A mathematical function to evaluate surgical complexity of cleft lip and palate.

The objective of this work is to show the modeling of a similarity function adapted to the medical environment using the logical-combinatorial approach of pattern recognition theory, and its application comparing the condition of patients with congenital malformations in the lip and/or palate, which are called cleft-primary palate and/or cleft-secondary palate, respectively. The similarity function is defined by the comparison criteria determined for each variable, taking into account their type (qualitative or quantitative), their domain and their initial space representation. In all, we defined 18 variables, with their domains and six different comparison criteria (fuzzy and absolute difference type). The model includes, further, the importance of every variable as well as a weight which reflects the surgical complexity of the cleft. Likewise, the usefulness of this function is shown by calculating the similarity among three patients. This work was developed jointly with the Cleft Palate Team at the Reconstructive Surgery Service of the Pediatric Hospital of Tacubaya, which belongs to the Health Institute of the Federal District in Mexico City.

A similarity function to evaluate the orthodontic condition in patients with cleft lip and palate.

The objective of this work is the modeling of a similarity function adapted to the medical environment using the logical-combinatorial approach of pattern recognition theory, and its application to compare the orthodontic conditions of patients with cleft-primary palate and/or cleft-secondary palate congenital malformations. The variables in domains with no a priori algebraic or topological structure are objects whose similarity or difference is evaluated by comparison criteria functions. The range of these functions is an ordered set normalized into the unit interval, and they are designed to allow differentiation and non-uniform treatment of the object-variables. The analogy between objects is formalized as a similarity function that stresses the relations among the comparison criteria and evaluates the partial descriptions (partial similarity/difference) or total descriptions (total similarity/difference) of the objects. For the orthodontic problem we defined a set of 12 variables featuring the unilateral/bilateral fissures, the conditions of maxilla, premaxilla, mandible and patient's bite. The comparison criteria (logical for malocclusion, fuzzy for maxillary collapse unilateral/anteroposterior and for overbite, and Boolean for protrusive/retrusive premaxilla conditions) were assigned a relevance factor based on the orthodontist accumulated knowledge and experience. The modeling of the similarity function and its effectiveness in comparing orthodontic conditions in patients are illustrated by the study of four clinical cases with different clefts. The results through similarity are close to the expected ones. Moreover evaluated at different moments it allows to assess the effect of treatment in a single patient, hence providing valuable auxiliary criteria for medical decision making as to the patient's rehabilitation. We include the potential extension of the methodology to other medical disciplines such as speech therapy and reconstructive surgery.

Inter-chromosome texture as a feature for automatic identification of metaphase spreads.

This paper reports results for a new measure of texture coarseness, as a step towards automation of metaphase finding in cell-proliferation studies. This measure is highly specific to grey-level inter-chromosome coarseness features in microscopic images of metaphase spreads and allows the texture quantification of cytological objects, analysing the intensity profile between chromosome-extrema samples. Chromosome fragments produce patterns of pixels at low resolution, and the local neighbourhood of their individual extrema presents a characteristic coarseness along intensity profiles, on randomly oriented test lines. Results of the use of this new measure on microscope images of fields of metaphases and artifacts are compared with some representative texture measures and the performance of reported metaphase finders. This new measure outperforms the latter, when applied in metaphase detection and elimination of artifacts. This coarseness feature provides a specific metaphase signature that can be used in conjunction with other morphological and textural parameters for automated metaphase discrimination.

A new approach to classify cleft lip and palate.

OBJECTIVE: To propose a new method, which allows for a complete description of primary and secondary cleft palates, incorporating elements that are related to the palate, lip, and nose that will also reflect the complexity of this problem. METHOD: To describe the type of cleft, two embryonic structures were considered: (1) the primary palate, formed by the prolabium, premaxilla, and columella and (2) the secondary palate, which begins at the incisive foramen and is formed by a horizontal portion of the maxilla, the horizontal portion of the palatine bones, and the soft palate. Anatomical characteristics to be considered were defined, and a new method is proposed to more fully describe any cleft. RESULTS: A description of five cases was made using the method proposed in this work and compared with other published methods for the classification and description of clefts. CONCLUSIONS: A mathematical expression was developed to characterize clefts of the primary palate, including the magnitude of palatal segment separation and the added complexity of bilateral clefts, yielding a numerical score that reflects overall complexity of the cleft. Clefts of the secondary palate are also considered in a separate score. Using this method, it is possible to incorporate elements that are not considered in other approaches and to describe all possible clefts that may exist.