predilection towards the racial and most of the times or most commonly is seen in mandibular molars that too most commonly in second molar of the mandibular arch. This morphology when present in the canal may posses difficulty in shaping of the canal, cleaning of the canal as well as debridement of the canal along with obturation of the canal. The one of the most common way in the management of this c shaped canal morphology is done by with the help of usage of rotary instruments and can also with the use of hand instruments that too assisted with sonics as well as ultrasonics.

Efficacy of MI Paste® on Bleaching-Related Sensitivity: Randomized Clinical Trial

Background. To evaluate the effectiveness of MI Paste® in reducing sensitivity associated with vital tooth bleaching. Methods. This randomized controlled split-mouth clinical trial included 45 subjects that were randomly divided into two groups. In Group 1, the maxillary arch was the control arch (only bleaching), while the mandibular arch was the intervention arch (bleaching and MI Paste®). In Group 2, the mandibular arch was the control arch (only bleaching), while the maxillary arch was the intervention arch (bleaching and MI Paste®). Subjects started with the control arch and then switched to the intervention arch after two weeks. Subjects were instructed to use MI Paste® in a custom tray for 5 minutes, wait for 1 hour, and then bleach overnight using a different tray. Sensitivity was measured using both a thermal sensitivity test and a daily log of sensitivity for 14 days. Shade was evaluated using a colorimeter and a shade guide. Results. Immediately after treatment, the thermal test sensitivity scores for the arches bleached without MI Paste® were greater than those with MI Paste® ( p = 0.011 ). Arches not receiving the MI Paste® treatment showed significantly higher VAS sensitivity scores during the 14-day period of bleaching ( p = 0.002 ). The mean score for the 14-day period was 37.9 for the arches not treated with MI Paste® versus 27.5 for the treated arches. Both the intervention group and the control group showed significantly lighter shade relative to baseline ( p < 0.001 ) with no significant difference between them ( p = 0.42 ). Conclusion. MI Paste® significantly reduced the sensitivity associated with bleaching and did not interfere with shade change.